WorldWideScience

Sample records for satellite ip networks

  1. Space Network IP Services (SNIS): An Architecture for Supporting Low Earth Orbiting IP Satellite Missions

    Science.gov (United States)

    Israel, David J.

    2005-01-01

    The NASA Space Network (SN) supports a variety of missions using the Tracking and Data Relay Satellite System (TDRSS), which includes ground stations in White Sands, New Mexico and Guam. A Space Network IP Services (SNIS) architecture is being developed to support future users with requirements for end-to-end Internet Protocol (IP) communications. This architecture will support all IP protocols, including Mobile IP, over TDRSS Single Access, Multiple Access, and Demand Access Radio Frequency (RF) links. This paper will describe this architecture and how it can enable Low Earth Orbiting IP satellite missions.

  2. Aviation-oriented Mobility Management Method in IP/LEO Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    Guo Xin; Zhang Jun; Zhang Tao; Ding Yanwen

    2008-01-01

    Taking into chief consideration the features of aviation nodes in satellite networks,such as high moving speed,long communication distance,and high connection frequency,this article proposes an aviatiun-oriented mobility management method for IP/low earth orbit (LEO) satellite networks.By introducing the concept of ground station real-time coverage area,the proposed method uses ground-station-based IP addressing method and cell paging scheme to decrease the frequency of IP binding update requests as well as the paging cost.In comparison with the paging mobile IP (P-MIP) method and the handover-independent IP mobility management method,as is verified by the mathematical analysis and simulation,the proposed method could decrease the management cost.It also possesses better ability to support the aviation nodes because it is subjected to fewer influences from increased node speeds and newly coming connection rates.

  3. Adaptive Distributed Load Balancing Routing Mechanism for LEO Satellite IP Networks

    Directory of Open Access Journals (Sweden)

    Xiao Ma

    2014-04-01

    Full Text Available LEO (Low Earth Orbit satellite constellation is an ideal scheme for the next generation wideband internet. The constellation is formed as a mesh-like network with inter satellite links (ISLs which are equipped between the neighbor satellites for transmitting directly. As to the future wideband IP services, an efficient routing mechanism will play an important role in improving the performance and balancing the network traffic. An Adaptive Distributed Load Balancing Routing Mechanism (ADLB is proposed in this paper to address the above-mentioned issues. This mechanism makes well-performed routing decision based on the current and historical status of each ISLs in each satellite node. With collecting historical information from network initiated, a proper mechanism is contained in ADLB for making required computing power and storage space in a reasonable range. The performance of ADLB is verified via a series of simulations which demonstrate that the scheme can provide better throughput and lower packet drop rate.

  4. SM_TCP: a new reliable multicast transport protocol for satellite IP networks

    Science.gov (United States)

    Liu, Gongliang; Gu, Xuemai; Li, Shizhong

    2005-11-01

    A new reliable multicast transport protocol SM_TCP is proposed for satellite IP networks in this paper. In SM_TCP, the XOR scheme with the aid of on-board buffering and processing is used for error recovery and an optimal retransmission algorithm is designed, which can reduce the recovery time by half of the RTT and minimize the number of retransmissions. In order to avoid the unnecessary decrease of congestion window in the high BER satellite channels, the occupied buffer sizes at bottlenecks are measured in adjusting the congestion window, instead of depending on the packet loss information. The average session rate of TCP sessions and of multicast sessions passing through the satellite are also measured and compared in adjusting the congestion window, which contributes to bandwidth fairness. Analysis and simulation results show fairness with TCP flows and scalability.

  5. Dynamic autonomous routing technology for IP-based satellite ad hoc networks

    Science.gov (United States)

    Wang, Xiaofei; Deng, Jing; Kostas, Theresa; Rajappan, Gowri

    2014-06-01

    IP-based routing for military LEO/MEO satellite ad hoc networks is very challenging due to network and traffic heterogeneity, network topology and traffic dynamics. In this paper, we describe a traffic priority-aware routing scheme for such networks, namely Dynamic Autonomous Routing Technology (DART) for satellite ad hoc networks. DART has a cross-layer design, and conducts routing and resource reservation concurrently for optimal performance in the fluid but predictable satellite ad hoc networks. DART ensures end-to-end data delivery with QoS assurances by only choosing routing paths that have sufficient resources, supporting different packet priority levels. In order to do so, DART incorporates several resource management and innovative routing mechanisms, which dynamically adapt to best fit the prevailing conditions. In particular, DART integrates a resource reservation mechanism to reserve network bandwidth resources; a proactive routing mechanism to set up non-overlapping spanning trees to segregate high priority traffic flows from lower priority flows so that the high priority flows do not face contention from low priority flows; a reactive routing mechanism to arbitrate resources between various traffic priorities when needed; a predictive routing mechanism to set up routes for scheduled missions and for anticipated topology changes for QoS assurance. We present simulation results showing the performance of DART. We have conducted these simulations using the Iridium constellation and trajectories as well as realistic military communications scenarios. The simulation results demonstrate DART's ability to discriminate between high-priority and low-priority traffic flows and ensure disparate QoS requirements of these traffic flows.

  6. Core-based Shared Tree Multicast Routing Algorithms for LEO Satellite IP Networks

    Institute of Scientific and Technical Information of China (English)

    Cheng Lianzhen; Zhang Jun; Liu Kai

    2007-01-01

    A new core-based shared tree algorithm, viz core-cluster combination-based shared tree (CCST) algorithm and the weighted version (i.e. w-CCST algorithm) are proposed in order to resolve the channel resources waste problem in typical source-based multicast routing algorithms in low earth orbit (LEO) satellite IP networks. The CCST algorithm includes the dynamic approximate center (DAC)core selection method and the core-cluster combination multicast route construction scheme. Without complicated onboard computation,the DAC method is uniquely developed for highly dynamic networks of periodical and regular movement. The core-cluster combination method takes core node as the initial core-cluster, and expands it stepwise to construct an entire multicast tree at the lowest tree cost by a shortest path scheme between the newly-generated core-cluster and surplus group members, which results in great bandwidth utilization.Moreover, the w-CCST algorithm is able to strike a balance between performance of tree cost and that of end-to-end propagation delay by adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast services at the expense of a slight increase in tree cost. Finally, performance comparison is conducted between the proposed algorithms and typical algorithms in LEO satellite IP networks. Simulation results show that the CCST algorithm significantly decreases the average tree cost against to the others, and also the average end-to-end propagation delay of w-CCST algorithm is lower than that of the CCST algorithm.

  7. A Time and Space-based Dynamic IP Routing in Broadband Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The topology architecture, characteristics and routing technologies of broadband satellite networks are studied in this paper. The authors propose the routing scheme of satellite networks and design a time and space-based distributed routing algorithm whose complexity is O(1). Simulation results aiming at satellite mobility show that the new algorithm can determine the minimum propagation delay paths effectively.

  8. A native IP satellite communications system

    Science.gov (United States)

    Koudelka, O.; Schmidt, M.; Ebert, J.; Schlemmer, H.; Kastner-Puschl, S.; Riedler, W.

    2004-08-01

    ≪ In the framework of ESA's ARTES-5 program the Institute of Applied Systems Technology (Joanneum Research) in cooperation with the Department of Communications and Wave Propagation has developed a novel meshed satellite communications system which is optimised for Internet traffic and applications (L*IP—Local Network Interconnection via Satellite Systems Using the IP Protocol Suite). Both symmetrical and asymmetrical connections are supported. Bandwidth on demand and guaranteed quality of service are key features of the system. A novel multi-frequency TDMA access scheme utilises efficient methods of IP encapsulation. In contrast to other solutions it avoids legacy transport network techniques. While the DVB-RCS standard is based on ATM or MPEG transport cells, the solution of the L*IP system uses variable-length cells which reduces the overhead significantly. A flexible and programmable platform based on Linux machines was chosen to allow the easy implementation and adaptation to different standards. This offers the possibility to apply the system not only to satellite communications, but provides seamless integration with terrestrial fixed broadcast wireless access systems. The platform is also an ideal test-bed for a variety of interactive broadband communications systems. The paper describes the system architecture and the key features of the system.

  9. TCP/IP Network Administration

    CERN Document Server

    Hunt, Craig

    2002-01-01

    This complete guide to setting up and running a TCP/IP network is essential for network administrators, and invaluable for users of home systems that access the Internet. The book starts with the fundamentals -- what protocols do and how they work, how addresses and routing are used to move data through the network, how to set up your network connection -- and then covers, in detail, everything you need to know to exchange information via the Internet. Included are discussions on advanced routing protocols (RIPv2, OSPF, and BGP) and the gated software package that implements them, a tutorial

  10. Voice over IP in Wireless Heterogeneous Networks

    DEFF Research Database (Denmark)

    Fathi, Hanane; Chakraborty, Shyam; Prasad, Ramjee

    The convergence of different types of traffic has preceded the convergence of systems and services in a wireless heterogeneous network. Voice and data traffic are usually treated separate in both 2G and 2.5G wireless networks. With advances in packet switching technology and especially......IP communications are difficult to achieve in a time-varying environment due to channel errors and traffic congestion and across different systems. The provision of VoIP in wireless heterogeneous networks requires a set of time-efficient control mechanisms to support a VoIP session with acceptable quality...

  11. Active Network Supports for Mobile IP

    Institute of Scientific and Technical Information of China (English)

    LU Yueming; QIAN Depei; XU Bin; WANG Lei

    2001-01-01

    The basic mobile IP protocol is difficult to implement on the traditional IP network and not flexible and efficient under certain conditions. For example, firewalls or boundary routers may drop packets sent by mobile nodes for security reasons. Traditional networking devices such as routers cannot dynamically load and unload extended services to achieve different qualities of services. In this paper, a new scheme of using the active network to support the mobile IP is presented. The Softnet, a prototype of active networks based on mobile agents,is introduced. The active network is characterized by the programmability of its intermediatenodes and therefore presents dynamic and flexible behaviors. Special services can be dynamically deployed onto the active nodes in the Softnet. This property is definitely required in implementing the mobile IP protocols. The Softnet supports not only the basic mobile IP protocol but also other extended mobile IP protocols. Virtual networks for mobile IP services are dynamically formed by mobile agents in the Softnet to provide different qualities of services.

  12. Voice over IP in Wireless Heterogeneous Networks

    DEFF Research Database (Denmark)

    Fathi, Hanane; Chakraborty, Shyam; Prasad, Ramjee

    The convergence of different types of traffic has preceded the convergence of systems and services in a wireless heterogeneous network. Voice and data traffic are usually treated separate in both 2G and 2.5G wireless networks. With advances in packet switching technology and especially with the d...... and to the discruption caused by the user mobility during the session. Voice over IP in Wireless Hetetrogeneous Networks thus investigates and proposes cross-layer techniques for realizing time-efficient control mechanisms for VoIP: signaling, mobility and security.......The convergence of different types of traffic has preceded the convergence of systems and services in a wireless heterogeneous network. Voice and data traffic are usually treated separate in both 2G and 2.5G wireless networks. With advances in packet switching technology and especially....... The focus of Voice over IP in Wierless Heterogeneous Networks is on mechanisms that affect the VoIP user satisfaction  while not explicitly involved in the media session. This relates to the extra delays introduced by the security and the signaling protocols used to set up an authorized VoIP session...

  13. Space-Based Voice over IP Networks

    Science.gov (United States)

    Nguyen, Sam P.; Okino, Clayton; Walsh, William; Clare, Loren

    2007-01-01

    In human space exploration missions (e.g. a return to the Moon and for future missions to Mars), there will be a need to provide voice communications services. In this work we focus on the performance of Voice over IP (VoIP) techniques applied to space networks, where long range latencies, simplex links, and significant bit error rates occur. Link layer and network layer overhead issues are examined. Finally, we provide some discussion on issues related to voice conferencing in the space network environment.

  14. Optimization of OSPF Routing in IP Networks

    Science.gov (United States)

    Bley, Andreas; Fortz, Bernard; Gourdin, Eric; Holmberg, Kaj; Klopfenstein, Olivier; Pióro, Michał; Tomaszewski, Artur; Ümit, Hakan

    The Internet is a huge world-wide packet switching network comprised of more than 13,000 distinct subnetworks, referred to as Autonomous Systems (ASs) autonomous system AS . They all rely on the Internet Protocol (IP) internet protocol IP for transport of packets across the network. And most of them use shortest path routing protocols shortest path routing!protocols , such as OSPF or IS-IS, to control the routing of IP packets routing!of IP packets within an AS. The idea of the routing is extremely simple — every packet is forwarded on IP links along the shortest route between its source and destination nodes of the AS. The AS network administrator can manage the routing of packets in the AS by supplying the so-called administrative weights of IP links, which specify the link lengths that are used by the routing protocols for their shortest path computations. The main advantage of the shortest path routing policy is its simplicity, allowing for little administrative overhead. From the network engineering perspective, however, shortest path routing can pose problems in achieving satisfactory traffic handling efficiency. As all routing paths depend on the same routing metric routing!metric , it is not possible to configure the routing paths for the communication demands between different pairs of nodes explicitly or individually; the routing can be controlled only indirectly and only as a whole by modifying the routing metric. Thus, one of the main tasks when planning such networks is to find administrative link weights that induce a globally efficient traffic routing traffic!routing configuration of an AS. It turns out that this task leads to very difficult mathematical optimization problems. In this chapter, we discuss and describe exact integer programming models and solution approaches as well as practically efficient smart heuristics for such shortest path routing problems shortest path routing!problems .

  15. IP Network Management Model Based on NGOSS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin-yu; LI Hong-hui; LIU Feng

    2004-01-01

    This paper addresses a management model for IP network based on Next Generation Operation Support System (NGOSS). It makes the network management on the base of all the operation actions of ISP, It provides QoS to user service through the whole path by providing end-to-end Service Level Agreements (SLA) management through whole path. Based on web and coordination technology, this paper gives an implement architecture of this model.

  16. Dynamic Mobile IP routers in ad hoc networks

    NARCIS (Netherlands)

    Kock, B.A.; Schmidt, J.R.

    2005-01-01

    This paper describes a concept combining mobile IP and ad hoc routing to create a robust mobile network. In this network all nodes are mobile and globally and locally reachable under the same IP address. Essential for implementing this network are the dynamic mobile IP routers. They act as gateways

  17. Dynamic Mobile IP routers in ad hoc networks

    NARCIS (Netherlands)

    Kock, B.A.; Schmidt, J.R.

    2005-01-01

    This paper describes a concept combining mobile IP and ad hoc routing to create a robust mobile network. In this network all nodes are mobile and globally and locally reachable under the same IP address. Essential for implementing this network are the dynamic mobile IP routers. They act as gateways

  18. Chaos Based Secure IP Communications over Satellite DVB

    Science.gov (United States)

    Caragata, Daniel; El Assad, Safwan; Tutanescu, Ion; Sofron, Emil

    2010-06-01

    The Digital Video Broadcasting—Satellite (DVB-S) standard was originally conceived for TV and radio broadcasting. Later, it became possible to send IP packets using encapsulation methods such as Multi Protocol Encapsulation, MPE, or Unidirectional Lightweight Encapsulation, ULE. This paper proposes a chaos based security system for IP communications over DVB-S with ULE encapsulation. The proposed security system satisfies all the security requirements while respecting the characteristics of satellite links, such as the importance of efficient bandwidth utilization and high latency time. It uses chaotic functions to generate the keys and to encrypt the data. The key management is realized using a multi-layer architecture. A theoretical analysis of the system and a simulation of FTP and HTTP traffic are presented and discussed to show the cost of the security enhancement and to provide the necessary tools for security parameters setup.

  19. Performance Comparison of IP-Networked Storage

    Institute of Scientific and Technical Information of China (English)

    JU Dapeng; LIU Chuanyi; WANG Dongsheng; LIU Hong; TANG Zhizhong

    2009-01-01

    Dramatically increasing amounts of digital data are placing huge requirements on storage systems.IP-networked storage systems,such as the network file system (NFS)-based network-attached storage (NAS) systems and the iSCSI-storage area network (SAN) systems,have become increasingly common in today's local area network (LAN) environments.The emergence of new storage techniques,such as object-based storage (OBS) and content aware storage (CAS),significantly improves the functionality of storage devices to meet further needs for storage sub-systems.However,these may impact system performance.This paper compares the performance of NFS,iSCSI storage,object-based storage devices (OSDs),and CAS-based storage systems in an environment with no data sharing across host machines.A gigabit ethernet network is used as the storage network.Test results demonstrate that the performances of these systems are comparable with CAS being much better than the others for write operations.The performance bottlenecks in these systems are analyzed to provide insight into how future storage systems may be improved and possible optimization methods.The analysis shows how the I/O interfaces in these systems affect the application performance and that network-based storage systems require optimized I/O latency and reduced network and buffer processing in the servers.

  20. Securing VoIP keeping your VoIP network safe

    CERN Document Server

    (Bud) Bates, Regis J Jr

    2015-01-01

    Securing VoIP: Keeping Your VoIP Network Safe will show you how to take the initiative to prevent hackers from recording and exploiting your company's secrets. Drawing upon years of practical experience and using numerous examples and case studies, technology guru Bud Bates discusses the business realities that necessitate VoIP system security and the threats to VoIP over both wire and wireless networks. He also provides essential guidance on how to conduct system security audits and how to integrate your existing IT security plan with your VoIP system and security plans, helping you prevent

  1. Gigabit Satellite Network for NASA's Advanced Communication Technology Satellite (ACTS)

    Science.gov (United States)

    Hoder, Douglas; Bergamo, Marcos

    1996-01-01

    The advanced communication technology satellite (ACTS) gigabit satellite network provides long-haul point-to-point and point-to-multipoint full-duplex SONET services over NASA's ACTS. at rates up to 622 Mbit/s (SONET OC-12), with signal quality comparable to that obtained with terrestrial fiber networks. Data multiplexing over the satellite is accomplished using time-division multiple access (TDMA) techniques coordinated with the switching and beam hopping facilities provided by ACTS. Transmissions through the satellite are protected with Reed-Solomon encoding. providing virtually error-free transmission under most weather conditions. Unique to the system are a TDMA frame structure and satellite synchronization mechanism that allow: (a) very efficient utilization of the satellite capacity: (b) over-the-satellite dosed-loop synchronization of the network in configurations with up to 64 ground stations: and (c) ground station initial acquisition without collisions with existing signalling or data traffic. The user interfaces are compatible with SONET standards, performing the function of conventional SONET multiplexers and. as such. can be: readily integrated with standard SONET fiber-based terrestrial networks. Management of the network is based upon the simple network management protocol (SNMP). and includes an over-the-satellite signalling network and backup terrestrial internet (IP-based) connectivity. A description of the ground stations is also included.

  2. Strategies Towords Next Generation IP Over Optical Networks

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A consensus is emerging in industry on utilizing an IP-Centric control plane within optical networks to support dynamic provisioning and restoration of lightpaths. At the same time, there are divergent views of how IP routers interact with optical core networks to achieve end-to-end connectivity. This paper describes the strategies of optical communication's future development towards next generation IP over Optical Networks. The desirable extent of network transparency in advanced all-optical network architecture is studied. Architectural alternatives for interconnecting IP routers over optical networks, and the concerned routing and signaling issues are described.

  3. Running TCP/IP over ATM Networks.

    Science.gov (United States)

    Witt, Michael

    1995-01-01

    Discusses Internet protocol (IP) and subnets and describes how IP may operate over asynchronous transfer mode (ATM). Topics include TCP (transmission control protocol), ATM cells and adaptation layers, a basic architectural model for IP over ATM, address resolution, mapping IP to a subnet technology, and connection management strategy. (LRW)

  4. Network Configuration Analysis for Formation Flying Satellites

    Science.gov (United States)

    Knoblock, Eric J.; Wallett, Thomas M.; Konangi, Vijay K.; Bhasin, Kul B.

    2001-01-01

    The performance of two networks to support autonomous multi-spacecraft formation flying systems is presented. Both systems are comprised of a ten-satellite formation, with one of the satellites designated as the central or 'mother ship.' All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/EP over ATM protocol architecture within the formation, and the second system uses the IEEE 802.11 protocol architecture within the formation. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IP queuing delay, IP queue size and IP processing delay at the mother ship as well as end-to-end delay for both systems. In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  5. Mobility and QoS Support in Mobile IP Networks

    Institute of Scientific and Technical Information of China (English)

    DUAN Lian; WU Wei-ling

    2004-01-01

    This paper presents the state of the art of the Quality of Service (QoS) and mobility support mechanisms for mobile IP networks, which includes the issues and challenges in QoS support, an overview of the Mobile IP protocol, a general description of the QoS and Mobility framework, and the End-To-End QoS architecture in the next-generation all-IP mobile network.

  6. TCP-IP Model in Data Communication and Networking

    OpenAIRE

    Pranab Bandhu Nath; Md.Mofiz Uddin

    2015-01-01

    The Internet protocol suite is the computer networking model and set of communications protocols used on the Internet and similar computer networks. It is commonly known as TCP/IP, because it’s most important protocols, the Transmission Control Protocol (TCP) and the Internet Protocol (IP), were the first networking protocols defined in this standard. Often also called the Internet model, it was originally also known as the DoD model, because the development of the networking mode...

  7. Survivable IP/MPLS-Over-WSON Multilayer Network Optimization

    OpenAIRE

    Ruiz M.; Pedrola O.; Velasco L.; Careglio D.; Fernandez-Palacios J.; Junyent G.

    2011-01-01

    Network operators are facing the problem of dimensioning their networks for the expected huge IP traffic volumes while keeping constant or even reducing the connectivity prices. Therefore, new architectural solutions able to cope with the expected traffic increase in a more cost-effective way are needed. In this work, we study the survivable IP/multi-protocol label switching (MPLS) over wavelength switched optical network (WSON) multilayer network problem as a capital expenditure (CAPEX...

  8. IP ADDRESS AUTOCONFIGURATION FOR WIRELESS AD HOC NETWORKS

    Institute of Scientific and Technical Information of China (English)

    阿姆贾德

    2002-01-01

    A novel mechanism was specified by which a node in ad hoc network may autoconfigure an IP address which is unique throughout the mobile ad hoc network. This new algorithm imposes less and constant overhead and delay in obtaining an IP address, and fully utilizes the available addresses space of an ad hoc network, and independent of the existing routing protocol, and less prone to security threats. Moreover, a new Join/Leave mechanism was proposed as an enhancement to the new IP address autoconfiguration algorithm, to support the overall operation of the existing routing protocol of wireless ad hoc networks.

  9. TCP/IP Interface for the Satellite Orbit Analysis Program (SOAP)

    Science.gov (United States)

    Carnright, Robert; Stodden, David; Coggi, John

    2009-01-01

    The Transmission Control Protocol/ Internet protocol (TCP/IP) interface for the Satellite Orbit Analysis Program (SOAP) provides the means for the software to establish real-time interfaces with other software. Such interfaces can operate between two programs, either on the same computer or on different computers joined by a network. The SOAP TCP/IP module employs a client/server interface where SOAP is the server and other applications can be clients. Real-time interfaces between software offer a number of advantages over embedding all of the common functionality within a single program. One advantage is that they allow each program to divide the computation labor between processors or computers running the separate applications. Secondly, each program can be allowed to provide its own expertise domain with other programs able to use this expertise.

  10. Crosslayer Survivability in Overlay-IP-WDM Networks

    Science.gov (United States)

    Pacharintanakul, Peera

    2010-01-01

    As the Internet moves towards a three-layer architecture consisting of overlay networks on top of the IP network layer on top of WDM-based physical networks, incorporating the interaction between and among network layers is crucial for efficient and effective implementation of survivability. This dissertation has four major foci as follows:…

  11. Crosslayer Survivability in Overlay-IP-WDM Networks

    Science.gov (United States)

    Pacharintanakul, Peera

    2010-01-01

    As the Internet moves towards a three-layer architecture consisting of overlay networks on top of the IP network layer on top of WDM-based physical networks, incorporating the interaction between and among network layers is crucial for efficient and effective implementation of survivability. This dissertation has four major foci as follows:…

  12. Mobile location services over the next generation IP core network

    DEFF Research Database (Denmark)

    Thongthammachart, Saowanee; Olesen, Henning

    2003-01-01

    network is changing from circuit-switched to packet-switched technology and evolving to an IP core network based on IPv6. The IP core network will allow all IP devices to be connected seamlessly. Due to the movement detection mechanism of Mobile IPv6, mobile terminals will periodically update......Mobile communication networks are evolving towards smaller cells, higher throughput, better security and provision of better services. Wireless short-range technologies, such as the WLAN 802.11 standards family and Bluetooth, are expected to play a major role in future networks. The mobile core...... their current point of attachment to the network and hence provide the current location of the mobile user automatically. The convergence of wireless short-range networks, mobile networks and Internet technology will provide the mobile user's location without any add-in equipment for location measurement...

  13. Congestion Avoidance in IP Based CDMA Radio Access Network

    Directory of Open Access Journals (Sweden)

    Syed Shakeel Hashmi

    2011-02-01

    Full Text Available CDMA is an important air interface technologies for cellular wireless networks. As CDMAbasedcellular networks mature, the current point-to-point links will evolve to an IP-based Radio AccessNetwork (RAN. mechanisms must be designed to control the IP Radio Access Network congestion.This Paper implements a congestion control mechanism using Router control and channelcontrol method for IP-RAN on CDMA cellular network. The Router control mechanism uses the featuresof CDMA networks using active Queue Management technique to reduce delay and to minimize thecorrelated losses. The Random Early Detection Active Queue Management scheme (REDAQM is to berealized for the router control for data transmission over the radio network using routers as the channel.The channel control mechanism control the congestion by bifurcating the access channel into multiplelayer namely RACH, BCCH and DCH for data accessing. The proposed paper work is realized usingMatlab platform.

  14. EFFICIENT DEFENSE SYSTEM FOR IP SPOOFING IN NETWORKS

    Directory of Open Access Journals (Sweden)

    Emil Kuriakose John

    2012-10-01

    Full Text Available In this age of gigabit Ethernet and broadband internet, network security has been the top priority for most of the researchers. Technology advancements have advantages as well as disadvantages. Most of the communication of present world, the e-world, takes place online, through the internet. Thus the context of network intrusions and attacks to hack into servers also came into existence. A technique to perform this activity is made possible by preventing the discovery of the sender’s identity through IP Spoofing [7]. Many popular internet sites have been hacked and attackers try to forge or spoof the source addresses in IP packets. Using spoofing detection technique, the user can retrieve the list of IP addresses and able to identify the malicious IP addresses.Hence mechanisms must be designed to prevent hacking. This paper proposes a novel technique to detect IP spoofing based on traffic verification and filtering.

  15. Hybrid Terrestrial-Satellite DVB/IP Infrastructure in Overlay Constellations for Triple-Play Services Access in Rural Areas

    Directory of Open Access Journals (Sweden)

    E. Pallis

    2010-01-01

    Full Text Available This paper discusses the convergence of digital broadcasting and Internet technologies, by elaborating on the design, implementation, and performance evaluation of a hybrid terrestrial/satellite networking infrastructure, enabling triple-play services access in rural areas. At local/district level, the paper proposes the exploitation of DVB-T platforms in regenerative configurations for creating terrestrial DVB/IP backhaul between the core backbone (in urban areas and a number of intermediate communication nodes distributed within the DVB-T broadcasting footprint (in rural areas. In this way, triple play services that are available at the core backbone, are transferred via the regenerative DVB-T/IP backhaul to the entire district and can be accessed by rural users via the corresponding intermediate node. On the other hand, at regional/national level, the paper proposes the exploitation of a satellite interactive digital video broadcasting platform (DVB S2/RCS as an overlay network that interconnects the regenerative DVB-T/IP platforms, as well as individual users, and services providers, to each other. Performance of the proposed hybrid terrestrial/satellite networking environment is validated through experimental tests that were conducted under real transmission/reception conditions (for the terrestrial segment and via simulation experiments (for the satellite segment at a prototype network infrastructure.

  16. Integrated Differentiated Survivability in IP over WDM Networks

    Institute of Scientific and Technical Information of China (English)

    Wei Wei; Qing-Ji Zeng

    2004-01-01

    The problem of differentiated Multi-Layer Integrated Survivability (MLIS) in IP over WDM networks is studied, which is decomposed into three sub-problems: survivable strategies design (SSD), spare capacity dimensioning (SCD), and dynamic survivable routing (DSR). A related work of network survivability in IP over WDM networks is firstly provided, and adaptive survivable strategies are also designed. A new Integrated Shared Pool (ISP) approach for SCD is then proposed, which is formulated by using integer-programming theory. Moreover, a novel survivable routing scheme called Differentiated Integrated Survivability Algorithm (DISA) for DSR is developed. Simulation results show that the proposed integrated survivability scheme performs much better than other solutions (e.g., "highest layer recovery" and "lowest layer recovery" schemes) in terms of traffic blocking ratio, spare resource requirement, and average traffic recovery ratio in IP over WDM networks.

  17. Network Resource Provisioning for IP over Multi-Granular Optical Networks

    Institute of Scientific and Technical Information of China (English)

    SUN Jian-wei; POO Gee-Swee

    2007-01-01

    In the internet protocol(IP) over multi-granular optical switch network (IP/MG-OXC), the network node is a typical multilayer switch comprising several layers, the IP packet switching (PXC) layer, wavelength switching (WXC) layer and fiber switching (FXC) layer.This network is capable of both IP layer grooming and wavelength grooming in a hierarchical manner.Resource provisioning in the multi-granular network paradigm is called hierarchical grooming problem.An integer linear programming (ILP) model is proposed to formulate the problem.An iterative heuristic approach is developed for solving the problem in large networks.Case study shows that IP/MG-OXC network is much more extendible and can significantly save the overall network cost as compared with IP over wavelength division multiplexing network.

  18. Credibility and validation of simulation models for tactical IP networks

    NARCIS (Netherlands)

    Boltjes, B.; Thiele, F.; Diaz, I.F.

    2007-01-01

    The task of TNO is to provide predictions of the scalability and performance of the new all-IP tactical networks of the Royal Netherlands Army (RNLA) that are likely to be fielded. The inherent properties of fielded tactical networks, such as low bandwidth and Quality of Service (QoS) policies

  19. Performance Comparison and Analysis of IP and MPLS Networks

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With the increasing need for Quality of Service(QoS),the traditional IP network is becoming less competitive. In order to give readers quantitative and convictive performance comparisons between IP and MPLS network,we choose Berkeleys NS-2 simulator[1] in our research on network throughput and end-to-end TCP behavior. Using NS-2 simulator,we analyze the performance of a network with MPLS Traffic Engineering(MPLS-TE).Specifically,the throughput and TCP end-to-end delay time under two different queuing algorithms are obtained and compared between the MPLS network and traditional IP network. We find that in the IP network using SFQ queuing algorithm will help traffic balance compared to the simple FIFO scheme,but it still can not utilize the available bandwidth,which in turn leads to the poor performance as in the FIFO case.With MPLS-TE, the throughput will be higher and the end-to-end TCP delay time remains almost the same even in heavy load case.We notice that if flows are isolated partially,using SFQ scheme will have a comparable performance as the fully isolation case using FIFO scheme in a MPLS network,and that if flows are isolated fully for FIFO and SFQ schemes,both will have the same result.Finally,we conclude that a better queuing algorithm will help reduce the label space requirement.

  20. Performance Comparison and Analysis of IP and MPLS Networks

    Institute of Scientific and Technical Information of China (English)

    LIUEr-wu; CAOMing-cui; 等

    2001-01-01

    With the increasing need for Quality of Service(QoS), the traditional IP network is becoming less com-petitive.In order to give readers quantitative and convictive performance comparisons between IP and MPLS net-work, we choose Berkeley's NS-2 simulator[1] in our research on network throughput and end-to-end TCP behavior.Using NS-2 simulator,we analyze the performance of a network with MPLS Traffic Engineering (MPLS-TE).Specifically, the throughput and TCP end-to-end delay time under two different queuing algorithms are obtained and compared between the MPLS network and traditional IP network .We find that in the IP network using SFQ queuing algorithm will help traffic balance compared to the simple FIFO scheme,but it still can ont utilize the available bandwidth,which in turn leads to the poor performance as in the FIFO case.With MPLS-TE,the throughput will be higher and the end-to-end TCP delay time remains almost the same even in heavy load case.We notice that if flows are isolated partially,using SFQ scheme will have a comparable performance as the fully isola-tion case using FIFO scheme in a MPLS network, and that if flows are isolated fully for FIFO and SFQ schemes, both will have the same result.Finally,we conclude that a better queuing algorithm will help reduce the label space requirement.

  1. TCP-IP Model in Data Communication and Networking

    Directory of Open Access Journals (Sweden)

    Pranab Bandhu Nath

    2015-10-01

    Full Text Available The Internet protocol suite is the computer networking model and set of communications protocols used on the Internet and similar computer networks. It is commonly known as TCP/IP, because it’s most important protocols, the Transmission Control Protocol (TCP and the Internet Protocol (IP, were the first networking protocols defined in this standard. Often also called the Internet model, it was originally also known as the DoD model, because the development of the networking model was funded by DARPA, an agency of the United States Department of Defense. TCP/IP provides end-to-end connectivity specifying how data should be packetized, addressed, transmitted, routed and received at the destination. This functionality is organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved. From lowest to highest, the layers are the link layer, containing communication technologies for a single network segment (link; the internet layer, connecting hosts across independent networks, thus establishing internetworking; the transport layer handling host-to-host communication; and the application layer, which provides process-to-process application data exchange. Our aim is describe operation & models of TCP-IP suite in data communication networking

  2. Novel Node Structures for IP over WDM Networks

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    IP over WDM is being envisioned as one of the most attractive architectures for the next generation Internet. This paper introduces two novel backbone node structures for IP over WDM networks. These node structures can be used as improvement approaches to DPDP (default path and dedicated path) method. The flow classifiers, which are the main components of these node structures, and the performance metrics of these structures, are also discussed.

  3. An effective dynamic reconfiguration algorithm for IP over WDM networks

    Science.gov (United States)

    Yu, Hongfang; Zhou, Tao; Wang, Sheng; Li, Lemin

    2005-02-01

    WDM (Wavelength Division Multiplexing) technology can provide multiple wavelengths on a fiber. IP directly over WDM (or IP over WDM) has become the hot topic of industry. A promising approach for building an IP over WDM network is that a logical network consisting of the wavelength channels (lightpaths) is built on the physical WDM network. Then, IP traffic is carried on the logical topology, by utilizing the MPLS (Multiple Protocol Label Switching) or GMPLS (Generalized MPLS). When the traffic demand pattern changes in the IP layer, the network performance may become poor. In order to improve the network performance, the virtual topology can be reconfigured to suit the changing traffic patterns. In this paper, dynamic slowly-adaptation scheme (e.g. tearing down a lightpath that is lightly loaded or setting up a new lightpath when congestion occurs) is adopted. How to select the source and the destination nodes of the new lightpath to be added and the underutilized lightpath to be deleted if it is necessary to do so is our key issue. Four selection ways are developed. These ways are evaluated through detail simulations and various performances are investigated.

  4. IP Broadcasting Network Communications Security%浅谈 IP 广电网络的通信安全

    Institute of Scientific and Technical Information of China (English)

    吴永伟

    2015-01-01

    The IP digital broadcasting system is a fully digital audio-broadcasting system based on the IP net-works.Its physical structure completely syncretize with the IP networks,it breaks through the function limit of the traditional broadcasting.The IP digital broadcasting system has the security problems of communication,as it base on the IP networks.This paper discusses the security issues about the IP digital broadcasting system.%IP 数字广电网络是一套基于 IP 网络的纯数字化广播系统,基于 IP 网络的数字化广播、直播、点播,推送功能强大,灵活性强,并突破了传统模拟广播系统的局限性。但 IP 数字广电网络系统也继承了IP 网络安全的问题,主要分析 IP 广电网络所面对的安全问题,并提出解决方法。

  5. Measuring an IP Network In Situ

    Science.gov (United States)

    2005-05-06

    outage caused by the Loma Prieta earthquake using pings. IMP’s data captured one aspect of the NATO bombing of Yugoslavia in the spring of 1999. 19 0 10...the Internet is becoming vital to national and world economies. As the Internet grows in importance, the ability to monitor and measure it effectively ...to be robust to network changes, this can occur without action by the central ad- ministrators. The net effect of such a change is that anyone in the

  6. Effectiveness of Intrusion Prevention Systems (IPS) in Fast Networks

    CERN Document Server

    Shafi, Muhammad Imran; Hayat, Sikandar; Sohail, Imran

    2010-01-01

    Computer systems are facing biggest threat in the form of malicious data which causing denial of service, information theft, financial and credibility loss etc. No defense technique has been proved successful in handling these threats. Intrusion Detection and Prevention Systems (IDPSs) being best of available solutions. These techniques are getting more and more attention. Although Intrusion Prevention Systems (IPSs) show a good level of success in detecting and preventing intrusion attempts to networks, they show a visible deficiency in their performance when they are employed on fast networks. In this paper we have presented a design including quantitative and qualitative methods to identify improvement areas in IPSs. Focus group is used for qualitative analysis and experiment is used for quantitative analysis. This paper also describes how to reduce the responding time for IPS when an intrusion occurs on network, and how can IPS be made to perform its tasks successfully without effecting network speed nega...

  7. Congested Link Inference Algorithms in Dynamic Routing IP Network

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2017-01-01

    Full Text Available The performance descending of current congested link inference algorithms is obviously in dynamic routing IP network, such as the most classical algorithm CLINK. To overcome this problem, based on the assumptions of Markov property and time homogeneity, we build a kind of Variable Structure Discrete Dynamic Bayesian (VSDDB network simplified model of dynamic routing IP network. Under the simplified VSDDB model, based on the Bayesian Maximum A Posteriori (BMAP and Rest Bayesian Network Model (RBNM, we proposed an Improved CLINK (ICLINK algorithm. Considering the concurrent phenomenon of multiple link congestion usually happens, we also proposed algorithm CLILRS (Congested Link Inference algorithm based on Lagrangian Relaxation Subgradient to infer the set of congested links. We validated our results by the experiments of analogy, simulation, and actual Internet.

  8. Topology-aware Overlay Multicast over IP Multicast Networks

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao; SHAO Hua-gang; WANG Wei-nong

    2008-01-01

    Most existing overlay multicast approaches refuse to consider any network layer support no matter whether it is available or not. This design principle greatly increases the complexity of the routing algorithms and makes the overlay topologies incompatible with the underlying network. To address these issues, topology-aware overlay multicast over IP multicast networks (TOMIMN) was proposed as a novel overlay multicast protocol, which exploits the cooperation between end-hosts and IP multicast routers to construct a topology-aware overlay tree. Through a little modification to protocol independent multicast sparse mode (PIM-SM),a multicast router is able to receive registration from nearby group members and redirect passing-by join re-quests to them. Due to the multicast router's support, TOMIMN organizes its group members into an overlay multicast tree efficiently, which matches the physical network topology well.

  9. Maintaining high-quality IP audio services in lossy IP network environments

    Science.gov (United States)

    Barton, Robert J., III; Chodura, Hartmut

    2000-07-01

    In this paper we present our research activities in the area of digital audio processing and transmission. Today's available teleconference audio solutions are lacking in flexibility, robustness and fidelity. There was a need for enhancing the quality of audio for IP-based applications to guarantee optimal services under varying conditions. Multiple tests and user evaluations have shown that a reliable audio communication toolkit is essential for any teleconference application. This paper summarizes our research activities and gives an overview of developed applications. In a first step the parameters, which influence the audio quality, were evaluated. All of these parameters have to be optimized in order to result into the best achievable quality. Therefore it was necessary to enhance existing schemes or develop new methods. Applications were developed for Internet-Telephony, broadcast of live music and spatial audio for Virtual Reality environments. This paper describes these applications and issues of delivering high quality digital audio services over lossy IP networks.

  10. VoIP attacks detection engine based on neural network

    Science.gov (United States)

    Safarik, Jakub; Slachta, Jiri

    2015-05-01

    The security is crucial for any system nowadays, especially communications. One of the most successful protocols in the field of communication over IP networks is Session Initiation Protocol. It is an open-source project used by different kinds of applications, both open-source and proprietary. High penetration and text-based principle made SIP number one target in IP telephony infrastructure, so security of SIP server is essential. To keep up with hackers and to detect potential malicious attacks, security administrator needs to monitor and evaluate SIP traffic in the network. But monitoring and following evaluation could easily overwhelm the security administrator in networks, typically in networks with a number of SIP servers, users and logically or geographically separated networks. The proposed solution lies in automatic attack detection systems. The article covers detection of VoIP attacks through a distributed network of nodes. Then the gathered data analyze aggregation server with artificial neural network. Artificial neural network means multilayer perceptron network trained with a set of collected attacks. Attack data could also be preprocessed and verified with a self-organizing map. The source data is detected by distributed network of detection nodes. Each node contains a honeypot application and traffic monitoring mechanism. Aggregation of data from each node creates an input for neural networks. The automatic classification on a centralized server with low false positive detection reduce the cost of attack detection resources. The detection system uses modular design for easy deployment in final infrastructure. The centralized server collects and process detected traffic. It also maintains all detection nodes.

  11. Satellite Upper Air Network (SUAN)

    Science.gov (United States)

    Reale, Tony L.; Thorne, Peter

    2004-10-01

    During the past 20 years of NOAA operational polar satellites, it has become evident that a growing problem concerning their utilization in Climate and also Numerical Weather Prediction (NWP) applications are the systematic errors and uncertainties inherent in the satellite measurements. Similar arguments can be made for global radiosonde observations. These uncertainties are often larger than the sensitive signals and processes, that satellite and radiosonde measurements are designed to reveal, particularly in the realm of climate. Possible strategies to quantify and compensate for these problems include the analysis of satellite overlap data and/or available collocations of satellite and ground truth (radiosonde) observations. However, overlap observations are typically not available except in extreme polar regions and current sampling strategies for compiling collocated radiosonde and satellite observations are insufficient, further compounding the inherent uncertainties in the ground-truth radiosonde data. A Satellite Upper Air Network is proposed to provide reference radiosonde launches coincident with operational polar satellite(s) overpass. The SUAN consist of 36 global radiosonde stations sub-sampled from the Global Upper Air Network (GUAN), and is designed to provide a robust, global sample of collocated radiosonde and satellite observations conducive to the monitoring and validation of satellite and radiosonde observations. The routine operation of such a network in conjunction with operational polar satellites would provide a long-term of performance for critical observations of particular importance for climate. The following report presents a candidate network of 36 upper-air sites that could comprise a SUAN. Their selection along with the mutual benefit across the satellite, radiosonde, climate, numerical weather prediction (NWP) and radiative transfer (RT) model areas are discussed.

  12. A Framework for an IP-Based DVB Transmission Network

    Directory of Open Access Journals (Sweden)

    Nimbe L. Ewald-Arostegui

    2010-01-01

    Full Text Available One of the most important challenges for next generation all-IP networks is the convergence and interaction of wireless and wired networks in a smooth and efficient manner. This challenge will need to be faced if broadcast transmission networks are to converge with IP infrastructure. The 2nd generation of DVB standards supports the Generic Stream, allowing the direct transmission of IP-based content using the Generic Stream Encapsulation (GSE, in addition to the native Transport Stream (TS. However, the current signalling framework is based on MPEG-2 Tables that rely upon the TS. This paper examines the feasibility of providing a GSE signalling framework, eliminating the need for the TS. The requirements and potential benefits of this new approach are described. It reviews prospective methods that may be suitable for network discovery and selection and analyses different options for the transport and syntax of this signalling metadata. It is anticipated that the design of a GSE-only signalling system will enable DVB networks to function as a part of the Internet.

  13. IP, ethernet and MPLS networks resource and fault management

    CERN Document Server

    Perez, André

    2013-01-01

    This book summarizes the key Quality of Service technologies deployed in telecommunications networks: Ethernet, IP, and MPLS. The QoS of the network is made up of two parts: fault and resource management. Network operation quality is among the functions to be fulfilled in order to offer QoS to the end user. It is characterized by four parameters: packet loss, delay, jitter or the variation of delay over time, and availability. Resource management employs mechanisms that enable the first three parameters to be guaranteed or optimized. Fault management aims to ensure continuity of service.

  14. The CASCAM network control system based on TCP/IP

    Science.gov (United States)

    Ren, S. B.; Yao, Y. Q.; Yao, D. Z.

    2004-05-01

    The paper presents the CASCAM network control system based on the TCP/IP protocol. In order to realize the Client/Server model in network communication between the workstation and personal computer efficiently, two C++ classes, client and server, were developed in the system. The script language Tcl/Tk was used in programming the system control pane in the Client. With loading the dynamic library, the Client sends the request to the Server through the network, then the Server analyzes the request and controls the camera system.

  15. Multicast Routing in Satellite Network

    Institute of Scientific and Technical Information of China (English)

    郭惠玲; 宋姝; 李磊; 刘志涛; 郭鹏程

    2004-01-01

    There are some problems in the dual-layer satellite MPLs metworks to be composed of LEO and MEO. In order to solve the problems, this paper presents a plan by means of unicast LSP to implement multicast in the dual-layer satellite MPLs networks. It has advantages of saving space and reducing extra charge.

  16. Multicast and IP Multicast Support in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jorge Sá Silva

    2008-03-01

    Full Text Available Multicast potentially optimises bandwidth consumption and node resources, when several users simultaneously participate in a communication session. Nevertheless, contrary to the expectations, IP multicast has not experienced widespread deployment, with the exception of IPTV. On the other hand, emerging Wireless Sensor Network (WSN applications could greatly benefit from multicast and constitute another field where multicast can be an effective and efficient technique. The questions are: do multicast advantages hold in WSN scenarios? Can we use IP Multicast functionality in WSNs? This paper discusses and evaluates the use of multicast in WSNs. Specifically, we evaluate the use of Source-Specific Multicast, as it is one of the most promising paradigms for IP networking, considering both IPv4 and IPv6 in WSNs. A sensor platform with IP and multicast support that is being developed in our lab is presented. Concurrently, simulation studies were performed in order to assess the usefulness of multicast in WSNs. The results clearly point to the benefits of the use of this technique in processing and energy-restricted environments such as this one.

  17. Satellite communication on pipeline supervision using TCP-IP Protocol; Comunicacao via satelite na supervisao de dutos usando o protocolo TCP-IP

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Agliberto Pessoa da [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Brunette, Sergio Henrique de Moraes

    2003-07-01

    Bit transparent type or X-25 protocols have been used in VSAT satellite communication by PETROBRAS pipeline Supervisory Control and Data Acquisition System (SCADA) as access protocol. Both solutions have inconveniences. By the first one, difficulties exist for analysis and diagnosis of connection flaws, and therefore, for a ready identification by the system management stations of abnormality location. On the other hand, the usage of the X-25 brings an additional over-head in the communication since this is not an available option in most of the equipment that compose the SCADA. The access to VSAT through Ethernet, in the opposite, makes available all networks management tools of the TCP/IP platform and it allows a direct connection to the field devices, since the main models of the several makers of Programmable Controllers and Remote Terminal Units have Ethernet port. An additional earnings is the possibility of standardization that this solution allows. This paper describes a series of communication tests between two Programmable Controllers communicating through the satellite, using a protocol over Ethernet/TCP/IP. (author)

  18. Packet flow analysis in IP networks via abstract interpretation

    CERN Document Server

    Komondoor, Raghavan; Seetharam, Deva P; Balodia, Sudha

    2011-01-01

    Static analysis (aka offline analysis) of a model of an IP network is useful for understanding, debugging, and verifying packet flow properties of the network. There have been static analysis approaches proposed in the literature for networks based on model checking as well as graph reachability. Abstract interpretation is a method that has typically been applied to static analysis of programs. We propose a new, abstract-interpretation based approach for analysis of networks. We formalize our approach, mention its correctness guarantee, and demonstrate its flexibility in addressing multiple network-analysis problems that have been previously solved via tailor-made approaches. Finally, we investigate an application of our analysis to a novel problem -- inferring a high-level policy for the network -- which has been addressed in the past only in the restricted single-router setting.

  19. Real-time services in IP network architectures

    Science.gov (United States)

    Gilardi, Antonella

    1996-12-01

    The worldwide internet system seems to be the success key for the provision of real time multimedia services to both residential and business users and someone says that in such a way broadband networks will have a reason to exist. This new class of applications that use multiple media (voice, video and data) impose constraints to the global network nowadays consisting of subnets with various data links. The attention will be focused on the interconnection of IP non ATM and ATM networks. IETF and ATM forum are currently involved in the developing specifications suited to adapt the connectionless IP protocol to the connection oriented ATM protocol. First of all the link between the ATM and the IP service model has to be set in order to match the QoS and traffic requirements defined in the relative environment. A further significant topic is represented by the mapping of IP resource reservation model onto the ATM signalling and in the end it is necessary to define how the routing works when there are QoS parameters associated. This paper, considering only unicast applications, will examine the above issues taking as a starting point the situation where an host launches as call set up request with the relevant QoS and traffic descriptor and at some point a router at the edge of the ATM network has to decide how forwarding and request in order to establish an end to end link with the right capabilities. The aim is to compare the proposals emerging from different standard bodies to point out convergency or incompatibility.

  20. Building RNC in All-IP Wireless Networks using Network Processors

    Institute of Scientific and Technical Information of China (English)

    CHENG Sheng; NI Xian-le; ZHU Xin-ning; DING Wei

    2004-01-01

    This paper describes a solution to build network-processor-based Radio Network Controller (RNC) in all-IP wireless networks, it includes the structure of the 3rd Generation (3G) wireless networks and the role of network nodes, such as Base Station (BS), RNC, and Packet-Switched Core Networks (PSCN). The architecture of IXP2800 network processor; the detailed implementation of the solution on IXP2800-based RNC are also covered. This solution can provide scalable IP forward features and it will be widely used in 3G RNCs.

  1. Optimal design of an IP/MPLS over DWDM network

    Directory of Open Access Journals (Sweden)

    Eduardo Canale

    2014-04-01

    Full Text Available Different approaches for deploying resilient optical networks of low cost constitute a traditional group of NP-Hard problems that have been widely studied. Most of them are based on the construction of low cost networks that fulfill connectivity constraints. However, recent trends to virtualize optical networks over the legacy fiber infrastructure, modified the nature of network design problems and turned inappropriate many of these models and algorithms. In this paper we study a design problem arising from the deployment of an IP/MPLS network over an existing DWDM infrastructure. Besides cost and resiliency, this problem integrates traffic and capacity constraints. We present: an integer programming formulation for the problem, theoretical results, and describe how several metaheuristics were applied in order to find good quality solutions, for a real application case of a telecommunications company.

  2. Networks for Autonomous Formation Flying Satellite Systems

    Science.gov (United States)

    Knoblock, Eric J.; Konangi, Vijay K.; Wallett, Thomas M.; Bhasin, Kul B.

    2001-01-01

    The performance of three communications networks to support autonomous multi-spacecraft formation flying systems is presented. All systems are comprised of a ten-satellite formation arranged in a star topology, with one of the satellites designated as the central or "mother ship." All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/lP over ATM protocol architecture within the formation the second system uses the IEEE 802.11 protocol architecture within the formation and the last system uses both of the previous architectures with a constellation of geosynchronous satellites serving as an intermediate point-of-contact between the formation and the terrestrial network. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IF queuing delay, and IP processing delay at the mother ship as well as application-level round-trip time for both systems, In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  3. SINET3: advanced optical and IP hybrid network

    Science.gov (United States)

    Urushidani, Shigeo

    2007-11-01

    This paper introduces the new Japanese academic backbone network called SINET3, which has been in full-scale operation since June 2007. SINET3 provides a wide variety of network services, such as multi-layer transfer, enriched VPN, enhanced QoS, and layer-1 bandwidth on demand (BoD) services to create an innovative and prolific science infrastructure for more than 700 universities and research institutions. The network applies an advanced hybrid network architecture composed of 75 layer-1 switches and 12 high-performance IP routers to accommodate such diversified services in a single network platform, and provides sufficient bandwidth using Japan's first STM256 (40 Gbps) lines. The network adopts lots of the latest networking technologies, such as next-generation SDH (VCAT/GFP/LCAS), GMPLS, advanced MPLS, and logical-router technologies, for high network convergence, flexible resource assignment, and high service availability. This paper covers the network services, network design, and networking technologies of SINET3.

  4. Evaluation of impact of backbone outages in IP networks

    Science.gov (United States)

    Kogan, Yaakov; Choudhury, Gagan L.; Tarapore, Percy

    2004-09-01

    Nationwide IP networks typically include nodes in major cities and the following elements: customer equipment, access routers, backbone routers, peering routers, access links connecting customer equipment to access routers, access routers to backbone routers, and backbone links interconnecting backbone routers. The part of this network consisting of backbone routers and related interconnecting links is referred to as the "backbone". We develop a new approach for accurately computing the Availability measure of IP networks by directly simulating each type of backbone outage event and its impact on traffic loss. We use this approach to quantify availability improvement as a result of introducing various technological changes in the network such as IGP tuning, high availability router architecture, MPLS-TE and Fast Reroute. A situation, where operational backbone links do not have enough spare capacity to carry additional traffic during the outage time, is referred to as bandwidth loss. We concentrate on one unidirectional backbone link and derive asymptotic approximations for the expected bandwidth loss in the framework of generalized Erlang and Engset models when the total number of resource units and request arrival rates are proportionally large. Simulation results demonstrate good accuracy of the approximations.

  5. Photonic MPLS Network Technologies to Create Bandwidth-Abundant IP Networks

    Institute of Scientific and Technical Information of China (English)

    Atsushi; Watanabe

    2003-01-01

    This paper describes the prototypes of the Photonic MPLS router that can create bandwidth-abundant IP networks in a cost-effective manner. The characteristics of and recent advances in these prototypes are also described.

  6. Network architecture in a converged optical + IP network

    Science.gov (United States)

    Wakim, Walid; Zottmann, Harald

    2012-01-01

    As demands on Provider Networks continue to grow at exponential rates, providers are forced to evaluate how to continue to grow the network while increasing service velocity, enhancing resiliency while decreasing the total cost of ownership (TCO). The bandwidth growth that networks are experiencing is in the form packet based multimedia services such as video, video conferencing, gaming, etc... mixed with Over the Top (OTT) content providers such as Netflix, and the customer's expectations that best effort is not enough you end up with a situation that forces the provider to analyze how to gain more out of the network with less cost. In this paper we will discuss changes in the network that are driving us to a tighter integration between packet and optical layers and how to improve on today's multi - layer inefficiencies to drive down network TCO and provide for a fully integrated and dynamic network that will decrease time to revenue.

  7. Pheromone-Based Ant Routing System for IP Networks

    Institute of Scientific and Technical Information of China (English)

    张林; 任勇; 山秀明

    2004-01-01

    The pheromone-based ant routing algorithm is a distributed routing algorithm with good scalability and robustness. A 2-D cellular automata (CA) model of the computer network was presented to analyze the algorithm. The results show that the procedure of establishing a stable route is self-organized towards the attractive peculiar state, and the duration of time for the routing establishment is power-law distributed. A practical ant routing protocol over an IP network was also presented, and two simulations were done to compare the performance dynamic and the load balancing performance between this protocol and the open shortest path first (OSPF) protocol. The results show that the ant routing protocol out-performs OSPF in these aspects.

  8. Integrated Control Plane for IP Enabled Optical Networks

    Institute of Scientific and Technical Information of China (English)

    LIZhengbin; YINHongxi; YUDeming; XUAnshi

    2003-01-01

    With the exponential growth of the Internet traffle for the intense demand for broadband services,providing bandwidth and connectivity on demand has risen to be a hot topic involving establishing connections from client ent systems to another through the optical backbone.So that,control plane and signaling in the optical network seems to be a critical component.This paper proposes and integrated control plane(ICP)and signaling related in IP enabled optical networks.Signaling processing for ensuring dynamic end-to-end lightpath setup has also been presented.Path provisioning comprises a string of operations like service & neighbor discovery,route computation,signaling requests,and path setup.

  9. TCP I-Vegas in Mobile-IP Network

    Directory of Open Access Journals (Sweden)

    Nitin Jain

    2014-01-01

    Full Text Available Mobile Internet Protocol (Mobile-IP or MIP provides hosts with the ability to change their point of attachment to the network without compromising their ability to communicate. However, when TCP Vegas is used over a MIP network, its performance degrades because it may respond to a handoff by invoking its congestion control algorithm. TCP Vegas is sensitive to the change of Round-Trip Time (RTT and it may recognize the increased RTT as a result of network congestion. This is because TCP Vegas could not differentiate whether the increased RTT is due to route change or network congestion. This paper presents a new and improved version of conventional TCP Vegas, which we named as TCP I-Vegas (where “I”, stands for Improved. Vegas performs well when compared to Reno but when sharing bandwidth with Reno its performance degrades. I-Vegas has been designed keeping in mind that whenever TCP variants like Reno has to share the bandwidth with Vegas then instead of using Vegas, if we use I-Vegas then the loss which Vegas would have to bear will not be more. We compared the performance of I-Vegas with Vegas in MIP environment using Network Simulator (NS-2. Simulation results show that I-Vegas performs better than Vegas in terms of providing better throughput and congestion window behavior.

  10. Leo Satellite Communication through a LEO Constellation using TCP/IP Over ATM

    Science.gov (United States)

    Foore, Lawrence R.; Konangi, Vijay K.; Wallett, Thomas M.

    1999-01-01

    The simulated performance characteristics for communication between a terrestrial client and a Low Earth Orbit (LEO) satellite server are presented. The client and server nodes consist of a Transmission Control Protocol /Internet Protocol (TCP/IP) over ATM configuration. The ATM cells from the client or the server are transmitted to a gateway, packaged with some header information and transferred to a commercial LEO satellite constellation. These cells are then routed through the constellation to a gateway on the globe that allows the client/server communication to take place. Unspecified Bit Rate (UBR) is specified as the quality of service (QoS). Various data rates are considered.

  11. NOVEL APPROACH TO RESOLVE NETWORK SECURITY ISSUES IN IP-PBX IN CONVERGED ARCHITECTURE

    Directory of Open Access Journals (Sweden)

    MUNIR B. SAYYAD,

    2010-10-01

    Full Text Available This paper aims to examine the security issues in the IP-PBX (IP Private Branch Exchange .The Traces are taken on the live environment using Vendor ‘X’ CDMA MSC. The traces are also taken at SBC (Session Boarder Controller. The PBX services can be provided over IP via a SIP (session initiation protocol trunk provided by network operator. The SIP trunk is connected to a switch i.e. MSC. Thus IP connectivity is available at IP-PBX end. Now calls can be originated from IP-PBX which is terminating on a mobile handset registered with MSC. The problem arises when a dummy/blank/fake CLI (caller line identification is configured at IP-PBX. As MSC isdoing only part of routing depending upon called party number, such calls with fake CLI pass through MSC without any intervention. So called party and even MSC are unaware of real number of calling party. Similar security issue arises when IP-PBX sends dummy IP addresses of IP phones connected to IP-PBX. Thus conflict of IP addresses and or called party numbers creates a major security concern. These are important issues for interfacing IP with traditional wire line or wireless network. Such a security issue can be resolved by registering IP-PBX and its extension numbers with MSC. This paper describes the probable methods to resolve above issues.

  12. Stochastic TCO minimization for Video Transmission over IP Networks

    CERN Document Server

    Goudarzi, Pejman

    2012-01-01

    From the viewpoint of service operators the Total Cost of Ownership (TCO) for developing a communication service comprises from two parts; CAPital EXpenditure (CAPEX) and OPerational EXpenditure (OPEX). These two types of costs are interrelated and affect any service provider's deployment strategy. In many traditional methods, selection of critical elements of a new service is performed in a heuristic manner aimed at reducing only the OPEX part of the TCO which is not necessarily optimal. Furthermore, exact cost modeling for such services is not always possible and contains some uncertainties. In the current work, after cost modeling of each video streaming element by capturing the effect of the model uncertainties, the TCO optimization problem for video streaming over IP networks is formulated as a stochastic optimization problem. The solution of the proposed optimization problem can cope with the cost modeling uncertainties and track the dynamism in the TCO and lead to a time-varying optimal solution. Numer...

  13. A Novel Switching Architecture for IP Over WDM Networks

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Integrating IP and WDM is an attractive direction for research.Many solutions have been presented but it is noted that the existing switching technologies still need more concern. Since optical packet switching is not practical yet, there are just two possible solutions left. One is wavelength routing(WR), which is circuit switching in essence and the other is newly proposed optical burst switching (OBS). In this paper, characteristics of WR and OBS are first described, then, compared in several aspects. It is notice that in many aspects, the wavelength routing and burst switching are complement. This stimulates us to propose a new switching architecture, which may be considered as “mixture” of WR and OBS. We beleve the network built on new switching structure can accommodate the requirements of practicability, flexibility, robustness, effciency and etc. simultaneously. However, many related problems still need to be further researched.

  14. IP-Switch网络通信业务%Communication Services of IP-Switch Network

    Institute of Scientific and Technical Information of China (English)

    马泽旭; 邢兆宏

    2005-01-01

    IP-Switch网是基于IP网络、采用软交换体系架构的、新一代网络通信平台,具有强大的业务提供能力及良好的业务扩展能力,给企业带来很大的收益.介绍IP-Switch网的业务种类、接入方式和实现方法.

  15. Internet Connection of a Broadband Wireless IP Network Based on a Fast Mobile IP Algorithm with Link Layer Support

    Institute of Scientific and Technical Information of China (English)

    XIONGYan; MIAOFuyou; HUABei; WANGXingfu

    2003-01-01

    Commercialized wireless LANs (local area networks) are emerging one after another. Because a lot of useful information and resources are residing in the wired network, Internet, the strong requirement to access In-ternet for mobile hosts in wireless LANs is growing more and more. In this paper, we simply describe the topoi-ogy and feature of a broadband wireless Internet protocol network (BWIPN) in which data transmitted on wireless link is encapsulated within Internet protocol (IP) packets.To connect to Internet, there is an Internet connecting server (ICS) which is also a router within every BWIPN.A fast mobile IP hand-offalgorithm with link layer supportto reduce handoff overhead has been proposed to providemobility support for wireless terminals (WTs, i.e. note-book computers) roaming among BWIPNs without chang-ing their IP addresses. An indirect TCP (transfer control protocol) scheme is used to improve the performance ofwireless TCP. To match data transmission rate on the wire-less link with that on the wired link, an adaptive wireless congestion control algorithms are added at IP layers in the WT and the ICS. Both performance analysis and experi-mental result have shown that the fast mobile IP hand-off algorithm reduces the hand-off delay by about 10 times and TCP disconnection times is reduced greatly, compared with the three known mobile IP hand-off algorithms. By our work, users on WTs can explore Internet using Web browser, File Transfer Protocol, Telnet and Ping utilities while moving among different BWIPNs very well.

  16. An attacker-defender model for IP-based networks

    OpenAIRE

    Barkley, Timothy R.

    2008-01-01

    The Internet Protocol (IP) has emerged as the dominant technology for determining how data is routed across the Internet. Because IP flows are defined essentially in terms of origin-destination (O-D) pairs, we represent IP traffic engineering as a multi-commodity flow problem in which each O-D pair is treated as a separate commodity. We account for the diversity in IP routing by modeling opposite extremes of traffic engineering: "naive" traffic engineering where the IP routes data between...

  17. Incorporate design of on-board network and inter-satellite network

    Science.gov (United States)

    Li, Bin; You, Zheng; Zhang, Chenguang

    2005-11-01

    In satellite, Data transferring is very important and must be reliable. This paper first introduced an on-board network based on Control Area Network (CAN). As a kind of field bus, CAN is simple and reliable, and has been tested by previous flights. In this paper, the CAN frame is redefined, including the identifier and message data, the addresses for source and destination as well as the frame types. On-board network provides datagram transmission and buffer transmission. Data gram transmission is used to carry out TTC functions, and buffer transmission is used to transfer mass data such as images. Inter-satellite network for satellite formation flying is not designed individually. It takes the advantage of TCP/IP model and inherits and extends on-board network protocols. The inter-satellite network includes a linkage layer, a network layer and a transport layer. There are 8 virtual channels for various space missions or requirements and 4 kinds of services to be selected. The network layer is designed to manage the whole net, calculate and select the route table and gather the network information, while the transport layer mainly routes data, which correspondingly makes it possible for communication between each two nodes. Structures of the linkage frame and transport layer data segment are similar, thus there is no complex packing and unpacking. At last, this paper gives the methods for data conversion between the on-board network and the inter-satellite network.

  18. A policy-based billing management architecture for the next generation IP-based network

    Institute of Scientific and Technical Information of China (English)

    Cheng Lu; Qiu Xuesong; Meng Luoming

    2006-01-01

    IP billing is not only a basic functionality to operate IP services, but also it is fundamental to offer customers with a stable and QoS-enabled network environment. As IP-based network has been widely agreed to be the core network of NGN, and existing IP billing system is too simple to fulfill the emerging requirements, the next generation IP billing has become an interesting topic in recent years. Policy-based management brings flexibility and scalability to systems by describing management logic and functions through policies, and thus reduces the complexity of the management of large-scale systems. Working on existing efforts, this paper proposed an improved IETF policy framework based upon which a policy-based billing management architecture for the next generation IP-based network was presented. Then a prototype with some basic functionalities was developed. The results of the experiment validated the expected improvements specified in this paper.

  19. Architecture and Engineering Issues in Building an IP over WDM Networks

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The technologies of IP over WDM have presently received increasing attention owing to the rapid growth in Internet traffic and the need for next-generation Internet technologies. The challenge now is how to integrate the services of IP over WDM optical networks to take full advantages of WDM technologies and IP technologies, and yield a high-throughput optical platform directly underpinning next generation data networks. This article discusses some of the architecture and technology issues for the design of IP over WDM optical networks.

  20. Advances Made in the Next Generation of Satellite Networks

    Science.gov (United States)

    Bhasin, Kul B.

    1999-01-01

    Because of the unique networking characteristics of communications satellites, global satellite networks are moving to the forefront in enhancing national and global information infrastructures. Simultaneously, broadband data services, which are emerging as the major market driver for future satellite and terrestrial networks, are being widely acknowledged as the foundation for an efficient global information infrastructure. In the past 2 years, various task forces and working groups around the globe have identified pivotal topics and key issues to address if we are to realize such networks in a timely fashion. In response, industry, government, and academia undertook efforts to address these topics and issues. A workshop was organized to provide a forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. The Satellite Networks: Architectures, Applications, and Technologies Workshop was hosted by the Space Communication Program at the NASA Lewis Research Center in Cleveland, Ohio. Nearly 300 executives and technical experts from academia, industry, and government, representing the United States and eight other countries, attended the event (June 2 to 4, 1998). The program included seven panels and invited sessions and nine breakout sessions in which 42 speakers presented on technical topics. The proceedings covers a wide range of topics: access technology and protocols, architectures and network simulations, asynchronous transfer mode (ATM) over satellite networks, Internet over satellite networks, interoperability experiments and applications, multicasting, NASA interoperability experiment programs, NASA mission applications, and Transmission Control Protocol/Internet Protocol (TCP/IP) over satellite: issues, relevance, and experience.

  1. Evaluation and Investigation of the Delay in VoIP Networks

    Directory of Open Access Journals (Sweden)

    V. Janata

    2011-06-01

    Full Text Available The paper is focused mainly on the delay problems, which considerably influence the final quality of connections in VoIP (Voice over IP networks. The paper provides a detailed exploration of the nature and mechanisms of the delay. The main purpose of the investigation was an attempt to formulate a mathematical model of delay in the VoIP network and its subsequent analysis by laboratory data.

  2. Reducing handover latency in future IP-based wireless networks: Fast Proxy Mobile IPv6

    NARCIS (Netherlands)

    Heijenk, Geert; Bargh, Mortaza S.; Laganier, Julien; Prasad, Anand R.

    2008-01-01

    Current IP-level mobility protocols have difficulties meeting the stringent handover delay requirements of future wireless networks. At the same time they do not give sufficient control to the network to control the handover process. This paper presents an extension to Proxy Mobile IP, which is the

  3. A Traffic Forecasting Method with Function to Control Residual Error Distribution for IP Access Networks

    Science.gov (United States)

    Kitahara, Takeshi; Furuya, Hiroki; Nakamura, Hajime

    Since traffic in IP access networks is less aggregated than in backbone networks, its variance could be significant and its distribution may be long-tailed rather than Gaussian in nature. Such characteristics make it difficult to forecast traffic volume in IP access networks for appropriate capacity planning. This paper proposes a traffic forecasting method that includes a function to control residual error distribution in IP access networks. The objective of the proposed method is to grasp the statistical characteristics of peak traffic variations, while conventional methods focus on average rather than peak values. In the proposed method, a neural network model is built recursively while weighting residual errors around the peaks. This enables network operators to control the trade-off between underestimation and overestimation errors according to their planning policy. Evaluation with a total of 136 daily traffic volume data sequences measured in actual IP access networks demonstrates the performance of the proposed method.

  4. AN OPTIMIZED SCHEME FOR FAST HANDOFF IN IP-BASED CDMA WIRELESS COMMUNICATION NETWORKS

    Institute of Scientific and Technical Information of China (English)

    段世平; 徐友云; 宋文涛; 罗汉文

    2002-01-01

    This paper proposed an optimized fast handoff scheme for real-time applications in next generation IPbased CDMA wireless networks. The idea is to utilize optimized IP multicasting handoff (based on PIM-SM),which is triggered by CDMA layer-2 functionality. An IP-based cellular network model with WCDMA FDD air interface and IP-based packet traffic is adopted. No special network entities and signaling for handoff are added in our network model. The simulation results show that low delay and low packet-lost-rate can be obtained.

  5. Satellite communications network design and analysis

    CERN Document Server

    Jo, Kenneth Y

    2011-01-01

    This authoritative book provides a thorough understanding of the fundamental concepts of satellite communications (SATCOM) network design and performance assessments. You find discussions on a wide class of SATCOM networks using satellites as core components, as well as coverage key applications in the field. This in-depth resource presents a broad range of critical topics, from geosynchronous Earth orbiting (GEO) satellites and direct broadcast satellite systems, to low Earth orbiting (LEO) satellites, radio standards and protocols.This invaluable reference explains the many specific uses of

  6. New-generation security network with synergistic IP sensors

    Science.gov (United States)

    Peshko, Igor

    2007-09-01

    Global Dynamic Monitoring and Security Network (GDMSN) for real-time monitoring of (1) environmental and atmospheric conditions: chemical, biological, radiological and nuclear hazards, climate/man-induced catastrophe areas and terrorism threats; (2) water, soil, food chain quantifiers, and public health care; (3) large government/public/ industrial/ military areas is proposed. Each GDMSN branch contains stationary or mobile terminals (ground, sea, air, or space manned/unmanned vehicles) equipped with portable sensors. The sensory data are transferred via telephone, Internet, TV, security camera and other wire/wireless or optical communication lines. Each sensor is a self-registering, self-reporting, plug-and-play, portable unit that uses unified electrical and/or optical connectors and operates with IP communication protocol. The variant of the system based just on optical technologies cannot be disabled by artificial high-power radio- or gamma-pulses or sunbursts. Each sensor, being supplied with a battery and monitoring means, can be used as a separate portable unit. Military personnel, police officers, firefighters, miners, rescue teams, and nuclear power plant personnel may individually use these sensors. Terminals may be supplied with sensors essential for that specific location. A miniature "universal" optical gas sensor for specific applications in life support and monitoring systems was designed and tested. The sensor is based on the physics of absorption and/or luminescence spectroscopy. It can operate at high pressures and elevated temperatures, such as in professional and military diving equipment, submarines, underground shelters, mines, command stations, aircraft, space shuttles, etc. To enable this capability, the multiple light emitters, detectors and data processing electronics are located within a specially protected chamber.

  7. Optimizing Low Speed VoIP Network for Rural Next Generation Network (R-NGN

    Directory of Open Access Journals (Sweden)

    Yoanes Bandung

    2007-11-01

    Full Text Available In this research, we propose an optimization method based-on E-Model for designing an efficient low speed VoIP network for Rural Next Generation Network (R-NGN. We are choosing 128 kbps and 256 kbps bandwidth as the typical community link to be used in the designing of R-NGN infrastructure. The method is based on selection of some VoIP network parameters such as voice coder, communication protocol, packet loss level, network utilization and resource allocation. We draw analytic approach for achieving rating value (R of E-model that represent level of quality of service. In this approach, we focus on delay and packet loss calculation to find the rating value. We state the rating value = 70 as minimum level of quality of service for each call, equivalent to 3.6 of Mean Opinion Score (MOS. In our experiments, either G.723.1 5.3 kbps or G.729 is chosen for maximizing the number of VoIP calls, it depends on link utilization and level of packet loss.

  8. Managing the PSTN transformation a blueprint for a successful migration to IP-based networks

    CERN Document Server

    Dornheim, Sandra

    2015-01-01

    While there are many scholarly books and papers that cover the technical issues behind the public switched telephone network (PSTN) migration, few books describe exactly how to manage the migration process economically. Filling this need, Managing the PSTN Transformation: A Blueprint for a Successful Migration to IP-Based Networks reflects the latest understanding of the challenges behind migrating customers from the old PSTN network to an IP infrastructure. The IP transformation blueprint described in this book is not a theoretical cookbook that describes how this could work. Instead, the boo

  9. Deploying a simple voice over IP network using a simulation tool

    OpenAIRE

    Limbu, Prajil

    2016-01-01

    Voice over IP is a major advancement in the field of IP communications systems technology since the advent of Internet. It is a communication technology which enables a device to transmit and receive voice traffic with the help of an IP-based network such as the Internet. Various types and deployments of Voice over IP are prevailing due to its popularity since its origin. Since its advent, it has managed to evolve and has given a platform to be benefited with its numerous advantages not only ...

  10. GMPLS: IP-Centric Control Protocols for Optical Networks(Tutorial)

    Institute of Scientific and Technical Information of China (English)

    Yaohui Jin; Weisheng Hu

    2003-01-01

    Recent advances in optical networking technologies, particularly DWDM and MEMS, promise the transmission and switching of huge bandwidth capacity. The carriers have convinced of that their revenue must be earned from efficient bandwidth management instead of unsophisticated increase in capacity. The distributed control plane can offer more flexibility, reliability and scalability, whose functions include addressing, resource and topology discovery, route computation, provisioning and restoration. Generalized Multi-Protocol Label Switching (GMPLS), an IP-centric control plane, inherit the best features of IP and ATM technologies in terms of QoS and traffic engineering. Besides,GMPLS introduces enhancements to the existing IP routing and signaling protocols by supporting not only packet switching networks (IP) and frame/cell switching networks (ATM), but also networks that perform switching in time (e.g. SDH/SONET, PDH, G.709), wavelength (lambdas), and space (fiber) domain.

  11. Efficient IP Traffic over Optical Network Based on Wavelength Translation Switching

    DEFF Research Database (Denmark)

    Jha, Vikas; Kalia, Kartik; Chowdhary, Bhawani Shankar;

    2016-01-01

    With the advent of TCP/IP protocol suite the overall era of communication technologies had been redefined. Now, we can’t ignore the presence of huge amount of IP traffic; data, voice or video increasing day by day creating more pressure on existing communicating media and supporting back bone....... With the humongous popularity of Internet the overall traffic on Internet has the same story. Focusing on transmission of IP traffic in an optical network with signals remaining in their optical nature generated at particular wavelength, proposed is the switching of optically generated IP packets through optical...... cross connects based on translation of wavelength when an IP packet is crossing the optical cross connect. Adding the concepts of layer 3 routing protocols along with the wavelength translation scheme, will help in spanning the overall optical network for a larger area....

  12. Adaptive Multiplexing Scheme for Voice Flow Transmission Across Best-Effort IP Networks

    OpenAIRE

    Trad, Abdelbasset; Afifi, Hossam

    2003-01-01

    We investigate the performance limitations in the case of a large number of long distance voice over IP calls originating from different sources and transported through a best-effort IP network. We focus on the potentially negative effects of total protocol header overhead, which is twice the voice payload generated by the high-compression audio codecs. These negative effects range from the inefficient use of bandwidth to the network congestion caused by the large number of short voice packet...

  13. Modeling and performance analysis of IP access interface in optical transmission networks with packet switching

    OpenAIRE

    Lackovic, Marko; Bungarzeanu, Cristian

    2006-01-01

    The article analyzes the influence of the Internet Protocol (IP) access interface on the packet loss probability and delay times in the optical packet switched network. The network and node model have been proposed, and the structure of the IP access interface, including assembler and holder, have been included in the analysis. It has been shown that the increase of the maximum optical packet sizes, as well as use of the holding feature as contention resolution mechanism, decrease the packet ...

  14. Improvement of Ka-band satellite link availability for real-time IP-based video contribution

    Directory of Open Access Journals (Sweden)

    G. Berretta

    2017-09-01

    Full Text Available New High Throughput Satellite (HTS systems allow high throughput IP uplinks/contribution at Ka-band frequencies for relatively lower costs when compared to broadcasting satellite uplinks at Ku band. This technology offers an advantage for live video contribution from remote areas, where the terrestrial infrastructure may not be adequate. On the other hand, the Ka-band is more subject to impairments due to rain or bad weather. This paper addresses the target system specification and provides an optimized approach for the transmission of IP-based video flows through HTS commercial services operating at Ka-band frequencies. In particular, the focus of this study is on the service requirements and the propagation analysis that provide a reference architecture to improve the overall link availability. The approach proposed herein leads to the introduction of a new concept of live service contribution using pairs of small satellite antennas and cheap satellite terminals.

  15. Satellite ATM Networks: Architectures and Guidelines Developed

    Science.gov (United States)

    vonDeak, Thomas C.; Yegendu, Ferit

    1999-01-01

    An important element of satellite-supported asynchronous transfer mode (ATM) networking will involve support for the routing and rerouting of active connections. Work published under the auspices of the Telecommunications Industry Association (http://www.tiaonline.org), describes basic architectures and routing protocol issues for satellite ATM (SATATM) networks. The architectures and issues identified will serve as a basis for further development of technical specifications for these SATATM networks. Three ATM network architectures for bent pipe satellites and three ATM network architectures for satellites with onboard ATM switches were developed. The architectures differ from one another in terms of required level of mobility, supported data rates, supported terrestrial interfaces, and onboard processing and switching requirements. The documentation addresses low-, middle-, and geosynchronous-Earth-orbit satellite configurations. The satellite environment may require real-time routing to support the mobility of end devices and nodes of the ATM network itself. This requires the network to be able to reroute active circuits in real time. In addition to supporting mobility, rerouting can also be used to (1) optimize network routing, (2) respond to changing quality-of-service requirements, and (3) provide a fault tolerance mechanism. Traffic management and control functions are necessary in ATM to ensure that the quality-of-service requirements associated with each connection are not violated and also to provide flow and congestion control functions. Functions related to traffic management were identified and described. Most of these traffic management functions will be supported by on-ground ATM switches, but in a hybrid terrestrial-satellite ATM network, some of the traffic management functions may have to be supported by the onboard satellite ATM switch. Future work is planned to examine the tradeoffs of placing traffic management functions onboard a satellite as

  16. Application Oriented Flow Routing Algorithm for VoIP Overlay Networks

    Science.gov (United States)

    Wipusitwarakun, Komwut; Chimmanee, Sanon

    Overlay networks which are dynamically created over underlying IP networks are becoming widely used for delivering multimedia contents since they can provide several additional user-definable services. Multiple overlay paths between a source-destination overlay node pair are designed to improve service robustness against failures and bandwidth fluctuation of the underlying networks. Multimedia traffic can be distributed over those multiple paths in order to maximize paths' utilization and to increase application throughputs. Most of flow-based routing algorithms consider only common metrics such as paths' bandwidth or delay, which may be effective for data applications but not for real-time applications such as Voice over IP (VoIP), in which different levels of such performance metrics may give the same level of the performance experienced by end users. This paper focuses on such VoIP overlay networks and proposes a novel alternative path based flow routing algorithm using an application-specific traffic metric, i.e. “VoIP Path Capacity (VPCap), ” to calculate the maximum number of QoS satisfied VoIP flows which may be distributed over each available overlay path at a moment. The simulation results proved that more QoS-satisfied VoIP sessions can be established over the same multiple overlay paths, comparing to traditional approaches.

  17. Satellite Networks: Architectures, Applications, and Technologies

    Science.gov (United States)

    Bhasin, Kul (Compiler)

    1998-01-01

    Since global satellite networks are moving to the forefront in enhancing the national and global information infrastructures due to communication satellites' unique networking characteristics, a workshop was organized to assess the progress made to date and chart the future. This workshop provided the forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. Presentations on overview, state-of-the-art in research, development, deployment and applications and future trends on satellite networks are assembled.

  18. A Study of the Next Generation Intelligent Networks Interworking with IP Networks

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the past three years, the author has participated in several projects involved in Intelligent Network (IN). In 1997, we started our research on the project “The Integration of IN and B-ISDN” supported by National Science Foundation. Since 1999, the author has engaged in the project “the Next Generation IN Based Service Platform Interworking with IP Networks” supported by the National 863 Project. While working on the project, the author made a deep research on the architecture and the key technology of the next generation IN defined by ITU-T IN CS3 and CS4. In the following parts. 1. I conclude the research work and the innovation in my dissertation. The early research on the interworking of IN and Internet, despite the shortage of materials, the interworking architecture by means of IAF is analyzed. Some key techniques like triggering intelligent service and reporting dynamic IP address are solved. Some new SIBs and INAPs are added, and the dial-up software of users is enhanced, too. The incoming call notification service is designed. What we have done paves the way for the future research. 2. The gateway based architecture for the interworking of IN and Internet is described. Considering the research results from ITU, PINT work group and TIPHON work group, we emphasize that the interworking scenario through MG,SCG and C/BG is promising. Based on the CIN software developed by ourselves, we provide the scenario to enhance the function entities and signaling protocol. We address the function of entities and the interaction of signaling with an example like ICW service. 3. With the introduction of mobile agent technology, the author proposes the distributed IN which can be integrated with IP networks. According to the drawbacks of the centralized IN, we address the architecture and conceptual model of distributed IN to support advanced service in IP Telephony. We try to illustrate the role and relationship between function entities. We also present a

  19. A New Verification Method to Prevent Security Threads of Unsolicited Message in IP Over Ethernet Networks

    Directory of Open Access Journals (Sweden)

    Waleed Kh. Alzubaidi

    2012-12-01

    Full Text Available Internet is widely depends on the IP over Ethernet networks architecture. IP and Ethernet protocols uses in each Local Area Network LAN, wire and wireless. Due to the rapid expansion of the technology field this architecture reveals many shortcomings. TCP/IP suite protocols are consists from layers, each layer accomplish its jobs separately. However, these layers susceptible to different attacks. Data link layer one of the most layers targeted by the attackers. Attack at lower layer may lead to more sophisticated attacks to upper layers, like Man-in-The-Middle (MiTM, DNS spoofing and Denial of Service (DoS. These attacks applicable even with encrypted protocols such as HTTPS and SSL. In this paper we discuss the security in the Data Link Layer in IP over Ethernet networks and the attacks depend on the Address resolution protocol (ARP. Moreover, explain our proposed method to prevent address resolution protocol attacks.

  20. IP Switching Network of The Entire Network%交换网络的全网IP化

    Institute of Scientific and Technical Information of China (English)

    王武伦

    2015-01-01

    电话交换网络的全IP化是电信网发展的方向,使得语音业务能够融入到综合的IMS系统中.克服了传统电信网络多层次业务多平台,资源难以融合、共享的弊端,为三网合一打下基础.本文介绍了全IP化的交换网络的组网思路,网络结构和现阶段根据条件进行端局改造实现ip化的具体方案,为将来完全接入IMS系统的IP化做好准备.%Full IP telephone switching network, the developing direction of telecommunication network, enables the voice business to integrated into the IMS system. This paper introduces the whole exchange network of IP network and present a specific plan to transform the bureau.

  1. Traffic Measurement for Traffic Engineering in IP/MPLS Based Telecom Core Networks

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Telecommunication networks will become IP-based networks with all voice, data and multimedia traffic carried as packets with appropriate quality and class of service for each traffic type. It is very important for service provider to apply Traffic Engineering (TE) with the dramatic growth of networks traffic. In this paper, we discuss traffic engineering based on IP/MPLS and emphasize traffic measurement in telecom core networks. We specify the technology and scientific principles of the measurement, modeling, characterization, and the traffic flow matrix. The paper concludes with a preliminary analysis of TE measurement and a discussion about the development of TE measurement.

  2. Energy star compliant voice over internet protocol (VoIP) telecommunications network including energy star compliant VoIP devices

    Energy Technology Data Exchange (ETDEWEB)

    Kouchri, Farrokh Mohammadzadeh

    2012-11-06

    A Voice over Internet Protocol (VoIP) communications system, a method of managing a communications network in such a system and a program product therefore. The system/network includes an ENERGY STAR (E-star) aware softswitch and E-star compliant communications devices at system endpoints. The E-star aware softswitch allows E-star compliant communications devices to enter and remain in power saving mode. The E-star aware softswitch spools messages and forwards only selected messages (e.g., calls) to the devices in power saving mode. When the E-star compliant communications devices exit power saving mode, the E-star aware softswitch forwards spooled messages.

  3. RIDES: Robust Intrusion Detection System for IP-Based Ubiquitous Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sungwon Lee

    2009-05-01

    Full Text Available TheIP-based Ubiquitous Sensor Network (IP-USN is an effort to build the “Internet of things”. By utilizing IP for low power networks, we can benefit from existing well established tools and technologies of IP networks. Along with many other unresolved issues, securing IP-USN is of great concern for researchers so that future market satisfaction and demands can be met. Without proper security measures, both reactive and proactive, it is hard to envisage an IP-USN realm. In this paper we present a design of an IDS (Intrusion Detection System called RIDES (Robust Intrusion DEtection System for IP-USN. RIDES is a hybrid intrusion detection system, which incorporates both Signature and Anomaly based intrusion detection components. For signature based intrusion detection this paper only discusses the implementation of distributed pattern matching algorithm with the help of signature-code, a dynamically created attack-signature identifier. Other aspects, such as creation of rules are not discussed. On the other hand, for anomaly based detection we propose a scoring classifier based on the SPC (Statistical Process Control technique called CUSUM charts. We also investigate the settings and their effects on the performance of related parameters for both of the components.

  4. Global path and bandwidth scheduling in inter-data-center IP/optical transport network

    Science.gov (United States)

    Zhao, Yang; Wang, Lei; Chen, Xue; Yang, Futao; Shi, Sheping; Wang, Huitao

    2016-07-01

    We propose a flow-oriented global path and bandwidth scheduling scheme for inter-data-center IP/optical network. To improve the throughput of network and reduce the mutual impact between flows, we allow each flow to be carried by a multi-path optical channel data unit (ODU) channel. In addition bandwidth is allocated to flows fairly according to weight. Simulation results reveal that compared to high-priority-first mechanism, the method proposed improves average bandwidth allocation ratio by about 15% and allocation fairness between flows by 30%. Furthermore, compared to pure IP network, router ports are significantly saved and network cost can be reduced by up to 40% with scheme proposed in unified controlled IP/optical network.

  5. Improving Control Mechanism at Routers in TCP/IP Network

    Directory of Open Access Journals (Sweden)

    Nguyen Kim Quoc

    2014-09-01

    Full Text Available The existing control mechanisms at the network nodes have a good active and very effective at each local router, but they do not still strong enough to control nonlinear and dynamical behaviour of the network. Therefore, the control system requirements must be designed to be flexible to fully grasp the important status information of the variation and intelligent control methods to control network congestion in nonlinear network. To solve this problem, we propose a solution combined fuzzy reasoning with neural network control put on active queue management mechanisms at the network nodes.

  6. WISER: realistic and scalable wireless mobile IP network emulator

    Science.gov (United States)

    Kaplan, M. A.; Cichocki, A.; Demers, S.; Fecko, M. A.; Hokelek, I.; Samtani, S.; Unger, J. W.; Uyar, M. U.; Greear, B.

    2009-05-01

    WISER is a scalable network emulation tool for networks with several hundred heterogeneous wireless nodes. It provides high-fidelity network modeling, exchanges packets in real-time, and faithfully captures the complex interactions among network entities. WISER runs on inexpensive COTS platforms and represents multiple full network stacks, one for each individual virtual node. It supports a flexible open source router platform (XORP) to implement routing protocol stacks. WISER offers wireless MAC emulation capabilities for different types of links, waveforms, radio devices, etc. We present experiments to demonstrate WISER's capabilities enabling a new paradigm for performance evaluation of mobile sensor and ad-hoc networks.

  7. IPTV based on IP network and streaming media service station

    Science.gov (United States)

    Sun, Jifeng; Gao, Songbo

    2007-11-01

    IPTV can be a new service performed on the Internet in that network transmission and streaming media technologies are getting mature. In this paper, IPTV system infrastructure of UTStarcom, key technologies deployed, and applications will be discussed and evaluated. The key technologies to achieve IPTV services include 1) codec and compression; 2) streaming media; and 3) broadband networks and access to such networks. The implementation of Media Switch IPTV system in Harbin CNC city network is also discussed.

  8. An access alternative for mobile satellite networks

    Science.gov (United States)

    Wu, W. W.

    1988-05-01

    Conceptually, this paper discusses strategies of digital satellite communication networks for a very large number of low density traffic stations. These stations can be either aeronautical, land mobile, or maritime. The techniques can be applied to international, domestic, regional, and special purpose satellite networks. The applications can be commercial, scientific, military, emergency, navigational or educational. The key strategy is the use of a non-orthogonal access method, which tolerates overlapping signals. With n being either time or frequency partitions, and with a single overlapping signal allowed, a low cost mobile satellite system can be designed with n squared (n squared + n + 1) number of terminals.

  9. Architecture and Design of IP Broadcasting System Using Passive Optical Network

    Science.gov (United States)

    Ikeda, Hiroki; Sugawa, Jun; Ashi, Yoshihiro; Sakamoto, Kenichi

    We propose an IP broadcasting system architecture using passive optical networks (PON) utilizing the optical broadcast links of a PON with a downstream bandwidth allocation algorithm to provide a multi-channel IP broadcasting service to home subscribers on single broadband IP network infrastructures. We introduce the design and adaptation of the optical broadcast links to effectively broadcast video contents to home subscribers. We present a performance analysis that includes the downstream bandwidth utilization efficiency of the broadcast link and the bandwidth control of the IP broadcasting and Internet data. Our analysis and simulation results show that the proposed system can provide 100 HDTV channels to every user over fiber lines. We also propose an IPTV channel selection mechanism in an ONT by selecting a broadcast stream. We developed and evaluated a prototype that can achieve a 15-msec IPTV channel selection speed.

  10. On the stability of multicast flow aggregation in IP over optical network for IPTV delivery

    Institute of Scientific and Technical Information of China (English)

    Xuan Luo; Yaohui Jin; Qingji Zeng; Weiqiang Sun; Wei Guo; Weisheng Hu

    2008-01-01

    The stable multicast flow aggregation (MFA) problem in internet protocol (IP) over optical network under the dynamical scenario is studied. Given an optical network topology, there is a set of head ends and access routers attached to the optical network, in which each head end can provide a set of programs (IP multicasting flows) and each access router requests a set of programs, we find a set of stable light-trees to accommodate the optimally aggregated multicast IP flows if the requests of access routers changed dynamically. We introduce a program correlation matrix to describe the preference of end users' requests. As the original MFA problem is NP-complete, a heuristic approach, named most correlated program first (MCPF), is presented and compared with the extended least tree first (ELTF) algorithm which is topologyaware. Simulation results show that MCPF can achieve better performance than ELTF in terms of stability with negligible increment of network resource usage.

  11. Intrusion detection for IP-based multimedia communications over wireless networks

    CERN Document Server

    Tang, Jin

    2013-01-01

    IP-based multimedia communications have become increasingly popular in recent years. With the increasing coverage of the IEEE 802:11™ based wireless networks, IP-based multimedia communications over wireless networks are also drawing extensive attention in both academia and industry. Due to the openness and distributed nature of the protocols involved, such as the session initiation protocol (SIP) and the IEEE 802:11™ standard, it becomes easy for malicious users in the network to achieve their own gain or disrupt the service by deviating from the normal protocol behaviors. This SpringerBrief

  12. A Method for Detecting Intrusion on Networks in Real-time Based on IP Weight

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new rule to detect intrusion based on IP weight, which is also well implemented in the rule base of author's NMS, is presented. Compared with traditional ones, intrusion detecting based on IP weight enhanced analysis to packet content. The method also provides a real-time efficient way to analyze traffic on high-speed network and can help to increase valid usage rates of network resources. Practical implementation as a rule in the rule base of our NMS has verified that the rule can detect not only attacks on network, but also other unusual behaviors.

  13. Threshold-based generic scheme for encrypted and tunneled Voice Flows Detection over IP Networks

    Directory of Open Access Journals (Sweden)

    M. Mazhar U. Rathore

    2015-07-01

    Full Text Available VoIP usage is rapidly growing due to its cost effectiveness, dramatic functionality over the traditional telephone network and its compatibility with public switched telephone network (PSTN. In some countries, like Pakistan, the commercial usage of VoIP is prohibited. Internet service providers (ISPs and telecommunication authorities are interested in detecting VoIP calls to either block or prioritize them. So detection of VoIP calls is important for both types of authorities. Signature-based, port-based, and pattern-based VoIP detection techniques are inefficient due to complex and confidential security and tunneling mechanisms used by VoIP. In this paper, we propose a generic, robust, efficient, and practically implementable statistical analysis-based solution to identify encrypted, non-encrypted, or tunneled VoIP media (voice flows using threshold values of flow statistical parameters. We have made a comparison with existing techniques and evaluated our system with respect to accuracy and efficiency. Our system has 97.54% direct rate and .00015% false positive rate.

  14. Efficient IP Traffic over Optical Network Based on Wavelength Translation Switching

    DEFF Research Database (Denmark)

    Jha, Vikas; Kalia, Kartik; Chowdhary, Bhawani Shankar

    2016-01-01

    With the advent of TCP/IP protocol suite the overall era of communication technologies had been redefined. Now, we can’t ignore the presence of huge amount of IP traffic; data, voice or video increasing day by day creating more pressure on existing communicating media and supporting back bone...... cross connects based on translation of wavelength when an IP packet is crossing the optical cross connect. Adding the concepts of layer 3 routing protocols along with the wavelength translation scheme, will help in spanning the overall optical network for a larger area....

  15. Using a CLIPS expert system to automatically manage TCP/IP networks and their components

    Science.gov (United States)

    Faul, Ben M.

    1991-01-01

    A expert system that can directly manage networks components on a Transmission Control Protocol/Internet Protocol (TCP/IP) network is described. Previous expert systems for managing networks have focused on managing network faults after they occur. However, this proactive expert system can monitor and control network components in near real time. The ability to directly manage network elements from the C Language Integrated Production System (CLIPS) is accomplished by the integration of the Simple Network Management Protocol (SNMP) and a Abstract Syntax Notation (ASN) parser into the CLIPS artificial intelligence language.

  16. Using IP as Transport Technology in Third Generation and Beyond Radio Access Networks

    NARCIS (Netherlands)

    Bader, Attila; Westberg, Lars; Karagiannis, Georgios; de Meer, H; Bhatti, N.T.

    This paper discusses the motivation for developing a new QoS signaling protocol for IP-based Radio Access Networks. It describes the main characteristics of these networks and the special requirements imposed by these characteristics on QoS signaling solutions.

  17. A Novel Onboard-gateway-based Mechanism to Improve TCP Performance in Aeronautical Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The IP-based networks on aircraft serve to support Internet services via satellites. However, in aeronautical satellite hybrid networks, the TCP protocol performance often deteriorates due to improper decreases and slow recovery of the congestion window. This paper proposes a window size determination and notification mechanism, onboard-gateway-based mechanism (OGBM), which is based on the onboard gateway in the networks on aircraft. A cross-layer approach is adopted by the onboard gateway to obtain the satellite link bandwidth information. And then, by the gateway, through changing the receiver's advertised window field in ACK packets, TCP sources are notified of the window size of each TCP source calculated on the ground of bandwidth delay product and flow numbers. The mechanism is able to avoid improper changes of TCP window and serve multiple users. Simulation results show that the mechanism with the fairness index close to 1 improves TCP performance in aeronautical satellite networks.

  18. Satellite Tracking Astrometric Network (STAN)

    Science.gov (United States)

    Vecchiato, Alberto; Gai, Mario

    2015-08-01

    The possibility of precise orbit tracking and determination of different types of satellites has been explored for at least some 25 years (Arimoto et al., 1990). Proposals in this sense made use mainly of astrometric observations, but multiple tracking techniques combining transfer and laser ranging was also suggested (Guo et al., 2009; Montojo et al., 2011), with different requirements and performances ranging from $\\sim100$~m to tenths of meters.In this work we explore the possible improvements and a novel implementation of a technique relying on large angle, high precision astrometry from ground for the determination of satellite orbits. The concept is based on combined observation of geostationary satellites and other near-Earth space objects from two or more telescopes, applying the triangulation principle over widely separated regions of the sky. An accuracy of a few $10^{-2}$~m can be attained with 1-meter-class telescopes and a field of vied of some arcminutes.We discuss the feasibility of the technique, some of the implementation aspects, and the limitations imposed by atmospheric turbulence. The potential benefits for satellite orbit control and navigation systems are presented, depending on the number and position of the contributing telescopes.We also discuss the possibility that, by reversing the roles of stars and satellites, the same kind of observations can be used for verification and maintenance of astrometric catalogs.

  19. A source-based congestion control strategy for real-time video transport on IP network

    Science.gov (United States)

    Chen, Xia; Cai, Canhui

    2005-07-01

    The goal of this paper is to design a TCP friendly real-time video transport protocol that will not only utilize network resource efficiently, but also prevent network congestion from the real-time video transmitting effectively. To this end, we proposed a source based congestion control scheme to adapt video coding rate to the channel capacity of the IP network, including three stages: rate control, rate-adaptive video encoding, and rate shaping.

  20. Future large broadband switched satellite communications networks

    Science.gov (United States)

    Staelin, D. H.; Harvey, R. R.

    1979-01-01

    Critical technical, market, and policy issues relevant to future large broadband switched satellite networks are summarized. Our market projections for the period 1980 to 2000 are compared. Clusters of switched satellites, in lieu of large platforms, etc., are shown to have significant advantages. Analysis of an optimum terrestrial network architecture suggests the proper densities of ground stations and that link reliabilities 99.99% may entail less than a 10% cost premium for diversity protection at 20/30 GHz. These analyses suggest that system costs increase as the 0.6 power of traffic. Cost estimates for nominal 20/30 GHz satellite and ground facilities suggest optimum system configurations might employ satellites with 285 beams, multiple TDMA bands each carrying 256 Mbps, and 16 ft ground station antennas. A nominal development program is outlined.

  1. Dissecting regulatory networks in host-pathogen interaction using chIP-on-chip technology.

    Science.gov (United States)

    Sala, Claudia; Grainger, David C; Cole, Stewart T

    2009-05-08

    Understanding host-microbe interactions has been greatly enhanced by our broadening knowledge of the regulatory mechanisms at the heart of pathogenesis. The "transcriptomics" approach of measuring global gene expression has identified genes involved in bacterial pathogenesis. More recently, chromatin immunoprecipitation (ChIP) and hybridization to microarrays (chIP-on-chip) has emerged as a complementary tool that permits protein-DNA interactions to be studied in vivo. Thus, chIP-on-chip can be used to map the binding sites of transcription factors, thereby teasing apart gene regulatory networks. In this Review, we discuss the ChIP-on-chip technique and focus on its application to the study of host-pathogen interactions.

  2. Congestion control and routing over satellite networks

    Science.gov (United States)

    Cao, Jinhua

    Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE

  3. Integrated Survivability Strategies of IP/GMPLS/Optical Multi-layer Network

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ji-jun; JI Yue-feng; XU Da-xiong

    2003-01-01

    In last decade,due to that the popularity of the internet, data-central traffic kept growing,some emerging networking requirements have been posed on the today's telecommunication networks,especially in the area of network survivability.Obviously,as a key networking problem,network reliability will be more and more important.The integration of different technologies such as ATM,SDH,and WDM in multilayer transport networks raises many questions regarding the coordination of the individual network layers.This problem is referred as multilayer network survivability.The integrated multilayer network survivability is investingated as well as the representation of an interworking strategy between different single layer survivability schemes in IP via generalized multi-protocol label switching over optical network.

  4. Voice Quality Estimation in Combined Radio-VoIP Networks for Dispatching Systems

    Directory of Open Access Journals (Sweden)

    Jiri Vodrazka

    2016-01-01

    Full Text Available The voice quality modelling assessment and planning field is deeply and widely theoretically and practically mastered for common voice communication systems, especially for the public fixed and mobile telephone networks including Next Generation Networks (NGN - internet protocol based networks. This article seeks to contribute voice quality modelling assessment and planning for dispatching communication systems based on Internet Protocol (IP and private radio networks. The network plan, correction in E-model calculation and default values for the model are presented and discussed.

  5. Multirate IP traffic transmission in flexible access networks based on optical FFH-CDMA

    DEFF Research Database (Denmark)

    Raddo, Thiago R.; Sanches, Anderson L.; Tafur Monroy, Idelfonso

    2016-01-01

    In this paper, we propose a new IP transmission architecture over optical fast frequency hopping code-division multiple-access (OFFH-CDMA) network capable of supporting multirate transmissions for applications in flexible optical access networks. The proposed network architecture is independent...... transmission rate. Furthermore, to evaluate the network performance, we derive new expressions for the decoder bit error rate (BER), total BER, packet error rate (PER), and packet throughput. We analyze the performance of a two-class OFFH-CDMA packet network, where multirate transmissions are achieved via...

  6. Considerations on VoIP Throughput in 802.11 Networks

    Directory of Open Access Journals (Sweden)

    POTORAC, A. D.

    2009-10-01

    Full Text Available Voice data packets have to arrive at the destination in time, with a defined cadence and with low and constant delay in order to allow the real time voice reconstruction. From this point of view, transmitting voice over IP networks is the most sensitive category of applications, especially when wireless medium is involved. The paper discusses the possibilities of transmitting the maximum number of simultaneous voice streams over 802.11 wireless networks considering the main factors which impact with VoIP throughput, in a basic scenario. Starting from a proposed communication model, the number of simultaneous possible VoIP sessions is calculated, taking into consideration the contribution of the protocol overheads, the security overheads, the PHY level timings and the CODEC proprieties. Numerical results are generated and compared.

  7. P2P Networks with IP Based Communication

    OpenAIRE

    Anupriya Koneru; Krishna Prasad MHM

    2012-01-01

    P2P communities can be seen as truly Distributed Computing applications in which group members communicate with one another to exchange information. The authors consider security issues in Peer to Peer Networks. For secure exchange of data between the group members the authors present a cryptography protocol and an Identity mechanism which can able to check even the Trust of the Peers based on the available reputation information. The authors are encapsulating the reputations of both the prov...

  8. Achieving QoS for TCP Traffic in Satellite Networks with Differentiated Services

    Science.gov (United States)

    Durresi, Arjan; Kota, Sastri; Goyal, Mukul; Jain, Raj; Bharani, Venkata

    2001-01-01

    Satellite networks play an indispensable role in providing global Internet access and electronic connectivity. To achieve such a global communications, provisioning of quality of service (QoS) within the advanced satellite systems is the main requirement. One of the key mechanisms of implementing the quality of service is traffic management. Traffic management becomes a crucial factor in the case of satellite network because of the limited availability of their resources. Currently, Internet Protocol (IP) only has minimal traffic management capabilities and provides best effort services. In this paper, we presented a broadband satellite network QoS model and simulated performance results. In particular, we discussed the TCP flow aggregates performance for their good behavior in the presence of competing UDP flow aggregates in the same assured forwarding. We identified several factors that affect the performance in the mixed environments and quantified their effects using a full factorial design of experiment methodology.

  9. Chiaro Networks' Enstara IP/MPLS platform selected by CERN for trans-Atlantic trial

    CERN Multimedia

    2004-01-01

    "Chiaro Networks, the developer of true infrastructure-class Internet Protocol/Multi-Protocol Label Switching (IP/MPLS) platforms, today announced that its Enstara router has been selected by the European Organization for Nuclear Research (CERN) for its DataTAG project" (1 page)

  10. A Network Steganography Lab on Detecting TCP/IP Covert Channels

    Science.gov (United States)

    Zseby, Tanja; Vázquez, Félix Iglesias; Bernhardt, Valentin; Frkat, Davor; Annessi, Robert

    2016-01-01

    This paper presents a network security laboratory to teach data analysis for detecting TCP/IP covert channels. The laboratory is mainly designed for students of electrical engineering, but is open to students of other technical disciplines with similar background. Covert channels provide a method for leaking data from protected systems, which is a…

  11. Cooperative Power Saving Strategies for IP-Services Supported over DVB-H Networks

    DEFF Research Database (Denmark)

    Zhang, Qi; Fitzek, F.H.P.; Katz, Marcos

    2007-01-01

    This paper introduces power saving strategies for cooperative wireless communication systems. The described scenario focuses on IP-services over DVB-H networks showing the strength of non-altruistic cooperation between mobile devices. The envisioned cooperation is based on cellular reception of d...

  12. Perceptual Evaluation Of Playout Buffer Algorithm For Enhancing Perceived Quality Of Voice Transmission Over Ip Network

    CERN Document Server

    Perwej, Yusuf; 10.5121/ijmnct.2012.2201

    2012-01-01

    Voice over Internet Protocol (VoIP) is a technology that allows you to make voice calls using a broadband Internet connection instead of a regular (or analog) phone line. Voice over Internet Protocol (VoIP) has led human speech to a new level, where conversation across continents can be much cheaper & faster. However, as IP networks are not designed for real-time applications, the network impairments such as packet loss, jitter and delay have a severe impact on speech quality. The playout buffer at the receiver side is used to compensate jitter at a trade-off of delay and loss. We found the characteristics of delay and loss are dependent on IP network and sudden variable delay (spike) often performs both regular and irregular characteristics. Different playout buffer algorithms can have different impacts on the achievement speech quality. It is important to design a playout buffer algorithm which can help achieve an optimum speech quality. In this paper, we investigate to the understanding how network imp...

  13. Broadband IP Stream Transmission Experiments over Global and Long Distance Networks

    Institute of Scientific and Technical Information of China (English)

    Kimio; Oguchi; Tetsuro; Fujii; Atsushi; Takahara; Toshiaki; Miyazaki; Kazuo; Hagimoto; Sadayasu; Ono

    2003-01-01

    Super High Definition (SHD) movies were successfully transmitted as streaming contents at about 300 Mbps for the first time over a long distance IP network (more than 3,000 km), in conjunction with the experimental verification of traffic control and scalable multicast technologies.

  14. Online industrial process broadcast and control based on IP and serial networks

    Directory of Open Access Journals (Sweden)

    Nicolae PARASCHIV

    2007-12-01

    Full Text Available The Internet network in conjunction with a strong security policy can be an ideal online broadcast system for the industrial processes monitoring and control. Because the distributed controllers are connected through industrial serial connection, the network between controllers cannot be extended very much. The problem appears when the plant is away and cannot be accessed via a serial connection. For administrative and control purposes the serial network can be interconnected with an IP network. In this case the operator can be anywhere in the world and can interact via an interface with the process. This paper will describe flow process remote controlled using a mixture of two communication technologies: RS485 and TCP/IP. The junction between these technologies is transparent and the operator is able to monitor the process using an interface console.

  15. Efficient Control Channel Resource Allocation for VoIP in OFDMA-Based Packet Radio Networks

    Directory of Open Access Journals (Sweden)

    Fan Yong

    2011-01-01

    Full Text Available We propose an efficient control channel resource allocation approach to enhance the performance of voice-over-IP (VoIP in orthogonal frequency division multiple access- (OFDMA- based next generation mobile communication systems. As the long-term evolution (LTE of universal terrestrial radio access network (UTRAN, evolved UTRAN (E-UTRAN is the first OFDMA-based packet radio network and thus selected in this paper as an application example. Our proposed physical downlink control channel (PDCCH resource allocation approach for E-UTRAN is composed of bidirectional power control, inner loop link adaptation (ILLA, and outer loop link adaptation (OLLA algorithms. Its effectiveness is validated through large-scale radio system level simulations, and simulation results confirm that VoIP capacity with dynamic scheduling can be further enhanced with this PDCCH resource allocation approach. Moreover, the VoIP performance requirements for international mobile telecommunications-advanced (IMT-Advanced radio interface technologies can be met with dynamic scheduling together with proposed PDCCH resource allocation. Besides E-UTRAN, this approach can be introduced to other OFDMA-based mobile communication systems for VoIP performance enhancement as well.

  16. Supporting IP dense mode multicast routing protocols in WDM all-optical networks

    Science.gov (United States)

    Salvador, Marcos R.; Heemstra de Groot, Sonia; Dey, Diptish

    2000-09-01

    Recent developments in all-optical networking and wavelength division multiplexing technologies allow for the support of optical multicasting, a missing feature towards the optical Internet. In this paper we propose a protocol to construct source-rooted WDM multicast trees. The protocol works under dense mode multicasting routing IP protocols and supports network nodes with different degrees of light splitting, wavelength conversion, and add/drop capabilities.

  17. Interim Service ISDN Satellite (ISIS) network model for advanced satellite designs and experiments

    Science.gov (United States)

    Pepin, Gerard R.; Hager, E. Paul

    1991-01-01

    The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Network Model for Advanced Satellite Designs and Experiments describes a model suitable for discrete event simulations. A top-down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ISDN modeling abstractions are added to permit the determination and performance for the NASA Satellite Communications Research (SCAR) Program.

  18. IP VPN及Internet VPN分类研究%A methodology of IP and internet virtual private network classification

    Institute of Scientific and Technical Information of China (English)

    王桐

    2009-01-01

    关于IP VPN的分类目前已经有很多研究,但目前还没有一个统一的说法,而对于Inter-net VPN的分类研究目前还没有见到.因此,PN和VPN,以及IP VPN和Internet VPN的区别和联系很容易被混淆,本文尝试给出了VPN、IP VPN及Internet VPN的一个准确定义,并在定义的基础上对IP VPN和Internet VPN提出了一种分类方法,最后给出了IP VPN和Internet VPN的比较及研究结果.

  19. Analisis Unjuk Kerja Aplikasi VoIP Call Android di Jaringan MANET [Performance Analysis of VoIP Call Application Android in MANET (Mobile Ad Hoc Network

    Directory of Open Access Journals (Sweden)

    Ryan Ari Setyawan

    2015-06-01

    Full Text Available Penelitian ini bertujuan menganalisis kinerja aplikasi  VoIP call android di jaringan MANET (mobile ad hoc network.  Hasil pengujian menunjukan bahwa aplikasi VoIP call android dapat digunakan di jaringan MANET. Delay yang dihasilkan paling besar di pengujian indoor dengan jarak 11-15 meter yakni sebesar 0,014624811 seconds. Packet loss yang dihasilkan pada range 1%-2% sedangkan standar packet loss yang ditetapkan oleh CISCO untuk layanan aplikasi VoIP adalah < 5%. Jitter yang dihasilkan yakni antara 0,01-0,06 seconds sedangkan standar yang ditetapkan oleh CISCO adalah ≤ 30 ms atau 0,03 seconds. Throughput yang dihasilkan pada proses pengujian yakni antar 161 kbps-481 kbps. *****This study aims to analyze the performance of VOIP call android application in the MANET (mobile ad hoc network. The results showed that VoIP applications could be implemented in MANET network. The highest  delay is produced in indoor testing  with distance of 11-15 meters,  which is equal to 0.014624811 seconds. Packet loss is generated in the range of 1% -2%, while packet loss standards set by Cisco for VoIP application services are <5%. The jitter is between 0.01 to 0.06 seconds, while the standard set by CISCO is ≤ 30 ms or 0.03 seconds. Throughput generated in the testing process is between 161 kbps-481 kbps.

  20. Predicting Packet Transmission Data over IP Networks Using Adaptive Neuro-Fuzzy Inference Systems

    Directory of Open Access Journals (Sweden)

    Samira Chabaa

    2009-01-01

    Full Text Available Problem statement: The statistical modeling for predicting network traffic has now become a major tool used for network and is of significant interest in many domains: Adaptive application, congestion and admission control, wireless, network management and network anomalies. To comprehend the properties of IP-network traffic and system conditions, many kinds of reports based on measured network traffic data have been reported by several researchers. The goal of the present contribution was to complement these previous researches by predicting network traffic data. Approach: The Adaptive Neuro-Fuzzy Inference System (ANFIS was realized by an appropriate combination of fuzzy systems and neural networks. It was applied in different applications which have been increased in recent years and have multidisciplinary in several domains with a high accuracy. For this reason, we used a set of input and output data of packet transmission over Internet Protocol (IP networks as input and output of ANFIS to develop a model for predicting data. Results: ANFIS was compared with some existing model based on Volterra system with Laguerre functions. The obtained results demonstrate that the sequences of generated values have the same statistical characteristics as those really observed. Furthermore, the relative error using ANFIS model was better than this obtained by Volterra system model. Conclusion: The developed model fits well real data and can be used for predicting purpose with a high accuracy.

  1. Inter-Profile Similarity (IPS): A Method for Semantic Analysis of Online Social Networks

    Science.gov (United States)

    Spear, Matt; Lu, Xiaoming; Matloff, Norman S.; Wu, S. Felix

    Online Social Networks (OSN)[OSN] are experiencing an explosive growth rate and are becoming an increasingly important part of people’s lives. There is an increasing desire to aid online users in identifying potential friends, interesting groups, and compelling products to users. These networks have offered researchers almost total access to large corpora of data. An interesting goal in utilizing this data is to analyze user profiles and identify how similar subsets of users are. The current techniques for comparing users are limited as they require common terms to be shared by users. We present a simple and novel extension to a word-comparison algorithm [6], entitled Inter-Profile Similarity (IPS), which allows comparison of short text phrases even if they share no common terms. The output of Inter-Profile Similarity (IPS) is simply a scalar value in [0,1], with 1 denoting complete similarity and 0 the opposite. Therefore it is easy to understand and can provide a total ordering of users. We, first, evaluated the effectiveness of Inter-Profile Similarity (IPS) with a user-study, and then applied it to datasets from Facebook and Orkut verifying and extending earlier results. We show that Inter-Profile Similarity (IPS) yields both a larger range for the similarity value and obtains a higher value than intersection-based mechanisms. Both Inter-Profile Similarity (IPS) and the output from the analysis of the two Online Social Networks (OSN)[OSN] should help to predict and classify social links, make recommendations, and annotate friends relations for social network analysis.

  2. Performance analysis and comparison of PTOP and LANE for IP transmission over ATM networks

    Science.gov (United States)

    Zubairi, Junaid A.; Al-Irhayim, Sufyan; Al-Khateeb, Wajdi; Wajdi, Yahya

    1998-12-01

    Due to its traffic control and performance assurance characteristics, ATM is being employed as the core network in most campuses. However, bulk of the workstations remain on Ethernet, generating IP traffic that passes through ATM using special schemes such as PTOP or LANE. In such a network, the performance is affected due to the extra overheads in multiple conversions between cells and packets and managing virtual circuits. The aim of this paper is to compare the performance of PTOP and LANE in passing the IP traffic under various conditions. This study helps in understanding the various performance issues in these environments in order to define the end-to-end quality of service for Ethernet-ATM networks.

  3. QoS multicast routing scheme using QGA in IP/DWDM networks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This article studies multi-constraints least-cost multicast routing problem in internet protocol over dense wavelength division multiplexing (IP/DWDM) networks. To address this problem, an individual-difference-based quantum genetic algorithm (IDQGA) is proposed. This algorithm considers individual differences among chromosomes by introducing an adaptive rotation angle step determination scheme and a grouping-based quantum mutation operation. Simulations are conducted over network topologies. The results indicate that compared with other heuristic algorithms, IDQGA has better optimal performance on solving quality of service (QoS) multicast routing problem in IP/DWDM networks and is characterized by strong robustness, high success ratio and excellent capability on global searching.

  4. Performance Analysis of VoIP Codecs over WiMAX Networks

    Directory of Open Access Journals (Sweden)

    M.A. Mohamed

    2012-11-01

    Full Text Available Real-time services such as VoIP are becoming popular and are major revenue earners for network service providers. These services no longer confined to the wired domain and extended over wireless networks. Although some of the existing wireless technologies can support some low-band width applications, the bandwidth demands of many multimedia applications exceed the capacity of these technologies. The WiMAX promises to be one of the wireless access technologies capable of supporting very high bandwidth applications. However, there are still many challenges that need to be addressed to provide a steady and good quality voice connection over the best-effort WiMAX network. In This paper, we evaluate the performance of different VoIP codecs over the WiMAX network. The network performance metrics such as MOS, packet end-to-end delay, jitter and packet delay variation have been used to evaluate the performance of VoIP codecs. The results showed that, the codec G.723 provides the best results among all discussed Codecs in all presented performance metrics; the lowest delay, the highest MOS and the highest Throughput.

  5. Research of differentiated QoS routing in GMPLS-based IP/WDM networks

    Science.gov (United States)

    Wang, YiYun; Zeng, QingJi; Cao, JunWen

    2004-04-01

    At this point in technology's evolution, the simplicity, elegance, extensibility, and broad compatibility of the Internet protocol suite has made it the automatic choice for most forms of communication. The attempts at resolution of this apparent dichotomy consist of a collection of technologies and philosophies known as Quality of Service. In an IP network, QoS defines the ability to compensate for traffic characteristics without compromising average throughput. Clearly, optimizing QoS performance for all traffic types on an IP network presents a daunting challenge. To partially address this challenge, several Internet Engineering Task Force groups have been working on standardized approaches for IP-based QoS technologies. The IETF"s approaches fall into four categories: prioritization using differentiated services, reservation using integrated services, label switching using multi-protocol label switching, bandwidth management using the subnet bandwidth manager. Differentiated services classify per-hop behaviors on the basis of a Diffserv code point attached to the type of service byte in each packet"s IP header. This DSCP approach represents a form of soft QoS that rather coarsely classifies services through packet marking. The differentiated QoS routing in GMPLS-based IP/WDM Networks are a promising candidate for the next generation optical Internet networks. By using a unified control plane, such networks make more efficient usage of network resources both at the IP layer and the WDM optical layer. In this paper, we consider prioritized routing of bandwidth-guaranteed Label Switched paths (LSPs) providing service differentiation between classes of high and normal priority traffic. The QoS delay requirements are assumed to be translated into bandwidth and O-E-O conversion requirements. We present a graphical representation of the integrated network state which is different from other conventional graphical representations in that it models the cost of usage of

  6. Rural telemedicine networks using store-and-forward Voice-over-IP.

    Science.gov (United States)

    Scholl, Jeremiah; Lambrinos, Lambros; Lindgren, Anders

    2009-01-01

    Store and forward Voice-over-IP is a suggested solution for supporting Telemedicine at rural health clinics in developing countries. Solutions described to date are designed to support communication by establishing point-to-point connectivity between two sites. In this paper we present an approach for creating scalable Telemedicine networks based on Delay Tolerant Networking. This holds potential for allowing Telemedicine networks to be created that can enable sharing of Teleconsultation and other medical information among a large number of locations in areas that cannot be served by existing solutions.

  7. A Framework for Real-Time Resource Allocation in IP Multimedia Subsystem Network

    Directory of Open Access Journals (Sweden)

    Muhammad Naeem

    2013-03-01

    Full Text Available IMS (IP Multimedia Subsystem is designed to provide multiple-services and can be accessed from any access network. With the advent of new multimedia services; user requirement also changed and required delay tolerant services from the service providers. The new multimedia services demands the restrictions on network parameters and this can be achieved by analyzing the traffic flow from the core as well as access network capabilities. As access and core IMS network are independent of each other and does not exchange user SLA with each other. In this paper we proposed framework based on Session border controller (SBC that proactively monitored the traffic statistics as well as interact with access network operator for getting user’s SLA and reserve resources accordingly. We are also proposing alterations in SIP invite and re-invite message to incorporate requested information. These alterations will be useful in ensuring availability of user’s handset capabilities to IMS core network.

  8. Design and analysis of the satellite laser communications network

    Science.gov (United States)

    Ren, Pei-an; Qian, Fengchen; Liu, Qiang; Jin, Linlin

    2015-02-01

    A satellite laser communications network structure with two layers and multiple domains has been proposed, which performance has been simulated by OPENT. To simulation, we design several OPNET models of the network's components based on a satellite constellation with two layers and multiple domains, as network model, node model, MAC layer protocol and optical antenna model. The network model consists of core layer and access layer. The core network consists of four geostationary orbit (GEO) satellites which are uniformly distributed in the geostationary orbit. The access network consists of 6 low Earth orbit (LEO) satellites which is the walker delta (walk-δ) constellation with three orbit planes. In access layer, each plane has two satellites, and the constellation is stably. The satellite constellation presented for space laser network can meet the demand of coverage in the middle and low latitude by a few satellites. Also several terminal device models such as the space laser transmitter, receiver, protocol layer module and optical antenna have been designed according to the inter-satellite links in different orbits t from GEO to LEO or GEO to ground. The influence to network of different transmitting throughput, receiving throughput, network protocol and average time delay are simulated. Simulation results of network coverage, connectivity and traffic load performance in different scenes show that the satellite laser network presented by the paper can be fit for high-speed satellite communications. Such analysis can provide effective reference for the research of satellite laser networking and communication protocol.

  9. Mobile IP

    NARCIS (Netherlands)

    Heijenk, Geert; Sallent, S.; Pras, A.

    1999-01-01

    The Internet is growing exponentially, both in the amount of traffic carried, and in the amount of hosts connected. IP technology is becoming more and more important, in company networks (Intranets), and also in the core networks for the next generation mobile networks. Further, wireless access to I

  10. Mobile IP

    NARCIS (Netherlands)

    Heijenk, Gerhard J.; Sallent, S.; Pras, Aiko

    1999-01-01

    The Internet is growing exponentially, both in the amount of traffic carried, and in the amount of hosts connected. IP technology is becoming more and more important, in company networks (Intranets), and also in the core networks for the next generation mobile networks. Further, wireless access to

  11. Content-Adaptive Packetization and Streaming of Wavelet Video over IP Networks

    Directory of Open Access Journals (Sweden)

    Chien-Peng Ho

    2007-03-01

    Full Text Available This paper presents a framework of content-adaptive packetization scheme for streaming of 3D wavelet-based video content over lossy IP networks. The tradeoff between rate and distortion is controlled by jointly adapting scalable source coding rate and level of forward error correction (FEC protection. A content dependent packetization mechanism with data-interleaving and Reed-Solomon protection for wavelet-based video codecs is proposed to provide unequal error protection. This paper also tries to answer an important question for scalable video streaming systems: given extra bandwidth, should one increase the level of channel protection for the most important packets, or transmit more scalable source data? Experimental results show that the proposed framework achieves good balance between quality of the received video and level of error protection under bandwidth-varying lossy IP networks.

  12. IP Connected Low Power Wireless Personal Area Networks in the Future Internet

    DEFF Research Database (Denmark)

    Jacobsen, Rune Hylsberg; Toftegaard, Thomas Skjødeberg; Kjærgaard, Jens Kristian

    2012-01-01

    The Internet of Things is a key concept of the Future Internet. The Internet of Things potentially interconnects billions of small devices in a large ubiquitous infrastructure based on the Internet Protocol (IP). Typically, these devices will be limited in computational capacity, memory......WPANs). The authors address the key mechanisms from network aspects down to device design aspects and discuss how technologies interplay to make real application deployment practical for the Internet of Things....

  13. Communication in Change - Voice over IP in Safety and Security Critical Communication Networks

    Science.gov (United States)

    Zeilinger, Heimo; Sevcik, Berndt; Turek, Thomas; Zucker, Gerhard

    During the last decade communication technology has changed rapidly. Due to its decreasing costs and rising expansion, IP (Internet Protocol) technology has found its way to areas that have long been the domain of public-switched telephone networks (PSTN). Voice over IP (VoIP) applications are widely used not only for phone calls or common Internet conferences, but also tend to be used for safety critical communication applications. Hence security and safety topics arise, which pose new challenges in this area of research. The authors are convinced that new issues on the network layer as well as on the application layer require detailed analysis. Hence this paper gives an overview on latest developments in this area, and states the authors’ view on this topic. Thereby safety and security issues are faced from different abstraction layers. On the one hand the network layer and on the other hand the application layer focusing on middleware systems in the area of service oriented architectures (SOAs).

  14. A GA-based PID active queue management control design for TCP/IP networks

    Science.gov (United States)

    Kuo, H.-H.; Chen, C.-K.; Yan, J.-J.; Liao, T.-L.

    2008-02-01

    In this paper, a genetic algorithm-based (GA-based) proportional-integral-derivative (PID) controller as an active queue manager for Internet routers is proposed to reduce packet loss and improve network utilization in TCP/IP networks. Based on the window-based nonlinear dynamics, the TCP network was modeled as a time-delayed system with a saturated input due to the limitations of packet-dropping probability and the effects of propagation delays in TCP networks. An improved genetic algorithm is employed to derive optimal or near optimal PID control gains such that a performance index of integrated-absolute error (IAE) in terms of the error between the router queue length and the desired queue length is minimized. The performance of the proposed control scheme was evaluated in various network scenarios via a series of numerical simulations. The simulation results confirm that the proposed scheme outperforms other AQM schemes.

  15. IP2P K-means: an efficient method for data clustering on sensor networks

    Directory of Open Access Journals (Sweden)

    Peyman Mirhadi

    2013-03-01

    Full Text Available Many wireless sensor network applications require data gathering as the most important parts of their operations. There are increasing demands for innovative methods to improve energy efficiency and to prolong the network lifetime. Clustering is considered as an efficient topology control methods in wireless sensor networks, which can increase network scalability and lifetime. This paper presents a method, IP2P K-means – Improved P2P K-means, which uses efficient leveling in clustering approach, reduces false labeling and restricts the necessary communication among various sensors, which obviously saves more energy. The proposed method is examined in Network Simulator Ver.2 (NS2 and the preliminary results show that the algorithm works effectively and relatively more precisely.

  16. Proxying UPnP service discovery and access to a non-IP Bluetooth network on a mobile phone

    NARCIS (Netherlands)

    Delphinanto, A.; Koonen, A.M.J.; Peeters, M.E.; Hartog, F.T.H. den

    2007-01-01

    The current service- and device discovery protocols are not platform- and network independent. Therefore, proxy servers will be needed to extend the range of IP-based discovery protocols to non-IP domains. We developed an architecture of a proxy that enables Universal Plug and Play (UPnP) devices

  17. Proxying UPnP service discovery and access to a non-IP Bluetooth network on a mobile phone

    NARCIS (Netherlands)

    Delphinanto, A.; Koonen, A.M.J.; Peeters, M.E.; Hartog, F.T.H. den

    2007-01-01

    The current service- and device discovery protocols are not platform- and network independent. Therefore, proxy servers will be needed to extend the range of IP-based discovery protocols to non-IP domains. We developed an architecture of a proxy that enables Universal Plug and Play (UPnP) devices an

  18. Advanced Models and Algorithms for Self-Similar IP Network Traffic Simulation and Performance Analysis

    Science.gov (United States)

    Radev, Dimitar; Lokshina, Izabella

    2010-11-01

    The paper examines self-similar (or fractal) properties of real communication network traffic data over a wide range of time scales. These self-similar properties are very different from the properties of traditional models based on Poisson and Markov-modulated Poisson processes. Advanced fractal models of sequentional generators and fixed-length sequence generators, and efficient algorithms that are used to simulate self-similar behavior of IP network traffic data are developed and applied. Numerical examples are provided; and simulation results are obtained and analyzed.

  19. Dynamic energy management employing renewable energy sources in IP over DWDM networks

    DEFF Research Database (Denmark)

    Chen, Xin; Phillips, Chris; Wang, Jiayuan

    2013-01-01

    The continued growth of energy consumption has been one of the main constraints for the development of the Internet. The increasing emissions of greenhouse gases associated with electricity generation also raise public concern for the environment. In this paper, we propose a dynamic energy...... management framework employing renewable energy sources in IP over DWDM core networks. The main concept is to combine infrastructure sleeping and virtual router migration to improve the network energy efficiency. By using the energy source information provided by the smart grid, the nodes that are powered...

  20. Proposal for Implementation of Novel Routing Protocols for IP Radio Networks above 70 GHz in MPLS

    Directory of Open Access Journals (Sweden)

    D. B. Perić

    2013-06-01

    Full Text Available In this paper, a proposal for implementation of novel routing protocols for IP radio networks at frequencies above 70 GHz is described. The protocols are designed to improve a network performance in the presence of the rain that has an intensity that causes a link down state and/or capacity reduction of some links in the network, but a network graph remains connected. New protocols, named OSPF-BPI and OSPF-BNI, are modifications of standard OSPF routing protocol which imply traffic sharing between the main shortest path route and specially defined backup routes. It is shown that the majority of novel routing protocols' features can be achieved just with a proper configuration of routers with standardized multi protocol label switching (MPLS traffic engineering (TE capabilities. For both types of backup routes attention is paid to avoid an additional unavailability due to equipment failure. The same MTTR time is kept for the same IP network when no protection mechanism are applied.

  1. Recent Research Progress in Green IP over WDM Network%绿色IP over WDM网络研究进展

    Institute of Scientific and Technical Information of China (English)

    郭爱煌; 薛琳

    2012-01-01

    近年来光网络朝着高速率、大带宽的方向迅猛发展,设备数目快速增加导致网络能耗急剧增长.为了降低网络能耗,提高能量利用率,绿色IP over WDM网络的概念被提出,并成为光网络领域的最新研究热点之一.对现有光网络节能方法的研究状况进行综述,从网络设备入手,讨论业务负载和设备能耗的关系,建立了两种能耗模型.基于IP over WDM网络结构,利用数学表达式描述了网络能耗最小化问题.对当前网络级的节能方法进行分类,分析了其基本原理和节能效果,并选取代表性的节能方法进行比较,得出了现有方法存在的局限性和不足,对进一步的研究方向提出了建议.%In recent years, optical network is developing towards high rate and wide bandwidth. As the number of network equipments in optical network increases, the network power consumption has a sharp rising. In order to decrease the energy consumption and improve the energy efficiency, the concept of green IP over WDM network has been proposed and it has become a hotspot for research in the area of optical network. The existing research status for energy-saving approaches in optical network is reviewed. Specifically, starting with network equipment, the relationship between traffic load and energy consumption of network equipments is discussed and two power consumption models are established. Then a mathematical expression of minimized energy consumption for IP over WDM network is introduced based on the network structure. Subsequently, the methods to reduce the energy consumption at network level are divided into different categories, whose fundamental principles and energy saving effects are summarized, and several typical energy-saving approaches are compared as well. Finally, the limitations of existing approaches are analyzed and some suggestions are provided for the further research directions.

  2. Forwarding techniques for IP fragmented packets in a real 6LoWPAN network.

    Science.gov (United States)

    Ludovici, Alessandro; Calveras, Anna; Casademont, Jordi

    2011-01-01

    Wireless Sensor Networks (WSNs) are attracting more and more interest since they offer a low-cost solution to the problem of providing a means to deploy large sensor networks in a number of application domains. We believe that a crucial aspect to facilitate WSN diffusion is to make them interoperable with external IP networks. This can be achieved by using the 6LoWPAN protocol stack. 6LoWPAN enables the transmission of IPv6 packets over WSNs based on the IEEE 802.15.4 standard. IPv6 packet size is considerably larger than that of IEEE 802.15.4 data frame. To overcome this problem, 6LoWPAN introduces an adaptation layer between the network and data link layers, allowing IPv6 packets to be adapted to the lower layer constraints. This adaptation layer provides fragmentation and header compression of IP packets. Furthermore, it also can be involved in routing decisions. Depending on which layer is responsible for routing decisions, 6LoWPAN divides routing in two categories: mesh under if the layer concerned is the adaptation layer and route over if it is the network layer. In this paper we analyze different routing solutions (route over, mesh under and enhanced route over) focusing on how they forward fragments. We evaluate their performance in terms of latency and energy consumption when transmitting IP fragmented packets. All the tests have been performed in a real 6LoWPAN implementation. After consideration of the main problems in forwarding of mesh frames in WSN, we propose and analyze a new alternative scheme based on mesh under, which we call controlled mesh under.

  3. LTE Adaptation for Mobile Broadband Satellite Networks

    Directory of Open Access Journals (Sweden)

    Bastia Francesco

    2009-01-01

    Full Text Available One of the key factors for the successful deployment of mobile satellite systems in 4G networks is the maximization of the technology commonalities with the terrestrial systems. An effective way of achieving this objective consists in considering the terrestrial radio interface as the baseline for the satellite radio interface. Since the 3GPP Long Term Evolution (LTE standard will be one of the main players in the 4G scenario, along with other emerging technologies, such as mobile WiMAX; this paper analyzes the possible applicability of the 3GPP LTE interface to satellite transmission, presenting several enabling techniques for this adaptation. In particular, we propose the introduction of an inter-TTI interleaving technique that exploits the existing H-ARQ facilities provided by the LTE physical layer, the use of PAPR reduction techniques to increase the resilience of the OFDM waveform to non linear distortion, and the design of the sequences for Random Access, taking into account the requirements deriving from the large round trip times. The outcomes of this analysis show that, with the required proposed enablers, it is possible to reuse the existing terrestrial air interface to transmit over the satellite link.

  4. Network coding and its applications to satellite systems

    DEFF Research Database (Denmark)

    Vieira, Fausto; Roetter, Daniel Enrique Lucani

    2015-01-01

    Network coding has its roots in information theory where it was initially proposed as a way to improve a two-node communication using a (broadcasting) relay. For this theoretical construct, a satellite communications system was proposed as an illustrative example, where the relay node would...... be a satellite covering the two nodes. The benefits in terms of throughput, resilience, and flexibility of network coding are quite relevant for wireless networks in general, and for satellite systems in particular. This chapter presents some of the basics in network coding, as well as an overview of specific...... scenarios where network coding provides a significant improvement compared to existing solutions, for example, in broadcast and multicast satellite networks, hybrid satellite-terrestrial networks, and broadband multibeam satellites. The chapter also compares coding perspectives and revisits the layered...

  5. Network coding and its applications to satellite systems

    DEFF Research Database (Denmark)

    Vieira, Fausto; Roetter, Daniel Enrique Lucani

    2015-01-01

    Network coding has its roots in information theory where it was initially proposed as a way to improve a two-node communication using a (broadcasting) relay. For this theoretical construct, a satellite communications system was proposed as an illustrative example, where the relay node would...... be a satellite covering the two nodes. The benefits in terms of throughput, resilience, and flexibility of network coding are quite relevant for wireless networks in general, and for satellite systems in particular. This chapter presents some of the basics in network coding, as well as an overview of specific...... scenarios where network coding provides a significant improvement compared to existing solutions, for example, in broadcast and multicast satellite networks, hybrid satellite-terrestrial networks, and broadband multibeam satellites. The chapter also compares coding perspectives and revisits the layered...

  6. AN EFFICIENT PACKET SCHEDULING ALGORITHM FOR 4G IP-BASED MOBILE NETWORKS

    Directory of Open Access Journals (Sweden)

    Hussaim Mohammed

    2010-09-01

    Full Text Available Next generation mobile networks are expected to provide seamless personal mobile communication and quality of service (QoS. Lossless handoff is a key issue for providing the QoS. This paper presents 4G node B Architecture, a two-layer downlink queuing model and proposes a scheduling mechanism for providing lossless handoff and QoS in mobile networks, which exploit IP as a transport technology for transferring datagrams between base stations and the high-speed downlink packet access (HSDPA at the radio layer. In order to reduce handoff packet dropping rate at the radio layer and packet forwarding rate at the IP layer and to provide high system performance, new scheduling algorithms are performed at both IP and radio layer, which exploit handoff priority scheduling principles and take into account buffer occupancy and channel conditions. Performance results obtained by computer simulation show that, by exploiting the downlink queuing model and scheduling algorithms, the system is able to provide low handoff packet dropping rate, low packet forwarding rate, and high downlink throughput.

  7. Performance of TCP/IP/ UDP adaptive header compression algorithm for wireless network

    Directory of Open Access Journals (Sweden)

    Prof.N.Penchalaiah

    2010-08-01

    Full Text Available The convergence of mobile technologies will characterize the future telecommunication systems based on TCP/IP protocols. These Protocols can be used to build both wired and wireless parts on same platform. But TCP/IP headers overheads are large, so it utilizes more bandwidth even small services, whose payload is small. So it definitely needheader compression to save bandwidth, as we know bandwidth is the most expensive and scared resource in wireless systems.There are many approaches used to compress the headers overloads. Most commonly used approaches are, an adaptive robust TCP/IP header compression lgorithm for 3G wireless networks and an adaptive robust header compression algorithm based on UDP-RTS/CTS handshake for real-timestreams in wireless networks such a 3G platforms. But these approaches are not efficient in adaptive nature. So In this paper we are proposing one approach to solve the problem efficiently even in adaptive nature. The aim of this algorithm is to adjust the dimension of Variable Sliding Window (VSW in W-LSB encoding with the accurate estimation of wireless channel state to achieve the good balance of compression ratio and error-resistant robustness for the adaptive use in wireless link. We present simulation results that demonstrate theeffectiveness of this adaptive algorithm over wireless link and comparative study of existing approaches

  8. A Novel Framework for IP DiffServ over Optical Burst Switching Networks

    Institute of Scientific and Technical Information of China (English)

    Ke-Ping Long; Yun Li; Rodney S.Tucker; Chong-Gang Wang

    2004-01-01

    This paper presents a novel framework for IP Differentiated Services (DiffServ) over optical burst switching (OBS), namely, DS-OBS. The network architecture, functional model of edge nodes and core nodes, the control packet format, a novel burst assembly scheme at ingress nodes and scheduling algorithm of core nodes are presented. The basic idea is to apply DiffServ capable burst assembly at ingress nodes and perform different per hop behavior (PHB) electronic treatments for control packets of different QoS class services at core nodes. Simulation results show that the proposed schemes can provide the best differentiated service for expedited forwarding (EF), assured forwarding (AF) and best effort (BE) services in terms of end-to-end deay, throughput and IP packet loss probability.

  9. A New QoS Management Scheme for VoIP Application over Wireless Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Said El brak

    2014-01-01

    Full Text Available Nowadays, mobile ad hoc networks (MANETs have to support new applications including VoIP (voice over IP that impose stringent QoS (quality of service constraints and requirements. However, VoIP applications make a very inefficient use of the MANET resources. Our work represents a first step toward improving aspects at the network layer by addressing issues from the standpoint of adaptation, claiming that effective adaptation of routing parameters can enhance VoIP quality. The most important contribution is the adaptive OLSR-VA algorithm which provides an integrated environment where VoIP activity is constantly detected and routing parameters are adapted in order to meet the application requirements. To investigate the performance advantage achieved by such algorithm, a number of realistic simulations (MANET scenarios are performed under different conditions. The most important observation is that performance is satisfactory in terms of the perceived voice quality.

  10. Full Service ISDN Satellite (FSIS) network model for advanced ISDN satellite design and experiments

    Science.gov (United States)

    Pepin, Gerard R.

    1992-01-01

    The Full Service Integrated Services Digital Network (FSIS) network model for advanced satellite designs describes a model suitable for discrete event simulations. A top down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ACTS and the Interim Service ISDN Satellite (ISIS) perform ISDN protocol analyses and switching decisions in the terrestrial domain, whereas FSIS makes all its analyses and decisions on-board the ISDN satellite.

  11. Estimating the geoeffectiveness of halo CMEs from associated solar and IP parameters using neural networks

    Directory of Open Access Journals (Sweden)

    J. Uwamahoro

    2012-06-01

    Full Text Available Estimating the geoeffectiveness of solar events is of significant importance for space weather modelling and prediction. This paper describes the development of a neural network-based model for estimating the probability occurrence of geomagnetic storms following halo coronal mass ejection (CME and related interplanetary (IP events. This model incorporates both solar and IP variable inputs that characterize geoeffective halo CMEs. Solar inputs include numeric values of the halo CME angular width (AW, the CME speed (Vcme, and the comprehensive flare index (cfi, which represents the flaring activity associated with halo CMEs. IP parameters used as inputs are the numeric peak values of the solar wind speed (Vsw and the southward Z-component of the interplanetary magnetic field (IMF or Bs. IP inputs were considered within a 5-day time window after a halo CME eruption. The neural network (NN model training and testing data sets were constructed based on 1202 halo CMEs (both full and partial halo and their properties observed between 1997 and 2006. The performance of the developed NN model was tested using a validation data set (not part of the training data set covering the years 2000 and 2005. Under the condition of halo CME occurrence, this model could capture 100% of the subsequent intense geomagnetic storms (Dst ≤ −100 nT. For moderate storms (−100 < Dst ≤ −50, the model is successful up to 75%. This model's estimate of the storm occurrence rate from halo CMEs is estimated at a probability of 86%.

  12. IP网关键资产价值研究%Study on Value of IP Network Critical Asset

    Institute of Scientific and Technical Information of China (English)

    王娟; 范九伦

    2011-01-01

    Due to the attribute of Intemet, open, international and freedom, and the IP network itself is poor in network security, IP network security is facing more and greater threats. The identification and value of assets of IP network is key to risk assessment of IP. This article set IP network assets into three types, that is physical assets, information assets, and services assets. And it gives uniform formula, and presents value of the assets. It forms foundation for the IP network risk assessment.%由于Intemet的开放性、国际性和自由性,以及IP网络自身较差的网络安全性,使IP网络的安全面临更多更大的威胁.对于IP网关键资产的识别和价值研究是IP风险评估的关键性工作,将IP网的资产分为物理资产、信息资产和服务资产三类,并对其进行了统一口径的赋值,给出了详细的现值计算赋值公式,为IP网的风险评估提供了基础.

  13. 47 CFR 76.122 - Satellite network non-duplication.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Satellite network non-duplication. 76.122... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.122 Satellite network non-duplication. (a) Upon receiving notification pursuant...

  14. Dynamic Fuzzy Controlled RWA Algorithm for IP/GMPLS over WDM Networks

    Institute of Scientific and Technical Information of China (English)

    I-Shyan Hwang; I-Feng Huang; Shin-Cheng Yu

    2005-01-01

    This paper proposes a dynamic RWA scheme using fuzzy logic control on IP/GMPLS over WDM networks to achieve the best quality of network transmission. The proposed algorithm dynamically allocates network resources and reserves partial bandwidth based on the current network status, which includes the request bandwidth, average utilization for each wavelength and its coefficient of variance (C.V.) of data traffic, to determine whether the connection can be set up. Five fuzzy sets for request bandwidth, average rate and C.V. of data traffic are used to divide the variable space: very large (LP), large (SP), normal (ZE), small (SN), and very small (LN). Setting the fuzzy limit is a key part in the proposed algorithm. The simulation of scenarios in this paper has two steps. In the first step, the adaptive fuzzy limits are evaluated based on average transmission cost pertaining to ten network statuses. The second step is to compare the proposed algorithm with periodic measurement of traffic (PMT) in ATM networks in six network situations to show that the proposed FC-RWA algorithm can provide better network transmission.

  15. IP over CCSDS空间组网应用浅析%Analysis of Application of IP over CCSDS in Space Networking

    Institute of Scientific and Technical Information of China (English)

    王晓波; 孙甲琦

    2011-01-01

    建立天地一体化的互联网络,实现任意时刻任意两点之间的端到端通信,是空间数据系统发展的必然趋势.CCSDS(空间数据系统咨询委员会)针对空间互联网业务,于2010年4月发布了CCSDS 702. 1-R-4,提出了IP over CCSDS最新推荐方法.本文根据CCSDS空间互联网业务空间链路工作组的研究,阐述了在CCSDS空间数据链路协议中承载IP数据报的实现方法、服务及业务接口,并探讨了未来基于IP over CCSDS的空间网络结构.%End-to-end communication between any two points in space at any time through a space-ground integrated network will be an inevitable trend of development of space data systems. CCSDS (Consultative Committee for Space Data Systems) issued CCSDS 702. L-R-4 in April 2010 and proposed the latest recommended practice specification for implementation of IP over CCSDS. Based on study of the CCSDS space internet service space link Work Group, this paper describes the method of transferring IP protocol data units over CCSDS space links, service and interface, and discusses the structure of future space networks based on IP over CCSDS.

  16. Distributed Grooming in Multi-Domain IP/MPLS-DWDM Networks

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qing [ORNL

    2009-12-01

    This paper studies distributed multi-domain, multilayer provisioning (grooming) in IP/MPLS-DWDM networks. Although many multi-domain studies have emerged over the years, these have primarily considered 'homogeneous' network layers. Meanwhile, most grooming studies have assumed idealized settings with 'global' link state across all layers. Hence there is a critical need to develop practical distributed grooming schemes for real-world networks consisting of multiple domains and technology layers. Along these lines, a detailed hierarchical framework is proposed to implement inter-layer routing, distributed grooming, and setup signaling. The performance of this solution is analyzed in detail using simulation studies and future work directions are also high-lighted.

  17. Error Protection for Scalable Image Over 3G-IP Network

    Institute of Scientific and Technical Information of China (English)

    WANGGuijin; LINXinggang

    2003-01-01

    Digital media, like image and video, transmitred over third-generation wireless networks is a challenging task because the wireless networks present not only packet loss, but also bit errors. To address this problem, this paper proposes a novel error protection scheme for scalable image over 3G-IP networks. Taking into consideration of the scalable nature of the image data, error protection is provided by layered product channel codes to mitigate the effect of the packet loss and bit errors. Meanwhile, rate-distortion optimization is presented to determine the protection levels of both the row and the column codes so as to minimize the expected end-to-end distortion. Simulation results show that our proposed approach is very efficient at a wide range of bits budget and under different channel conditions.

  18. A FUZZY-LOGIC CONTROL ALGORITHM FOR ACTIVE QUEUE MANAGEMENT IN IP NETWORKS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the predominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theoretical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network.

  19. Inference of hierarchical regulatory network of estrogen-dependent breast cancer through ChIP-based data

    Directory of Open Access Journals (Sweden)

    Parvin Jeffrey

    2010-12-01

    Full Text Available Abstract Background Global profiling of in vivo protein-DNA interactions using ChIP-based technologies has evolved rapidly in recent years. Although many genome-wide studies have identified thousands of ERα binding sites and have revealed the associated transcription factor (TF partners, such as AP1, FOXA1 and CEBP, little is known about ERα associated hierarchical transcriptional regulatory networks. Results In this study, we applied computational approaches to analyze three public available ChIP-based datasets: ChIP-seq, ChIP-PET and ChIP-chip, and to investigate the hierarchical regulatory network for ERα and ERα partner TFs regulation in estrogen-dependent breast cancer MCF7 cells. 16 common TFs and two common new TF partners (RORA and PITX2 were found among ChIP-seq, ChIP-chip and ChIP-PET datasets. The regulatory networks were constructed by scanning the ChIP-peak region with TF specific position weight matrix (PWM. A permutation test was performed to test the reliability of each connection of the network. We then used DREM software to perform gene ontology function analysis on the common genes. We found that FOS, PITX2, RORA and FOXA1 were involved in the up-regulated genes. We also conducted the ERα and Pol-II ChIP-seq experiments in tamoxifen resistance MCF7 cells (denoted as MCF7-T in this study and compared the difference between MCF7 and MCF7-T cells. The result showed very little overlap between these two cells in terms of targeted genes (21.2% of common genes and targeted TFs (25% of common TFs. The significant dissimilarity may indicate totally different transcriptional regulatory mechanisms between these two cancer cells. Conclusions Our study uncovers new estrogen-mediated regulatory networks by mining three ChIP-based data in MCF7 cells and ChIP-seq data in MCF7-T cells. We compared the different ChIP-based technologies as well as different breast cancer cells. Our computational analytical approach may guide biologists to

  20. Inference of hierarchical regulatory network of estrogen-dependent breast cancer through ChIP-based data

    Science.gov (United States)

    2010-01-01

    Background Global profiling of in vivo protein-DNA interactions using ChIP-based technologies has evolved rapidly in recent years. Although many genome-wide studies have identified thousands of ERα binding sites and have revealed the associated transcription factor (TF) partners, such as AP1, FOXA1 and CEBP, little is known about ERα associated hierarchical transcriptional regulatory networks. Results In this study, we applied computational approaches to analyze three public available ChIP-based datasets: ChIP-seq, ChIP-PET and ChIP-chip, and to investigate the hierarchical regulatory network for ERα and ERα partner TFs regulation in estrogen-dependent breast cancer MCF7 cells. 16 common TFs and two common new TF partners (RORA and PITX2) were found among ChIP-seq, ChIP-chip and ChIP-PET datasets. The regulatory networks were constructed by scanning the ChIP-peak region with TF specific position weight matrix (PWM). A permutation test was performed to test the reliability of each connection of the network. We then used DREM software to perform gene ontology function analysis on the common genes. We found that FOS, PITX2, RORA and FOXA1 were involved in the up-regulated genes. We also conducted the ERα and Pol-II ChIP-seq experiments in tamoxifen resistance MCF7 cells (denoted as MCF7-T in this study) and compared the difference between MCF7 and MCF7-T cells. The result showed very little overlap between these two cells in terms of targeted genes (21.2% of common genes) and targeted TFs (25% of common TFs). The significant dissimilarity may indicate totally different transcriptional regulatory mechanisms between these two cancer cells. Conclusions Our study uncovers new estrogen-mediated regulatory networks by mining three ChIP-based data in MCF7 cells and ChIP-seq data in MCF7-T cells. We compared the different ChIP-based technologies as well as different breast cancer cells. Our computational analytical approach may guide biologists to further study the

  1. HIMIPv6: An Efficient IP Mobility Management Protocol for Broadband Wireless Networks

    Science.gov (United States)

    Jeong, Hyunku; Maeng, Seungryoul; Chae, Youngsu

    With the increasing deployment of mobile devices and the advent of broadband wireless access systems such as WiBro, mWiMAX, and HSDPA, an efficient IP mobility management protocol becomes one of the most important technical issues for the successful deployment of the broadband wireless data networking service. IETF has proposed the Mobile IPv6 as the basic mobility management protocol for IPv6 networks. To enhance the performance of the basic MIPv6, researchers have been actively working on HMIPv6 and FMIPv6 protocols. In this paper, we propose a new mobility management protocol, HIMIPv6 (Highly Integrated MIPv6), which tightly integrates the hierarchical mobility management mechanism of the HMIPv6 and the proactive handover support of the FMIPv6 to enhance the handover performance especially for the cellular networking environment with high frequent handover activities. We have performed extensive simulation study using ns2 and the results show that the proposed HIMIPv6 outperforms FMIPv6 and HMIPv6. There is no packet loss and consequent service interruption caused by IP handover in HIMIP.

  2. Integrated Adaptive Analysis and Visualization of Satellite Network Data Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a system that enables integrated and adaptive analysis and visualization of satellite network management data. Integrated analysis and...

  3. All-IP wireless sensor networks for real-time patient monitoring.

    Science.gov (United States)

    Wang, Xiaonan; Le, Deguang; Cheng, Hongbin; Xie, Conghua

    2014-12-01

    This paper proposes the all-IP WSNs (wireless sensor networks) for real-time patient monitoring. In this paper, the all-IP WSN architecture based on gateway trees is proposed and the hierarchical address structure is presented. Based on this architecture, the all-IP WSN can perform routing without route discovery. Moreover, a mobile node is always identified by a home address and it does not need to be configured with a care-of address during the mobility process, so the communication disruption caused by the address change is avoided. Through the proposed scheme, a physician can monitor the vital signs of a patient at any time and at any places, and according to the IPv6 address he can also obtain the location information of the patient in order to perform effective and timely treatment. Finally, the proposed scheme is evaluated based on the simulation, and the simulation data indicate that the proposed scheme might effectively reduce the communication delay and control cost, and lower the packet loss rate.

  4. Scalable Video Streaming Traffic Delivery in IP/UMTS Networking Environments

    Directory of Open Access Journals (Sweden)

    Thomas Pliakas

    2007-04-01

    Full Text Available The paper discusses the end-to-end QoS provisioning for scalable video streaming traffic delivery over heterogeneous IP/UMTS networks. A prototype architecture is proposed, and is further validated, that explores the joint use of packet prioritization and scalable video coding (SVC together with the appropriate mapping of UMTS traffic classes to the DiffServ traffic classes. A complete set of simulation scenarios, involving eight different video sequences and using two different scalable encoders, demonstrates the quality gains of both scalable video coding and prioritized packetization.

  5. Improving Mobility Management for All-IP Radio Heterogeneous Network Using SCTP

    Institute of Scientific and Technical Information of China (English)

    GUO Qiang; XU Xiang-hua; ZHU Jie

    2005-01-01

    Mobility management is a very important function of mobile communication in all-IP radio heterogeneous network. In order to achieve an efficient mobility management, with low delay and low beacon overhead, a micromobile stream control transmission protocol (mmSCTP) scheme was proposed. This scheme reasonably utilizes SCTP features and elaborately designs execution-steps for vertical handoff. Moreover, it provides fast locating for idle mobile node when a session is initiated by the correspondent node. The analytical and simulation results show that the proposed scheme is effective in supporting fast vertical handoff and effective location management.

  6. 10 Gbps TCP/IP streams from the FPGA for the CMS DAQ Eventbuilder Network

    CERN Document Server

    Bauer, Gerry; Branson, James; Chaze, Olivier; Cittolin, Sergio; Coarasa Perez, Jose Antonio; Darlea, Georgiana Lavinia; Deldicque, Christian; Dobson, Marc; Dupont, Aymeric; Erhan, Samim; Gigi, Dominique; Glege, Frank; Gomez Ceballos, Guillelmo; Gomez-Reino Garrido, Robert; Hartl, Christian; Hegeman, Jeroen Guido; Holzner, Andre Georg; Masetti, Lorenzo; Meijers, Franciscus; Meschi, Emilio; Mommsen, Remigius; Morovic, Srecko; Nunez Barranco Fernandez, Carlos; O'Dell, Vivian; Orsini, Luciano; Ozga, Wojciech Andrzej; Paus, Christoph Maria Ernst; Petrucci, Andrea; Pieri, Marco; Racz, Attila; Raginel, Olivier; Sakulin, Hannes; Sani, Matteo; Schwick, Christoph; Spataru, Andrei Cristian; Stieger, Benjamin Bastian; Sumorok, Konstanty; Veverka, Jan; Wakefield, Christopher Colin; Zejdl, Petr

    2013-01-01

    For the upgrade of the DAQ of the CMS experiment in 2013/2014 an interface between the custom detector Front End Drivers (FEDs) and the new DAQ eventbuilder network has to be designed. For a loss-less data collection from more then 600 FEDs a new FPGA based card implementing the TCP/IP protocol suite over 10Gbps Ethernet has been developed. We present the hardware challenges and protocol modifications made to TCP in order to simplify its FPGA implementation together with a set of performance measurements which were carried out with the current prototype.

  7. Delivery of medical multimedia contents through the TCP/IP network using RealSystem.

    Science.gov (United States)

    Suzuki, Ichiro; Yamada, Kazuhiro; Yamakawa, Tomoko; Hashiba, Masao; Akazawa, Kouhei

    2003-03-01

    We developed a low cost, user-friendly multimedia delivery system, to provide medical lectures saved as multimedia contents to persons engaged in medicine. This system was created using the RealSystem package with the TCP/IP network. Users can review lectures and medical meeting presentations with video and audio through the Internet, whenever convenient. Each medical source of video and slide has been clearly displayed on a screen. Members of medical associations or medical students can easily review the most interesting parts of these files. This system is being used efficiently in distance learning and aids the diffusion of the latest information and technology to busy physicians and medical students.

  8. 浅析IP分片对网络的影响%Analysis on Influence of IP Fragment on Network

    Institute of Scientific and Technical Information of China (English)

    张明

    2014-01-01

    The IP fragments are generated when the size of IP messages usually to be transmitted exceeds the Maximum Transmission Unit (MTU) of link layer. A large number of IP fragments will produce a variety of influences on network. Aiming at the phenomenon of IP fragment, this paper introduces the basic principles of IP fragment, analyzes the influences of IP fragment on network performance parameters such as network package loss rate, time-delay, etc. by testing the message fragment. The analysis on application case of virtual private network (VPN) show that the IP fragment may make the service data not get the corresponding guarantee of Quality of Service (QoS) level. Based on analysis on VPN technology networking case , this paper proposes the opinion that the network design should comprehensively plan MTU to avoid IP fragment.%通常要传输的IP报文的大小超过链路层最大传输单元(MTU)时就会产生IP分片,大量的IP分片会对网络产生多种影响。针对IP分片现象,首先介绍了IP分片的基本原理,通过对报文分片的测试,分析了IP分片对网络丢包率和延时等网络性能参数的影响;通过对专网应用案例的分析,说明了IP分片会造成业务数据不能得到相应服务质量QoS等级的保障。通过虚拟专用网络VPN技术组网案例的分析,提出了网络设计应整体规划MTU以避免IP分片的观点。

  9. Design and Implementation of a VoIP Broadcasting Service over Embedded Systems in a Heterogeneous Network Environment

    Directory of Open Access Journals (Sweden)

    Jenq-Shiou Leu

    2014-01-01

    Full Text Available As the digitization is integrated into daily life, media including video and audio are heavily transferred over the Internet nowadays. Voice-over-Internet Protocol (VoIP, the most popular and mature technology, becomes the focus attracting many researches and investments. However, most of the existing studies focused on a one-to-one communication model in a homogeneous network, instead of one-to-many broadcasting model among diverse embedded devices in a heterogeneous network. In this paper, we present the implementation of a VoIP broadcasting service on the open source—Linphone—in a heterogeneous network environment, including WiFi, 3G, and LAN networks. The proposed system featuring VoIP broadcasting over heterogeneous networks can be integrated with heterogeneous agile devices, such as embedded devices or mobile phones. VoIP broadcasting over heterogeneous networks can be integrated into modern smartphones or other embedded devices; thus when users run in a traditional AM/FM signal unreachable area, they still can receive the broadcast voice through the IP network. Also, comprehensive evaluations are conducted to verify the effectiveness of the proposed implementation.

  10. Design and Implementation of a VoIP Broadcasting Service over Embedded Systems in a Heterogeneous Network Environment

    Science.gov (United States)

    Lin, Wei-Hsiang; Hsieh, Wen-Bin; Lo, Chien-Chih

    2014-01-01

    As the digitization is integrated into daily life, media including video and audio are heavily transferred over the Internet nowadays. Voice-over-Internet Protocol (VoIP), the most popular and mature technology, becomes the focus attracting many researches and investments. However, most of the existing studies focused on a one-to-one communication model in a homogeneous network, instead of one-to-many broadcasting model among diverse embedded devices in a heterogeneous network. In this paper, we present the implementation of a VoIP broadcasting service on the open source—Linphone—in a heterogeneous network environment, including WiFi, 3G, and LAN networks. The proposed system featuring VoIP broadcasting over heterogeneous networks can be integrated with heterogeneous agile devices, such as embedded devices or mobile phones. VoIP broadcasting over heterogeneous networks can be integrated into modern smartphones or other embedded devices; thus when users run in a traditional AM/FM signal unreachable area, they still can receive the broadcast voice through the IP network. Also, comprehensive evaluations are conducted to verify the effectiveness of the proposed implementation. PMID:25300280

  11. Design and implementation of a VoIP broadcasting service over embedded systems in a heterogeneous network environment.

    Science.gov (United States)

    Leu, Jenq-Shiou; Lin, Wei-Hsiang; Hsieh, Wen-Bin; Lo, Chien-Chih

    2014-01-01

    As the digitization is integrated into daily life, media including video and audio are heavily transferred over the Internet nowadays. Voice-over-Internet Protocol (VoIP), the most popular and mature technology, becomes the focus attracting many researches and investments. However, most of the existing studies focused on a one-to-one communication model in a homogeneous network, instead of one-to-many broadcasting model among diverse embedded devices in a heterogeneous network. In this paper, we present the implementation of a VoIP broadcasting service on the open source-Linphone-in a heterogeneous network environment, including WiFi, 3G, and LAN networks. The proposed system featuring VoIP broadcasting over heterogeneous networks can be integrated with heterogeneous agile devices, such as embedded devices or mobile phones. VoIP broadcasting over heterogeneous networks can be integrated into modern smartphones or other embedded devices; thus when users run in a traditional AM/FM signal unreachable area, they still can receive the broadcast voice through the IP network. Also, comprehensive evaluations are conducted to verify the effectiveness of the proposed implementation.

  12. Satellite communications for the next generation telecommunication services and networks

    Science.gov (United States)

    Chitre, D. M.

    1991-01-01

    Satellite communications can play an important role in provisioning the next-generation telecommunication services and networks, provided the protocols specifying these services and networks are satellite-compatible and the satellite subnetworks, consisting of earth stations interconnected by the processor and the switch on board the satellite, interwork effectively with the terrestrial networks. The specific parameters and procedures of frame relay and broadband integrated services digital network (B-ISDN) protocols which are impacted by a satellite delay. Congestion and resource management functions for frame relay and B-ISDN are discussed in detail, describing the division of these functions between earth stations and on board the satellite. Specific onboard and ground functions are identified as potential candidates for their implementation via neural network technology.

  13. Research TCP/IP Network Communication Programming on Java Socket%JAVA TCP/IP Socket网络通信编程研究

    Institute of Scientific and Technical Information of China (English)

    戴歆

    2013-01-01

    First Java is a programming language for Internet. network Communication is the advantage of Java language. Using TCP/IP communication protocol in the program development is to realize the C/S model of point to point communication net-work. This thesis focuses on the study of Java Socket network programming framework and network communication program implementation in C/S mode.%Java最初是一种网络编程语言网络通信是Java语言的优势,在程序开发中利用TCP/IP通信协议则能实现C/S模式下的点对点的网络通信。该文主要研究在C/S模式下使用Java Socket实现TCP/IP网络程序框架及网络通信的程序实现。

  14. Fast remote data access for control of TCP/IP network using android Mobile device

    Directory of Open Access Journals (Sweden)

    Vaibhav Muddebihalkar

    2014-04-01

    Full Text Available In this paper we will creating architecture which will helps user to control LAN using the android mobile. As the most of the all application are now creating the cross platform version for the android, we will also make the control using the android platform. This is purely network administrative application which useful for the controlling network. The architecture will consist the nodes in the LAN and one server as well as one android phone which use to control the nodes. We use connectivity options as Wi-Fi or Internet; if connectivity internet is taken in grant then we will provide the static IP address to the server. For all this kind of application we should use JAVA technology and the android SDK in programming point of view. After testing application on LAN it works very well while file browsing and controlling the process.

  15. Mobile IP and protocol authentication extension

    CERN Document Server

    Nguyen, Phuc V

    2011-01-01

    Mobile IP is an open standard, defined by the Internet Engineering Task Force (IETF) RFC 3220. By using Mobile IP, you can keep the same IP address, stay connected, and maintain ongoing applications while roaming between IP networks. Mobile IP is scalable for the Internet because it is based on IP - any media that can support IP can support Mobile IP.

  16. Study on Service Level Management in Integrated Satellite Information Network

    Institute of Scientific and Technical Information of China (English)

    SHANG Rui-qiang; ZHAO Jian-li; WANG Guang-xing

    2005-01-01

    Integrated Satellite Information Network (ISIN) includes those nodes in space and those on ground. It is the way to realize the fusion of satellite communication and traditional network technology. A satellite network management system based on Multiplex Network Management Protocol (MNMP) has accomplished traditional management, such as configuration, performance and fault management. An architecture of Service Level Management (SLM) in ISIN is proposed, and a service topology management and Service Level Agreement (SLA) are deeply researched. At last, service security and fault management are briefly discussed, and a simulation system is accomplished.

  17. Favqchoke: To Allocate Fair Buffer to A Dynamically Varying Traffic In An IP Network

    Directory of Open Access Journals (Sweden)

    K.Chitra

    2011-02-01

    Full Text Available In IP networks, AQM attempts to provide high network utilization with low loss and low delay by regulating queues at bottleneck links. Many AQM algorithms have been proposed, most suffer from instability of queue, bursty packet drop, require careful configuration of control parameters, or slow response to dynamic traffic changes and unfairness. The deployment of active queue management techniques such as RED based is used that results in increased bursty packet loss and unfairness caused by an exponential increase in network traffic. The inherent problem with these queue management algorithms is that they all use queue lengths as the indicator of the severity of congestion. In order to solve this problem, a new active queue management algorithm called FAVQCHOKe is proposed. In this paper, arrival rate at the network link is maintained as a principal measure of congestion to improve the transient performances of the system and ensures the entire utilization of link capacity. In addition thisproposed algorithm uses queue length and flow information that enhances fairness. This characteristic is particularly beneficial to real-time multimedia applications. Further, FAVQCHOKe achieves the above while maintaining high link utilization and low packet loss. This paper discusses about the inherent weaknesses of current techniques and how the proposed algorithm overcomes the weaknesses andensures high degree of effectiveness in the performance of the system.

  18. Traffic-engineering-aware shortest-path routing and its application in IP-over-WDM networks [Invited

    Science.gov (United States)

    Lee, Youngseok; Mukherjee, Biswanath

    2004-03-01

    Single shortest-path routing is known to perform poorly for Internet traffic engineering (TE) where the typical optimization objective is to minimize the maximum link load. Splitting traffic uniformly over equal-cost multiple shortest paths in open shortest path first and intermediate system-intermediate system protocols does not always minimize the maximum link load when multiple paths are not carefully selected for the global traffic demand matrix. However, a TE-aware shortest path among all the equal-cost multiple shortest paths between each ingress-egress pair can be selected such that the maximum link load is significantly reduced. IP routers can use the globally optimal TE-aware shortest path without any change to existing routing protocols and without any serious configuration overhead. While calculating TE-aware shortest paths, the destination-based forwarding constraint at a node should be satisfied, because an IP router will forward a packet to the next hop toward the destination by looking up the destination prefix. We present a mathematical problem formulation for finding a set of TE-aware shortest paths for the given network as an integer linear program, and we propose a simple heuristic for solving large instances of the problem. Then we explore the usage of our proposed algorithm for the integrated TE method in IP-over-WDM networks. The proposed algorithm is evaluated through simulations in IP networks as well as in IP-over-WDM networks.

  19. Measuring Data and VoIP Traffic in WiMAX Networks

    CERN Document Server

    Adhicandra, Iwan

    2010-01-01

    Due to its large coverage area, low cost of deployment and high speed data rates, WiMAX is a promising technology for providing wireless last-mile connectivity. Physical and MAC layer of this technology refer to the IEEE 802.16e standard, which defines 5 different data delivery service classes that can be used in order to satisfy Quality of Service (QoS) requirements of different applications, such as VoIP, videoconference, FTP, Web, etc. The main aim of the paper is to examine a case of QoS deployment over a cellular WiMAX network. In particular, the paper compares the performance obtained using two different QoS configurations differing from the delivery service class used to transport VoIP traffic, i.e. UGS or ertPS. Results indicate that for delay-sensitive traffic that fluctuates beyond its nominal rate, having the possibility to give back some of its reserved bandwidth, ertPS has the advantage to permit the transmission of BE traffic.

  20. Mobile IP: Security & application

    NARCIS (Netherlands)

    Tuquerres, Gloria; Salvador, Marcos Rogério; Sprenkels, Ron

    1999-01-01

    As required in the TGS Mobile IP Advanced Module, this paper presents a survey of common security threats which mobile IP networks are exposed to as well as some proposed solutions to deal with such threats.

  1. Frequency-Domain Adaptive Algorithm for Network Echo Cancellation in VoIP

    Directory of Open Access Journals (Sweden)

    Patrick A. Naylor

    2008-05-01

    Full Text Available We propose a new low complexity, low delay, and fast converging frequency-domain adaptive algorithm for network echo cancellation in VoIP exploiting MMax and sparse partial (SP tap-selection criteria in the frequency domain. We incorporate these tap-selection techniques into the multidelay filtering (MDF algorithm in order to mitigate the delay inherent in frequency-domain algorithms. We illustrate two such approaches and discuss their tradeoff between convergence performance and computational complexity. Simulation results show an improvement in convergence rate for the proposed algorithm over MDF and significantly reduced complexity. The proposed algorithm achieves a convergence performance close to that of the recently proposed, but substantially more complex improved proportionate MDF (IPMDF algorithm.

  2. A Feedback Control Mechanism of QoS Management for IP Telecommunication Network

    Institute of Scientific and Technical Information of China (English)

    CUI Yi-dong; JIAO Li; LIN Yu; WANG Wen-dong

    2005-01-01

    In this paper a feedback control mechanism of Quality of Service (QoS) management is proposed. By measuring and monitoring the operational information of the IP telecommunication network, the feedback control-loops tune the network according to the trends of the traffic characteristics in order to gain a favorable network status. With theoretical analysis, it is concluded that the QoS of an arbitrary k-class flow can be guaranteed when the capacity of the k-class traffic is not fully filled. Thus by distributing the bandwidth of the egress bottleneck link among the ingress links, the congestion can be relieved. Moreover, the capacity of each traffic class that shares the same link affects one another. Therefore, the feedback control also aims at adjusting the capacity proportion among the traffic classes. In order to realize the goals, three feedback control-loops are designed in the QoS management system. A CORBA-based implementation is deployed on the testbed.

  3. Packet routing algorithm for polar orbit LEO satellite constellation network

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Broadband satellite networks are capable of providing global coverage and support various services. The networks constructed by Low Earth Orbit (LEO) satellite constellations have attracted great interests because of their short round-trip delays and wide bandwidths. A challenging problem is to develop a simple and efficient packet routing algorithm for the LEO satellite constellation network. This paper presents a SpiderWeb Topological Network (SWTN) and a distributed packet routing algorithm for the LEO satellite constellation network based on the SWTN. The algorithm gives the minimum propagation delay paths with low computational complexity and requires no routing tables, which is practical for on-board processing. The performance of the algorithm is demonstrated through simulations.

  4. A study on efficient detection of network-based IP spoofing DDoS and malware-infected Systems.

    Science.gov (United States)

    Seo, Jung Woo; Lee, Sang Jin

    2016-01-01

    Large-scale network environments require effective detection and response methods against DDoS attacks. Depending on the advancement of IT infrastructure such as the server or network equipment, DDoS attack traffic arising from a few malware-infected systems capable of crippling the organization's internal network has become a significant threat. This study calculates the frequency of network-based packet attributes and analyzes the anomalies of the attributes in order to detect IP-spoofed DDoS attacks. Also, a method is proposed for the effective detection of malware infection systems triggering IP-spoofed DDoS attacks on an edge network. Detection accuracy and performance of the collected real-time traffic on a core network is analyzed thru the use of the proposed algorithm, and a prototype was developed to evaluate the performance of the algorithm. As a result, DDoS attacks on the internal network were detected in real-time and whether or not IP addresses were spoofed was confirmed. Detecting hosts infected by malware in real-time allowed the execution of intrusion responses before stoppage of the internal network caused by large-scale attack traffic.

  5. Test using communication satellite for security telecommunication network

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, M.

    1988-01-01

    The authors confirmed by their experiment results that the satellite communication could be practically used for remote monitoring and control in gas distribution systems and data communication not only in emergency but also as the reinforced means of communication network. This report deals with the general description of the security communication network, our experiment of satellite operating system, the results and further plan for the practical application. Their company has started the test on the utilization of a communication satellite (CS-2 Japanese domestic communication satellite) since July, 1984, for the purpose of securing the telecommunication network in case of disaster and applying the satellite communications to data communication suitable for the information age, as for a gas utility industry.

  6. Reducing handover latency in future IP-based wireless networks: Proxy Mobile IPv6 with simultaneous bindings

    NARCIS (Netherlands)

    Bargh, Mortaza S.; Hulsebosch, Bob; Eertink, Henk; Heijenk, Geert; Idserda, Jeroen; Laganier, Julien; Prasad, Anand R.; Zugenmaier, Alf

    2008-01-01

    Handover in future wireless communication systems must be seamless. Current IP-level mobility protocols have difficulties meeting the stringent handover delay requirements. At the same time they do not give sufficient control to the network to optimize the handover process and they do not deal well

  7. Reducing handover latency in future IP-based wireless networks: Proxy Mobile IPv6 with simultaneous bindings

    NARCIS (Netherlands)

    Bargh, Mortaza S.; Hulsebosch, Bob; Eertink, Henk; Eertink, E.H.; Heijenk, Geert; Idserda, Jeroen; Laganier, Julien; Prasad, Anand R.; Zugenmaier, Alf

    2008-01-01

    Handover in future wireless communication systems must be seamless. Current IP-level mobility protocols have difficulties meeting the stringent handover delay requirements. At the same time they do not give sufficient control to the network to optimize the handover process and they do not deal well

  8. Dynamic Characteristics of Inter-Satellite Links in LEO Networks

    Institute of Scientific and Technical Information of China (English)

    王亮; 张乃通; 温萍萍

    2003-01-01

    To establish an efficient inter-satellite link (ISL) in an LEO network, the effect of geometric characteristics of ISL on the ISLs and the devices on the LEO satellite should be examined. Because of the continuous movement of the LEO satellite, the time-varying behaviours of the ISL's geometric charactersistics continuously change with the changes of the satellite's position on the orbit. These dynamic geometric characteristics of the ISLs are important for ISL's performance analyzing and the design of the devices on the LEO satellite. This paper describes dynamic geometric characteristics of ISL, analyzes the impact of these regulations on the tracking system of the satellite's antenna and the power adjusting system of the satellite's transmitter, with the Iridium system as an example.

  9. Transmission Technique towards Seamless Handover for NGEO Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    Wang LU; Liu Lixiang; Hu Xiaohui

    2011-01-01

    This paper presents a seamless transmission technique for Non-Geostationary Earth Orbit (NGEO) satellite networks.The seamless transmission technique combines the concept of Hop-by-Hop and network coding to alleviate the negative impacts of handovers,high bit error rate,and long delay,and to achieve high throughput and complete delivery in NGEO satellite networks.This network coding algorithm is able to maintain expected small queue size and low decoding latency.Furthermore,the seamless transmission technique applies a novel explicit congestion notification mechanism and can achieve high bandwidth utilization.Various aspects of this seamless transmission technique are evaluated.

  10. Network design for telemedicine--e-health using satellite technology.

    Science.gov (United States)

    Graschew, Georgi; Roelofs, Theo A; Rakowsky, Stefan; Schlag, Peter M

    2008-01-01

    Over the last decade various international Information and Communications Technology networks have been created for a global access to high-level medical care. OP 2000 has designed and validated the high-end interactive video communication system WinVicos especially for telemedical applications, training of the physician in a distributed environment, teleconsultation and second opinion. WinVicos is operated on a workstation (WoTeSa) using standard hardware components and offers a superior image quality at a moderate transmission bandwidth of up to 2 Mbps. WoTeSa / WinVicos have been applied for IP-based communication in different satellite-based telemedical networks. In the DELTASS-project a disaster scenario was analysed and an appropriate telecommunication system for effective rescue measures for the victims was set up and evaluated. In the MEDASHIP project an integrated system for telemedical services (teleconsultation, teleelectro-cardiography, telesonography) on board of cruise ships and ferries has been set up. EMISPHER offers an equal access for most of the countries of the Euro-Mediterranean area to on-line services for health care in the required quality of service. E-learning applications, real-time telemedicine and shared management of medical assistance have been realized. The innovative developments in ICT with the aim of realizing a ubiquitous access to medical resources for everyone at any time and anywhere (u-Health) bear the risk of creating and amplifying a digital divide in the world. Therefore we have analyzed how the objective needs of the heterogeneous partners can be joined with the result that there is a need for real integration of the various platforms and services. A virtual combination of applications serves as the basic idea for the Virtual Hospital. The development of virtual hospitals and digital medicine helps to bridge the digital divide between different regions of the world and enables equal access to high-level medical care. Pre

  11. Electrical Design and Application of Equipment IP Network Based on TCP / IP%基于TCP/IP的设备IP网的电气设计与应用

    Institute of Scientific and Technical Information of China (English)

    王东林

    2011-01-01

    针对现有弱电系统在大型建筑应用中存在的不足.探讨具有TCP/IP连接功能的弱电系统和相对应的综合布线与网络系统.提出运用TCP/IP网络技术构建设备IP网的可行性和重要性.并给出实际应用案例。%With respect to the deficiencies of existing weak current system in the application for largescale buildings, this paper discusses a weak current system with the function of TCP/IP connection and the corresponding generic cabling and network system, propo

  12. QoS-guaranteed burst transmission for VoIP service over optical burst switching networks

    Science.gov (United States)

    Tachibana, Takuji; Kasahara, Shoji

    2007-08-01

    We propose a burst transmission method that guarantees the voice over Internet protocol (VoIP) service. The proposed method consists of three techniques: round-robin burst assembly with slotted scheduling, priority control with void filling, and hop-based preemption. Each technique is utilized so that the burst loss probability and the burst transmission delay satisfy VoIP quality of service (QoS). We evaluate by simulation the performance of the proposed method in NSFNET with 14 nodes. Numerical examples show that our proposed method is effective for guaranteeing the VoIP QoS while accommodating a large number of VoIP users.

  13. Distributed Traffic Balancing Routing for LEO Satellite Networks

    Directory of Open Access Journals (Sweden)

    Yong Lu

    2013-11-01

    Full Text Available Satellite networks have been widely investigated both in the business and academia for many years, with many important routing algorithms reported in the literatures. However, fewer existing routing algorithms focus on the trade-off between the routing survivability and the routing computation and storage overheads. Due to topological dynamics, it is difficult to effectively apply the conventional routing protocols such as RIP or OSPF to Low Earth Orbit (LEO satellite networks. According to the virtual topology model based on virtual node, this paper propose a new fully distributed routing protocol for LEO satellite networks, called Distributed Traffic Balancing Routing (DTBR. The proposed protocol not only guarantees the routing survivability and provides the ability of traffic balancing, but also result in few additional computation and storage overheads only deriving from the information flooding of failed satellites. Simulation results demonstrate positive conclusions of our methods.

  14. Dynamic Routing Algorithm for Increasing Robustness in Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    LI Dong-ni; ZHANG Da-kun

    2008-01-01

    In low earth orbit(LEO)and medium earth orbit(MEO)satellite networks,the network topology changes rapidly because of the high relative speed movement of satellites.When some inter-satellite links (ISLs)fail,they can not be repaired in a short time.In order to increase the robustness for LEO/MEO satellite networks,an effective dynamic routing algorithm is proposed.All the routes to a certain node are found by constructing a destination oriented acyclic directed graph(DOADG)with the node as the destination.In this algorithm,multiple routes are provided,loop-free is guaranteed,and as long as the DOADG maintains,it is not necessary to reroute even if some ISLs fail.Simulation results show that comparing to the conventional routing algorithms,it is more efficient and reliable,costs less transmission overhead and converges faster.

  15. Design and implementation of a system to interconnect VoIP services and CERN’s telephony networks

    CERN Document Server

    Pohančeník, Martin; Segeč, Pavel

    The purpose of this diploma thesis was to design and implement a system that would provide an interface of CERN’s telephony network for Voice over IP services (SIP-based services specifically). This system thus serves as an entry point for calls originating from outside of CERN’s telephony network and enables users of these services to call CERN’s fixed and mobile phone numbers. The theoretical part of the thesis talks in detail about the project specification and describes the goals that were trying to be achieved. It also describes the topic of VoIP telephony and current trends, alongside with analysis of the current telephone network of CERN. The practical part is targeted to explain the design of the solution and deployment of the system at CERN. The final part of the thesis shows testing scenarios and results and states several extension capabilities.

  16. Internetworking satellite and local exchange networks for personal communications applications

    Science.gov (United States)

    Wolff, Richard S.; Pinck, Deborah

    1993-01-01

    The demand for personal communications services has shown unprecedented growth, and the next decade and beyond promise an era in which the needs for ubiquitous, transparent and personalized access to information will continue to expand in both scale and scope. The exchange of personalized information is growing from two-way voice to include data communications, electronic messaging and information services, image transfer, video, and interactive multimedia. The emergence of new land-based and satellite-based wireless networks illustrates the expanding scale and trend toward globalization and the need to establish new local exchange and exchange access services to meet the communications needs of people on the move. An important issue is to identify the roles that satellite networking can play in meeting these new communications needs. The unique capabilities of satellites, in providing coverage to large geographic areas, reaching widely dispersed users, for position location determination, and in offering broadcast and multicast services, can complement and extend the capabilities of terrestrial networks. As an initial step in exploring the opportunities afforded by the merger of satellite-based and land-based networks, several experiments utilizing the NASA ACTS satellite and the public switched local exchange network were undertaken to demonstrate the use of satellites in the delivery of personal communications services.

  17. The ChIP-seq-defined networks of Bcl-3 gene binding support its required role in skeletal muscle atrophy.

    Directory of Open Access Journals (Sweden)

    Robert W Jackman

    Full Text Available NF-kappaB transcriptional activation is required for skeletal muscle disuse atrophy. We are continuing to study how the activation of NF-kB regulates the genes that encode the protein products that cause atrophy. Using ChIP-sequencing we found that Bcl-3, an NF-kB transcriptional activator required for atrophy, binds to the promoters of a number of genes whose collective function describes two major aspects of muscle wasting. By means of bioinformatics analysis of ChIP-sequencing data we found Bcl-3 to be directing transcription networks of proteolysis and energy metabolism. The proteolytic arm of the Bcl-3 networks includes many E3 ligases associated with proteasomal protein degradation, including that of the N-end rule pathway. The metabolic arm appears to be involved in organizing the change from oxidative phosphorylation to glycolysis in atrophying muscle. For one gene, MuRF1, ChIP-sequencing data identified the location of Bcl-3 and p50 binding in the promoter region which directed the creation of deletant and base-substitution mutations of MuRF1 promoter constructs to determine the effect on gene transcription. The results provide the first direct confirmation that the NF-kB binding site is involved in the muscle unloading regulation of MuRF1. Finally, we have combined the ChIP-sequencing results with gene expression microarray data from unloaded muscle to map several direct targets of Bcl-3 that are transcription factors whose own targets describe a set of indirect targets for NF-kB in atrophy. ChIP-sequencing provides the first molecular explanation for the finding that Bcl3 knockout mice are resistant to disuse muscle atrophy. Mapping the transcriptional regulation of muscle atrophy requires an unbiased analysis of the whole genome, which we show is now possible with ChIP-sequencing.

  18. A Minimum Cost Handover Algorithm for Mobile Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    Zhang Tao; Zhang Jun

    2008-01-01

    For mobile satellite networks,an appropriate handover scheme should be devised to shorten handover delay with optimized application of network resources.By introducing the handover cost model of service,this article proposes a rerouting triggering scheme for path optimization after handover and a new minimum cost handover algorithm for mobile satellite networks.This algorithm ensures the quality of service (QoS) parameters,such as delay,during the handover and minimizes the handover costs.Simulation indicates that this algorithm is superior to other current algorithms in guaranteeing the QoS and decreasing handover costs.

  19. Designing the next phase domestic satellites - A step to communication satellites as intelligent network nodes

    Science.gov (United States)

    Majus, J.

    1982-09-01

    Applications of satellite systems for telecommunication networks are discussed in terms of harmonizing the satellite capabilities with ground-based equipment, and design for the satellites are discussed. Modern network services are becoming increasingly digitized and use optic fiber switching and information transfer. Spaceborne nodes can be used for telephony, television, packet switching, leased lines, and teletex, with reserved sectors for point-to-point communications. Space systems are capable of 100% coverage, while terrestrial systems frequently have utilization rates near 5%, implying that demand-oriented satellite expansion of local systems is the suitable methodology. Technological requirements are explored, including exclusive use of digital processing, flexible flow rates, signal transmission times, and short time availability.

  20. Transient time period analysis of smooth handoffs in mobile IP networks and its application to media streaming

    Science.gov (United States)

    Lee, Dongwook; Kim, JongWon

    2003-11-01

    Streaming media applications over mobile IP networks suffer from playback disruptions resulting from handoff blackout period as well as bandwidth fluctuation. To overcome buffer shortage, pre-buffering technique can be adopted where the client stores sufficient amount of stream in advance. However, under the mobile IP handoff that may take up to several seconds, it is extremely difficult to sustain seamless playback. Inaccurate and conservative choice on the required buffering size can waste limited latency budget, resulting in quality degradation. In this paper, we are extending--from smooth handoff to fast handoff of mobile IPv6--the transient time analysis recently proposed to approximate transient time durations, STP (silent time period) and UTP (unstable time period). The approximated time periods are utilized to estimate the required buffering buffer size accurately. Network simulation result evaluted under simplified buffering strategies shows that the proposed scheme can provide appropriate guideline on the buffer parameters and thus can improve seamless streaming.

  1. β-catenin promoter ChIP-chip reveals potential schizophrenia and bipolar disorder gene network.

    Science.gov (United States)

    Pedrosa, Erika; Shah, Abhishek; Tenore, Christopher; Capogna, Michael; Villa, Catalina; Guo, Xingyi; Zheng, Deyou; Lachman, Herbert M

    2010-12-01

    Therapeutic concentrations of lithium salts inhibit glycogen synthase kinase 3 beta (GSK3β) and phosphoinositide (PI) signaling suggesting that abnormal activation of these pathways could be a factor in the pathophysiology of bipolar disorder (BD). Involvement of these pathways is also supported by recent genome-wide association studies (GWASs). One way investigators have investigated the molecular basis of BD and the therapeutic action of lithium is by microarray expression studies, since both GSK3β- and PI-mediated signal transduction pathways are coupled to transcriptional activation and inhibition. However, expression profiling has some limitations and investigators cannot use the approach to analyze fetal brain tissue, arguably the most relevant biological structure related to the development of genetically based psychiatric disorders. To address these shortcomings, the authors have taken a novel approach using chromatin immunoprecipitation-enriched material annealed to microarrays (ChIP-chip) targeting genes in fetal brain tissue bound by β-catenin, a transcription factor that is directly regulated by GSK3β. The promoters for 640 genes were found to be bound by β-catenin, many of which are known schizophrenia (SZ), autism spectrum disorder (ASD), and BD candidates, including CACNA1B, NRNG, SNAP29, FGFR1, PCDH9, and nine others identified in recently published GWASs and genome-wide searches for copy number variants (CNVs). The findings suggest that seemingly disparate candidate genes for SZ and BD can be incorporated into a common molecular network revolving around GSK3β/β-catenin signaling. In addition, the finding that a putative lithium-responsive pathway may influence a subgroup of SZ and ASD candidate genes could have therapeutic implications.

  2. Next generation communications satellites: multiple access and network studies

    Science.gov (United States)

    Meadows, H. E.; Schwartz, M.; Stern, T. E.; Ganguly, S.; Kraimeche, B.; Matsuo, K.; Gopal, I.

    1982-01-01

    Efficient resource allocation and network design for satellite systems serving heterogeneous user populations with large numbers of small direct-to-user Earth stations are discussed. Focus is on TDMA systems involving a high degree of frequency reuse by means of satellite-switched multiple beams (SSMB) with varying degrees of onboard processing. Algorithms for the efficient utilization of the satellite resources were developed. The effect of skewed traffic, overlapping beams and batched arrivals in packet-switched SSMB systems, integration of stream and bursty traffic, and optimal circuit scheduling in SSMB systems: performance bounds and computational complexity are discussed.

  3. Satellite network robust QoS-aware routing

    CERN Document Server

    Long, Fei

    2014-01-01

    Satellite Network Robust QoS-aware Routing presents a novel routing strategy for satellite networks. This strategy is useful for the design of multi-layered satellite networks as it can greatly reduce the number of time slots in one system cycle. The traffic prediction and engineering approaches make the system robust so that the traffic spikes can be handled effectively. The multi-QoS optimization routing algorithm can satisfy various potential user requirements. Clear and sufficient illustrations are also presented in the book. As the chapters cover the above topics independently, readers from different research backgrounds in constellation design, multi-QoS routing, and traffic engineering can benefit from the book.   Fei Long is a senior engineer at Beijing R&D Center of 54th Research Institute of China Electronics Technology Group Corporation.

  4. Wavelength dimensioning for wavelength-routed WDM satellite network

    Institute of Scientific and Technical Information of China (English)

    Liu Zhe; Guo Wei; Deng Changlin; Hu Weisheng

    2016-01-01

    Internet and broadband applications driven by data traffic demand have become key dri-vers for satellite constellations. The key technology to satisfy the high capacity requirements between satellites is optical satellite networks by means of wavelength division multiplexing inter-satellite links (ISLs) with wavelength routing (WDM-OSN). Due to the limited optical amplifier bandwidth onboard the satellite, it is important to minimize the wavelength requirements to provi-sion requests. However, ISLs should be dynamically established and deleted for each satellite according to its visible satellites. Furthermore, different link assignments will result in different topologies, hence yielding different routings and wavelength assignments. Thus, a perfect match model-based link assignment scheme (LAS-PMM) is proposed to design an appropriate topology such that shorter path could be routed and less wavelengths could be assigned for each ISL along the path. Finally, simulation results show that in comparison to the regular Manhattan street net-work (MSN) topology, wavelength requirements and average end-to-end delay based on the topol-ogy generated by LAS-PMM could be reduced by 24.8%and 12.4%, respectively.

  5. Integration of Quantum Cryptography through Satellite Networks Transmission

    Directory of Open Access Journals (Sweden)

    Skander Aris

    2011-01-01

    Full Text Available Problem statement: The security of the telecommunications satellite has become a crucial issue. The telecommunications can be set using the classical cryptography. But this so-called classical cryptography provides cryptographic security. This means that security is based on the difficulty of some mathematics problems. On the other hand, quantum cryptography provides security without conditions based on the law of quantum physics. This method, called the theoretic information security is evidenced using the theory of information. Approach: In this study, we study whether quantum cryptography can be applied in the frame of the satellite telecommunications network. To do this in our project, we present theories regarding the following issues: Telecommunications Station and Satellite Communication Networks, Quantum Key Distribution, Open Space and Satellites, Analyses in different Scenarios between the Satellite and Earth station. Results: Quantum communications offers many advantages for secure data transmission, in our implementation study, we presented different scenarios of quantum key exchange between satellites and ground stations for possible approach to subsystem with quantum communication in space, capable of generating and detecting entangled photons as well as faint laser pulses. Conclusion: The use of satellites to distribute quantum photon provides a unique solution for long-distance. Moreover, quantum cryptography is a satisfactory solution to improve the safety problem. So, the quantum transmissions are the future of telecommunications.

  6. Satellite link augmentation of ground based packet switched data networks

    Science.gov (United States)

    Farrell, J. B.; McLane, P. J.; Campbell, L. L.

    Use of satellite link augmentation to improve the performance of a packet switched data network is considered. Particular attention is paid to the analysis of two queues in series from the standpoint of time delay. A finite state machine model is used to aid the analysis. The results from the analysis are then used in a flow deviation routing algorithm. This algorithm is applied to study the performance improvement when satellite links are used to augment the Canadian DATAPAC network. The results are backed up by extensive simulations on a digital computer.

  7. E3MS: A traffic engineering prototype for autoprovisioning services in IP/DiffServ/MPLS networks

    OpenAIRE

    Hesselbach Serra, Xavier; García-Espín, Joan Antoni; Gonzalez, Miquel; Gonzalo, Javier; Figuerola, Sergi

    2010-01-01

    This paper presents the testbed definition, implementation and trials of a new strategy for traffic autoprovisioning for MPLS and IP/DiffServ. This is the proof of concept of a new scenario for traffic engineering, for selfconfiguring control and end-to-end quality of service management by means of a tool based on Web Services. The system is structured in 3 layers: A Graphical User Interface, a Network Elements layer (an interface to physical devices) and, in the middle, a Network Management ...

  8. A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks

    Science.gov (United States)

    Kerczewski, Robert J.; Chomos, Gerald J.; Griner, James H.; Mainger, Steven W.; Martzaklis, Konstantinos S.; Kachmar, Brian A.

    2000-01-01

    Rapid growth in air travel has been projected to continue for the foreseeable future. To maintain a safe and efficient national and global aviation system, significant advances in communications systems supporting aviation are required. Satellites will increasingly play a critical role in the aeronautical communications network. At the same time, current ground-based communications links, primarily very high frequency (VHF), will continue to be employed due to cost advantages and legacy issues. Hence a hybrid satellite-terrestrial network, or group of networks, will emerge. The increased complexity of future aeronautical communications networks dictates that system-level modeling be employed to obtain an optimal system fulfilling a majority of user needs. The NASA Glenn Research Center is investigating the current and potential future state of aeronautical communications, and is developing a simulation and modeling program to research future communications architectures for national and global aeronautical needs. This paper describes the primary requirements, the current infrastructure, and emerging trends of aeronautical communications, including a growing role for satellite communications. The need for a hybrid communications system architecture approach including both satellite and ground-based communications links is explained. Future aeronautical communication network topologies and key issues in simulation and modeling of future aeronautical communications systems are described.

  9. Fast-response liquid crystal display by the VA-IPS display mode with nematic liquid crystal and polymer networks

    Science.gov (United States)

    Chen, Tien-Jung; Lin, Guan-Jhong; Chen, Bo-Yu; Wu, Jin-Jei; Yang, Ying-Jay

    2012-10-01

    To improve electrooptical characteristics of the vertical aligned (VA) liquid crystal displays (LCDs), the monomer material and in-plane switching (IPS) field produced by interdigital electrodes are employed in LC cells. The fast switching response and well optical transmittance of the VA-IPS display mode are successfully achieved by mixing the nematic LC with polymer networks, attributed to the surface anchoring, and the molecular orientation of the LC cell will be further governed, especially under the greater applied voltage. Furthermore, the high concentration doping of the monomer can effectively improve the response behavior, but it also results in the transmittance sacrificed due to the light scattering, and the threshold voltage (Vth) increased.

  10. Understanding VoIP Internet Telephony and the Future Voice Network

    CERN Document Server

    Flanagan, William A

    2012-01-01

    Translates technical jargon into practical business communications solutions This book takes readers from traditional voice, fax, video, and data services delivered via separate platforms to a single, unified platform delivering all of these services seamlessly via the Internet. With its clear, jargon-free explanations, the author enables all readers to better understand and assess the growing number of voice over Internet protocol (VoIP) and unified communications (UC) products and services that are available for businesses. VoIP and Unified Communications is based on the author's careful rev

  11. PACKET ROUTING ALGORITHM FOR LEO SATELLITE CONSTELLATION NETWORK

    Institute of Scientific and Technical Information of China (English)

    Wang Kaidong; Tian Bin; Yi Kechu

    2005-01-01

    A novel distributed packet routing algorithm for Low Earth Orbit (LEO) satellite networks based on spiderweb topology is presented. The algorithm gives the shortest path with very low computational complexity and without on-board routing tables, which is suitable and practical for on-board processing. Simulation results show its practicability and feasibility.

  12. Network design tool for EHF satellite communications networks

    Science.gov (United States)

    Norvell, S.; Brown, G. J.

    1983-06-01

    This document describes the design concept of the network design tool. The network design tool (NDT) is a collection of analytical techniques, algorithms and simulation methods that may be used to characterize the performance of a computer communication network. Much work has been done over the past several years in network performance analysis and many techniques have been developed or proposed. Each of these methods applies to a particular aspect of the network design and is based on a particular modeling point of view. We define the computer communication network and then describe the different ways the network may be modeled. Each network model is related to the particular design problem being addressed. The various analytical approaches are briefly described and their relationship to the network models discussed. Chapter 2 is a survey of the major approaches to specific network design problems while chapters 3 and 4 discuss two fairly well defined areas of network analysis: topological design/optimization and protocol validation. Chapter 5 is a survey of network design tools presently available locally or on the advanced research projects agency network (ARPANET). Finally, chapter 6 presents an outline of the NDT specification.

  13. Future integrated broadband fiber, wireless, and satellite networks

    Science.gov (United States)

    Chan, Vincent W. S.

    2006-10-01

    With the increasing technical maturity in fiber, wireless and satellite communication technologies, new horizons are becoming feasible for future broadband networks, providing economical data rates well in excess of Gbps for stationary and mobile users as well as novel applications these advanced network services will permit. This talk explores the future architecture possibilities of such a network using new and radical technology building blocks such as: free space laser communications, multiple access multi-beam data satellite communications, novel all-optical network transport/switching and analog transmission and processing over optical carriers that support coherent distributed platform sensing and communications. We will articulate why we have to design this new network across layers from the Physical Layer to the Network and Transport Layers (even the Application Layer). Not only can future network performance and cost undergo quantum-leap improvements; such a network can have profound transforming effects on space and terrestrial system architectures for sensing, healthcare, early warning systems, disaster relief, research collaborations and other new commercial applications.

  14. 基于IP网络的QoS策略研究%Based on the IP Network QoS Strategy Research

    Institute of Scientific and Technical Information of China (English)

    刘士贤

    2015-01-01

    IP网络的发展和多媒体业务的出现,使得IP灵活地根据具体业务提供给客户满意的服务,是IP业界亟待解决的问题。文中从IP QoS的定义和机制出发,研究了几种常用的网络服务模型和影响网络服务质量的因素,以及网络服务质量QoS的控制策略。%The development of IP network and the emergence of multimedia services,the IP QoS arises at the historic moment.How to solve the IP network QoS requirements,make network can flexibly according to specific business to provide satisfactory service to customers,is the problem to be solved IP industry.In this paper,starting from the definition and mechanism of IP QoS,several commonly used network service model is studied and the factors affecting the quality of network service,and network quality of service QoS control strategy.

  15. Mesh Networks within A Distributed Operations Framework Utilizing IP Based Radios

    Science.gov (United States)

    2007-09-01

    9 Nikola Tesla , Modern Mechanics and Inventions, July, 1934 10 When discussing or referencing IP the authors are specifically...they wander off through equation after equation, and eventually build a structure which has no relation to reality. Nikola Tesla9 A. OVERVIEW

  16. 基于IP-P2P的校园网资源共享平台的研究%Study of Campus Network Resource Sharing Platform Based on IP-P2P

    Institute of Scientific and Technical Information of China (English)

    肖刚

    2011-01-01

    In order to adapt to highly dynamic and the efficient search, this paper puts forward thestructured P2P networks based on index (IP-P2P), which has the double-indexing mechanism, the index of such a layer is body composition of a structured P2P network, another layer is formed by ordinary peer P2P network. Then it realizes campus network resource sharing platform using IP-P2P, the test results are proved the effectiveness.%为了能够适应高度动态性,同时又能进行高效搜索,文章提出基于索引的结构化P2P网络IP-P2P(Index-PeerP2P)模型,它具有双层索引机制,一层是由索引对等体组成的有结构P2P网络,另一层是由普通对等体组成P2P网络,然后实现了基于IP-P2P校园网资源共享平台的方案并通过测试证明了该平台的有效性.

  17. Cost Analysis of Algorithm Based Billboard Manger Based Handover Method in LEO satellite Networks

    Directory of Open Access Journals (Sweden)

    Suman Kumar Sikdar

    2012-12-01

    Full Text Available Now-a-days LEO satellites have an important role in global communication system. They have some advantages like low power requirement and low end-to-end delay, more efficient frequency spectrum utilization between satellites and spot beams over GEO and MEO. So in future they can be used as a replacement of modern terrestrial wireless networks. But the handover occurrence is more due to the speed of the LEOs. Different protocol has been proposed for a successful handover among which BMBHO is more efficient. But it had a problem during the selection of the mobile node during handover. In our previous work we have proposed an algorithm so that the connection can be established easily with the appropriate satellite. In this paper we will evaluate the mobility management cost of Algorithm based Billboard Manager Based Handover method (BMBHO. A simulation result shows that the cost is lower than the cost of Mobile IP of SeaHO-LEO and PatHOLEO

  18. NFV and Its Application to IP Networks%NFV及其在IP网中应用的探讨

    Institute of Scientific and Technical Information of China (English)

    华一强; 郭晓琳; 杨艳松

    2015-01-01

    The concept and background of NFV were introduced, and concept of NFV and SDN was compared. In the scenario of standard progress, the recent two years’achievements and the latest research progress of NFV standard organization were introduced. After status overview of carriers’IP networks, NFV application requirements for IP networks were analyzed. Then the NFV ap-plication of IP MAN service control layer were discussed and emphasized. The idea was proposed that NFV application in the service control layer may go through three stages:single stage, pool stage and the cloud stage. In each stage, the characteris-tics of the network and the requirements of NFV were also described.%首先介绍了NFV的概念及其产生的背景,并将NFV和SDN的概念进行了对比。在标准进展方面,对NFV标准组织近2年的研究成果以及NFV标准组织的最新进展进行了介绍。在概述电信运营商IP网络现状后对IP网络的NFV应用需求进行了分析。在此基础上,重点对NFV在IP城域网业务控制层的应用进行了探讨,提出了NFV设备在业务控制层的应用,可能会经历单机阶段、池组化阶段、云化阶段等3个阶段的观点,并介绍了每个阶段的网络特征和对NFV的功能需求。

  19. The Mobile IP(IPv6) Based on Cellular Wireless Network Technology%基于蜂窝无线网络的移动IP(IPv6)研究

    Institute of Scientific and Technical Information of China (English)

    张全新; 宋瀚涛

    2003-01-01

    Introduce method and technology of combination of the TCP/IP protocol based on IPv6 and the cellular wireless communication network. Analyze the cut-in point and key technology of the combination from the view of frame, system structure and the realization of protocols. The 3G cellular wireless communication is a hotspot today and the mobile IP technology is one of the developing directions for the Internet's future. We put forward a new idea and method for the mobile communication technology from the practical view.

  20. Dynamic traffic grooming in distributed-controlled IP/WDM optical mesh networks

    Institute of Scientific and Technical Information of China (English)

    Huang Jun; Zeng Qingji; Liu Jimin; Xiao Pengcheng; Liu Hua; Xiao Shilin

    2005-01-01

    In this paper, the study was devoted to the traffic-grooming problem in a distributed-controlled WDM mesh network. We studied the optimization of the maximal number of ports configured at each node in the network. We gave the maximumnumber simulation results in different network environment, which could be taken as a reference for network design.

  1. Design and Evaluation of IP Header Compression for Cellular-Controlled P2P Networks

    DEFF Research Database (Denmark)

    Madsen, T.K.; Zhang, Qi; Fitzek, F.H.P.

    2007-01-01

    In this paper we advocate to exploit terminal cooperation to stabilize IP communication using header compression. The terminal cooperation is based on direct communication between terminals using short range communication and simultaneously being connected to the cellular service access point....... The short range link is than used to provide first aid information to heal the decompressor state of the neighboring node in case of a packet loss on the cellular link. IP header compression schemes are used to increase the spectral and power efficiency loosing robustness of the communication compared...... to the uncompressed version. By introducing the terminal cooperation supporting header compression the robustness is increased. Within this article we will show that header compression should be applied to reduce the energy consumption of the terminals and moreover the header compression should be supported...

  2. QoS Management and Control for an All-IP WiMAX Network Architecture: Design, Implementation and Evaluation

    Directory of Open Access Journals (Sweden)

    Thomas Michael Bohnert

    2008-01-01

    Full Text Available The IEEE 802.16 standard provides a specification for a fixed and mobile broadband wireless access system, offering high data rate transmission of multimedia services with different Quality-of-Service (QoS requirements through the air interface. The WiMAX Forum, going beyond the air interface, defined an end-to-end WiMAX network architecture, based on an all-IP platform in order to complete the standards required for a commercial rollout of WiMAX as broadband wireless access solution. As the WiMAX network architecture is only a functional specification, this paper focuses on an innovative solution for an end-to-end WiMAX network architecture offering in compliance with the WiMAX Forum specification. To our best knowledge, this is the first WiMAX architecture built by a research consortium globally and was performed within the framework of the European IST project WEIRD (WiMAX Extension to Isolated Research Data networks. One of the principal features of our architecture is support for end-to-end QoS achieved by the integration of resource control in the WiMAX wireless link and the resource management in the wired domains in the network core. In this paper we present the architectural design of these QoS features in the overall WiMAX all-IP framework and their functional as well as performance evaluation. The presented results can safely be considered as unique and timely for any WiMAX system integrator.

  3. Channel Resource Allocation for VoIP Applications in Collaborative IEEE 802.11/802.16 Networks

    Directory of Open Access Journals (Sweden)

    Foh ChuanHeng

    2010-01-01

    Full Text Available Collaborations between the IEEE 802.11 and the IEEE 802.16 networks operating in a common spectrum offers dynamic allocate bandwidth resources to achieve improved performance for network applications. This paper studies the bandwidth resource allocation of collaborative IEEE 802.11 and IEEE 802.16 networks. Consider delivering data packets between mobile stations and Internet users through an access point (AP of the IEEE 802.11 network and a base station (BS of the IEEE 802.16 network operating on a common frequency band, we analyze their medium access control (MAC protocols, frame structures, and design a cooperation mechanism for the IEEE 802.11 and the IEEE 802.16 networks to share the same medium with adaptive resource allocation. Based on the mechanism, an optimized resource allocation scheme is proposed for VoIP applications. An analytical model is developed for the study to show significant improvements in voice capacity for our optimized resource allocation scheme.

  4. Wireless IP Telephony

    CERN Document Server

    Gerami, Mohsen

    2010-01-01

    The convergence of traditional telecommunications and the Internet is creating new network-based service delivery opportunities for telecommunications companies carriers, service providers, and network equipment providers. Voice over Wireless IP is one of the most exciting new developments emerging within the telephony market. It is set to revolutionize the delivery of mobile voice Services and provide exciting new opportunities for operators and service providers alike. This survey discusses principal of Wireless IP Telephony.

  5. NNIC—neural network image compressor for satellite positioning system

    Science.gov (United States)

    Danchenko, Pavel; Lifshits, Feodor; Orion, Itzhak; Koren, Sion; Solomon, Alan D.; Mark, Shlomo

    2007-04-01

    We have developed an algorithm, based on novel techniques of data compression and neural networks for the optimal positioning of a satellite. The algorithm is described in detail, and examples of its application are given. The heart of this algorithm is the program NNIC—neural network image compressor. This program was developed for compression color and grayscale images with artificial neural networks (ANNs). NNIC applies three different methods for compression. Two of them are based on neural networks architectures—multilayer perceptron and kohonen network. The third is based on a widely used method of discrete cosine transform, the basis for the JPEG standard. The program also serves as a tool for determining numerical and visual quality parameters of compression and comparison between different methods. A number of advantages and disadvantages of the compression using ANNs were discovered in the course of the present research, some of them presented in this report. The thrust of the report is the discussion of ANNs implementation problems for modern platforms, such as a satellite positioning system that include intensive image flowing and processing.

  6. How to build networks based on IP Video Conference System Technology%基于IP网络构建视频会议系统技术

    Institute of Scientific and Technical Information of China (English)

    詹玉印

    2011-01-01

    According to the main features of the IP network,focusing on network bandwidth,compression technology,multicast technology,transport protocol,QOS,and other aspects of the five IP-based video conferencing system,building a network of technical requirements%根据IP网络的主要特点,重点从网络带宽、压缩技术、多播技术、传输协议、QOS等五个方面论述了基于IP网络构建视频会议系统的技术要求.

  7. Analysis on the Optimized Application of IP Address in Campus Network%校园网中IP地址资源的合理使用

    Institute of Scientific and Technical Information of China (English)

    王强; 陆际光

    2001-01-01

    According to the environment of the campus, this paper focus on the optimized application of IP address, including certain methods of distribution , multi-utilization and defense plagiarism of IP address. Firstly the difference between multi-utilization of IP network address and that of IP host address is introduced, then the two technologies of IP address multi-utilization——IP masquerade and IP agent ,as well as the merit and defect comparison involved. Lastly, the author discussed the methods to defense IP plagiarism.%讨论了校园网环境下IP地址的合理使用,包括IP地址的分配、复用及防止盗用等,说明了IP网络地址复用与IP主机地址复用的区别,阐述了2种IP主机地址复用技术——IP伪装和IP代理,并比较了两者的优缺点.最后讨论了IP盗用的防范技术.

  8. Resource management in radio access and IP-based core networks for IMT Advanced and Beyond

    Institute of Scientific and Technical Information of China (English)

    SU Gang; HIDELL Markus; ABRAHAMSSON Henrik; AHLGREN Bengt; LI Dan; SJDIN Peter; TANYINGYONG Voravit; XU Ke

    2013-01-01

    The increased capacity needs, primarily driven by content distribution, and the vision of Internet-of-Things with billions of connected devices pose radically new demands on future wireless and mobile systems. In general the increased diversity and scale result in complex resource management and optimization problems in both radio access networks and the wired core network infrastructure. We summarize results in this area from a collaborative Sino-Swedish project within IMT Advanced and Beyond, covering adaptive radio resource management, energy-aware routing, OpenFlow-based network virtualization, data center networking, and access network caching for TV on demand.

  9. How to Maximize User Satisfaction Degree in Multi-service IP Networks

    CERN Document Server

    Nguyen, Huy; Choi, Deokjai

    2010-01-01

    Bandwidth allocation is a fundamental problem in communication networks. With current network moving towards the Future Internet model, the problem is further intensified as network traffic demanding far from exceeds network bandwidth capability. Maintaining a certain user satisfaction degree therefore becomes a challenge research topic. In this paper, we deal with the problem by proposing BASMIN, a novel bandwidth allocation scheme that aims to maximize network user's happiness. We also defined a new metric for evaluating network user satisfaction degree: network worth. A three-step evaluation process is then conducted to compare BASMIN efficiency with other three popular bandwidth allocation schemes. Throughout the tests, we experienced BASMIN's advantages over the others; we even found out that one of the most widely used bandwidth allocation schemes, in fact, is not effective at all.

  10. Internet and Intranet Use with a PC: Effects of Adapter Cards, Windows Versions and TCP/IP Software on Networking Performance.

    Science.gov (United States)

    Nieuwenhuysen, Paul

    1997-01-01

    Explores data transfer speeds obtained with various combinations of hardware and software components through a study of access to the Internet from a notebook computer connected to a local area network based on Ethernet and TCP/IP (transmission control protocol/Internet protocol) network protocols. Upgrading is recommended for higher transfer…

  11. Network Programming tcp/ip protocol and socket discussion%网络编程tcp/ip协议与socket论述

    Institute of Scientific and Technical Information of China (English)

    严谦; 阳泳

    2016-01-01

    随着互联网技术的不断发展,网络通信成为当前互联网技术的重要技术,所以当前网络编程技术成为当前互联网通信发展的核心技术。网络编程主要是的通过使用套接字来实现进程间的编程,在Windows系统中的网络编程的套接字winscok,而在linux系统中最常见的套接字就是socket,本文就linux网络编程中的tcp、ip协议以及socket套接字问题进行详细的论述。%With the continuous development of Internet technology, network communications become an important technology of Internet technology, so the current network programming technology as the core technology of the current development of Internet communications. Network programming primarily achieved through the use of socket programming between processes in Windows system network programming socket winscok, while in linux system is the most common socket socket, paper linux Network Programming the tcp, ip protocol and socket socket issues are discussed in detail.

  12. IP技术在卫星通信中的应用及发展趋势%The Application and Developing Trend of IP Technology in Satellite Communication

    Institute of Scientific and Technical Information of China (English)

    程磊; 孔博; 吴久银

    2012-01-01

    Internet Protocol(IP) technology has ubiquitous along with the development of communication,it is one of the hot points in the fields communication that combine IP technology with satellite communication(SATCOM).Addressed the characteristic of SATCOM,the paper analyses the peculiarity of SATCOM link in Internet and presents the im- provement of SATCOM link protocol,then predicts the developing trend of IP technology in SATCOM%随着通信的发展,IP技术已经泛化,将IP技术与卫星通信相结合的卫星IP网络是通信领域众多研究的热点之一。该文针对卫星通信的传输特性,分析了卫星链路在Intemet应用中的特点,介绍了对卫星链路协汉的改进,给出了当前卫星lP网络技术的发展趋势。

  13. Hierarchical Supervisor and Agent Routing Algorithm in LEO/MEO Double-layered Optical Satellite Network

    Science.gov (United States)

    Li, Yongjun; Zhao, Shanghong

    2016-09-01

    A novel routing algorithm (Hierarchical Supervisor and Agent Routing Algorithm, HSARA) for LEO/MEO (low earth orbit/medium earth orbit) double-layered optical satellite network is brought forward. The so-called supervisor (MEO satellite) is designed for failure recovery and network management. LEO satellites are grouped according to the virtual managed field of MEO which is different from coverage area of MEO satellite in RF satellite network. In each LEO group, one LEO satellite which has maximal persistent link with its supervisor is called the agent. A LEO group is updated when this optical inter-orbit links between agent LEO satellite and the corresponding MEO satellite supervisor cuts off. In this way, computations of topology changes and LEO group updating can be decreased. Expense of routing is integration of delay and wavelength utilization. HSARA algorithm simulations are implemented and the results are as follows: average network delay of HSARA can reduce 21 ms and 31.2 ms compared with traditional multilayered satellite routing and single-layer LEO satellite respectively; LEO/MEO double-layered optical satellite network can cover polar region which cannot be covered by single-layered LEO satellite and throughput is 1% more than that of single-layered LEO satellite averagely. Therefore, exact global coverage can be achieved with this double-layered optical satellite network.

  14. TCP/IP Jumbo Frames Network Performance Evaluation on A Testbed Infrastructure

    Directory of Open Access Journals (Sweden)

    Paula Raymond Lutui

    2012-12-01

    Full Text Available Enhancing network performance has been studied by a number of researchers. The need to provide greater throughput on network infrastructure has been the key driver for these studies. The use of jumbo frames is considered one of the methodologies that can be employed to increase data throughput on networks. In this research undertaking, the authors implement jumbo frames on a test-bed implemented with Windows Server 2003/2008 networks and performance related metrics are measured for both IPv4 and IPv6 implementations. The results obtained in this empirical study shows that performance metrics values are different in various scenarios.

  15. Prototype for Integrating Internet of Things and Emergency Service in an IP Multimedia Subsystem for Wireless Body Area Networks

    Institute of Scientific and Technical Information of China (English)

    KaiDi Chang; JiannLiang Chen; HanChieh Chao

    2014-01-01

    In recent years, the application of the Internet of Things (IoT) has become an emerging business. The most important concept of next-generation network for providing a common global IT platform is combining seamless networks and networked things, objects or sensors. Also, wireless body area networks (WBANs) are becoming mature with the widespread usage of the IoT. In order to support WBAN, the platform, scenario and emergency service are necessary due to the sensors in WBAN being related to wearer's life. The sensors on the body detect a lot of information about bioinformatics and medical signals, such as heartbeat and blood. Thus, the integration of IoT and network communication in daily life is important. However, there is not only a lack of common fabric for integrating IoT with current Internet and but also no emergency call process in the current network communication envi-ronment. To overcome such situations, the prototype of integrating IoT and emergency call process is discussed. A simulated boot-strap platform to provide the discussion of open challenges and solutions for deploying IoT in Internet and the emergency commu-nication system are analyzed by using a service of 3GPP IP multimedia subsystem. Finally, the prototype for supporting WBAN with emergence service is also addressed and the performance results are useful to service providers and network operators that they can estimate their migration to IoT by referring to this experience and experiment results. Furthermore, the queuing model used to achieve the performance of emergency service in IMS and the delay time of the proposed model is analyzed.

  16. Performance of TCP Vegas, Bic and Reno Congestion Control Algorithms on Iridium Satellite Constellations

    Directory of Open Access Journals (Sweden)

    M.Nirmala

    2012-11-01

    Full Text Available Satellite networking is different from wired or wireless networks. The behavior and the performance of TCP/IP in normal wireless network as well as in wired network are different from one another. The TCP/IP protocol was not designed to perform well over high-latency or noisy channels so its performance over satellite networks are totally different. Each satellite networks/constellations have different properties. The deployment height, motion, direction, link capacity – all differ from one satellite constellations to another. So, certainly the behavior of TCP/IP will considerably differ from one satellite constellations than another.The Performance of three different TCP Congestion algorithms, Vegas, Reno and Bic are taken for evaluation on the simulated satellite network Iridium and the performance of the three algorithms under the satellites constellation is measured using suitable metrics. It is observed that, irrespective of the high end to end delay, the behavior of TCP/IP under Satellite network is somewhat resembling a high latency wired network. TCP under satellite network is not like that of a mobile ADHOC network. The observation resulted that the overall performance of Vegas was good in Iridium constellations. These reasons should be explored for designing a better congestion control algorithm exclusively for Satellite Networks.

  17. Voice and Data Network of Convergence and the Application of Voice over IP

    Energy Technology Data Exchange (ETDEWEB)

    Eldridge, J.M.

    2000-11-01

    This paper looks at emerging technologies for converging voice and data networks and telephony transport over a data network using Internet Protocols. Considered are the benefits and drivers for this convergence. The paper describes these new technologies, how they are being used, and their application to Sandia.

  18. Easy Handling of Sensors and Actuators over TCP/IP Networks by Open Source Hardware/Software.

    Science.gov (United States)

    Mejías, Andrés; Herrera, Reyes S; Márquez, Marco A; Calderón, Antonio José; González, Isaías; Andújar, José Manuel

    2017-01-05

    There are several specific solutions for accessing sensors and actuators present in any process or system through a TCP/IP network, either local or a wide area type like the Internet. The usage of sensors and actuators of different nature and diverse interfaces (SPI, I2C, analogue, etc.) makes access to them from a network in a homogeneous and secure way more complex. A framework, including both software and hardware resources, is necessary to simplify and unify networked access to these devices. In this paper, a set of open-source software tools, specifically designed to cover the different issues concerning the access to sensors and actuators, and two proposed low-cost hardware architectures to operate with the abovementioned software tools are presented. They allow integrated and easy access to local or remote sensors and actuators. The software tools, integrated in the free authoring tool Easy Java and Javascript Simulations (EJS) solve the interaction issues between the subsystem that integrates sensors and actuators into the network, called convergence subsystem in this paper, and the Human Machine Interface (HMI)-this one designed using the intuitive graphical system of EJS-located on the user's computer. The proposed hardware architectures and software tools are described and experimental implementations with the proposed tools are presented.

  19. Easy Handling of Sensors and Actuators over TCP/IP Networks by Open Source Hardware/Software

    Science.gov (United States)

    Mejías, Andrés; Herrera, Reyes S.; Márquez, Marco A.; Calderón, Antonio José; González, Isaías; Andújar, José Manuel

    2017-01-01

    There are several specific solutions for accessing sensors and actuators present in any process or system through a TCP/IP network, either local or a wide area type like the Internet. The usage of sensors and actuators of different nature and diverse interfaces (SPI, I2C, analogue, etc.) makes access to them from a network in a homogeneous and secure way more complex. A framework, including both software and hardware resources, is necessary to simplify and unify networked access to these devices. In this paper, a set of open-source software tools, specifically designed to cover the different issues concerning the access to sensors and actuators, and two proposed low-cost hardware architectures to operate with the abovementioned software tools are presented. They allow integrated and easy access to local or remote sensors and actuators. The software tools, integrated in the free authoring tool Easy Java and Javascript Simulations (EJS) solve the interaction issues between the subsystem that integrates sensors and actuators into the network, called convergence subsystem in this paper, and the Human Machine Interface (HMI)—this one designed using the intuitive graphical system of EJS—located on the user’s computer. The proposed hardware architectures and software tools are described and experimental implementations with the proposed tools are presented. PMID:28067801

  20. Investigation on TCP/IP Congestion Control in Optical Burst Switched (OBS Network

    Directory of Open Access Journals (Sweden)

    Ms. Payal Daryani

    2012-03-01

    Full Text Available Transport Control Protocol (TCP is the dominant protocol in modern communication networks, in which the issues of reliability, flow, and congestion control must be handled efficiently. In this review paper an analytical switching is used to exploit the huge bandwidth of optical fibers for future high speed internet backbone. It carries multiple packets, in their turn. Different aggregation schemes have been considered and evaluated.TCP performance greatly depends on the TCP congestion window behavior that is related to loss events occurring in the optical burst switched network, there is a special term called traffic shaping by which we control over the network according to the network load .that means we increase or decrease the send rate according to the network demand.

  1. Optimization of mobile IPv6-based handovers to support VoIP services in wireless heterogeneous networks

    DEFF Research Database (Denmark)

    Fathi, Hanane; Chakraborty, Shyam; Prasad, Ramjee

    2007-01-01

    The support of the voice over Internet Protocol (VoIP) services in next-generation wireless systems requires the coupling of mobility with quality of service. The mobile node can experience disruptions or even intermittent disconnections of an ongoing real-time session due to handovers....... The duration of such interruptions is called disruption time or handover delay and can heavily affect user satisfaction. Therefore, this delay needs to be minimized to provide good-quality VoIP services. In this paper, the focus is on the network layer mobility, specifically on dates for providing mobility...... in this paper. The results obtained using the adaptive timer technique show that for a 3% frame error rate and a 128-kb/s channel, the handoff delay is about 0.075 s (predictive) and 0.051 s (reactive) for FMIPv6. It is around 0.047 s [intra-mobile anchor point (MAP)] and 1.47 s (inter-MAP) for HMIPv6, around 1...

  2. Intrusion Prevention/Intrusion Detection System (IPS/IDS for Wifi Networks

    Directory of Open Access Journals (Sweden)

    Michal Korcak

    2014-07-01

    Full Text Available The nature of wireless networks itself created new vulnerabilities that in the classical wired network s do not exist. This results in an evolutional requireme nt to implement new sophisticated security mechanis m in form of Intrusion Detection and Prevention Systems. This paper deals with security issues of small off ice and home office wireless networks. The goal of our work is to design and evaluate wireless IDPS with u se of packet injection method. Decrease of attacker’s traffic by 95% was observed when compared to attacker’s traffic without deployment of proposed I DPS system.

  3. Imprvoing QoS of all-IP Generation of Pre-WiMax Networks Using Delay-Jitter Model

    CERN Document Server

    Dahmouni, H; Bonacci, D; Sanso, B; Girard, A

    2010-01-01

    The topic of this paper is the evaluation of QoS parameters in live Pre-Wimax environments. The main contribution is the validation of an analytical delay-jitter behavior model. These models can be used in optimization algorithms in order to provide opportunistic and reliable all-IP networks. It allows understanding the impact of the jitter constraints on the throughput and packet loss in wireless systems. However, we show that the real-time QoS requirements of real-time and interactive services can be avoided to a large degree by controlling only the packet delay-jitter in a fixed and mobile environment. The QoS metrics have been computed from live measurements in a Pre-Wimax realistic environment (Toulouse/Blagnac Airport).

  4. Reconstructing regional climate networks from irregularly sampled satellite data

    Science.gov (United States)

    Wiedermann, Marc; Donner, Reik V.; Sykioti, Olga; Papadimitriou, Constantinos; Kurths, Jürgen

    2015-04-01

    With the increasing availability of remote sensing data Earth System Analysis has taken a great step forward. Satellite data with high resolution in time and space allow for an in-depth analysis of small-scale processes in the climate as well as ecosystems. This data type, however, also harbors crucial conceptual complications. First, depending on whether the satellite is orbiting on an ascending or descending path systematic biases are induced into the dataset and both measurements can not be evaluated simultaneously without an appropriate preprocessing. Second, remote sensing data are usually not produced with equidistant temporal sampling, but might contain huge gaps, due to cloud cover or maintenance work and irregular time steps, due to the orbiting time of the satellite. In this work, we utilize sea surface temperature (SST) data obtained from the SMOS satellite as part of ESA's Earth Explorer Mission to study small-scale regional interactions between different parts of the Mediterranean, Aegean and Black Sea. In a first step, we create homogeneous time series for each grid point by combining data from ascending and descending satellite paths by utilizing principal component and singular spectrum analysis. To address the issue of irregular temporal sampling we utilize a kernel weighted version of the linear cross-correlation function to compute lagged correlations between all pairs of grid points in the dataset. By setting a threshold to the thus obtained correlation matrix we obtain a binary matrix which can be interpreted as the adjacency matrix of a complex network. We then use tools from complex network theory to study regional interdependencies in the study area for different time lags of up to forty days. We find that the obtained networks represent well the observed average wind directions and speeds and display interaction structures between small regions in the Aegean Sea, which are in good agreement with earlier observations. The methods presented

  5. Interactive Video Coding and Transmission over Heterogeneous Wired-to-Wireless IP Networks Using an Edge Proxy

    Directory of Open Access Journals (Sweden)

    Modestino James W

    2004-01-01

    Full Text Available Digital video delivered over wired-to-wireless networks is expected to suffer quality degradation from both packet loss and bit errors in the payload. In this paper, the quality degradation due to packet loss and bit errors in the payload are quantitatively evaluated and their effects are assessed. We propose the use of a concatenated forward error correction (FEC coding scheme employing Reed-Solomon (RS codes and rate-compatible punctured convolutional (RCPC codes to protect the video data from packet loss and bit errors, respectively. Furthermore, the performance of a joint source-channel coding (JSCC approach employing this concatenated FEC coding scheme for video transmission is studied. Finally, we describe an improved end-to-end architecture using an edge proxy in a mobile support station to implement differential error protection for the corresponding channel impairments expected on the two networks. Results indicate that with an appropriate JSCC approach and the use of an edge proxy, FEC-based error-control techniques together with passive error-recovery techniques can significantly improve the effective video throughput and lead to acceptable video delivery quality over time-varying heterogeneous wired-to-wireless IP networks.

  6. Predictive functional control for active queue management in congested TCP/IP networks.

    Science.gov (United States)

    Bigdeli, N; Haeri, M

    2009-01-01

    Predictive functional control (PFC) as a new active queue management (AQM) method in dynamic TCP networks supporting explicit congestion notification (ECN) is proposed. The ability of the controller in handling system delay along with its simplicity and low computational load makes PFC a privileged AQM method in the high speed networks. Besides, considering the disturbance term (which represents model/process mismatches, external disturbances, and existing noise) in the control formulation adds some level of robustness into the PFC-AQM controller. This is an important and desired property in the control of dynamically-varying computer networks. In this paper, the controller is designed based on a small signal linearized fluid-flow model of the TCP/AQM networks. Then, closed-loop transfer function representation of the system is derived to analyze the robustness with respect to the network and controller parameters. The analytical as well as the packet-level ns-2 simulation results show the out-performance of the developed controller for both queue regulation and resource utilization. Fast response, low queue fluctuations (and consequently low delay jitter), high link utilization, good disturbance rejection, scalability, and low packet marking probability are other features of the developed method with respect to other well-known AQM methods such as RED, PI, and REM which are also simulated for comparison.

  7. 入侵防御系统(IPS)在教育城域网中的应用%A Solution for IPS in the Field of Education Network

    Institute of Scientific and Technical Information of China (English)

    李斌

    2010-01-01

    在分析了教育系统中网络应用特点的基础上,结合安全技术发展趋势,以信息技术的可用性、完整性、机密性为方案设计准则,提出了以入侵防御系统(IPS Intrusion Protection System)为代表的关注教育城域网应用安全的网络安全解决方案.

  8. Study on SLA Management of IP QoS Network%IP QoS网络中的SLA管理研究

    Institute of Scientific and Technical Information of China (English)

    翟红刚; 吴宇红

    2003-01-01

    本文就IP QoS 网络上如何部署SLA 管理作了讨论,给出了SLA 管理的整体架构,并就具体SLA 部署中的两个问题: SLA 到具体网络设备配置的映射和SLA的监视/报告作了更近一步的分析,给出了一些指导性方案.

  9. Satellite -Based Networks for U-Health & U-Learning

    Science.gov (United States)

    Graschew, G.; Roelofs, T. A.; Rakowsky, S.; Schlag, P. M.

    2008-08-01

    The use of modern Information and Communication Technologies (ICT) as enabling tools for healthcare services (eHealth) introduces new ways of creating ubiquitous access to high-level medical care for all, anytime and anywhere (uHealth). Satellite communication constitutes one of the most flexible methods of broadband communication offering high reliability and cost-effectiveness of connections meeting telemedicine communication requirements. Global networks and the use of computers for educational purposes stimulate and support the development of virtual universities for e-learning. Especially real-time interactive applications can play an important role in tailored and personalised services.

  10. Analysis of Various Computer System Monitoring and LCD Projector through the Network TCP/IP

    Directory of Open Access Journals (Sweden)

    Santoso Budijono

    2015-09-01

    Full Text Available Many electronic devices have a network connection facility. Projectors today have network facilities to bolster its customer satisfaction in everyday use. By using a device that can be controlled, the expected availability and reliability of the presentation system (computer and projector can be maintained to keep itscondition ready to use for presentation. Nevertheless, there is still a projector device that has no network facilities so that the necessary additional equipment with expensive price. Besides, control equipment in large quantities has problems in timing and the number of technicians in performing controls. This study began with study of literature, from searching for the projectors that has LAN and software to control and finding a number of computer control softwares where the focus is easy to use and affordable. Result of this research is creating asystem which contains suggestions of procurement of computer hardware, hardware and software projectors each of which can be controlled centrally from a distance.

  11. Analysis of Various Computer System Monitoring and LCD Projector through the Network TCP/IP

    Directory of Open Access Journals (Sweden)

    Santoso Budijono

    2015-12-01

    Full Text Available Many electronic devices have a network connection facility. Projectors today have network facilities to bolster its customer satisfaction in everyday use. By using a device that can be controlled, the expected availability and reliability of the presentation system (computer and projector can be maintained to keep its condition ready to use for presentation. Nevertheless, there is still a projector device that has no network facilities so that the necessary additional equipment with expensive price. Besides, control equipment in large quantities has problems in timing and the number of technicians in performing controls. This study began with study of literature, from searching for the projectors that has LAN and software to control and finding a number of computer control softwares where the focus is easy to use and affordable. Result of this research is creating a system which contains suggestions of procurement of computer hardware, hardware and software projectors each of which can be controlled centrally from a distance.

  12. TCP/IP optimization over wide area networks: implications for teleradiology.

    Science.gov (United States)

    Langer, Steve G; French, Todd; Segovis, Colin

    2011-04-01

    Radiology examinations are large. The advent of fast volume imaging is making that statement truer every year. PACS are based on the assumption of fast local networking and just-in-time image pull to the desktop. On the other hand, teleradiology has been developed on a push model to accommodate the challenges of moderate bandwidth, high-latency wide area networks (WANs). Our group faced the challenging task of creating a PACS environment that felt local, while pulling images across a 3,000-mile roundtrip WAN link. Initial tests showed WAN performance lagging local area network (LAN) performance by a factor of 30 times. A 16-month journey of explorations pulled the WAN value down to only 1.5 times slower than the LAN.

  13. New dynamic routing algorithm based on MANET in LEO/MEO satellite network

    Institute of Scientific and Technical Information of China (English)

    LI Zhe; LI Dong-ni; WANG Guang-xing

    2006-01-01

    The features of low earth orbit/medium earth orbit (LEO/MEO) satellite networks routing algorithm based on inter-satellite link are analyzed and the similarities between satellite networks and mobile Ad Hoc network (MANET) are pointed out.The similar parts in MANET routing protocol are used in the satellite network for reference.A new dynamic routing algorithm based on MANET in LEO/MEO satellite networks,which fits for the LEO/MEO satellite communication system,is proposed.At the same time,the model of the algorithm is simulated and features are analyzed.It is shown that the algorithm has strong adaptability.It can give the network high autonomy,perfect function,low system overhead and great compatibility.

  14. IP Routing Protocols

    Science.gov (United States)

    Nolasco Pinto, Armando

    2002-03-01

    Uyless Black is a widely known expert in computer networks and data communications. He is author of more than ten books in the communication technologies field, which puts him in a good position to address this topic. In IP Routing Protocols he starts by providing the background and concepts required for understanding TCP/IP technology. This is done clearly and assumes little prior knowledge of the area. As might be expected, he emphasizes the IP route discovery problem. Later he details several routing protocols.

  15. End to end adaptive congestion control in TCP/IP networks

    CERN Document Server

    Houmkozlis, Christos N

    2012-01-01

    This book provides an adaptive control theory perspective on designing congestion controls for packet-switching networks. Relevant to a wide range of disciplines and industries, including the music industry, computers, image trading, and virtual groups, the text extensively discusses source oriented, or end to end, congestion control algorithms. The book empowers readers with clear understanding of the characteristics of packet-switching networks and their effects on system stability and performance. It provides schemes capable of controlling congestion and fairness and presents real-world app

  16. Hardware demonstration of high-speed networks for satellite applications.

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, Jonathon W.; Lee, David S.

    2008-09-01

    This report documents the implementation results of a hardware demonstration utilizing the Serial RapidIO{trademark} and SpaceWire protocols that was funded by Sandia National Laboratories (SNL's) Laboratory Directed Research and Development (LDRD) office. This demonstration was one of the activities in the Modeling and Design of High-Speed Networks for Satellite Applications LDRD. This effort has demonstrated the transport of application layer packets across both RapidIO and SpaceWire networks to a common downlink destination using small topologies comprised of commercial-off-the-shelf and custom devices. The RapidFET and NEX-SRIO debug and verification tools were instrumental in the successful implementation of the RapidIO hardware demonstration. The SpaceWire hardware demonstration successfully demonstrated the transfer and routing of application data packets between multiple nodes and also was able reprogram remote nodes using configuration bitfiles transmitted over the network, a key feature proposed in node-based architectures (NBAs). Although a much larger network (at least 18 to 27 nodes) would be required to fully verify the design for use in a real-world application, this demonstration has shown that both RapidIO and SpaceWire are capable of routing application packets across a network to a common downlink node, illustrating their potential use in real-world NBAs.

  17. A Protection Approach for Video Information transmitted in TCP/IP based networks

    CERN Document Server

    Stoianov, Nikolai

    2010-01-01

    In this paper an analysis of the existing video information protection methods is made. Analysis of current H.323 protocol stack has been made. A new encryption/decryption layer has been suggested. An approach for partial data encryption in the H.323 protocol stack is proposed and sample architecture of a Virtual Private Video Network is given.

  18. VoIP and Mission Critical Data Traffic over Heterogeneous Military Networks

    Science.gov (United States)

    2006-12-01

    Systems ( DESes ). Simulation results concern a comparison with an heuristic much used in industrial applications as well as some experimental tests...users attached to access networks supported by different QoS technologies reveals to be a hot topic of research . This problem is enforced by the fact

  19. A survey of Attacks on VoIP networks and Countermeasures

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    2015-06-01

    Jun 1, 2015 ... Julius N. Obidinnu 1 and Ayei E. Ibor ... convergence of the voice and data networks pose a plethora of threats to ... insight into the unpredictable nature of ..... "Security analysis and countermeasures assessment against spit ... Artificial Intelligence, Management Science and Electronic Commerce (AIMSEC),.

  20. Quality Evaluation of Mobile Networks Using VoIP Applications: A Case Study with Skype and LINE based-on Stationary Tests in Bangkok

    Directory of Open Access Journals (Sweden)

    Pongpisit Wuttidittachotti

    2015-11-01

    Full Text Available This paper presents the performance evaluation of 3G mobile networks for one kind of multimedia application called Voice over IP (VoIP within Bangkok, the capital city of Thailand, using Line and Skype, two popular VoIP applications. This study used evaluation of voice quality provided by both applications. The tests have been conducted using stationary scenarios over 5 major 3G mobile networks, served by 5 operators, within 14 universities in the inner city of Bangkok in order to gather data of degraded speech files. Then, the data was measured using Perceptual Evaluation of Speech Quality (PESQ to find Mean Opinion Score (MOS before analyzing with ANOVA and T-test, which are statistical tools, so that the discussion and conclusion can be eventually derived.

  1. Convolutional neural network features based change detection in satellite images

    Science.gov (United States)

    Mohammed El Amin, Arabi; Liu, Qingjie; Wang, Yunhong

    2016-07-01

    With the popular use of high resolution remote sensing (HRRS) satellite images, a huge research efforts have been placed on change detection (CD) problem. An effective feature selection method can significantly boost the final result. While hand-designed features have proven difficulties to design features that effectively capture high and mid-level representations, the recent developments in machine learning (Deep Learning) omit this problem by learning hierarchical representation in an unsupervised manner directly from data without human intervention. In this letter, we propose approaching the change detection problem from a feature learning perspective. A novel deep Convolutional Neural Networks (CNN) features based HR satellite images change detection method is proposed. The main guideline is to produce a change detection map directly from two images using a pretrained CNN. This method can omit the limited performance of hand-crafted features. Firstly, CNN features are extracted through different convolutional layers. Then, a concatenation step is evaluated after an normalization step, resulting in a unique higher dimensional feature map. Finally, a change map was computed using pixel-wise Euclidean distance. Our method has been validated on real bitemporal HRRS satellite images according to qualitative and quantitative analyses. The results obtained confirm the interest of the proposed method.

  2. A study of multiple access schemes in satellite control network

    Science.gov (United States)

    Mo, Zijian; Wang, Zhonghai; Xiang, Xingyu; Wang, Gang; Chen, Genshe; Nguyen, Tien; Pham, Khanh; Blasch, Erik

    2016-05-01

    Satellite Control Networks (SCN) have provided launch control for space lift vehicles; tracking, telemetry and commanding (TTC) for on-orbit satellites; and, test support for space experiments since the 1960s. Currently, SCNs encounter a new challenge: how to maintain the high reliability of services when sharing the spectrum with emerging commercial services. To achieve this goal, the capability of multiple satellites reception is deserved as an update/modernization of SCN in the future. In this paper, we conducts an investigation of multiple access techniques in SCN scenario, e.g., frequency division multiple access (FDMA) and coded division multiple access (CDMA). First, we introduce two upgrade options of SCN based on FDMA and CDMA techniques. Correspondingly, we also provide their performance analysis, especially the system improvement in spectrum efficiency and interference mitigation. Finally, to determine the optimum upgrade option, this work uses CRISP, i.e., Cost, Risk, Installation, Supportability and Performance, as the baseline approach for a comprehensive trade study of these two options. Extensive numerical and simulation results are presented to illustrate the theoretical development.

  3. Regional climate network analysis from irregularly sampled satellite data

    Science.gov (United States)

    Wiedermann, Marc; Sykioti, Olga; Papadimitriou, Constantinos; Balasis, George; Kurths, Jürgen; Donner, Reik V.

    2016-04-01

    With the increasing availability of remote sensing data Earth System Analysis has taken a great step forward. This type of data, however, also harbors a variety of conceptual complications. First, depending on whether the satellite is orbiting on an ascending or descending path systematic biases are induced into the data, and both measurements cannot be evaluated simultaneously without an appropriate preprocessing. Second, remote sensing data are usually not produced with equidistant temporal sampling, but might contain huge gaps and irregular time steps. Third, the time period covered by the data is often too short to perform an appropriate seasonal detrending. Here, we propose a general framework to create homogeneous anomalized time series for a (multivariate) satellite data set by combining time series from ascending and descending satellite paths or even different missions using principal component and singular spectrum analysis. We then exemplarily apply our method to sea surface temperature data obtained from the SMOS satellite mission to study small-scale regional correlative patterns covering different parts of the Aegean Sea. To address the issue of irregular temporal sampling we utilize a kernel weighted version of the linear cross-correlation function to compute lagged correlations between all pairs of grid points in the data set. By binarizing the thus obtained matrices, we obtain a network representation of the system's similarity structure. Ultimately, we use tools from complex network theory to study regional interdependencies in the study area for different time lags of up to forty days. We find that the obtained networks represent well the observed average wind directions and speeds and display interaction structures between small regions in the Aegean Sea, which are in good agreement with earlier observations. In a second step, we extend the study area to the whole Mediterranean and Black Sea and investigate lagged interactions between these two

  4. A Multicast Routing Algorithm for Datagram Service in Delta LEO Satellite Constellation Networks

    Directory of Open Access Journals (Sweden)

    Yanpeng Ma

    2014-04-01

    Full Text Available Satellites can broadcast datagram over wide areas, therefore, the satellite network has congenital advantages to implement multicast service. LEO satellite has the property of efficient bandwidth usage, lower propagation delay and lower power consumption in the user terminals and satellites. Therefore, the constellation network composed by LEO satellites is an essential part of future satellite communication networks. In this paper, we propose a virtual center based multicast (VCMulticast routing algorithm for LEO satellite constellation network. The algorithm uses the geographic center information of group users to route multicast datagrams, with less memory, computer power and signaling overhead. We evaluate the delay and performance of our algorithm by means of simulations in the OPENET simulator. The results indicate that the delay of the proposed multicast method exceeds the minimum propagation by at most 29.1% on the average, which is a quite acceptable achievement, considering the resource overhead reduction that can be introduced by our proposal

  5. Advanced Conveyance Security Device System Scalability Assessment: Combined 802.15.4 and IP Network Simulation

    Science.gov (United States)

    2009-02-01

    channel non-beaconed scan. The Test Report on CSD-DCP Latency [ 1 ] shows that using beacons for network discovery takes more time than not using beacons... 1 . SSC Pacific , “CSD Communications Test Report on CSD-DCP Latency and Multi- Lane Portal Wireless Range, Version 1.7,” Space and Naval Warfare...BIBLIOGRAPHY 1 . Bagrodia, R, et al, “An Accurate, Scalable Communication Effects Server for the FCS System of Systems Simulation Environment

  6. GMPLS: IP-Centric Control Protocols for Optical Networks(Tutorial)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Recent advances in optical networking technologies, particularly DWDM and MEMS, promise the transmission and switching of huge bandwidth capacity. The carriers have convinced of that their revenue must be earned from efficient bandwidth management instead of unsophisticated increase in capacity. The distributed control plane can offer more flexibility, reliability and scalability, whose functions include addressing, resource and topology discovery, route computation, provisioning and restoration. Genera...

  7. Theoretical mean-variance relationship of IP network traffic based on ON/OFF model

    Institute of Scientific and Technical Information of China (English)

    JIN Yi; ZHOU Gang; JIANG DongChen; YUAN Shuai; WANG LiLi; CAO JianTing

    2009-01-01

    Mean-variance relationship (MVR), nowadays agreed in power law form, is an important function. It Is currently used by traffic matrix estimation as a basic statistical assumption. Because all the existing papers obtain MVR only through empirical ways, they cannot provide theoretical support to power law MVR or the definition of its power exponent. Furthermore, because of the lack of theoretical model, all traffic matrix estimation methods based on MVR have not been theoretically supported yet. By observ-ing both our laboratory and campus network for more than one year, we find that such an empirical MVR is not sufficient to describe actual network traffic. In this paper, we derive a theoretical MVR from ON/OFF model. Then we prove that current empirical power law MVR is generally reasonable by the fact that it is an approximate form of theoretical MVR under specific precondition, which can theoretically support those traffic matrix estimation algorithms of using MVR. Through verifying our MVR by actual observation and public DECPKT traces, we verify that our theoretical MVR Is valid and more capable of describing actual network traffic than power law MVR.

  8. Quality incentive based congestion control for multimedia communication over IP networks

    Institute of Scientific and Technical Information of China (English)

    JOHANSEN Stian; KIM Anna N.; PERKIS Andrew

    2006-01-01

    In this paper we introduce a framework for using quality as an incentive to promote proper application level congestion control. Through integrating a joint-source channel coder and feedback-based congestion control scheme, we are able to construct accurate and efficient quality incentives. The framework is applicable in all network architectures where end-to-end congestion control may be used, and is as such not specific to either best-effort or traffic class-based architectures. The concept is presented along with preliminary simulations that highlight the resulting rate control accuracy. We also discuss how to implement some well-known congestion control schemes within our framework.

  9. A distributed location management strategy for next generation IP-based wireless networks

    Institute of Scientific and Technical Information of China (English)

    SONG Mei; FENG Rui-jun; HUANG Jian-wen; SONG Jun-de

    2006-01-01

    Location management is the most important function in mobility management technology. The hierarchical structure of the proposed hierarchical network-layer mobility management (HNMM) can reduce the signaling cost. The selforganizing topology scheme can enhance the robustness and quality of the mobility management. The information of location of the mobile node is stored in the distributed database,which makes the storage of the location information more reliable and robust, and more flexible strategies can be used.The numeric results show that HNMM can provide better performance than the general structure of mobile IPv6, when the mobile nodes move frequently and when there is high traffic throughput.

  10. Agent-Based Framework for Personalized Service Provisioning in Converged IP Networks

    Science.gov (United States)

    Podobnik, Vedran; Matijasevic, Maja; Lovrek, Ignac; Skorin-Kapov, Lea; Desic, Sasa

    In a global multi-service and multi-provider market, the Internet Service Providers will increasingly need to differentiate in the service quality they offer and base their operation on new, consumer-centric business models. In this paper, we propose an agent-based framework for the Business-to-Consumer (B2C) electronic market, comprising the Consumer Agents, Broker Agents and Content Agents, which enable Internet consumers to select a content provider in an automated manner. We also discuss how to dynamically allocate network resources to provide end-to-end Quality of Service (QoS) for a given consumer and content provider.

  11. Power-Aware Rationale for Using Coarse-Grained Transponders in IP-Over-WDM Networks

    DEFF Research Database (Denmark)

    Saldaña Cercos, Silvia; Resendo, Leandro C.; Ribeiro, Moises R. N.;

    2015-01-01

    generations. However, the adoption of such coarse-grained bit-rate granularity with lower flexibility for traffic grooming raises important questions: (1) What repercussions do they have on the overall power consumption and thus operational expenditures (OPEX) compared to legacy fine-grained designs (i.......e., using 10 Gbps technology)? (2) What is the long-term cost of coarse-grained designs? We define a power-aware mixed integer linear programming (MILP) formulation based on actual modular architectures where modules are upgraded as the network traffic increases. We introduce, for the first time, important...

  12. Infinite Queue Management via Cascade Control for Industrial Routers in Smart Grid IP Networks

    Directory of Open Access Journals (Sweden)

    Ku-Hwan Kim

    2016-01-01

    Full Text Available Smart grid applications experience an extremely wide range of communication delay. Data flows of those applications are normally aggregated at industrial network routers in substations, form infinite (long queues termed bufferbloat issue, and might damage the operation of transmission control protocol. The default queue management scheme, DropTail, in such routers just drops packets if queue is full while the others in literature are mostly based on one-loop feedback control where an optimal point of performance between queue length and drop rate is limited. In this paper, we study the problem of managing a long queue of industrial router at substation under heterogeneous smart grid networks. Specifically, we propose an enqueue-dequeue dropping cascade control using a two-loop design method to control both window size and queue length. Moreover, our proposal can be easily implemented into router firmware with provided discrete expressions. Finally, our simulation results are presented to validate the possible benefits that can be gained from cascade control and compare the existing queue management methods as well.

  13. Applications of a Networked Array of Small Satellites for Planetary Observation

    NARCIS (Netherlands)

    Gunter, B.C.; Maessen, D.C.

    2010-01-01

    The goal of this study is to explore those applications which can best utilize a network of orbiting satellites working as a distributed computing array. The satellites are presumed to be low-cost mini- or micro-satellites orbiting Earth or some other celestial body (i.e., an asteroid, moon, etc.),

  14. Applications of a Networked Array of Small Satellites for Planetary Observation

    NARCIS (Netherlands)

    Gunter, B.C.; Maessen, D.C.

    2010-01-01

    The goal of this study is to explore those applications which can best utilize a network of orbiting satellites working as a distributed computing array. The satellites are presumed to be low-cost mini- or micro-satellites orbiting Earth or some other celestial body (i.e., an asteroid, moon, etc.),

  15. IP over DWDM

    Science.gov (United States)

    Allen, Mark E.

    2003-04-01

    The industry has been full of many lively debates about exactly how the functions of layer 1 and 2 (physical layer and data-link layer) will be orchestrated to support the growing amount of IP traffic. In effect, this book must simultaneously address layers 1 through 3. Two main strengths of the book are in describing current state-of-the-art research in very-high-speed IP networks and in detailing the standards activities related to net-work management, software, and signaling.

  16. Underlay-friendly Overlay routing mechanism for IP networks%一种IP网络友好的Overlay路由机制

    Institute of Scientific and Technical Information of China (English)

    徐同亚; 王大彬; 陈超

    2011-01-01

    在现存的多层路由中,上层Overlay网络在路由决策时通常对底层的IP网络性能和状态缺乏有效的协调和感知,致使上层Overlay路由和底层IP路由常常处于非协同、非优化工作状态,产生大量路由抖动和次优路由.为解决这些问题,提出了一种底层IP网络友好的Overlay路由机制,其基本思路为:增加Overlay网络的层感知能力,减少路由抖动,增加Overlay路由的稳定性.Overlay网络根据底层IP网络的节点跳数、链路带宽、丢包率等反映底层IP网络性能的信息作出路由决策.实际网络中,通过调整Overlay网络的链路代价,有效控制Overlay网络的路由决策.仿真结果表明,与传统双重路由(dual routing)相比,此IP网络友好Overlay路由机制在减少Overlay网络路由抖动、降低Overlay网络路径代价膨胀、提高Overlay网络故障恢复成功率和满足Overlay业务需求等方面有优势.%Existent Overlay networks are not IP network-aware enough..The Overlay routing is usually lack of aware of the IP network' s performance and status.So the Overlay network appears sub-optimal routing and has route flaps that have seriously affected the Overlay network applications' performance.This paper proposed an IP network-friendly Overlay routing mechanism.The basic idea was: enhance the Overlay network' s ability of lay awareness and flexibility.Overlay network routes based on the IP.network' s information (e.g.: number of route hops, link bandwidth and packet loss rate).Changing the Overlay network' s linkcost was useful to control the Overlay routing.The simulation results show that: compared to the traditional dual routing, this IP network-friendly Overlay routing mechanism has advantages in reducing the path cost inflation and route flaps, increasing the success rate of recovery, meeting the need of Overlay applications.

  17. An Optimal Adaptive Resource Pricing Mechanism for IP-DiffServ Network%优化的IP-DiffServ动态资源定价机制

    Institute of Scientific and Technical Information of China (English)

    张晋豫; 孟洛明; 邱雪松; 关富英

    2005-01-01

    在参考了美国国家基金会(NSF)的CAREER提出的IP-DiffServ的动态定价机制后,提出了一个以市场和计划为基础的优化动态定价机制.该机制以业务计划和资源规划为基础,从实现用户的最大性能价格比和ISP的最大利益出发实现了对业务类的定价,在计算用户可感觉到的利益时,考虑了负荷因素,从而可以引导业务量按照业务计划有序分布.仿真实验证明了它对NSF CAREER的业务类价值评估公式进行的改进是合理而有效的.

  18. IP and Competitiveness of Chinese Telecom Firms

    Institute of Scientific and Technical Information of China (English)

    ZENG Jian-qiu

    2004-01-01

    Based on the influence, this paper discusses the perspectives of IP technology. It illustrates that IP is changing the service structure of China Telecom and IP is striking traditional telecom networks and changing the competitive structure of telecom markets. IP is one of core technologies in future telecom networks and there is an opportunity for Chinese telecom firms to quicken their network innovation and improve the competitiveness for their sustainable development.

  19. Live Broadcasting of High Definition Audiovisual Content Using HDTV over Broadband IP Networks

    Directory of Open Access Journals (Sweden)

    C. E. Vegiris

    2008-01-01

    Full Text Available The current paper focuses on validating an implementation of a state-of-the art audiovisual (AV technologies setup for live broadcasting of cultural shows, via broadband Internet. The main objective of the work was to study, configure, and setup dedicated audio-video equipment for the processes of capturing, processing, and transmission of extended resolution and high fidelity AV content in order to increase realism and achieve maximum audience sensation. Internet2 and GEANT broadband telecommunication networks were selected as the most applicable technology to deliver such traffic workloads. Validation procedures were conducted in combination with metric-based quality of service (QoS and quality of experience (QoE evaluation experiments for the quantification and the perceptual interpretation of the quality achieved during content reproduction. The implemented system was successfully applied in real-world applications, such as the transmission of cultural events from Thessaloniki Concert Hall throughout Greece as well as the reproduction of Philadelphia Orchestra performances (USA via Internet2 and GEANT backbones.

  20. Radio and Television Network Based on the IP VLAN Division and Address Planning%广电网络基于IP的VLAN划分及地址规划

    Institute of Scientific and Technical Information of China (English)

    林君芬

    2012-01-01

    在建设广电双向网络时,合理进行IP地址规划及VLAN划分是网络安全管理、业务开展的前提,根据业务开展、用户情况等对IP、VLAN规划进行简要分析与阐述,对本地经EPON+EoC/LAN双向化改造后的网络进行具体划分。%In the construction of broadcast television two-way network,rational planning and division of VLAN IP address is the network security management,business development the premise;according to business,users on the IP,VLAN planning to conduct a brief analysis and the elaboration,on the local EPON + EoC/LAN Bidirectional Transformation after the network specific division.

  1. TCP-ATCA: Improved Transmission Control Algorithm in Satellite Network

    Institute of Scientific and Technical Information of China (English)

    Liu Feng; Liu Hengna; Zhao Han

    2008-01-01

    An adaptive transmission control algorithm based on TCP (TCP-ATCA) is proposed to reduce the effects of long propagation de- lay and high link error rate of the satellite network on the performances. The flow control and the error recovery are differentiated by combined dynamic random early detection-explicit congestion notification (DRED-ECN) algorithm, and, moreover, the pertaining con- gestion control methods are used in TCP-ATCA to improve the throughput. By introducing the entire recovery algorithm, the unneces- sary congestion window decrease is reduced, and the throughput and fairness are improved. Simulation results show that, compared with TCP-Reno, TCP-ATCA provides a better throughput performance when the link capacity is higher (≥ 600 packet/s), and roughly the same when it is lower. At the same time, TCP-ATCA also increases fairness and reduces transmission delay.

  2. Economically sustainable public security and emergency network exploiting a broadband communications satellite

    OpenAIRE

    Lawal, Lasisi Salami

    2014-01-01

    The research contributes to work in Rapid Deployment of a National Public Security and Emergency Communications Network using Communication Satellite Broadband. Although studies in Public Security Communication networks have examined the use of communications satellite as an integral part of the Communication Infrastructure, there has not been an in-depth design analysis of an optimized regional broadband-based communication satellite in relation to the envisaged service coverage area, with l...

  3. Capacity Model and Constraints Analysis for Integrated Remote Wireless Sensor and Satellite Network in Emergency Scenarios

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2015-11-01

    Full Text Available This article investigates the capacity problem of an integrated remote wireless sensor and satellite network (IWSSN in emergency scenarios. We formulate a general model to evaluate the remote sensor and satellite network capacity. Compared to most existing works for ground networks, the proposed model is time varying and space oriented. To capture the characteristics of a practical network, we sift through major capacity-impacting constraints and analyze the influence of these constraints. Specifically, we combine the geometric satellite orbit model and satellite tool kit (STK engineering software to quantify the trends of the capacity constraints. Our objective in analyzing these trends is to provide insights and design guidelines for optimizing the integrated remote wireless sensor and satellite network schedules. Simulation results validate the theoretical analysis of capacity trends and show the optimization opportunities of the IWSSN.

  4. Enhancing End-to-End Performance of Information Services Over Ka-Band Global Satellite Networks

    Science.gov (United States)

    Bhasin, Kul B.; Glover, Daniel R.; Ivancic, William D.; vonDeak, Thomas C.

    1997-01-01

    The Internet has been growing at a rapid rate as the key medium to provide information services such as e-mail, WWW and multimedia etc., however its global reach is limited. Ka-band communication satellite networks are being developed to increase the accessibility of information services via the Internet at global scale. There is need to assess satellite networks in their ability to provide these services and interconnect seamlessly with existing and proposed terrestrial telecommunication networks. In this paper the significant issues and requirements in providing end-to-end high performance for the delivery of information services over satellite networks based on various layers in the OSI reference model are identified. Key experiments have been performed to evaluate the performance of digital video and Internet over satellite-like testbeds. The results of the early developments in ATM and TCP protocols over satellite networks are summarized.

  5. Energy-Efficient Optimal Power Allocation in Integrated Wireless Sensor and Cognitive Satellite Terrestrial Networks.

    Science.gov (United States)

    Shi, Shengchao; Li, Guangxia; An, Kang; Gao, Bin; Zheng, Gan

    2017-09-04

    This paper proposes novel satellite-based wireless sensor networks (WSNs), which integrate the WSN with the cognitive satellite terrestrial network. Having the ability to provide seamless network access and alleviate the spectrum scarcity, cognitive satellite terrestrial networks are considered as a promising candidate for future wireless networks with emerging requirements of ubiquitous broadband applications and increasing demand for spectral resources. With the emerging environmental and energy cost concerns in communication systems, explicit concerns on energy efficient resource allocation in satellite networks have also recently received considerable attention. In this regard, this paper proposes energy-efficient optimal power allocation schemes in the cognitive satellite terrestrial networks for non-real-time and real-time applications, respectively, which maximize the energy efficiency (EE) of the cognitive satellite user while guaranteeing the interference at the primary terrestrial user below an acceptable level. Specifically, average interference power (AIP) constraint is employed to protect the communication quality of the primary terrestrial user while average transmit power (ATP) or peak transmit power (PTP) constraint is adopted to regulate the transmit power of the satellite user. Since the energy-efficient power allocation optimization problem belongs to the nonlinear concave fractional programming problem, we solve it by combining Dinkelbach's method with Lagrange duality method. Simulation results demonstrate that the fading severity of the terrestrial interference link is favorable to the satellite user who can achieve EE gain under the ATP constraint comparing to the PTP constraint.

  6. LEO星座网络动态源路由算法%Dynamic Source Routing Algorithm for LEO Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    万鹏; 曹志刚; 王京林

    2007-01-01

    近年来,在低轨(LEO)卫星星座通信网络中采用网际协议(IP)路由算法的研究已经取得了一系列进展,文章论述了LEO星座通信网络的特点、拓扑结构和虚拟节点策略.在此基础上提出了基于泛洪路由的LEO星座动态源路由算法DSR-LSN(Dynamic Source Routing algorithm in LEO Satellite Networks),星座网络仿真表明,DSR-LSN算法具有网络路由状态稳定性好、时延小的优点.

  7. Neural Network Based Lna Design for Mobile Satellite Receiver

    Directory of Open Access Journals (Sweden)

    Abhijeet Upadhya

    2014-08-01

    Full Text Available Paper presents a Neural Network Modelling approach to microwave LNA design. To acknowledge the specifications of the amplifier, Mobile Satellite Systems are analyzed. Scattering parameters of the LNA in the frequency range 0.5 to 18 GHz are calculated using a Multilayer Perceptron Artificial Neural Network model and corresponding smith charts and polar charts are plotted as output to the model. From these plots, the microwave scattering parameter description of the LNA are obtained. Model is efficiently trained using Agilent ATF 331M4 InGaAs/InP Low Noise pHEMT amplifier datasheet and the neural model’s output seem to follow the various device characteristic curves with high regression. Next, Maximum Allowable Gain and Noise figure of the device are modelled and plotted for the same frequency range. Finally, the optimized model is utilized as an interpolator and the resolution of the amplifying capability with noise characteristics are obtained for the L Band of MSS operation.

  8. Study of IP Network Address Planning from Troubleshooting Multicast-Interruptions%从IP组播数据中断故障谈网络地址设计

    Institute of Scientific and Technical Information of China (English)

    王霞; 李敬; 鹿泽洲

    2012-01-01

    Interruptions encountered in multicast data flow in an IP network are described and reasons for the faults are analyzed. Then, the process of interruptions is analyzed in detail from the operational mechanism of IGMP (Internet Group Management Protocol) following introduction of multicast maintenance mechanism. Finally, a solution hased on redesigning of IP network addresses is given to avoid interruptions and a segmented IP network address assignment principle featuring switches or routers -VLAN (Virtual Local Area Network) -hosts incremental assignment is proposed.%首先描述了在IP网络环境中出现的组播数据偶断现象,分析定位了故障出现的原因.然后,详细阐述了组播维护机理,从组播管理协议的运行机制上进一步分析了组播数据偶断的过程.最后,给出了通过网络地址重新设计的方法解决问题的方案,并提出了交换机、路由器 VLAN(虚拟局域网) 主机的网络地址按顺序进行由小到大地分级分配的原则.

  9. IP and ATM Integration

    OpenAIRE

    Mannie, E.; Corridoni, J.; Cremonese, P.; Giordano, Silvia

    1999-01-01

    The performance limits of the current Internet make the integration of IP with ATM a hotly debated issue in the networking arena, leading to various competing approaches and products. Legitimate technical and market issues are, however, often intertwined with biased views and hype, with vendors competing in the standards arena as well as on the markets. Together with the speed of technical evolution, this causes confusion for purchasers of networking equipment who, usually preferring a single...

  10. Principle analysis of IP wavelength router

    Institute of Scientific and Technical Information of China (English)

    王勇; 殷洪玺; 徐安士; 吴德明

    2001-01-01

    Combining IP with WDM is an attractive direction for research. WDM will play an important role in IP network in future. Now, an urgent problem is how to introduce wavelength routing in an IP network. We solve this problem by designing IP wavelength router, implementing DPDP (default path and dedicated path) method. We prove the reasonableness and feasibility of this design by a principle experiment. A lot of problems related to this design are also discussed.

  11. Implementation of Identity-Address Separation Technology in IP Network%IP网络中名址分离机制实现研究

    Institute of Scientific and Technical Information of China (English)

    李鉴; 王邦礼

    2012-01-01

    The paper analyzes the problems of identifier and addressing architecture in the conventional IP network, tells of the necessity of identity-address separation. And the 2IP scheme of identity-address separation in current IP network is proposed, this architecture adopts an IP address as the host identity and an IP address as the host location. This paper also gives the overall architecture, labeling and addressing rules of this scheme, including also the mapping maintenance, system protocols and system communication mechanism etc. Finally it summarizes the advantages and disadvantages of the scheme, thus to provide a reference for acceptance or rejection in actual implementation.%文中分析了传统IP网络中的标识与编址体系存在的问题,指出了名址分离的必要性。研究提出了一种采用一个IP作为主机标识符,另外一个IP地址作为定位符,适应于通用型IP网络中实现名址分离的2IP方案,给出了该方案的总体体系结构、标识与地址的编址方式和映射维护、系统的协议组成,以及系统的通信流程机制等。并总结分析了方案的优缺点,以便于在实施过程进行选择和取舍。

  12. 基于IP网络的景观绿道公共广播设计%Design for IP Network Based Public Broadcasting System for Landscape Corridor

    Institute of Scientific and Technical Information of China (English)

    陈昕

    2014-01-01

    结合某景观长廊工程实例,分析景观绿道公共广播的特点,比选广播系统方案:模拟广播、数字广播、 IP广播系统,最终选择了IP广播系统。并介绍IP广播方案下该景观长廊广播系统的具体设计方案,总结基于IP网络的景观绿道公共广播具有的优势。%A landscape corridor project is taken as an example to analyze the features of public broadcasting system for landscape corridor and to compare the options for the public broadcasting system. After the comparison among analogue broadcasting system, digital broadcasting system, and IP network based broadcasting system, the last one is selected. And then, the detailed design for the public broadcasting system based on IP network for the landscape corridor is introduced and the advantages of IP network based public broadcasting system are summarized.

  13. Network Performance Evaluation of Abis Interface over DVB-S2 in the GSM over Satellite Network

    Directory of Open Access Journals (Sweden)

    S. B. Musabekov

    2010-01-01

    Full Text Available This paper deals with establishing a GSM link over Satellite. Abis interface, which is defined between Base Transceiver Station (BTS and Base Station Controller (BSC, in a GSM network is considered here to be routed over the Satellite. The satellite link enables a quick and cost-effective GSM link in meagerly populated areas. A different scenario comparison was done to understand the impact of Satellite environment on network availability comparing to terrestrial scenario. We have implemented an Abis interface over DVB S2 in NS2 and evaluated the performance over the high delay and loss satellite channel. Network performance was evaluated with respect to Satellite channel delay and DVB S2 encapsulation efficiency under different amount of user traffic and compared with the terrestrial scenario. The results clearly showed an increased amount of SDCCH and TCH channels required in the case of satellite scenario for the same amount of traffic in comparison to conventional terrestrial scenario. We have optimized the parameters based on the simulation results. Link budget estimation considering DVB-S2 platform was done to find satellite bandwidth and cost requirements for different network setups.

  14. Study on networking issues of medium earth orbit satellite communications systems

    Science.gov (United States)

    Araki, Noriyuki; Shinonaga, Hideyuki; Ito, Yasuhiko

    1993-01-01

    Two networking issues of communications systems with medium earth orbit (MEO) satellites, namely network architectures and location determination and registration methods for hand-held terminals, are investigated in this paper. For network architecture, five candidate architectures are considered and evaluated in terms of signaling traffic. For location determination and registration, two methods are discussed and evaluated.

  15. Beam forming networks for mm-wave satellite communications

    Science.gov (United States)

    Sharon, T. E.

    1983-01-01

    Technology features of a beam forming network (BFN) employing ferrite devices to provide multiple beam antenna pattern control for satellites used in telecommunications are described. The BFN produces the phase and amplitude distribution for each horn in an antenna array, with the number of horns in the array being equal to the number of outputs in the BFN. One configuration involves microwave switches and permits illumination of a single feed horn at a time using ferrite latching circulators that function by reversing the circulation direction. A more flexible version, yielding a variable amplitude distribution across the feed horn array to accommodate changing traffic patterns or serving a TDMA system, includes the capability of forming nulls in the system with a variable phase shifter in the input ports. The antenna scan angles in phased arrays can be limited to 8 deg from center. Acceptable insertion losses have been demonstrated in BFN with hundreds of ports and switching rates as high as 10 kHz.

  16. Beam forming networks for mm-wave satellite communications

    Science.gov (United States)

    Sharon, T. E.

    1983-08-01

    Technology features of a beam forming network (BFN) employing ferrite devices to provide multiple beam antenna pattern control for satellites used in telecommunications are described. The BFN produces the phase and amplitude distribution for each horn in an antenna array, with the number of horns in the array being equal to the number of outputs in the BFN. One configuration involves microwave switches and permits illumination of a single feed horn at a time using ferrite latching circulators that function by reversing the circulation direction. A more flexible version, yielding a variable amplitude distribution across the feed horn array to accommodate changing traffic patterns or serving a TDMA system, includes the capability of forming nulls in the system with a variable phase shifter in the input ports. The antenna scan angles in phased arrays can be limited to 8 deg from center. Acceptable insertion losses have been demonstrated in BFN with hundreds of ports and switching rates as high as 10 kHz.

  17. Potentials and Limitations of CDMA Networks for Combined Inter-Satellite Communication and Relative Navigation

    NARCIS (Netherlands)

    Sun, R.; Guo, J.; Gill, E.K.A.; Maessen, D.C.

    2012-01-01

    Precision formation flying missions require formation acquisition and maintenance through the interactions among spacecraft by the inter-satellite communication and relative navigation. This paper analyses the dedicated system constraints of the network architecture for precision formation flying mi

  18. Innovative Large Scale Wireless Sensor Network Architecture Using Satellites and High-Altitude Platforms

    Directory of Open Access Journals (Sweden)

    Yasser Albagory

    2014-03-01

    Full Text Available Wireless sensor network has many applications and very active research area. The coverage span of this network is very important parameter where wide coverage area is a challenge. This paper proposes an architecture for large-scale wireless sensor network (LSWSN based on satellites and the High-Altitude Platforms (HAP where the sensor nodes are located on the ground and a wide coverage sink station may be in the form of a satellite or a network of HAPs. A scenario is described for multilayer LSWSN and a study for the system requirements has been established showing the number of Satellites, HAPs and coverage per each sink according to the elevation angle requirements. The Satellite-HAP-Sensor multilayer LSWSN architecture has the feasibility for effective energy and earth coverage and is optimum for covering largely sparse regions.

  19. STUDY THE EFFECTIVENESS APPLICATIONS OF FUZZY CONTROLLER WITH TWO ENTRANCES IN THE SYSTEM OF ACTIVE QUEUE MANAGEMENT THE PACKETS IN TCP/IP NETWORKS

    Directory of Open Access Journals (Sweden)

    O. V. Nevdachyna

    2016-01-01

    Full Text Available The paper presents an approach to solving the overloading problem in TCP/IP networks. Offered fuzzy controller with two inputs for system of active queue management packages in TCP/IP networks, and investigated its use in these systems with a random change of traffic load. Proposed controller has two inputs, one of which is the value of the difference between the current queue length and the second – the difference between the current level of usage of the buffer. The output of the fuzzy controller calculates the probability of discarding packet.Mathematical model system of active queue management that is studied is presented in an interactive MATLAB system, in wherein also is demonstrated the processes occurring in the system with a random change of traffic load. The research results show that the AQM-system with fuzzy controller with two entrances stable enough maintains the desired current length the queue for sufficiently small values of the probability of dropping/marking packets (at acceptable size of queue q0= 200 packets, the average probability of dropping / marking is not more than 3,5×10–3 or less 0,35% packets is discarded or marked from the total number of incoming packets. The results obtained will help improve the efficiency of the functioning and operation of TCP / IP networks by increasing data transmission quality. this happens due introduction of the proposed controller at the design of new, more efficient routers for networks to minimize the delay of information.

  20. 建设IP承载网的意义与组网技术的研究%The Significance of IP Bearing Network Construction and Study on Organizing Network Technologies

    Institute of Scientific and Technical Information of China (English)

    张薇

    2012-01-01

      With the rapid development of the communication network technology,the demand for data,voice,video and other services is increasing quickly.In order to meet the demand of the mobile business expansion in next few years,the construction of IP bearing network is necessary.This paper discusses the significance of IP bearing network construction, proposes corresponding strategies of the organizing network technologies in IP bearing network butt joint,the project improve the network availability and benefit of investment,meet the needs of business development in the long term.%  随着通信网络技术的飞速发展,人们对于数据、话音、视频等新业务的要求也在迅速增长。为满足未来移动业务扩展的需求,建设IP承载网是非常必要的。本文探讨了建设IP承载网的意义,提出了基于IP承载网的组网技术方案,此方案提升了网络的利用率和网络投资的效益,满足了中远期业务发展的需要。

  1. Cooperative network clustering and task allocation for heterogeneous small satellite network

    Science.gov (United States)

    Qin, Jing

    The research of small satellite has emerged as a hot topic in recent years because of its economical prospects and convenience in launching and design. Due to the size and energy constraints of small satellites, forming a small satellite network(SSN) in which all the satellites cooperate with each other to finish tasks is an efficient and effective way to utilize them. In this dissertation, I designed and evaluated a weight based dominating set clustering algorithm, which efficiently organizes the satellites into stable clusters. The traditional clustering algorithms of large monolithic satellite networks, such as formation flying and satellite swarm, are often limited on automatic formation of clusters. Therefore, a novel Distributed Weight based Dominating Set(DWDS) clustering algorithm is designed to address the clustering problems in the stochastically deployed SSNs. Considering the unique features of small satellites, this algorithm is able to form the clusters efficiently and stably. In this algorithm, satellites are separated into different groups according to their spatial characteristics. A minimum dominating set is chosen as the candidate cluster head set based on their weights, which is a weighted combination of residual energy and connection degree. Then the cluster heads admit new neighbors that accept their invitations into the cluster, until the maximum cluster size is reached. Evaluated by the simulation results, in a SSN with 200 to 800 nodes, the algorithm is able to efficiently cluster more than 90% of nodes in 3 seconds. The Deadline Based Resource Balancing (DBRB) task allocation algorithm is designed for efficient task allocations in heterogeneous LEO small satellite networks. In the task allocation process, the dispatcher needs to consider the deadlines of the tasks as well as the residue energy of different resources for best energy utilization. We assume the tasks adopt a Map-Reduce framework, in which a task can consist of multiple

  2. Satellites vs. fiber optics based networks and services - Road map to strategic planning

    Science.gov (United States)

    Marandi, James H. R.

    An overview of a generic telecommunications network and its components is presented, and the current developments in satellite and fiber optics technologies are discussed with an eye on the trends in industry. A baseline model is proposed, and a cost comparison of fiber- vs satellite-based networks is made. A step-by-step 'road map' to the successful strategic planning of telecommunications services and facilities is presented. This road map provides for optimization of the current and future networks and services through effective utilization of both satellites and fiber optics. The road map is then applied to different segments of the telecommunications industry and market place, to show its effectiveness for the strategic planning of executives of three types: (1) those heading telecommunications manufacturing concerns, (2) those leading communication service companies, and (3) managers of telecommunication/MIS departments of major corporations. Future networking issues, such as developments in integrated-services digital network standards and technologies, are addressed.

  3. VoIP Forensic Analyzer

    Directory of Open Access Journals (Sweden)

    M Mohemmed Sha

    2016-01-01

    Full Text Available People have been utilizing Voice over Internet Protocol (VoIP in most of the conventional communication facilities which has been of assistance in the enormous attenuation of operating costs, as well as the promotion of next- generation communication services-based IP. As an intimidating upshot, cyber criminals have correspondingly started interjecting the environment and creating new challenges for the law enforcement system in any Country. This paper presents an idea of a framework for the forensic analysis of the VoIP traffic over the network. This forensic activity includes spotting and scrutinizing the network patterns of VoIP-SIP stream, which is used to initiate a session for the communication, and regenerate the content from VoIP-RTP stream, which is employed to convey the data. Proposed network forensic investigation framework also accentuates on developing an efficient packet restructuring algorithm for tracing the depraved users involved in a conversation. Network forensics is the basis of proposed work, and performs packet level surveillance of VoIP followed by reconstruction of original malicious content or network session between users for their prosecution in the court.

  4. Performance tests of a satellite-based asymmetric communication network for the 'hyper hospital'.

    Science.gov (United States)

    Yamaguchi, T

    1997-01-01

    The Hyper Hospital is a prototype networked telemedicine system which uses virtual reality. We measured the performance of a novel multimedia network based on satellite communications. The network was a hybrid system consisting of a satellite channel in one direction and a terrestrial channel in the other. Each user was equipped with a standard satellite communication receiver and a telephone connection. Requests from the users were sent by modern and telephone line and responses were received by satellite. The user requests were initiated by clicking buttons on a World Wide Web browser screen. The transmission rates of satellite and normal telephone-line communications were compared for standardized text data. Satellite communication was three to five times faster. The transmission rate was also measured for standardized graphical data (GIF format). With a file size of about 400 kByte, satellite-mediated communication was 10 times faster than telephone lines. The effect of simultaneous access on performance was also explored. For simultaneous access of nine users to a single graphics file, 78% of the transmission speed was obtained in comparison with that of a single user. The satellite-based system showed excellent high-speed communication performance, particularly for multimedia data.

  5. Analysis of Handoff Mechanisms in Mobile IP

    Science.gov (United States)

    Jayaraj, Maria Nadine Simonel; Issac, Biju; Haldar, Manas Kumar

    2011-06-01

    One of the most important challenges in mobile Internet Protocol (IP) is to provide service for a mobile node to maintain its connectivity to network when it moves from one domain to another. IP is responsible for routing packets across network. The first major version of IP is the Internet Protocol version 4 (IPv4). It is one of the dominant protocols relevant to wireless network. Later a newer version of IP called the IPv6 was proposed. Mobile IPv6 is mainly introduced for the purpose of mobility. Mobility management enables network to locate roaming nodes in order to deliver packets and maintain connections with them when moving into new domains. Handoff occurs when a mobile node moves from one network to another. It is a key factor of mobility because a mobile node can trigger several handoffs during a session. This paper briefly explains on mobile IP and its handoff issues, along with the drawbacks of mobile IP.

  6. Evolution of the NOAA National Weather Service Satellite Broadcast Network (SBN) to Europe's DVB-S satellite communications technology standard

    Science.gov (United States)

    Cragg, Phil; Brockman, William E.

    2006-08-01

    The National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) uses a commercial Satellite Broadcast Network (SBN) to distribute weather data to the NWS AWIPS workstations and National Centers and to NWS Family of Service Users. Advances in science and technology from NOAA's observing systems, such as remote sensing satellites and NEXRAD radars, and advances in Numeric Weather Prediction have greatly increased the volume of data to be transmitted via the SBN. The NOAA-NWS SBN Evolution Program did a trade study resulting in the selection of Europe's DVB-S communication protocol as the basis for enabling a significant increase in the SBN capacity. The Digital Video Broadcast (DVB) group, started to develop digital TV for Europe through satellite broadcasting, has become the current standard for defining technology for satellite broadcasting of digital data for much of the world. NOAA-NWS implemented the DVB-S with inexpensive, Commercial Off The Shelf receiving equipment. The modernized NOAA-NWS SBN meets current performance goals and provides the basis for continued future expansion with no increase in current communication costs. This paper discusses aspects of the NOAA-NWS decision and the migration to the DVB-S standard for its commercial satellite broadcasts of observations and Numerical Weather Prediction data.

  7. 企业网内PSTN向VoIP演进的方案%The Evolution of PSTN to VoIP within Enterprise Network

    Institute of Scientific and Technical Information of China (English)

    张玲丽

    2014-01-01

    The cost of creating and maintaining PSTN network is high which especially can not adapt to the diverse needs of the business. Although it cannot be completely eliminated in its core online temporarily, the voice and other integrated services are the irreversible historical trend. IP-PBX technology combining with effective business software technology can realize the fusion of VoIP voice, data and value-added services;provide the basis of integrated service platform for the enterprises. It is also a priority for operators and equipment vendors to launch effective solutions.%PSTN建网和运维成本都较高,尤其不能适应目前业务的多样化需求,虽然在核心网上暂时无法完全淘汰,但语音及其他综合业务IP化是不可逆转的历史潮流。 IP-PBX技术结合行之有效的业务软件技术,实现了VoIP语音、数据和增值业务的融合,为企业用户提供综合业务的基础平台,推出行之有效的解决方案也是运营商和设备商的要务。

  8. Design and Implement of the Anonymous Communications in the Mobile IP Networks%移动IP中通信匿名技术的设计与实现

    Institute of Scientific and Technical Information of China (English)

    康凯; 郭伟; 吴诗其

    2002-01-01

    One of the key problems in the mobile communication is the anonymous communication. The mobile userwants to hide his real identifying information to the visiting domain and the public network which he does not trust,and prevent from being tracked and located. In this paper, we have discoursed the anonymous communications in themobile IP, and presented a novel strategy of the dynamic address allocation and the routing with anonymity. The sug-gested method enables any identifying information can be carried over the anonymous and secure connections, andprovide end-to-end security. The implements of the mobile host and the mobile subnet are also presented.

  9. IP Network QoS Implementation Technology Research%IP网络QoS实现技术的研究

    Institute of Scientific and Technical Information of China (English)

    任伟

    2011-01-01

    随着基于TCP/IP技术的Internet在世界范围的飞速发展和普及,Internet上传送的业务已由E—mail,FTP,WWW等数据业务为主向传送语音、视频、数据等综合业务过渡,如何向用户提供不同级别的端到端服务质量保证也是IPQoS需要解决的问题。%With the TCP/IP based Internet technology in the world of rapid development and popularization,Intemet business has been transmitted on the E-mail,FTP, WWW-based data services to transmit voice,video,data and other comprehensive transitional services how to provide users with different levels of quality of service is end to end IP QoS issues to be addressed.

  10. 网络存储新技术IP-SAN在数字图书馆中的应用%The Application of IP-SAN in Digital Library: A New Technique of Network Storage

    Institute of Scientific and Technical Information of China (English)

    杨子伍

    2006-01-01

    FC-SAN存在着传播距离有限、成本高、管理困难等不足,IP-SAN的出现解决了FC-SAN的不足.文章介绍了基于iSCSI协议的SAN架构,讨论了FC-SAN和IP-SAN的区别,分析了IP-SAN在图书馆存储建设中的优势.

  11. ChIPBase v2.0: decoding transcriptional regulatory networks of non-coding RNAs and protein-coding genes from ChIP-seq data.

    Science.gov (United States)

    Zhou, Ke-Ren; Liu, Shun; Sun, Wen-Ju; Zheng, Ling-Ling; Zhou, Hui; Yang, Jian-Hua; Qu, Liang-Hu

    2017-01-04

    The abnormal transcriptional regulation of non-coding RNAs (ncRNAs) and protein-coding genes (PCGs) is contributed to various biological processes and linked with human diseases, but the underlying mechanisms remain elusive. In this study, we developed ChIPBase v2.0 (http://rna.sysu.edu.cn/chipbase/) to explore the transcriptional regulatory networks of ncRNAs and PCGs. ChIPBase v2.0 has been expanded with ∼10 200 curated ChIP-seq datasets, which represent about 20 times expansion when comparing to the previous released version. We identified thousands of binding motif matrices and their binding sites from ChIP-seq data of DNA-binding proteins and predicted millions of transcriptional regulatory relationships between transcription factors (TFs) and genes. We constructed 'Regulator' module to predict hundreds of TFs and histone modifications that were involved in or affected transcription of ncRNAs and PCGs. Moreover, we built a web-based tool, Co-Expression, to explore the co-expression patterns between DNA-binding proteins and various types of genes by integrating the gene expression profiles of ∼10 000 tumor samples and ∼9100 normal tissues and cell lines. ChIPBase also provides a ChIP-Function tool and a genome browser to predict functions of diverse genes and visualize various ChIP-seq data. This study will greatly expand our understanding of the transcriptional regulations of ncRNAs and PCGs. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  12. TCP/IP Network In Process Control Plants%过程控制中的TCP/IP网络

    Institute of Scientific and Technical Information of China (English)

    牟连佳; 王立明

    2002-01-01

    提出TCP/IP在过程控制中的应用. 评价TCP/IP控制系统性能,通过传统控制系统与TCP/IP控制系统的比较,指出采用TCP/IP 控制系统的优缺点. 说明过程控制技术中,采用TCP/IP是一种更好的选择.

  13. Experimental Evaluation of the IP Address Space Randomisation (IASR) Technique and Its Disruption to Selected Network Services

    Science.gov (United States)

    2014-11-01

    attacker, thus reducing the security benefits of using IASR. In their IASR implementation, Dunlop et al. [13] avoided using the DNS . Each of their...server for it to function. We could have used a central DNS server for this experiment. However, to mitigate the potential security risks with the...central DNS , we opted for a lightweight host DNS . The host DNS poses less security risks than the central DNS in that it only contains IP addresses for

  14. Gateway Design between ZigBee Wireless Sensor Network and IP Network%ZigBee无线传感网络与IP网络的网关设计

    Institute of Scientific and Technical Information of China (English)

    朱剑锋; 熊志斌; 尹成国

    2011-01-01

    在ZigBee 协议栈和TCP/IP 协议栈的基础上,通过分析ZigBee 网络与IP 网络的ZigBee 网关的逻辑模型,根据ARP 协议提出了ZigBee 路由表控制层,实现了ZigBee 协议与TCP/IP 协议的转换.Zigbee网关使Zigbee 网络和IP 网络融为一体,实现了无线传感网与互联网的数字信息交互与共享.

  15. Qos and Voice Over IP

    Directory of Open Access Journals (Sweden)

    Adrian GHENCEA

    Full Text Available As Voice over Internet Protocol (VoIP technology matures, companies are increasingly adopting it to cut costs, improve efficiency and enhance customer service. Using the Internet as an existing network for integrating data and telecom systems through intelligent VoIP, a range of benefits results: lower long distance costs, cost cuts in cabling processes and more flexible telephony management. However, as voice over IP services grow in popularity, major threats arise: this rapid growth leads to traffic congestion, security is jeopardizedand the poor quality of calls affects communication. The objective of this article is to present all the elements that can affect voicequality in a VoIP network and to provide methods for solving them. A detailed analysis to minimize the impact of implementation of QoS will be made, and at the end solutions to management strategies will be proposed.

  16. UMR: A utility-maximizing routing algorithm for delay-sensitive service in LEO satellite networks

    Directory of Open Access Journals (Sweden)

    Lu Yong

    2015-04-01

    Full Text Available This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit (MS-LEO network endures unstable link connection and frequent link congestion due to the uneven user distribution and the link capacity variations. The proposed routing algorithm, referred to as the utility maximizing routing (UMR algorithm, improve the network utility of the MS-LEO network for carrying flows with strict end-to-end delay bound requirement. In UMR, first, a link state parameter is defined to capture the link reliability on continuing to keep the end-to-end delay into constraint; then, on the basis of this parameter, a routing metric is formulated and a routing scheme is designed for balancing the reliability in delay bound guarantee among paths and building a path maximizing the network utility expectation. While the UMR algorithm has many advantages, it may result in a higher blocking rate of new calls. This phenomenon is discussed and a weight factor is introduced into UMR to provide a flexible performance option for network operator. A set of simulations are conducted to verify the good performance of UMR, in terms of balancing the traffic distribution on inter-satellite links, reducing the flow interruption rate, and improving the network utility.

  17. Design Issues for Traffic Management for the ATM UBR + Service for TCP Over Satellite Networks

    Science.gov (United States)

    Jain, Raj

    1999-01-01

    This project was a comprehensive research program for developing techniques for improving the performance of Internet protocols over Asynchronous Transfer Mode (ATM) based satellite networks. Among the service categories provided by ATM networks, the most commonly used category for data traffic is the unspecified bit rate (UBR) service. UBR allows sources to send data into the network without any feedback control. The project resulted in the numerous ATM Forum contributions and papers.

  18. Internet-Protocol-Based Satellite Bus Architecture Designed

    Science.gov (United States)

    Slywczak, Richard A.

    2004-01-01

    NASA is designing future complex satellite missions ranging from single satellites and constellations to space networks and sensor webs. These missions require more interoperability, autonomy, and coordination than previous missions; in addition, a desire exists to have scientists retrieve data directly from the satellite rather than a central distribution source. To meet these goals, NASA has been studying the possibility of extending the Transmission Control Protocol/Internet Protocol (TCP/IP) suite for spacebased applications.

  19. 基于IPRAN技术的综合业务接入网建设探讨%The Construction of Integrated Access Network Based on IP RAN

    Institute of Scientific and Technical Information of China (English)

    陆培隽

    2012-01-01

    Construction of integrated access network is the inevitable trend of network development. The necessity and feature of IAN are described, several technical programs are discussed. Finally, some suggestions on the construction of IAN based on IP RAN are given.%建设综合业务接入网是网络发展的必然趋势。描述了综合业务接入网的必要性和特点,并就其中的几种技术方案进行了讨论。最后,对基于IPRAN技术的综合业务接入网建设提出了自己的建议。

  20. Research on TCP/IP computer network congestion control%对TCP/IP计算机网络拥塞控制的研究

    Institute of Scientific and Technical Information of China (English)

    余学杰

    2014-01-01

    为提升计算机的网络性能,更好地避免拥塞现象的发生,需要对其进行必要的技术控制。鉴于此,对基于TCP/IP协议的网络拥塞控制方法进行分析。在TCP拥塞控制中主要采用TCP Tahoe,TCP Reno,TCP New Reno以及TCP Sack四种方法,其中TCP New Reno对快速恢复算法进行了改进,通过对TCP协议中的Reno进行可视化处理,实行对网络拥塞的有效管理。而IP拥塞控制方法则分为FIFO,FQ和WFQ,RED以及ECN四种类型,通过队列调度管理方式实现了对网络拥塞的有效管理。%To enhance the performance of the computer network and avoid the occurrence of the congestion phenomenon,it is necessary to carry out the effective technical control. In view of this,the network congestion control methods based on TCP/IP protocol are analyzed. Four methods of TCP Tahoe,TCP Reno,TCP New Reno and TCP Sack are used for TCP congestion control;in which fast recovery algorithm was improved by means of TCP New Reno. The visualization processing can be per-formed through the Reno in TCP protocol to implement the effective management of network congestion. The IP congestion con-trol method can be divided into FIFO,FQ/WFQ,RED and ECN to realize the effective management of network congestion by queue scheduling management pattern.

  1. A Model for the Handover Traffic and Channel Occupancy Time in LEO Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    WangJingyu; YaoYongyang

    1995-01-01

    This paper presents a method to determine the parameters of the traffic model for the LEO satellite networks-the handover traffic and the mean channel occupancy time.The main idea is that the handover traffic is mainly due to the movement of the satellites and the velocity of the mobile terminals and earth rotation is ignored.The performance level can be calculated accord-ing to different handover queuing model.

  2. A Neural Network MLSE Receiver Based on Natural Gradient Descent: Application to Satellite Communications

    Directory of Open Access Journals (Sweden)

    Ibnkahla Mohamed

    2004-01-01

    Full Text Available The paper proposes a maximum likelihood sequence estimator (MLSE receiver for satellite communications. The satellite channel model is composed of a nonlinear traveling wave tube (TWT amplifier followed by a multipath propagation channel. The receiver is composed of a neural network channel estimator (NNCE and a Viterbi detector. The natural gradient (NG descent is used for training. Computer simulations show that the performance of our receiver is close to the ideal MLSE receiver in which the channel is perfectly known.

  3. Combined Geometric and Neural Network Approach to Generic Fault Diagnosis in Satellite Actuators and Sensors

    OpenAIRE

    Baldi, P.; Blanke, Mogens; P. Castaldi; Mimmo, N.; S. Simani

    2016-01-01

    This paper presents a novel scheme for diagnosis of faults affecting the sensors measuring the satellite attitude, body angular velocity and flywheel spin rates as well as defects related to the control torques provided by satellite reaction wheels. A nonlinear geometric design is used to avoid that aerodynamic disturbance torques have unwanted influence on the residuals exploited for fault detection and isolation. Radial basis function neural networks are used to obtain fault estimation filt...

  4. Opportunities for IP  in Communications Beyond 3G

    DEFF Research Database (Denmark)

    Nielsen, Thomas Toftegaard; Jacobsen, Rune H.

    2005-01-01

    Future communication will be based on TCP/IP as common network and transport layers to provide global connectivity to users and applications. IP is used to provide ubiquitous access across different access networks and exploits the benefits of a common connectivity layer while reducing the cost...... of operation and maintenance of the network. This paper discusses the opportunities for IP in the evolution towards a future broadband, all-IP mobile communication network. In particular, we argue for three opportunities for the future: Interworking access technologies over IP, IP layer transparency...

  5. A DISTRIBUTED QOS ROUTING BASED ON ANT ALGORITHM FOR LEO SATELLITE NETWORK

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Low Earth Orbit (LEO) satellites provide short round-trip delays and are becoming increasingly important. One of the challenges in LEO satellite networks is the development of specialized and efficient routing algorithms. To satisfy the QoS requirements of multimedia applications, satellite routing protocols should consider handovers and minimize their effect on the active connections. A distributed QoS routing scheme based on heuristic ant algorithm is proposed for satisfying delay bound and avoiding link congestion. Simulation results show that the call blocking probabilities of this algorithm are less than that of Shortest Path First (SPF) with different delay bound.

  6. Combined Geometric and Neural Network Approach to Generic Fault Diagnosis in Satellite Actuators and Sensors

    DEFF Research Database (Denmark)

    Baldi, P.; Blanke, Mogens; Castaldi, P.;

    2016-01-01

    This paper presents a novel scheme for diagnosis of faults affecting the sensors measuring the satellite attitude, body angular velocity and flywheel spin rates as well as defects related to the control torques provided by satellite reaction wheels. A nonlinear geometric design is used to avoid...... that aerodynamic disturbance torques have unwanted influence on the residuals exploited for fault detection and isolation. Radial basis function neural networks are used to obtain fault estimation filters that do not need a priori information about the fault internal models. Simulation results are based...... on a detailed nonlinear satellite model with embedded disturbance description. The results document the efficacy of the proposed diagnosis scheme....

  7. A COMBINED ADMISSION CONTROL ALGORITHM WITH DA PROTOCOL FOR SATELLITE ATM NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Lu Rong; Cao Zhigang

    2006-01-01

    Admission control is an important strategy for Quality of Service (QoS) provisioning in Asynchronous Transfer Mode (ATM) networks. Based on a control-theory model of resources on-Demand Allocation (DA) protocol, the paper studies the effect of the protocol on the statistical characteristics of network traffic,and proposes a combined connection admission control algorithm with the DA protocol to achieve full utilization of link resources in satellite communication systems. The proposed algorithm is based on the cross-layer-design approach. Theoretical analysis and system simulation results show that the proposed algorithm can admit more connections within certain admission thresholds than one that does not take into account the DA protocol. Thus, the proposed algorithm can increase admission ratio of traffic sources for satellite ATM networks and improve satellite link utilization.

  8. LEO 卫星通信网络的移动性管理%Mobility management in LEO satellite communication networks

    Institute of Scientific and Technical Information of China (English)

    贺达健; 游鹏; 雍少为

    2016-01-01

    近年来,低轨道(Low Earth Orbit,LEO)卫星通信网络以全球覆盖、低传输时延、低功耗链路、较强的抗毁性等特点而受到广泛关注,是未来全球移动通信系统的重要组成部分。移动性管理是构建 LEO 卫星通信网络的关键技术,为推动移动性管理问题的研究,文章从 LEO 卫星通信网络的结构和特点入手,阐述了 LEO 卫星通信网络中移动性管理的分类,并分析了其相比地面移动无线网络的特殊性。从链路层、网络层、传输层三个协议层次综述了近年来 LEO 卫星通信网络移动性管理研究的国内外现状,重点介绍了移动 IPv6(Mobile IPv6,MIPv6)和无缝 IP 分集通用移动性结构(Seamless IP-diversity based Generalized Mobility Architecture,SIGMA)在 LEO 卫星通信网络中的应用。最后,指出了移动性管理的发展趋势。%In recent years,low Earth orbit (LEO)satellite communication networks attract a lot of researchers'attention for its global coverage,short propagation delay,low-power links and great invulnerabi lity performance,etc. It wi ll be an important part of the future global mobi le communication systems.Mobi lity management is a key technology for enabling service in LEO satellite communication networks.The characteristics, research status and problems of mobi lity management were analyzed.Fi rstly,a brief classification of mobi lity management of LEO satellite communications networks was provided and characteristics distinguished from terrestrial mobi lity wi reless networks were analyzed based on the architecture and features of LEO satellite communication networks. Then the state-of-the-art mobi lity management schemes in LEO satellite communication networks were summarized from link layer,network layer and transport layer.A detai led description of the application of MIPv6 and SIGMA in LEO satellite envi ronment was given. Finally,some trends of mobi lity management of LEO satellite communications networks

  9. Internetworking with TCP/IP

    CERN Document Server

    Comer, Douglas E

    2014-01-01

    An internationally best-selling, conceptual introduction to the TCP/IP protocols and Internetworking, this book interweaves a clear discussion of fundamentals and scientific principles with details and examples drawn from the latest technologies. Leading author Douglas Comer covers layering and packet formats for all the Internet protocols, includingTCP, IPv4, IPv6, DHCP, and DNS. In addition, the text explains new trends in Internet systems, including packet classification, Software Defined Networking (SDN), and mesh protocols used in The Internet of Things. The text is appropriate for individuals interested in learning more about TCP/IP protocols, Internet architecture, and current networking technologies, as well as engineers who build network systems. It is suitable for junior to graduate-level courses in Computer Networks, Data Networks, Network Protocols, and Internetworking.

  10. Dynamic communications for small satellites using disruption tolerant network concepts

    NARCIS (Netherlands)

    Giuditta, N.; Gill, E.K.A.; Fernández, B.; Isaac, D.

    2009-01-01

    New network technologies are providing interconnectivity in areas previously unheard of. One of these novel technologies, named Disruption Tolerant Networking (DTN), shows promise for the space industry. In order to study its suitability for University projects, a model of a University space mission

  11. An Implementation of IP-Phone Gateway

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To implement voice service over packet-based network (Internet) and TDM-based network (PSTN Public Switched Telephone Network), an IP phone gateway is necessary to transform media stream and convert signaling protocols used over both the two networks. In this article, the architecture of the IP-Phone gateway is described firstly. Then the communications mechanism between functional blocks and multi-thread consideration are presented.

  12. Chinese Surveying and Control Network for Earth-Orbit Satellites and Deep Space Detection

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The relationship between the surveying and control network(CSN) for earth-orbit satellite and spatial geodesy, and the relationship between the CSN for deep space celestial bodies and detectors, and deep space detection are briefly summarized, and so are the basic technical needs of the deep space surveying and control network(DSN). Then, the techniques, the constituents and the distributing of Chinese satellite CSN (CSCSN) and other radio observing establishments in China are introduced. Lastly, with the primary CSCSN and other observing establishments, some projects for China to rebuild a more perfect CSCSN, and to establish a DSN are analyzed and stated.

  13. Performance Analysis of Integrated Wireless Sensor and Multibeam Satellite Networks Under Terrestrial Interference

    Directory of Open Access Journals (Sweden)

    Hongjun Li

    2016-10-01

    Full Text Available This paper investigates the performance of integrated wireless sensor and multibeam satellite networks (IWSMSNs under terrestrial interference. The IWSMSNs constitute sensor nodes (SNs, satellite sinks (SSs, multibeam satellite and remote monitoring hosts (RMHs. The multibeam satellite covers multiple beams and multiple SSs in each beam. The SSs can be directly used as SNs to transmit sensing data to RMHs via the satellite, and they can also be used to collect the sensing data from other SNs to transmit to the RMHs. We propose the hybrid one-dimensional (1D and 2D beam models including the equivalent intra-beam interference factor β from terrestrial communication networks (TCNs and the equivalent inter-beam interference factor α from adjacent beams. The terrestrial interference is possibly due to the signals from the TCNs or the signals of sinks being transmitted to other satellite networks. The closed-form approximations of capacity per beam are derived for the return link of IWSMSNs under terrestrial interference by using the Haar approximations where the IWSMSNs experience the Rician fading channel. The optimal joint decoding capacity can be considered as the upper bound where all of the SSs’ signals can be jointly decoded by a super-receiver on board the multibeam satellite or a gateway station that knows all of the code books. While the linear minimum mean square error (MMSE capacity is where all of the signals of SSs are decoded singularly by a multibeam satellite or a gateway station. The simulations show that the optimal capacities are obviously higher than the MMSE capacities under the same conditions, while the capacities are lowered by Rician fading and converge as the Rician factor increases. α and β jointly affect the performance of hybrid 1D and 2D beam models, and the number of SSs also contributes different effects on the optimal capacity and MMSE capacity of the IWSMSNs.

  14. Performance Analysis of Integrated Wireless Sensor and Multibeam Satellite Networks Under Terrestrial Interference.

    Science.gov (United States)

    Li, Hongjun; Yin, Hao; Gong, Xiangwu; Dong, Feihong; Ren, Baoquan; He, Yuanzhi; Wang, Jingchao

    2016-10-14

    This paper investigates the performance of integrated wireless sensor and multibeam satellite networks (IWSMSNs) under terrestrial interference. The IWSMSNs constitute sensor nodes (SNs), satellite sinks (SSs), multibeam satellite and remote monitoring hosts (RMHs). The multibeam satellite covers multiple beams and multiple SSs in each beam. The SSs can be directly used as SNs to transmit sensing data to RMHs via the satellite, and they can also be used to collect the sensing data from other SNs to transmit to the RMHs. We propose the hybrid one-dimensional (1D) and 2D beam models including the equivalent intra-beam interference factor β from terrestrial communication networks (TCNs) and the equivalent inter-beam interference factor α from adjacent beams. The terrestrial interference is possibly due to the signals from the TCNs or the signals of sinks being transmitted to other satellite networks. The closed-form approximations of capacity per beam are derived for the return link of IWSMSNs under terrestrial interference by using the Haar approximations where the IWSMSNs experience the Rician fading channel. The optimal joint decoding capacity can be considered as the upper bound where all of the SSs' signals can be jointly decoded by a super-receiver on board the multibeam satellite or a gateway station that knows all of the code books. While the linear minimum mean square error (MMSE) capacity is where all of the signals of SSs are decoded singularly by a multibeam satellite or a gateway station. The simulations show that the optimal capacities are obviously higher than the MMSE capacities under the same conditions, while the capacities are lowered by Rician fading and converge as the Rician factor increases. α and β jointly affect the performance of hybrid 1D and 2D beam models, and the number of SSs also contributes different effects on the optimal capacity and MMSE capacity of the IWSMSNs.

  15. Interconnection Schemes of VoIP Service and Existing Common Network via HFC Network%HFC网络开展VoIP业务与现有公用网络互联的方案

    Institute of Scientific and Technical Information of China (English)

    王坚

    2005-01-01

    利用HFC网络开展VoIP业务所面临的首要问题是如何与现有公用网络互联互通.为此介绍了三个参考方案:本地汇聚方案、CPN(Customer Premise Network,用户驻地网)+IP,CPN+PSTN(Public Switched Telephone Network,公共交换电话网)方案,并对其进行了分析比较,提出了解决方案.

  16. TCP/IP foundations

    CERN Document Server

    Blank, Andrew G

    2006-01-01

    The world of IT is always evolving, but in every area there are stable, core concepts that anyone just setting out needed to know last year, needs to know this year, and will still need to know next year. The purpose of the Foundations series is to identify these concepts and present them in a way that gives you the strongest possible starting point, no matter what your endeavor. TCP/IP Foundations provides essential knowledge about the two protocols that form the basis for the Internet, as well as many other networks. What you learn here will benefit you in the short term, as you acquire and

  17. IP Address Management Principles and Practice

    CERN Document Server

    Rooney, Timothy

    2010-01-01

    This book will be the first covering the subject of IP address management (IPAM). The practice of IPAM includes the application of network management disciplines to IP address space and associated network services, namely DHCP (Dynamic Host Configuration Protocol) and DNS (Domain Name System). The consequence of inaccurately configuring DHCP is that end users may not be able to obtain IP addresses to access the network. Without proper DNS configuration, usability of the network will greatly suffer as the name-to-address lookup process may fail. Imagine having to navigate to a website or send a

  18. Requirements analysis and design for implementation of a satellite link for a local area computer network

    OpenAIRE

    Lorentzen, Richard B.

    1991-01-01

    Approved for public release; distribution is unlimited The purpose of this thesis is to provide naval computer students with a basic knowledge on Very Small Aperture Terminal (VSAT) satellite technology and to define the hardware and software requirements at the interface between a VSAT and a Local Area Network (LAN). By restricting a computer network to terrestrial links, a vast amount of knowledge is not accessed because either the terrestrial links can't access the information or the...

  19. Mapping mammalian cell-type-specific transcriptional regulatory networks using KD-CAGE and ChIP-seq data in the TC-YIK cell line.

    Directory of Open Access Journals (Sweden)

    Marina eLizio

    2015-11-01

    Full Text Available Mammals are composed of hundreds of different cell types with specialized functions. Each of these cellular phenotypes are controlled by different combinations of transcription factors. Using a human non islet cell insulinoma cell line (TC-YIK which expresses insulin and the majority of known pancreatic beta cell specific genes as an example, we describe a general approach to identify key cell-type-specific transcription factors (TFs and their direct and indirect targets. By ranking all human TFs by their level of enriched expression in TC-YIK relative to a broad collection of samples (FANTOM5, we confirmed known key regulators of pancreatic function and development. Systematic siRNA mediated perturbation of these TFs followed by qRT-PCR revealed their interconnections with NEUROD1 at the top of the regulation hierarchy and its depletion drastically reducing insulin levels. For 15 of the TF knock-downs (KD, we then used Cap Analysis of Gene Expression (CAGE to identify thousands of their targets genome-wide (KD-CAGE. The data confirm NEUROD1 as a key positive regulator in the transcriptional regulatory network (TRN, and ISL1 and PROX1 as antagonists. As a complimentary approach we used ChIP-seq on four of these factors to identify NEUROD1, LMX1A, PAX6 and RFX6 binding sites in the human genome. Examining the overlap between genes perturbed in the KD-CAGE experiments and genes with a ChIP-seq peak within 1kb of their promoter, we identified direct transcriptional targets of these TFs. Integration of KD-CAGE and ChIP-seq data shows that both NEUROD1 and LMX1A work as the main transcriptional activators. In the core TRN (i.e. TF-TF only, NEUROD1 directly transcriptionally activates the pancreatic TFs HSF4, INSM1, MLXIPL, MYT1, NKX6-3, ONECUT2, PAX4, PROX1, RFX6, ST18, DACH1 and SHOX2, while LMX1A directly transcriptionally activates DACH1, SHOX2, PAX6 and PDX1. Analysis of these complementary datasets suggests the need for caution in interpreting

  20. Mapping Mammalian Cell-type-specific Transcriptional Regulatory Networks Using KD-CAGE and ChIP-seq Data in the TC-YIK Cell Line.

    Science.gov (United States)

    Lizio, Marina; Ishizu, Yuri; Itoh, Masayoshi; Lassmann, Timo; Hasegawa, Akira; Kubosaki, Atsutaka; Severin, Jessica; Kawaji, Hideya; Nakamura, Yukio; Suzuki, Harukazu; Hayashizaki, Yoshihide; Carninci, Piero; Forrest, Alistair R R

    2015-01-01

    Mammals are composed of hundreds of different cell types with specialized functions. Each of these cellular phenotypes are controlled by different combinations of transcription factors. Using a human non islet cell insulinoma cell line (TC-YIK) which expresses insulin and the majority of known pancreatic beta cell specific genes as an example, we describe a general approach to identify key cell-type-specific transcription factors (TFs) and their direct and indirect targets. By ranking all human TFs by their level of enriched expression in TC-YIK relative to a broad collection of samples (FANTOM5), we confirmed known key regulators of pancreatic function and development. Systematic siRNA mediated perturbation of these TFs followed by qRT-PCR revealed their interconnections with NEUROD1 at the top of the regulation hierarchy and its depletion drastically reducing insulin levels. For 15 of the TF knock-downs (KD), we then used Cap Analysis of Gene Expression (CAGE) to identify thousands of their targets genome-wide (KD-CAGE). The data confirm NEUROD1 as a key positive regulator in the transcriptional regulatory network (TRN), and ISL1, and PROX1 as antagonists. As a complimentary approach we used ChIP-seq on four of these factors to identify NEUROD1, LMX1A, PAX6, and RFX6 binding sites in the human genome. Examining the overlap between genes perturbed in the KD-CAGE experiments and genes with a ChIP-seq peak within 50 kb of their promoter, we identified direct transcriptional targets of these TFs. Integration of KD-CAGE and ChIP-seq data shows that both NEUROD1 and LMX1A work as the main transcriptional activators. In the core TRN (i.e., TF-TF only), NEUROD1 directly transcriptionally activates the pancreatic TFs HSF4, INSM1, MLXIPL, MYT1, NKX6-3, ONECUT2, PAX4, PROX1, RFX6, ST18, DACH1, and SHOX2, while LMX1A directly transcriptionally activates DACH1, SHOX2, PAX6, and PDX1. Analysis of these complementary datasets suggests the need for caution in interpreting ChIP

  1. Continuously Connected With Mobile IP

    Science.gov (United States)

    2002-01-01

    Cisco Systems developed Cisco Mobile Networks, making IP devices mobile. With this innovation, a Cisco router and its connected IP devices can roam across network boundaries and connection types. Because a mobile user is able to keep the same IP address while roaming, a live IP connection can be maintained without interruption. Glenn Research Center jointly tested the technology with Cisco, and is working to use it on low-earth-orbiting research craft. With Cisco's Mobile Networks functionality now available in Cisco IOS Software release 12.2(4)T, the commercial advantages and benefits are numerous. The technology can be applied to public safety, military/homeland security, emergency management services, railroad and shipping systems, and the automotive industry. It will allow ambulances, police, firemen, and the U.S. Coast Guard to stay connected to their networks while on the move. In the wireless battlefield, the technology will provide rapid infrastructure deployment for U.S. national defense. Airline, train, and cruise passengers utilizing Cisco Mobile Networks can fly all around the world with a continuous Internet connection. Cisco IOS(R) Software is a registered trademark of Cisco Systems.

  2. Protocol Support for a New Satellite-Based Airspace Communication Network

    Science.gov (United States)

    Shang, Yadong; Hadjitheodosiou, Michael; Baras, John

    2004-01-01

    We recommend suitable transport protocols for an aeronautical network supporting Internet and data services via satellite. We study the characteristics of an aeronautical satellite hybrid network and focus on the problems that cause dramatically degraded performance of the Transport Protocol. We discuss various extensions to standard TCP that alleviate some of these performance problems. Through simulation, we identify those TCP implementations that can be expected to perform well. Based on the observation that it is difficult for an end-to-end solution to solve these problems effectively, we propose a new TCP-splitting protocol, termed Aeronautical Transport Control Protocol (AeroTCP). The main idea of this protocol is to use a fixed window for flow control and one duplicated acknowledgement (ACK) for fast recovery. Our simulation results show that AeroTCP can maintain higher utilization for the satellite link than end-to-end TCP, especially in high BER environment.

  3. A Handover Strategy in the LEO Satellite-Based Constellation Networks with ISLs

    Institute of Scientific and Technical Information of China (English)

    LIU Gang; GOU Dingyong; WU Shiqi

    2003-01-01

    A new handover strategy named minimal-hops handover(MHH) strategy for the low earth orbit(LEO) satellite constellations networks equipped with inter-satellite links(ISLs) is proposed.MHH strategy, which is based on the hops of the end-to-end connection paths and makes good use of the regularity of the constellation network topology, can appropriately combine the handover procedure with routing and efficiently solve the inter-satellite handover issue. Moreover, MHH strategy can provide quality of services( QoS) guarantees to some extent. The system performances of the MHH strategy, such as time propagation delay and handover frequency, are evaluated and compared with that of other previous strategies. The simulation results show that MHH strategy performs better than other previous handover strategies.

  4. How does the all-IP application change the fundamentals of the transport networks and product architecture?

    Science.gov (United States)

    Pan, Jin-Yi; Jing, Enhui; Cui, Xiaolong

    2007-11-01

    Initially deployed for voice service, Sonet/SDH has played a major role in today's service provider networks. In the past 10 years, the next generation SDH has become a robust platform solution to transport voice, video, and data. However, with the fundamental technology yet based on TDM, existing equipment architectures can not scale sufficiently to meet the tremendous data demands in future. Furthermore, as the number of network nodes increases, provisioning and managing these network nodes is becoming increasingly complicated. The evolution of optical transport networks poses challenges to service providers on how to support existing TDM services, while addressing the rapid growth of data services, such as triple play and Ethernet virtual private networks (VPNs), etc. To remain competence, carriers are looking for ways to cut Capex and Opex while delivering new revenue generating and profitable services.At the same time, this evolution is a challenge to equipment suppliers as well. Transport tend to integrate TDM and packet services seamlessly, which enables network element to deliver carrier-class, standardized and packet optimized services. In this paper, three technical solutions for transport node will be introduced, and their cost, functions, advantages and disadvantages will be compared as well.

  5. The performance evaluation of a new neural network based traffic management scheme for a satellite communication network

    Science.gov (United States)

    Ansari, Nirwan; Liu, Dequan

    1991-01-01

    A neural-network-based traffic management scheme for a satellite communication network is described. The scheme consists of two levels of management. The front end of the scheme is a derivation of Kohonen's self-organization model to configure maps for the satellite communication network dynamically. The model consists of three stages. The first stage is the pattern recognition task, in which an exemplar map that best meets the current network requirements is selected. The second stage is the analysis of the discrepancy between the chosen exemplar map and the state of the network, and the adaptive modification of the chosen exemplar map to conform closely to the network requirement (input data pattern) by means of Kohonen's self-organization. On the basis of certain performance criteria, whether a new map is generated to replace the original chosen map is decided in the third stage. A state-dependent routing algorithm, which arranges the incoming call to some proper path, is used to make the network more efficient and to lower the call block rate. Simulation results demonstrate that the scheme, which combines self-organization and the state-dependent routing mechanism, provides better performance in terms of call block rate than schemes that only have either the self-organization mechanism or the routing mechanism.

  6. The method of the antenna system positioning for satellite communication network radiomonitoring complex

    OpenAIRE

    Гребенюк, Олег Петрович

    2014-01-01

    The method of orientation of the antenna system of complex of radiomonitoring of satellite communication networks is offered. A method takes into account the features of construction and functional setting of a transport stream of standard of DVB ‑ S.

  7. TOLNet - A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Science.gov (United States)

    Newchurch, Michael J.; Kuang, Shi; Wang, Lihua; LeBlanc, Thierry; Alvarez II, Raul J.; Langford, Andrew O.; Senff, Christoph J.; Brown, Steve; Johnson, Bryan; Burris, John F.; hide

    2015-01-01

    NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly time-resolved (few minutes) tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation.

  8. Geometric Aspects of Ground Augmentation of Satellite Networks for the Needs of Deformation Monitoring

    Science.gov (United States)

    Protaziuk, Elżbieta

    2016-06-01

    Satellite measurements become competitive in many tasks of engineering surveys, however, in many requiring applications possibilities to apply such solutions are still limited. The possibility to widely apply satellite technologies for displacements measurements is related with new challenges; the most important of them relate to increasing requirements concerning the accuracy, reliability and continuity of results of position determination. One of the solutions is a ground augmentation of satellite network, which intention is to improve precision of positioning, ensure comparable accuracy of coordinates and reduce precision fluctuations over time. The need for augmentation of GNSS is particularly significant in situations: where the visibility of satellites is poor because of terrain obstacles, when the determined position is not precise enough or a satellites constellation does not allow for reliable positioning. Ground based source/sources of satellite signal placed at a ground, called pseudosatellites, or pseudolites were intensively investigated during the last two decades and finally were developed into groundbased, time-synchronized transceivers, that can transmit and receive a proprietary positioning signal. The paper presents geometric aspects of the ground based augmentation of the satellite networks using various quality measures of positioning geometry, which depends on access to the constellation of satellites and the conditions of the observation environment. The issue of minimizing these measures is the key problem that allows to obtain the position with high accuracy. For this purpose, the use of an error ellipsoid is proposed and compared with an error ellipse. The paper also describes the results of preliminary accuracy analysis obtained at test area and a comparison of various measures of the quality of positioning geometry.

  9. Scheduling mechanisms for VoIP in mobile WiMAX networks%移动WiMAX网络中的VoIP调度机制

    Institute of Scientific and Technical Information of China (English)

    李明; 吴燕玲; 杨雷; 韩清涛

    2011-01-01

    移动微波存取全球互通(WiMAX)网络使用了5种调度机制来保证服务质量,其中的3种被设计用于实时性业务.但是,这3种调度机制都缺乏公平性.在资源不足的时候,通过丢弃新用户的请求来保证旧用户的服务质量(QoS).为此,针对WiMAX中的因特网语音(VoIP)服务提出了一种基于优先权的新调度机制.该机制中,不同用户的业务请求将被赋予不同的优先权.新旧用户同时请求资源时,新用户的请求拥有更高的优先权;资源分配中心再根据优先权的高低为用户分配资源,从而在最大限度上保证了资源分配的公平性.仿真结果显示,新调度机制可以将网络中的因特网语音服务的连接数和总吞吐量分别提高15%和11%左右.%Five scheduling mechanisms have been proposed to ensure Quality of Service (QoS) in WiMAX network.Three of them are designed for real-time applications. However, fairness has not been considered while assigning resources in these scheduling mechanisms. In order to guarantee the existing services, new service requests will be rejected when lacking network resources. For resolving this problem, a new scheduling mechanism was proposed for Voice over Internet Protocol (VoIP) service, in which a Priority Decision Maker (PDM) was implanted. When new services and the existing services requested resources simultaneously, higher priority would be assigned to new service requests; and resource allocation would be achieved based on different level priorities by a resource distribution center for guaranteeing fairness. Detailed performance analysis was performed. The simulation results show the proposed scheduling mechanism could significantly increase number of VoIP connections and total throughput, about 15% and 11% respectively.

  10. IP network TV streaming media processing technology%IP网络电视中流媒体处理技术的应用

    Institute of Scientific and Technical Information of China (English)

    孙飞艳

    2011-01-01

    随着网络信息技术的迅速发展,多媒体应用逐步涉及到教育、娱乐等领域,流媒体技术在网络电视系统中得到广泛应用。本文主要从多种格式媒体的输入支持、传输流安全保障以及传输流软件复用处理等角度对IP网络电视中流媒体处理技术进行全面阐述。%With the rapid development of information technology, networks, multimedia applications and gradually comes to education, entertainment and other fields, streaming media technology in the network television system has been widely used. In this paper, the input from a variety of media formats supported, traffic safety and transport stream processing software reuse point of view of IP network TV streaming media processing technologies for a comprehensive exposition.

  11. Neural network based satellite tracking for deep space applications

    Science.gov (United States)

    Amoozegar, F.; Ruggier, C.

    2003-01-01

    The objective of this paper is to provide a survey of neural network trends as applied to the tracking of spacecrafts in deep space at Ka-band under various weather conditions and examine the trade-off between tracing accuracy and communication link performance.

  12. A Conjoint Analysis of Voice Over IP Attributes.

    Science.gov (United States)

    Zubey, Michael L.; Wagner, William; Otto, James R.

    2002-01-01

    Managers need to understand the tradeoffs associated with voice over Internet protocol (VoIP) networks as compared to the Public Switched Telephone Network (PSTN). This article measures the preference structures between IP telephony and PSTN services using conjoint analysis. The purpose is to suggest VoIP technology attributes that best meet…

  13. A gradual neural-network approach for frequency assignment in satellite communication systems.

    Science.gov (United States)

    Funabiki, N; Nishikawa, S

    1997-01-01

    A novel neural-network approach called gradual neural network (GNN) is presented for a class of combinatorial optimization problems of requiring the constraint satisfaction and the goal function optimization simultaneously. The frequency assignment problem in the satellite communication system is efficiently solved by GNN as the typical problem of this class. The goal of this NP-complete problem is to minimize the cochannel interference between satellite communication systems by rearranging the frequency assignment so that they can accommodate the increasing demands. The GNN consists of NxM binary neurons for the N-carrier-M-segment system with the gradual expansion scheme of activated neurons. The binary neural network achieves the constrain satisfaction with the help of heuristic methods, whereas the gradual expansion scheme seeks the cost optimization. The capability of GNN is demonstrated through solving 15 instances in practical size systems, where GNN can find far better solutions than the existing algorithm.

  14. Introduction to IP address management

    CERN Document Server

    Rooney, Tim

    2010-01-01

    "The book begins with a basic overview of IP networking, followed by chapters describing each of the three core IPAM technologies: IPv4 and IPv6 addressing, DHCP, and DNS. The next three chapters describe IPAM management techniques and practice, followed by chapters on IPv4-IPv6 co-existence, security and the IPAM business case"--

  15. Networked Operations of Hybrid Radio Optical Communications Satellites

    Science.gov (United States)

    Hylton, Alan; Raible, Daniel

    2014-01-01

    In order to address the increasing communications needs of modern equipment in space, and to address the increasing number of objects in space, NASA is demonstrating the potential capability of optical communications for both deep space and near-Earth applications. The Integrated Radio Optical Communications (iROC) is a hybrid communications system that capitalizes on the best of both the optical and RF domains while using each technology to compensate for the other's shortcomings. Specifically, the data rates of the optical links can be higher than their RF counterparts, whereas the RF links have greater link availability. The focus of this paper is twofold: to consider the operations of one or more iROC nodes from a networking point of view, and to suggest specific areas of research to further the field. We consider the utility of Disruption Tolerant Networking (DTN) and the Virtual Mission Operation Center (VMOC) model.

  16. Energy-Saving Routing Algorithm for Multiple Jump Grooming in IP over WDM Network based on Traffic%基于流量的IP OVER WDM 网络多跳疏导节能路由算法设计

    Institute of Scientific and Technical Information of China (English)

    邢移单

    2015-01-01

    The demand for decrease of network energy consumption and improvement of energy efficiency makes the green IP over WDM network a research hotspot in the area of optical communication network. For the purpose to reduce the network energy consumption and ensure the network performance for the traf-fic load, the hierarchical integrated auxiliary graph model is established, and the saving energy multiple jump grooming ( OMJG) routing algorithm for the optical layer node optimization configuration of IP over WDM network designed and simulated, Simulation and comparison with the shortest path first algorithm ( Dijkstra) inidcate that the OMJG algorithm is clearly superior to the traditional Dijkstra algorithm in total energy consumption and service request blocking probability of the netwok.%降低网络能耗和提高能量利用率的需求,使绿色IP over WDM网络成为光网络领域的研究热点。针对流量业务,以降低网络能耗和保证网络性能为优化目标,建立了分层集成辅助图模型,根据多跳疏导机制设计了IP over WDM 网络光层节点优化配置下的节能多跳疏导( Optical Multiple Jump Grooming,OMJG)路由算法,进行了仿真,并与最短路径优先算法( Dijkstra)进行了比较。结果表明:在网络总能耗和业务请求阻塞率方面,设计的OMJG算法均优于传统的Dijkstra算法。

  17. Deployment of VoIP Technology: QoS Concerns

    OpenAIRE

    Lazzez, Amor; Slimani, Thabet

    2013-01-01

    Voice over IP (VoIP) is an emerging communication service allowing voice transmission over a private or a public IP network. VoIP allows significant benefits for customers and service providers including cost savings, phone and service portability, mobility, and the integration with other applications. Nevertheless, the deployment of the VoIP technology encounters many challenges such as interoperability issues, security issues, and QoS concerns. Among these disadvantages, QoS issues are cons...

  18. Amazon Rainforest Deforestation Daily Detection Tool Using Artificial Neural Networks and Satellite Images

    Directory of Open Access Journals (Sweden)

    Silvio César Cazella

    2012-10-01

    Full Text Available The main purpose of this work was the development of a tool to detect daily deforestation in the Amazon rainforest, using satellite images from the MODIS/TERRA [1] sensor and Artificial Neural Networks. The developed tool provides the parameterization of the configuration for the neural network training to enable us to find the best neural architecture to address the problem. The tool makes use of confusion matrixes to determine the degree of success of the network. Part of the municipality of Porto Velho, in Rondônia state, is located inside the tile H11V09 of the MODIS/TERRA sensor, which was used as the study area. A spectrum-temporal analysis of this area was made on 57 images from 20 of May to 15 of July 2003 using the trained neural network. This analysis allowed us to verify the quality of the implemented neural network classification as well as helping our understanding of the dynamics of deforestation in the Amazon rainforest. The great potential of neural networks for image classification was perceived with this work. However, the generation of consistent alarms, in other words, detecting predatory actions at the beginning; instead of firing false alarms is a complex task that has not yet been solved. Therefore, the major contribution of this paper is to provide a theoretical basis and practical use of neural networks and satellite images to combat illegal deforestation.

  19. Research on handover algorithm to reduce the blocking probability in LEO satellite network

    Institute of Scientific and Technical Information of China (English)

    Chen Bingcai; Zhang Naitong; Nie Boxun; Zhou Tingxian

    2006-01-01

    Based on the characteristics of guaranteed handover (GH) algorithm, the finite capacity in one system makes the blocking probability (PB) of GH algorithm increase rapidly in the case of high traffic load. So, when large amounts of multimedia services are transmitted via a single low earth orbit (LEO) satellite system, the PB of it is much higher. In order to solve the problem, a novel handover scheme defined by multi-tier optiral layer selection is proposed. The scheme sufficienfly takes into ac count the characteristics of double-tier satellite network, which is constituted by LEO satellites combined with medium earth orbit (MEO) satellites, and the multimedia transmitted by such network, so it can augment this systematic capacity and effectively reduces the traffic load in the LEO which performs GH algorithm. The detailed processes are also presented. The simulation and numerical results show that the approach integrated with GH algorithm achieves a significant improvement in the PB and practicability, as compared to the single LEO layer network.

  20. TOLNET – A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Directory of Open Access Journals (Sweden)

    Newchurch Michael J.

    2016-01-01

    Full Text Available Ozone lidars measure continuous, high-resolution ozone profiles critical for process studies and for satellite validation in the lower troposphere. However, the effectiveness of lidar validation by using single-station data is limited. Recently, NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly timeresolved (few minutes tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation. This article briefly describes the concept, stations, major specifications of the TOLNet instruments, and data archiving.

  1. Diversity reception for advanced multi-satellite networks: A CDMA approach

    Science.gov (United States)

    Colzi, E.; Degaudenzi, R.; Elia, C.; Giannetti, F.; Viola, R.

    1993-01-01

    Diversity reception for Synchronous CDMA (S-CDMA) is introduced and analyzed. A Gaussian co-channel synchronous and asynchronous interference approximation is derived to evaluate the effects on the system bit error rate. Numerical results are provided for a simple mobile communication system where the signals transmitted by two distinct satellites in visibility are coherently combined by a three fingers Rake receiver. A second example showing performance of an integrated ground/satellite single frequency network for digital audio broadcasting is presented. Results show the capacity advantage of utilizing S-CDMA in combination with diversity reception.

  2. Satellite image processing for precision agriculture and agroindustry using convolutional neural network and genetic algorithm

    Science.gov (United States)

    Firdaus; Arkeman, Y.; Buono, A.; Hermadi, I.

    2017-01-01

    Translating satellite imagery to a useful data for decision making during this time are usually done manually by human. In this research, we are going to translate satellite imagery by using artificial intelligence method specifically using convolutional neural network and genetic algorithm to become a useful data for decision making, especially for precision agriculture and agroindustry. In this research, we are focused on how to made a sustainable land use planning with 3 objectives. The first is maximizing economic factor. Second is minimizing CO2 emission and the last is minimizing land degradation. Results show that by using artificial intelligence method, can produced a good pareto optimum solutions in a short time.

  3. Diversity reception for advanced multi-satellite networks: A CDMA approach

    Science.gov (United States)

    Colzi, E.; Degaudenzi, R.; Elia, C.; Giannetti, F.; Viola, R.

    Diversity reception for Synchronous CDMA (S-CDMA) is introduced and analyzed. A Gaussian co-channel synchronous and asynchronous interference approximation is derived to evaluate the effects on the system bit error rate. Numerical results are provided for a simple mobile communication system where the signals transmitted by two distinct satellites in visibility are coherently combined by a three fingers Rake receiver. A second example showing performance of an integrated ground/satellite single frequency network for digital audio broadcasting is presented. Results show the capacity advantage of utilizing S-CDMA in combination with diversity reception.

  4. Satellite Radar Interferometry For Risk Management Of Gas Pipeline Networks

    Science.gov (United States)

    Ianoschi, Raluca; Schouten, Mathijs; Bas Leezenberg, Pieter; Dheenathayalan, Prabu; Hanssen, Ramon

    2013-12-01

    InSAR time series analyses can be fine-tuned for specific applications, yielding a potential increase in benchmark density, precision and reliability. Here we demonstrate the algorithms developed for gas pipeline monitoring, enabling operators to precisely pinpoint unstable locations. This helps asset management in planning, prioritizing and focusing in-situ inspections, thus reducing maintenance costs. In unconsolidated Quaternary soils, ground settlement contributes to possible failure of brittle cast iron gas pipes and their connections to houses. Other risk factors include the age and material of the pipe. The soil dynamics have led to a catastrophic explosion in the city of Amsterdam, which triggered an increased awareness for the significance of this problem. As the extent of the networks can be very wide, InSAR is shown to be a valuable source of information for identifying the hazard regions. We monitor subsidence affecting an urban gas transportation network in the Netherlands using both medium and high resolution SAR data. Results for the 2003-2010 period provide clear insights on the differential subsidence rates in the area. This enables characterization of underground motion that affects the integrity of the pipeline. High resolution SAR data add extra detail of door-to-door pipeline connections, which are vulnerable due to different settlements between house connections and main pipelines. The rates which we measure represent important input in planning of maintenance works. Managers can decide the priority and timing for inspecting the pipelines. The service helps manage the risk and reduce operational cost in gas transportation networks.

  5. ChinaNet向SDN演进的方法探索%Study on IP RAN Technique Evolution and Network Construction

    Institute of Scientific and Technical Information of China (English)

    王素彬; 郭亮

    2013-01-01

    中国电信的ChinaNet是全球最大的Internet之一,承载着全球最大的流量,并且长期呈高速增长,今后也将继续保持高增长态势.超大流量的Internet可持续发展和网络每比特承载成本的降低,是两个关键的问题.从这两个方面出发,利用集中控制的技术优势,探索如何将ChinaNet逐步迁移到SDN,并利用集中控制技术解决ChinaNet面临的问题.%China Telecom's ChinaNet is one of the largest networks in the world,carrying the world's largest traffic.The network's traffic has increased dramatically for several years by about 50% per year,and will continually increase in the future.How to deal with the sustainable development of the network and cut down expansion cost are key issues.Gradual evolution of ChinaNet to SDN was focused on.Thanks to centralized control technology,some of the issues faced by ChinaNet would be solved at the same time.

  6. Extraction of DTM from Satellite Images Using Neural Networks

    OpenAIRE

    Tapper, Gustav

    2016-01-01

    This thesis presents a way to generate a Digital Terrain Model (dtm) from a Digital Surface Model (dsm) and multi spectral images (including the Near Infrared (nir) color band). An Artificial Neural Network (ann) is used to pre-classify the dsm and multi spectral images. This in turn is used to filter the dsm to a dtm. The use of an ann as a classifier provided good results. Additionally, the addition of the nir color band resulted in an improvement of the accuracy of the classifier. Using th...

  7. Load-Aware Radio Access Selection in Future Generation Satellite-Terrestrial Wireless Networks

    Directory of Open Access Journals (Sweden)

    M. Ali

    2012-03-01

    Full Text Available In the telecommunication networks the introduction of Next Generation Wireless Networks (NGWN has been described as the most significant change in wireless communication. The convergence of different access networks in NGWN allows generalized mobility, consistency and ubiquitous provision of services to mobile users. The general target of NGWN is to transport different types of information like voice,data, and other media like video in packets form like IP. The NGWNs offer significant savings in costs to the operators along with new and interesting services to the consumers. Major challenges in NGWN are efficient resource utilization, maintaining service quality, reliability and the security. This paper proposes a solution for seamless load aware Radio Access Technology (RAT selection based on interworking of different RATs in NGWN. In this paper novel load balancing algorithms have been proposed which have been simulated on the target network architecture for TCP data services. The IEEE 802.21 Media Independent Handover (MIH is utilized in load balancing specifically for mobility management, which enable low handover latency by reducing the target network detection time. The proposed method considers the network type, signal strength, data rate and network load as primary decision parameters for RAT selection process and consists of two different algorithms, one located inthe mobile terminal and the other at the network side. The network architecture, the proposed load balancing framework and RAT selection algorithms were simulated using NS2. Different attributes like load distribution in the wireless networks and average throughput to evaluate the effects of load balancing in considered scenarios.

  8. Intrusion and Defense of DDoS in TCP/IP Network%TCP/IP网络的DDOS攻击及对策

    Institute of Scientific and Technical Information of China (English)

    钱红燕; 周军

    2000-01-01

    Electronic trade increases quickly with the development of Internet, which requires high security of networks while it may be impaired by kinds of attacks. Distributed denial of service is getting more common in Internet these days and has caused great loss.This paper describes the principles of denial of service, distributed denial of service and analyzes some serious security flaws inherent in the TCP/IP protocol suit used by attackers.Because the attack of distributed denial of service includes two stages: developing the agents and attacking the destinations, special attention is paid to the concrete manners of both steps. According to the analysis, some methods are provided to defend the network servers against distributed denial of service intrusion. The paper discusses some security problems about networks based on TCP/IP protocol suite.%随着网络技术的发展,Internet逐渐渗入社会生活的各个方面,这些都要求计算机网络具有较高的安全性,但是网络在实际运行中可能受到多种攻击,从而削弱其安全性。文中介绍了在Internet上可能导致严重危害的拒绝服务、分布式拒绝服务的概念,分析了分布式拒绝服务的攻击原理,重点讨论其利用TCP/IP协议体系固有的安全漏洞,对Internet上的站点发动攻击的方式;对于发起分布式拒绝服务的两个阶段--发展代理端和实施对目标站点的攻击,分别讨论了具体的实现手段,并针对各种攻击技术提出了预防分布式拒绝服务攻击的安全策略。文中对TCP/IP网络的安全问题进行了一些探讨。

  9. Ku-band satellite data networks using very small aperture terminals. II - System design

    Science.gov (United States)

    Raychaudhuri, D.

    1987-12-01

    An overview is presented of system design for Ku-band star networks intended for interactive data applications. The component elements of such a network are discussed, and the critical items for performance, capacity, and cost are identified. A systematic design procedure combining delay-throughput characterization of the multiaccess inbound and TDM outbound channels with satellite link analysis is provided by which system components and their parameters are selected once the network response time and availability objectives are specified. The results are presented in the form of charts and tables which may serve as the basis for star network design over a range of typical traffic models, component parameters, and performance objectives. The methodology is potentially useful for evaluating alternative network architectures and traffic scenarios which may become important as VSAT technology evolves.

  10. 具有QoS特征宽带IP网络队列调度算法的研究%The Study of Queue Scheduling Algorithm with QoS Character in Broadband IP Network

    Institute of Scientific and Technical Information of China (English)

    刘宴兵; 李秉智

    2003-01-01

    IP Quality of Service (QoS) guarantee is realized by managing and avoiding congestion in network. In thispaper ,the primary queue algorithms are compared in managing congestion. On the basis of these theories, a newLLQ+CBWFQ algorithm is achieved, and the minimum bandwidth is assigned according to priority or request.

  11. Satellite clock corrections estimation to accomplish real time ppp: experiments for brazilian real time network

    Science.gov (United States)

    Marques, Haroldo; Monico, João; Aquino, Marcio; Melo, Weyller

    2014-05-01

    The real time PPP method requires the availability of real time precise orbits and satellites clocks corrections. Currently, it is possible to apply the solutions of clocks and orbits available by BKG within the context of IGS Pilot project or by using the operational predicted IGU ephemeris. The accuracy of the satellite position available in the IGU is enough for several applications requiring good quality. However, the satellites clocks corrections do not provide enough accuracy (3 ns ~ 0.9 m) to accomplish real time PPP with the same level of accuracy. Therefore, for real time PPP application it is necessary to further research and develop appropriated methodologies for estimating the satellite clock corrections in real time with better accuracy. Currently, it is possible to apply the real time solutions of clocks and orbits available by Federal Agency for Cartography and Geodesy (BKG) within the context of IGS Pilot project. The BKG corrections are disseminated by a new proposed format of the RTCM 3.x and can be applied in the broadcasted orbits and clocks. Some investigations have been proposed for the estimation of the satellite clock corrections using GNSS code and phase observable at the double difference level between satellites and epochs (MERVAT, DOUSA, 2007). Another possibility consists of applying a Kalman Filter in the PPP network mode (HAUSCHILD, 2010) and it is also possible the integration of both methods, using network PPP and observables at double difference level in specific time intervals (ZHANG; LI; GUO, 2010). For this work the methodology adopted consists in the estimation of the satellite clock corrections based on the data adjustment in the PPP mode, but for a network of GNSS stations. The clock solution can be solved by using two types of observables: code smoothed by carrier phase or undifferenced code together with carrier phase. In the former, we estimate receiver clock error; satellite clock correction and troposphere, considering

  12. A Topology Control Strategy with Reliability Assurance for Satellite Cluster Networks in Earth Observation.

    Science.gov (United States)

    Chen, Qing; Zhang, Jinxiu; Hu, Ze

    2017-02-23

    This article investigates the dynamic topology control problemof satellite cluster networks (SCNs) in Earth observation (EO) missions by applying a novel metric of stability for inter-satellite links (ISLs). The properties of the periodicity and predictability of satellites' relative position are involved in the link cost metric which is to give a selection criterion for choosing the most reliable data routing paths. Also, a cooperative work model with reliability is proposed for the situation of emergency EO missions. Based on the link cost metric and the proposed reliability model, a reliability assurance topology control algorithm and its corresponding dynamic topology control (RAT) strategy are established to maximize the stability of data transmission in the SCNs. The SCNs scenario is tested through some numeric simulations of the topology stability of average topology lifetime and average packet loss rate. Simulation results show that the proposed reliable strategy applied in SCNs significantly improves the data transmission performance and prolongs the average topology lifetime.

  13. The Integration of Small Satellites in Maritime Interdiction Operations (MIO)

    Science.gov (United States)

    2012-09-01

    BLANK xiii LIST OF ACRONYMS AND ABBREVIATIONS AIS Automatic Identification system BER Bit Error Rate BGAN Broadband Global Area Network bps...was the Broadband Global Area Network ( BGAN ), a global-coverage network that uses three satellites in geostationary orbits and is provided by...NOCTW WR BGAN Mutualink station Target Ship Interdiction Boat Interdiction Boat GPS Tracking Nuc/Rad Sensor Collaboration Station Nuc/Rad Sensor IP

  14. Implementasi Sistem IP PBX menggunakan Briker

    Directory of Open Access Journals (Sweden)

    DWI ARYANTA

    2017-06-01

    Full Text Available Abstrak VoIP (Voice over Internet Protocol adalah komunikasi suara jarak jauh yang digunakan melalui jaringan IP. Pada penelitian ini dirancang sistem IP PBX dengan menggunakan teknologi berbasis VoIP. IP PBX adalah perangkat switching komunikasi telepon dan data berbasis teknologi Internet Protocol (IP yang mengendalikan ekstension telepon analog maupun ekstension IP Phone. Software VirtualBox digunakan dengan tujuan agar lebih memudahkan dalam sistem pengoperasian Linux yang dimana program untuk membuat IP PBX adalah menggunakan Briker yang bekerja pada Operating System Linux 2.6. Setelah proses penginstalan Briker pada Virtualbox dilakukan implementasi jaringan IP PBX. Setelah mengimplementasikan jaringan IP PBX sesuai dengan topologi, kemudian melakukan pengujian success call rate dan analisis Quality of Service (QoS. Pengukuran QoS menggunakan parameter jitter, delay, dan packet loss yang dihasilkan dalam sistem IP PBX ini. Nilai jitter sesama user Briker (baik pada smartphone maupun komputer mempunyai rata-rata berada pada nilai 16,77 ms. Sedangkan nilai packetloss yang didapat pada saat terdapat pada saat user 1 sebagai pemanggil telepon adalah 0%. Sedangkan persentase packet loss pada saat user 1 sebagai penerima telepon adalah 0,01%. Nilai delay pada saat berkomunikasi antar user berada pada 11,75 ms. Secara keseluruhan nilai yang didapatkan melalui penelitian ini, dimana hasil pengujian parameter-parameter QOS sesuai dengan standar yang telah direkomendasikan oleh ITU dan didapatkan nilai QoS dengan hasil “baik”. Kata Kunci : Briker, VoIP, QoS, IP PBX, Smartphone. Abstract VoIP (Voice over Internet Protocol is a long-distance voice communications over IP networks are used. In this study, IP PBX systems designed using VoIP -based technologies. IP PBX is a telephone switching device and data communication technology-based Internet Protocol (IP which controls the analog phone extensions and IP Phone extensions. VirtualBox software is

  15. An Integrated Architecture to Support Hastily Formed Network (HFN)

    Science.gov (United States)

    2007-12-01

    Figure 8. EU 1000I, EU 2000I and EU 3000IS...............................................................52 Figure 9. Inmarsat BGAN Satellite Coverage...Hughes 9201 Broadband Satellite IP Terminal with Wireless LAN Access Point, which interfaces over the Inmarsat BGAN satellite network, has many...advantages that make it an attractive solution. (1) Global Coverage BGAN delivers seamless network coverage across most of the world’s land mass

  16. Simulink based VoIP Analysis

    CERN Document Server

    Singh, Hardeep; Mian, M

    2010-01-01

    Voice communication over internet not be possible without a reliable data network, this was first available when distributed network topologies were used in conjunction with data packets. Early network used single centre node network in which a single workstation (Server) is responsible for the communication. This posed problems as if there was a fault with the centre node, (workstation) nothing would work. This problem was solved by the distributed system in which reliability increases by spreading the load between many nodes. The idea of packet switching & distributed network were combined, this combination were increased reliability, speed & responsible for voice communication over internet, Voice-over-IP (VoIP)These data packets travel through a packet-switched network such as the Internet and arrive at their destination where they are decompressed using a compatible Codec (audio coder/decoder) and converted back to analogue audio. This paper deals with the Simulink architecture for VoIP network.

  17. A space weather forecasting system with multiple satellites based on a self-recognizing network.

    Science.gov (United States)

    Tokumitsu, Masahiro; Ishida, Yoshiteru

    2014-05-05

    This paper proposes a space weather forecasting system at geostationary orbit for high-energy electron flux (>2 MeV). The forecasting model involves multiple sensors on multiple satellites. The sensors interconnect and evaluate each other to predict future conditions at geostationary orbit. The proposed forecasting model is constructed using a dynamic relational network for sensor diagnosis and event monitoring. The sensors of the proposed model are located at different positions in space. The satellites for solar monitoring equip with monitoring devices for the interplanetary magnetic field and solar wind speed. The satellites orbit near the Earth monitoring high-energy electron flux. We investigate forecasting for typical two examples by comparing the performance of two models with different numbers of sensors. We demonstrate the prediction by the proposed model against coronal mass ejections and a coronal hole. This paper aims to investigate a possibility of space weather forecasting based on the satellite network with in-situ sensing.

  18. A Space Weather Forecasting System with Multiple Satellites Based on a Self-Recognizing Network

    Directory of Open Access Journals (Sweden)

    Masahiro Tokumitsu

    2014-05-01

    Full Text Available This paper proposes a space weather forecasting system at geostationary orbit for high-energy electron flux (>2 MeV. The forecasting model involves multiple sensors on multiple satellites. The sensors interconnect and evaluate each other to predict future conditions at geostationary orbit. The proposed forecasting model is constructed using a dynamic relational network for sensor diagnosis and event monitoring. The sensors of the proposed model are located at different positions in space. The satellites for solar monitoring equip with monitoring devices for the interplanetary magnetic field and solar wind speed. The satellites orbit near the Earth monitoring high-energy electron flux. We investigate forecasting for typical two examples by comparing the performance of two models with different numbers of sensors. We demonstrate the prediction by the proposed model against coronal mass ejections and a coronal hole. This paper aims to investigate a possibility of space weather forecasting based on the satellite network with in-situ sensing.

  19. A university-based distributed satellite mission control network for operating professional space missions

    Science.gov (United States)

    Kitts, Christopher; Rasay, Mike

    2016-03-01

    For more than a decade, Santa Clara University's Robotic Systems Laboratory has operated a unique, distributed, internet-based command and control network for providing professional satellite mission control services for a variety of government and industry space missions. The system has been developed and is operated by students who become critical members of the mission teams throughout the development, test, and on-orbit phases of these missions. The mission control system also supports research in satellite control technology and hands-on student aerospace education. This system serves as a benchmark for its comprehensive nature, its student-centric nature, its ability to support NASA and industry space missions, and its longevity in providing a consistent level of professional services. This paper highlights the unique features of this program, reviews the network's design and the supported spacecraft missions, and describes the critical programmatic features of the program that support the control of professional space missions.

  20. Reconstruction of an infrared band of meteorological satellite imagery with abductive networks

    Science.gov (United States)

    Singer, Harvey A.; Cockayne, John E.; Versteegen, Peter L.

    1995-01-01

    As the current fleet of meteorological satellites age, the accuracy of the imagery sensed on a spectral channel of the image scanning system is continually and progressively degraded by noise. In time, that data may even become unusable. We describe a novel approach to the reconstruction of the noisy satellite imagery according to empirical functional relationships that tie the spectral channels together. Abductive networks are applied to automatically learn the empirical functional relationships between the data sensed on the other spectral channels to calculate the data that should have been sensed on the corrupted channel. Using imagery unaffected by noise, it is demonstrated that abductive networks correctly predict the noise-free observed data.

  1. A hybrid hopfield network-simulated annealing approach for frequency assignment in satellite communications systems.

    Science.gov (United States)

    Salcedo-Sanz, Sancho; Santiago-Mozos, Ricardo; Bousoño-Calzón, Carlos

    2004-04-01

    A hybrid Hopfield network-simulated annealing algorithm (HopSA) is presented for the frequency assignment problem (FAP) in satellite communications. The goal of this NP-complete problem is minimizing the cochannel interference between satellite communication systems by rearranging the frequency assignment, for the systems can accommodate the increasing demands. The HopSA algorithm consists of a fast digital Hopfield neural network which manages the problem constraints hybridized with a simulated annealing which improves the quality of the solutions obtained. We analyze the problem and its formulation, describing and discussing the HopSA algorithm and solving a set of benchmark problems. The results obtained are compared with other existing approaches in order to show the performance of the HopSA approach.

  2. Classification and Segmentation of Satellite Orthoimagery Using Convolutional Neural Networks

    Directory of Open Access Journals (Sweden)

    Martin Längkvist

    2016-04-01

    Full Text Available The availability of high-resolution remote sensing (HRRS data has opened up the possibility for new interesting applications, such as per-pixel classification of individual objects in greater detail. This paper shows how a convolutional neural network (CNN can be applied to multispectral orthoimagery and a digital surface model (DSM of a small city for a full, fast and accurate per-pixel classification. The predicted low-level pixel classes are then used to improve the high-level segmentation. Various design choices of the CNN architecture are evaluated and analyzed. The investigated land area is fully manually labeled into five categories (vegetation, ground, roads, buildings and water, and the classification accuracy is compared to other per-pixel classification works on other land areas that have a similar choice of categories. The results of the full classification and segmentation on selected segments of the map show that CNNs are a viable tool for solving both the segmentation and object recognition task for remote sensing data.

  3. Using Satellite Images for Wireless Network Planing in Baku City

    Science.gov (United States)

    Gojamanov, M.; Ismayilov, J.

    2013-04-01

    It is a well known fact that the Information-Telecommunication and Space research technologies are the fields getting much more benefits from the achievements of the scientific and technical progress. In many cases, these areas supporting each other have improved the conditions for their further development. For instance, the intensive development in the field of the mobile communication has caused the rapid progress of the Space research technologies and vice versa.Today it is impossible to solve one of the most important tasks of the mobile communication as Radio Frecance planning without the 2D and 3D digital maps. The compiling of such maps is much more efficient by means of the space images. Because the quality of the space images has been improved and developed, especially at the both spectral and spatial resolution points. It has been possible to to use 8 Band images with the spatial resolution of 50 sm. At present, in relation to the function 3G of mobile communications one of the main issues facing mobile operator companies is a high-precision 3D digital maps. It should be noted that the number of mobile phone users in the Republic of Azerbaijan went forward other Community of Independent States Countries. Of course, using of aerial images for 3D mapping would be optimal. However, depending on a number of technical and administrative problems aerial photography cannot be used. Therefore, the experience of many countries shows that it will be more effective to use the space images with the higher resolution for these issues. Concerning the fact that the mobile communication within the city of Baku has included 3G function there were ordered stereo images wih the spatial resolution of 50 cm for the 150 sq.km territory occupying the central part of the city in order to compile 3D digital maps. The images collected from the WorldView-2 satellite are 4-Band Bundle(Pan+MS1) stereo images. Such kind of imagery enable to automatically classificate some required

  4. Multi-layered Security Approaches for a Modular Open Network Architecture-based Satellite

    OpenAIRE

    Shirley, Brandon; Young, Quinn; Wegner, Peter; Christensen, Jacob; Janicik, Jeffrey

    2014-01-01

    A growing trend in satellite development includes shortening the development lifecycle for hardware and software, cost reduction, and promoting reuse for future missions. Department of Defense (DoD) acquisition policies mandate system providers use Open Systems Architecture (OSA) where feasible. Modular Open Network Architecture (MONA) is a subset of OSA and paves the way to achieve cost reduction and reuse during a reduced development lifecycle. MONA approaches provide opportunities to enhan...

  5. TCP-ADaLR: TCP with adaptive delay and loss response for broadband GEO satellite networks

    OpenAIRE

    Omueti, Modupe Omogbohun

    2007-01-01

    Transmission Control Protocol (TCP) performance degrades in broadband geostationary satellite networks due to long propagation delays and high bit error rates. In this thesis, we propose TCP with algorithm modifications for adaptive delay and loss response (TCP-ADaLR) to improve TCP performance. TCP-ADaLR incorporates delayed acknowledgement mechanism recommended for Internet hosts. We evaluate and compare the performance of TCP-ADaLR, TCP SACK, and TCP NewReno, with and without delayed ackno...

  6. Defense Science Board Task Force on Military Satellite Communication and Tactical Networking. Executive Summary

    Science.gov (United States)

    2017-03-01

    product of the Defense Science Board (DSB). The DSB is a Federal Advisory Committee established to provide independent advice to the Secretary of Defense...December 2014, the Under Secretary of Defense for Acquisition, Technology, and Logistics (USD(AT&L)) signed the “Terms of Reference – Defense Science ...Board Task Force on Military Satellite Communication and Tactical Networking.” As a result, the Chairman of the Defense Science Board established a

  7. A QoS Architecture for DVB-RCS Next Generation Satellite Networks

    Directory of Open Access Journals (Sweden)

    Gayraud Thierry

    2007-01-01

    Full Text Available The standardization of a return channel via satellite (DVB-RCS and satellite community efforts in term of interoperability over the last few years leads to quite a positive outcome: geostationary satellite networks are intended to provide broadband access to interactive multimedia services in low-infrastructure areas. However, in order to take in account real-time multimedia traffic, an efficient resource management scheme is still necessary to maximize the scarce uplink capacities usage. To address this capacity issue, this paper proposes a complete DVB-RCS QoS architecture that is implemented, thanks to an emulation platform, and evaluated with real multimedia applications. This paper first gives an overview of the QoS architecture usually used in DVB-S/RCS satellite system, especially in layers 2 and 3. It then introduces the satellite system emulation used in the experimentation and its calibration. The main contribution of this work focuses on the signaling principle designed to allow applications to take benefit from the QoS features of the satellite system even if they are non-QoS aware. It is then shown how signaling in such QoS architecture allows the user to change dynamically the QoS of his application using QoS agent and QoS server applications even if the application is not QoS-aware. It is also given quantitative results related to such a dynamic QoS change in the experiments done on the satellite emulation system.

  8. A QoS Architecture for DVB-RCS Next Generation Satellite Networks

    Directory of Open Access Journals (Sweden)

    Pascal Berthou

    2007-12-01

    Full Text Available The standardization of a return channel via satellite (DVB-RCS and satellite community efforts in term of interoperability over the last few years leads to quite a positive outcome: geostationary satellite networks are intended to provide broadband access to interactive multimedia services in low-infrastructure areas. However, in order to take in account real-time multimedia traffic, an efficient resource management scheme is still necessary to maximize the scarce uplink capacities usage. To address this capacity issue, this paper proposes a complete DVB-RCS QoS architecture that is implemented, thanks to an emulation platform, and evaluated with real multimedia applications. This paper first gives an overview of the QoS architecture usually used in DVB-S/RCS satellite system, especially in layers 2 and 3. It then introduces the satellite system emulation used in the experimentation and its calibration. The main contribution of this work focuses on the signaling principle designed to allow applications to take benefit from the QoS features of the satellite system even if they are non-QoS aware. It is then shown how signaling in such QoS architecture allows the user to change dynamically the QoS of his application using QoS agent and QoS server applications even if the application is not QoS-aware. It is also given quantitative results related to such a dynamic QoS change in the experiments done on the satellite emulation system.

  9. Vaccines and IP Rights: A Multifaceted Relationship.

    Science.gov (United States)

    Durell, Karen

    2016-01-01

    Just as there are many forms of vaccines and components to vaccines-particular compositions, delivery systems, components, and distribution networks-there are a variety of intellectual property (IP) protections applicable for vaccines. IP rights such as patent, copyright, trademarks, plant breeders' rights, and trade secrets may all be applicable to vaccines. Thus, discussion of IP rights and vaccines should not begin and end with the application of one IP right to a vaccine. The discussion should engage considerations of multiple IP rights applicable to a vaccine and how these can be utilized in an integrated manner in a strategy aimed at supporting the development and distribution of the vaccine. Such an approach to IP rights to vaccines allows for the integrated rights to be considered in light of the justifications for protecting vaccines with IP rights, as well as the issues relating to specific IP rights for vaccines, such as compulsory license regimes, available humanitarian purpose IP credits, etc. To view vaccines as the subject of multiple IP protections involves a refocusing, but the outcome can provide significant benefits for vaccine development and distribution.

  10. UNSUPERVISED CLASSIFICATION OF HIGH RESOLUTION SATELLITE IMAGERY BY SELF-ORGANIZING NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    ÁRPÁD BARSI

    2010-06-01

    Full Text Available The current paper discusses the importance of the modern high resolution satellite imagery. The acquired high amount of data must be processed by an efficient way, where the used Kohonen-type self-organizing map has been proven as a suitable tool. The paper gives an introduction to this interesting method. The tests have shown that the multispectral image information can be taken after a resampling step as neural network inputs, and then the derived network weights are able to evaluate the whole image with acceptable thematic accuracy.

  11. World-wide interactive access to scientific databases via satellite and terrestrial data network

    Science.gov (United States)

    Sanderson, T. R.; Albrecht, M. A.; Ciarlo, A.; Brett, M.; Blank, K.; Hughes, P. M. T.; Wallum, G.; Hills, H. K.; Green, J. L.; Mcguire, R. E.; hide

    1990-01-01

    In order to demonstrate the possibilities for scientific networking and data transfer, a first temporary satellite network link was installed between Czecholovakia and the European space operations center in Darmstadt, during the meeting of the inter-agency consultative group for space science in Prague. Several experiments to show interactive nature of the facility and the capability of the system were carried out, and it was proven that, despite the temporary nature of the installation, the planned demonstrations could be conducted in real time. Demonstrations included electronic mail message, orbit prediction and solar X-ray data. The results of the experiment provided insight into possibilities of data exchange.

  12. World-wide interactive access to scientific databases via satellite and terrestrial data network

    Science.gov (United States)

    Sanderson, T. R.; Albrecht, M. A.; Ciarlo, A.; Brett, M.; Blank, K.; Hughes, P. M. T.; Wallum, G.; Hills, H. K.; Green, J. L.; Mcguire, R. E.; Kamei, T.; Kiplinger, A.; Waite, J. H., Jr.

    1990-01-01

    In order to demonstrate the possibilities for scientific networking and data transfer, a first temporary satellite network link was installed between Czecholovakia and the European space operations center in Darmstadt, during the meeting of the inter-agency consultative group for space science in Prague. Several experiments to show interactive nature of the facility and the capability of the system were carried out, and it was proven that, despite the temporary nature of the installation, the planned demonstrations could be conducted in real time. Demonstrations included electronic mail message, orbit prediction and solar X-ray data. The results of the experiment provided insight into possibilities of data exchange.

  13. Proximity graph analysis for linear networks extraction from high-resolution satellite imagery

    Science.gov (United States)

    Skourikhine, Alexei N.

    2006-05-01

    Reliable and accurate methods for detection and extraction of linear network, such as road networks, in satellite imagery are essential to many applications. We present an approach to the road network extraction from high-resolution satellite imagery that is based on proximity graph analysis. We are jumping off from the classification provided by existing spectral and textural classification tools, which produce a set of candidate road patches. Then, constrained Delaunay triangulation and Chordal Axis transform are used to extract centerline characterization of the delineated candidate road patches. We refine produced center lines to reduce noise influence on patch boundaries, resulting in a smaller set of robust center lines authentically representing their road patches. Refined center lines are triangulated using constrained Delaunay triangulation (CDT) algorithm to generate a sub-optimal mesh of interconnections among them. The generated triangle edges connecting different center lines are used for spatial analysis of the center lines relations. A subset of the Delaunay tessellation grid contains the Euclidian Minimum Spanning Tree (EMST) that provides an approximation of road network. The approach can be generalized to the multi-criteria MST and multi-criteria shortest path algorithms to integrate other factors important for road network extraction, in addition to proximity relations considered by standard EMST.

  14. An Ad-hoc Satellite Network to Measure Filamentary Current Structures in the Auroral Zone

    Science.gov (United States)

    Nabong, C.; Fritz, T. A.; Semeter, J. L.

    2014-12-01

    An ad-hoc cubesat-based satellite network project known as ANDESITE is under development at Boston University. It aims to develop a dense constellation of easy-to-use, rapidly-deployable low-cost wireless sensor nodes in space. The objectives of the project are threefold: 1) Demonstrate viability of satellite based sensor networks by deploying an 8-node miniature sensor network to study the filamentation of the field aligned currents in the auroral zones of the Earth's magnetosphere. 2) Test the scalability of proposed protocols, including localization techniques, tracking, data aggregation, and routing, for a 3 dimensional wireless sensor network using a "flock" of nodes. 3) Construct a 6U Cube-sat running the Android OS as an integrated constellation manager, data mule and sensor node deplorer. This small network of sensor nodes will resolve current densities at different spatial resolutions in the near-Earth magnetosphere using measurements from magnetometers with 1-nT sensitivities and 0.2 nT/√Hz self-noise. Mapping of these currents will provide new constraints for models of auroral particle acceleration, wave-particle interactions, ionospheric destabilization, and other kinetic processes operating in the low-beta plasma of the near Earth magnetosphere.

  15. Towards an Autonomous Turbidimeter Network for Multi-Mission Ocean Colour Satellite Data Validation Activities

    Science.gov (United States)

    Dogliotti, A. I.; Nechad, B.; Ruddick, K. G.; Gossn, J. I.

    2016-08-01

    Satellite-based optical sensors such as MODIS/Aqua, Sentinel-2, Sentinel-3, Landsat-8, Pléiades, SABIA/Mar, PROBA-V , etc. can be used to map turbidity and suspended particulate matter in coastal, estuarine and inland waters as support for water quality monitoring, sediment transport applications such as dredging and fisheries science. However, data quality is a critical problem and in situ data must be gathered from a wide range of test sites in order to provide validation for the diverse range of conditions that can be encountered all over the world. In this context, a network to validate satellite turbidity products called TURBINET is proposed with the goal to establish a long-term (autonomous) international network of collaboration and data-sharing. Joint measurements of turbidity, reflectance and in-water side/back-scattering have been performed in Belgium and Argentina in 2015. Instrument comparisons showed that comparable values could be retrieved using different sensors and field measurements were used to validate a Pléiades high resolution image (2m). The results presented in this work demonstrate the feasibility and usefulness of setting up a network to validate satellite turbidity products.

  16. Detection of land cover change using an Artificial Neural Network on a time-series of MODIS satellite data

    CSIR Research Space (South Africa)

    Olivier, JC

    2007-11-01

    Full Text Available An Artificial Neural Network (ANN) is proposed to detect human-induced land cover change using a sliding window through a time-series of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite surface reflectance pixel values. Training...

  17. Ensuring Software IP Cleanliness

    Directory of Open Access Journals (Sweden)

    Mahshad Koohgoli

    2007-12-01

    Full Text Available At many points in the life of a software enterprise, determination of intellectual property (IP cleanliness becomes critical. The value of an enterprise that develops and sells software may depend on how clean the software is from the IP perspective. This article examines various methods of ensuring software IP cleanliness and discusses some of the benefits and shortcomings of current solutions.

  18. Evaluation of IP Portfolios

    DEFF Research Database (Denmark)

    Søberg, Peder Veng

    2009-01-01

    As a result of an inquiry concerning how to evaluate IP (intellectual property) portfolios in order to enable the best possible use of IP resources within organizations, an IP evaluation approach primarily applicable for patents and utility models is developed. The developed approach is useful...

  19. Comprehensive Comparison of VoIP SIP Protocol Problems and Cisco VoIP System

    Directory of Open Access Journals (Sweden)

    TALAL AL-KHAROBI

    2012-08-01

    Full Text Available Voice over IP (VoIP, use of the packet switched internet for telephony, has improved substantially in the past few years. On the other hand, VoIP has many challenges that do not exist in the public switched telephone network (PSTN, a circuit switched system. VoIP is an application running on the internet, and therefore inherits the internet’s security issues. It is important to realise that VoIP is a relatively young technology, and with any new technology, security typically improves with maturity. This paper provides a comprehensive comparison of a VoIP SIP protocol and CISCO VoIP system. The comparison involves the investigation of the vulnerabilities that target both systems and how secure each system is. With this comparison we present our conclusion on which system is more secure.

  20. Artificial neural network prediction model for geosynchronous electron fluxes: Dependence on satellite position and particle energy

    Science.gov (United States)

    Shin, Dae-Kyu; Lee, Dae-Young; Kim, Kyung-Chan; Hwang, Junga; Kim, Jaehun

    2016-04-01

    Geosynchronous satellites are often exposed to energetic electrons, the flux of which varies often to a large extent. Since the electrons can cause irreparable damage to the satellites, efforts to develop electron flux prediction models have long been made until recently. In this study, we adopt a neural network scheme to construct a prediction model for the geosynchronous electron flux in a wide energy range (40 keV to >2 MeV) and at a high time resolution (as based on 5 min resolution data). As the model inputs, we take the solar wind variables, geomagnetic indices, and geosynchronous electron fluxes themselves. We also take into account the magnetic local time (MLT) dependence of the geosynchronous electron fluxes. We use the electron data from two geosynchronous satellites, GOES 13 and 15, and apply the same neural network scheme separately to each of the GOES satellite data. We focus on the dependence of prediction capability on satellite's magnetic latitude and MLT as well as particle energy. Our model prediction works less efficiently for magnetic latitudes more away from the equator (thus for GOES 13 than for GOES 15) and for MLTs nearer to midnight than noon. The magnetic latitude dependence is most significant for an intermediate energy range (a few hundreds of keV), and the MLT dependence is largest for the lowest energy (40 keV). We interpret this based on degree of variance in the electron fluxes, which depends on magnetic latitude and MLT at geosynchronous orbit as well as particle energy. We demonstrate how substorms affect the flux variance.

  1. Neural network-based recognition of whistlers on spectrograms detected by satellite

    Science.gov (United States)

    Conti, Livio

    2016-04-01

    We present a system to automatically recognize and classify the occurrence of whistler waves on spectrograms of electric field measurements performed by satellite. Whistlers - VLF waves generated by lightning, with a specific spectral dispersion relation - can induce precipitation of trapped Van Allen particles and have a role in the chemistry of some atmospheric components (mainly NOx). Moreover, it has also been suggested that the increase of the number of anomalous whistlers (i.e. whistlers with high value of dispersion constant) could be induced by disturbances in the Earth-ionosphere wave-guide, generated by seismo-electromagnetic emissions. On satellite, the recognition of whistlers asks for analyzing high-resolution spectrograms that cannot be downloaded to Earth, due to the limits of data transmission. For this reason, a real time identification and classification must be performed on satellite, by avoiding downloading all the unprocessed data. The procedure that we have developed is based on a Time Delay Neural Network (TDNN). The TDNN, proposed some years ago for speech recognition, can be fruitfully also applied in real-time analysis of electromagnetic spectrograms in order to detect phenomena characterized by a specific shape/signature such as those of the whistler waves. Some studies have been performed by the RNF experiment on board of the DEMETER satellite and our algorithm could be adopted on board of the satellite CSES (China Seismo-Electromagnetic Satellite), launch scheduled by the end of 2016. Moreover, the procedure can be also adopted to automatic analysis of whistlers detected on ground.

  2. The design and networking of dynamic satellite constellations for global mobile communication systems

    Science.gov (United States)

    Cullen, Cionaith J.; Benedicto, Xavier; Tafazolli, Rahim; Evans, Barry

    1993-01-01

    Various design factors for mobile satellite systems, whose aim is to provide worldwide voice and data communications to users with hand-held terminals, are examined. Two network segments are identified - the ground segment (GS) and the space segment (SS) - and are seen to be highly dependent on each other. The overall architecture must therefore be adapted to both of these segments, rather than each being optimized according to its own criteria. Terrestrial networks are grouped and called the terrestrial segment (TS). In the SS, of fundamental importance is the constellation altitude. The effect of the altitude on decisions such as constellation design choice and on network aspects like call handover statistics are fundamental. Orbit resonance is introduced and referred to throughout. It is specifically examined for its useful properties relating to GS/SS connectivities.

  3. Proactive TCP mechanism to improve Handover performance in Mobile Satellite and Terrestrial Networks

    CERN Document Server

    Vinayakray-Jani, Preetida

    2012-01-01

    Emerging standardization of Geo Mobile Radio (GMR-1) for satellite system is having strong resemblance to terrestrial GSM (Global System for Mobile communications) at the upper protocol layers and TCP (Transmission Control Protocol) is one of them. This space segment technology as well as terrestrial technology, is characterized by periodic variations in communication properties and coverage causing the termination of ongoing call as connections of Mobile Nodes (MN) alter stochastically. Although provisions are made to provide efficient communication infrastructure this hybrid space and terrestrial networks must ensure the end-to-end network performance so that MN can move seamlessly among these networks. However from connectivity point of view current TCP performance has not been engineered for mobility events in multi-radio MN. Traditionally, TCP has applied a set of congestion control algorithms (slow-start, congestion avoidance, fast retransmit, fast recovery) to probe the currently available bandwidth on...

  4. IP Rights and Technological Platforms

    OpenAIRE

    Robert P. Merges

    2008-01-01

    This paper is about intellectual property rights (IPRs) and platform technologies. After a brief introduction explaining some basics of networks, standards and platforms, I turn to three policy issues. The first is the role of IP in what might be termed platform policies, the decisions by courts and regulators concerning whether and how to promote multi-party access to important digital platforms such as media player hardware, cell phones, PCs, and the like. I argue that for the most part the...

  5. A small satellite design for deep space network testing and training

    Science.gov (United States)

    Mcwilliams, Dennis; Slatton, Clint; Norman, Cassidy; Araiza, Joe; Jones, Jason; Tedesco, Mark; Wortman, Michael; Opiela, John; Lett, Pat; Clavenna, Michael

    1993-01-01

    With the continuing exploration of the Solar System and the reemphasis on Earth focused missions, the need for faster data transmission rates has grown. Ka-band could allow a higher data delivery rate over the current X-band, however the adverse effects of the Earth's atmosphere on Ka are as yet unknown. The Deep Space Network and Jet Propulsion Lab have proposed to launch a small satellite that would simultaneously transmit X and Ka signals to test the viability of switching to Ka-band. The Mockingbird Design Team at the University of Texas at Austin applied small satellite design principles to achieve this objective. The Mockingbird design, named BATSAT, incorporates simple, low-cost systems designed for university production and testing. The BATSAT satellite is a 0.64 m diameter, spherical panel led satellite, mounted with solar cells and omni-directional antennae. The antennae configuration negates the need for active attitude control or spin stabilization. The space-frame truss structure was designed for 11 g launch loads while allowing for easy construction and solar-panel mounting. The communication system transmits at 1 mW by carrying the required Ka and X-band transmitters, as well as an S band transmitter used for DSN training. The power system provides the 8.6 W maximum power requirements via silicon solar arrays and nickel-cadmium batteries. The BATSAT satellite will be lofted into an 1163 km, 70 deg orbit by the Pegasus launch system. This orbit fulfills DSN dish slew rate requirements while keeping the satellite out of the heaviest regions of the Van Allen radiation belts. Each of the three DSN stations capable of receiving Ka-band (Goldstone, Canberra, and Madrid) will have an average of 85 minutes of view-time per day over the satellites ten year design life. Mockingbird Designs hopes that its small satellite design will not only be applicable to this specific mission scenario, but that it could easily be modified for instrument capability for

  6. Monitoring Animal Behaviour and Environmental Interactions Using Wireless Sensor Networks, GPS Collars and Satellite Remote Sensing

    Directory of Open Access Journals (Sweden)

    Peter Corke

    2009-05-01

    Full Text Available Remote monitoring of animal behaviour in the environment can assist in managing both the animal and its environmental impact. GPS collars which record animal locations with high temporal frequency allow researchers to monitor both animal behaviour and interactions with the environment. These ground-based sensors can be combined with remotely-sensed satellite images to understand animal-landscape interactions. The key to combining these technologies is communication methods such as wireless sensor networks (WSNs. We explore this concept using a case-study from an extensive cattle enterprise in northern Australia and demonstrate the potential for combining GPS collars and satellite images in a WSN to monitor behavioural preferences and social behaviour of cattle.

  7. Networks systems and operations. [wideband communication techniques for data links with satellites

    Science.gov (United States)

    1975-01-01

    The application of wideband communication techniques for data links with satellites is discussed. A diagram of the demand assigned voice communications system is provided. The development of prototype integrated spacecraft paramps at S- and C-bands is described and the performance of space-qualified paramps is tabulated. The characteristics of a dual parabolic cylinder monopulse zoom antenna for use with the tracking and data relay satellite system (TDRSS) are analyzed. The development of a universally applicable transponder at S-band is reported. A block diagram of the major subassemblies of the S-band transponder is included. The technology aspects of network timing and synchronization of communication systems are to show the use of the Omega navigation system. The telemetry data compression system used during the Skylab program is evaluated.

  8. A Signaling Abnormal Handling Detection Method in IP Multimedia Subsystem Network%一种IMS网络信令异常处理检测方法

    Institute of Scientific and Technical Information of China (English)

    谢晓龙; 季新生; 刘彩霞; 刘树新

    2012-01-01

    针对IMS网络中被入侵或劫持的网络实体可能对信令消息做出恶意篡改等异常处理的问题,提出一种基于信令处理规则的IMS 网络信令异常处理检测方法.该方法基于建立的信令处理规则库,模拟实体对信令消息的正常处理并生成一条预处理消息,通过判断预处理消息与经过实体处理后的信令消息是否匹配,检测IMS网络中是否存在信令异常处理.实验结果表明,该方法对信令异常处理的检测率达到了100%.%In order to solve the problem that entities in IP Multimedia Subsystem(IMS) network hijacked by attackers may make exception handling to signaling messages, this paper proposes a detection method for signaling exception handling in IMS based on signaling handling rules. It simulates the normal handling of the entity to signaling messages and generates a pre-processing message based on the database of signaling handling rules, and then matching detection is made between the pre-processing message and the message handled by the entity to detect signaling exception handling in IMS. Experimental results prove that the detection rate of exception handling in IMS achieves 100%.

  9. Magnetic resonance imaging research in sub-Saharan Africa: challenges and satellite-based networking implementation.

    Science.gov (United States)

    Latourette, Matthew T; Siebert, James E; Barto, Robert J; Marable, Kenneth L; Muyepa, Anthony; Hammond, Colleen A; Potchen, Michael J; Kampondeni, Samuel D; Taylor, Terrie E

    2011-08-01

    As part of an NIH-funded study of malaria pathogenesis, a magnetic resonance (MR) imaging research facility was established in Blantyre, Malaŵi to enhance the clinical characterization of pediatric patients with cerebral malaria through application of neurological MR methods. The research program requires daily transmission of MR studies to Michigan State University (MSU) for clinical research interpretation and quantitative post-processing. An intercontinental satellite-based network was implemented for transmission of MR image data in Digital Imaging and Communications in Medicine (DICOM) format, research data collection, project communications, and remote systems administration. Satellite Internet service costs limited the bandwidth to symmetrical 384 kbit/s. DICOM routers deployed at both the Malaŵi MRI facility and MSU manage the end-to-end encrypted compressed data transmission. Network performance between DICOM routers was measured while transmitting both mixed clinical MR studies and synthetic studies. Effective network latency averaged 715 ms. Within a mix of clinical MR studies, the average transmission time for a 256 × 256 image was ~2.25 and ~6.25 s for a 512 × 512 image. Using synthetic studies of 1,000 duplicate images, the interquartile range for 256 × 256 images was [2.30, 2.36] s and [5.94, 6.05] s for 512 × 512 images. Transmission of clinical MRI studies between the DICOM routers averaged 9.35 images per minute, representing an effective channel utilization of ~137% of the 384-kbit/s satellite service as computed using uncompressed image file sizes (including the effects of image compression, protocol overhead, channel latency, etc.). Power unreliability was the primary cause of interrupted operations in the first year, including an outage exceeding 10 days.

  10. Trans-Pacific HDR Satellite Communications Experiment Phase-2 Project Plan and Experimental Network

    Science.gov (United States)

    Hsu, Eddie; Kadowaki, Naoto; Yoshimura, Naoko; Takahashi, Takashi; Yoshikawa, Makoto; Bergman, Larry; Bhasin, Kul

    2000-01-01

    The trans-Pacific high data rate (TP-HDR) satellite communications experiment was proposed at the Japan-U.S. Cooperation in Space (JUCS) Program Workshop held in Hawaii in 1993 and remote high definition video post-production was demonstrated as the first phase trial. ATM-based 45 Mbps trans-Pacific link was established in the first phase, and the following experiments with 155 Mbps was planned as the phase 2. This paper describes the experimental network configuration and project plan of TP-HDR experiment phase 2. Additional information is provided in the original.

  11. Fast Road Network Extraction in Satellite Images Using Mathematical Morphology and Markov Random Fields

    Directory of Open Access Journals (Sweden)

    Thierry Géraud

    2004-12-01

    Full Text Available We present a fast method for road network extraction in satellite images. It can be seen as a transposition of the segmentation scheme “watershed transform + region adjacency graph + Markov random fields” to the extraction of curvilinear objects. Many road extractors which are composed of two stages can be found in the literature. The first one acts like a filter that can decide from a local analysis, at every image point, if there is a road or not. The second stage aims at obtaining the road network structure. In the method we propose to rely on a “potential” image, that is, unstructured image data that can be derived from any road extractor filter. In such a potential image, the value assigned to a point is a measure of its likelihood to be located in the middle of a road. A filtering step applied on the potential image relies on the area closing operator followed by the watershed transform to obtain a connected line which encloses the road network. Then a graph describing adjacency relationships between watershed lines is built. Defining Markov random fields upon this graph, associated with an energetic model of road networks, leads to the expression of road network extraction as a global energy minimization problem. This method can easily be adapted to other image processing fields, where the recognition of curvilinear structures is involved.

  12. What are suspicious VoIP delays?

    CERN Document Server

    Mazurczyk, Wojciech; Szczypiorski, Krzysztof

    2010-01-01

    Voice over IP (VoIP) is unquestionably the most popular real-time service in IP networks today. Recent studies have shown that it is also a suitable carrier for information hiding. Hidden communication may pose security concerns as it can lead to confidential information leakage. In VoIP, RTP (Real-time Transport Protocol) in particular, which provides the means for the successful transport of voice packets through IP networks, is suitable for steganographic purposes. It is characterised by a high packet rate compared to other protocols used in IP telephony, resulting in a potentially high steganographic bandwidth. The modification of an RTP packet stream provides many opportunities for hidden communication as the packets may be delayed, reordered or intentionally lost. In this paper, to enable the detection of steganographic exchanges in VoIP, we examined real RTP traffic traces to answer the questions, what do the "normal" delays in RTP packet streams look like? and, is it possible to detect the use of know...

  13. The Pointer Optimization Strategy Based on the distributed RSs in the Mobile IP Network%移动IP中基于分布式注册服务器的指针优化策略

    Institute of Scientific and Technical Information of China (English)

    康凯; 郭伟; 吴诗其

    2002-01-01

    Mobility management is one of the key problems in the mobile communication techniques. The performance of the mobile communication networks is heavily depended on the effectiveness of the mobility management. In this paper, we have presented a protocol of the mobility management in the mobile IP networks, based on the distributed RSs. When the mobile user in the inactive connection handoffs, some pointers are constructed and modified by the RSs and routers. It can realize the local registration; only when a call arrives, the possible update operations of the mobile database are needed. Consequently, the access of the RS is limited, and the cost of the mobility management is also reduced.

  14. Comparision of Clustering Algorithms usingNeural Network Classifier for Satellite Image Classification

    Directory of Open Access Journals (Sweden)

    S.Praveena

    2015-06-01

    Full Text Available This paper presents a hybrid clustering algorithm and feed-forward neural network classifier for land-cover mapping of trees, shade, building and road. It starts with the single step preprocessing procedure to make the image suitable for segmentation. The pre-processed image is segmented using the hybrid genetic-Artificial Bee Colony(ABC algorithm that is developed by hybridizing the ABC and FCM to obtain the effective segmentation in satellite image and classified using neural network . The performance of the proposed hybrid algorithm is compared with the algorithms like, k-means, Fuzzy C means(FCM, Moving K-means, Artificial Bee Colony(ABC algorithm, ABC-GA algorithm, Moving KFCM and KFCM algorithm.

  15. LACK - a VoIP Steganographic Method

    CERN Document Server

    Mazurczyk, Wojciech

    2008-01-01

    The paper presents a new steganographic method called LACK (Lost Audio PaCKets Steganography) which is intended mainly for VoIP. The method is presented in a broader context of network steganography and of VoIP steganography in particular. The analytical results presented in the paper concern the influence of LACK's hidden data insertion procedure on the method's impact on quality of voice transmission and its resistance to steganalysis.

  16. Automatic Classification of Attacks on IP Telephony

    Directory of Open Access Journals (Sweden)

    Jakub Safarik

    2013-01-01

    Full Text Available This article proposes an algorithm for automatic analysis of attack data in IP telephony network with a neural network. Data for the analysis is gathered from variable monitoring application running in the network. These monitoring systems are a typical part of nowadays network. Information from them is usually used after attack. It is possible to use an automatic classification of IP telephony attacks for nearly real-time classification and counter attack or mitigation of potential attacks. The classification use proposed neural network, and the article covers design of a neural network and its practical implementation. It contains also methods for neural network learning and data gathering functions from honeypot application.

  17. On using Mobile IP Protocols

    Directory of Open Access Journals (Sweden)

    Fayza A. Nada

    2006-01-01

    Full Text Available The recent advances in wireless communication technology and the unprecedented growth of the Internet have paved the way for wireless networking and IP mobility. Mobile Internet protocol has been designed within the IETF to support the mobility of users who wish to connect to the Internet and maintain communications as they move from place to place. This study describes and summarizes the current Internet draft for mobile IP (MIPv4 with its major components: agent discovery, registration and tunneling. In addition, we outline the available encapsulation techniques and route optimization procedure. In the end, we describe the design of the new protocol for transparent routing of IPv6 packets to mobile IPv6 nodes operating in the Internet.

  18. Minimum Number of Observation Points for LEO Satellite Orbit Estimation by OWL Network

    Science.gov (United States)

    Park, Maru; Jo, Jung Hyun; Cho, Sungki; Choi, Jin; Kim, Chun-Hwey; Park, Jang-Hyun; Yim, Hong-Suh; Choi, Young-Jun; Moon, Hong-Kyu; Bae, Young-Ho; Park, Sun-Youp; Kim, Ji-Hye; Roh, Dong-Goo; Jang, Hyun-Jung; Park, Young-Sik; Jeong, Min-Ji

    2015-12-01

    By using the Optical Wide-field Patrol (OWL) network developed by the Korea Astronomy and Space Science Institute (KASI) we generated the right ascension and declination angle data from optical observation of Low Earth Orbit (LEO) satellites. We performed an analysis to verify the optimum number of observations needed per arc for successful estimation of orbit. The currently functioning OWL observatories are located in Daejeon (South Korea), Songino (Mongolia), and Oukaïmeden (Morocco). The Daejeon Observatory is functioning as a test bed. In this study, the observed targets were Gravity Probe B, COSMOS 1455, COSMOS 1726, COSMOS 2428, SEASAT 1, ATV-5, and CryoSat-2 (all in LEO). These satellites were observed from the test bed and the Songino Observatory of the OWL network during 21 nights in 2014 and 2015. After we estimated the orbit from systematically selected sets of observation points (20, 50, 100, and 150) for each pass, we compared the difference between the orbit estimates for each case, and the Two Line Element set (TLE) from the Joint Space Operation Center (JSpOC). Then, we determined the average of the difference and selected the optimal observation points by comparing the average values.

  19. An Optical Sensor Network for Vegetation Phenology Monitoring and Satellite Data Calibration

    Directory of Open Access Journals (Sweden)

    Michal Heliasz

    2011-08-01

    Full Text Available We present a network of sites across Fennoscandia for optical sampling of vegetation properties relevant for phenology monitoring and satellite data calibration. The network currently consists of five sites, distributed along an N-S gradient through Sweden and Finland. Two sites are located in coniferous forests, one in a deciduous forest, and two on peatland. The instrumentation consists of dual-beam sensors measuring incoming and reflected red, green, NIR, and PAR fluxes at 10-min intervals, year-round. The sensors are mounted on separate masts or in flux towers in order to capture radiation reflected from within the flux footprint of current eddy covariance measurements. Our computations and model simulations demonstrate the validity of using off-nadir sampling, and we show the results from the first year of measurement. NDVI is computed and compared to that of the MODIS instrument on-board Aqua and Terra satellite platforms. PAR fluxes are partitioned into reflected and absorbed components for the ground and canopy. The measurements demonstrate that the instrumentation provides detailed information about the vegetation phenology and variations in reflectance due to snow cover variations and vegetation development. Valuable information about PAR absorption of ground and canopy is obtained that may be linked to vegetation productivity.

  20. An optical sensor network for vegetation phenology monitoring and satellite data calibration.

    Science.gov (United States)

    Eklundh, Lars; Jin, Hongxiao; Schubert, Per; Guzinski, Radoslaw; Heliasz, Michal

    2011-01-01

    We present a network of sites across Fennoscandia for optical sampling of vegetation properties relevant for phenology monitoring and satellite data calibration. The network currently consists of five sites, distributed along an N-S gradient through Sweden and Finland. Two sites are located in coniferous forests, one in a deciduous forest, and two on peatland. The instrumentation consists of dual-beam sensors measuring incoming and reflected red, green, NIR, and PAR fluxes at 10-min intervals, year-round. The sensors are mounted on separate masts or in flux towers in order to capture radiation reflected from within the flux footprint of current eddy covariance measurements. Our computations and model simulations demonstrate the validity of using off-nadir sampling, and we show the results from the first year of measurement. NDVI is computed and compared to that of the MODIS instrument on-board Aqua and Terra satellite platforms. PAR fluxes are partitioned into reflected and absorbed components for the ground and canopy. The measurements demonstrate that the instrumentation provides detailed information about the vegetation phenology and variations in reflectance due to snow cover variations and vegetation development. Valuable information about PAR absorption of ground and canopy is obtained that may be linked to vegetation productivity.

  1. Modulation Classification of Satellite Communication Signals Using Cumulants and Neural Networks

    Science.gov (United States)

    Smith, Aaron; Evans, Michael; Downey, Joseph

    2017-01-01

    National Aeronautics and Space Administration (NASA)'s future communication architecture is evaluating cognitive technologies and increased system intelligence. These technologies are expected to reduce the operational complexity of the network, increase science data return, and reduce interference to self and others. In order to increase situational awareness, signal classification algorithms could be applied to identify users and distinguish sources of interference. A significant amount of previous work has been done in the area of automatic signal classification for military and commercial applications. As a preliminary step, we seek to develop a system with the ability to discern signals typically encountered in satellite communication. Proposed is an automatic modulation classifier which utilizes higher order statistics (cumulants) and an estimate of the signal-to-noise ratio. These features are extracted from baseband symbols and then processed by a neural network for classification. The modulation types considered are phase-shift keying (PSK), amplitude and phase-shift keying (APSK),and quadrature amplitude modulation (QAM). Physical layer properties specific to the Digital Video Broadcasting - Satellite- Second Generation (DVB-S2) standard, such as pilots and variable ring ratios, are also considered. This paper will provide simulation results of a candidate modulation classifier, and performance will be evaluated over a range of signal-to-noise ratios, frequency offsets, and nonlinear amplifier distortions.

  2. A system for the simulation and evaluation of satellite communication networks

    Science.gov (United States)

    Bagwell, J. W.

    1984-01-01

    With the emergence of a new era in satellite communications, brought about by NASA's thrust into the Ka band with multibeam and onboard processing technologies, new and innovative techniques for evaluating these concepts and systems are required. To this end, NASA, in conjunction with its extensive program for advanced communications technology development, has undertaken to develop a concept for the simulation and evaluation of a complete communications network. Incorporated in this network will be proof-of-concept models of the latest technologies proposed for future satellite communications systems. These include low noise receivers, matrix switches, baseband processors, and solid state and tube type high power amplifiers. To accomplish this, numerous supporting technologies must be added to those aforementioned proof-of-concept models. These include controllers for synchronization, order wire, resource allocation, gain compensation, signal leveling, power augmentation, and rain fade and range delay simulation. Taken together, these will be assembled to comprise a system capable of addressing numerous design and performance questions. The simulation and evaluation system, as planned, will be modular in design and implementation, capable of modification and updating to track and evaluate a continuum of emerging concepts and technologies. Previously announced in STAR as N84-13400

  3. Quantum communication for satellite-to-ground networks with partially entangled states

    Science.gov (United States)

    Chen, Na; Quan, Dong-Xiao; Pei, Chang-Xing; Yang-Hong

    2015-02-01

    To realize practical wide-area quantum communication, a satellite-to-ground network with partially entangled states is developed in this paper. For efficiency and security reasons, the existing method of quantum communication in distributed wireless quantum networks with partially entangled states cannot be applied directly to the proposed quantum network. Based on this point, an efficient and secure quantum communication scheme with partially entangled states is presented. In our scheme, the source node performs teleportation only after an end-to-end entangled state has been established by entanglement swapping with partially entangled states. Thus, the security of quantum communication is guaranteed. The destination node recovers the transmitted quantum bit with the help of an auxiliary quantum bit and specially defined unitary matrices. Detailed calculations and simulation analyses show that the probability of successfully transferring a quantum bit in the presented scheme is high. In addition, the auxiliary quantum bit provides a heralded mechanism for successful communication. Based on the critical components that are presented in this article an efficient, secure, and practical wide-area quantum communication can be achieved. Project supported by the National Natural Science Foundation of China (Grant Nos. 61072067 and 61372076), the 111 Project (Grant No. B08038), the Fund from the State Key Laboratory of Integrated Services Networks (Grant No. ISN 1001004), and the Fundamental Research Funds for the Central Universities (Grant Nos. K5051301059 and K5051201021).

  4. Resilient Sensor Networks with Spatiotemporal Interpolation of Missing Sensors: An Example of Space Weather Forecasting by Multiple Satellites.

    Science.gov (United States)

    Tokumitsu, Masahiro; Hasegawa, Keisuke; Ishida, Yoshiteru

    2016-04-15

    This paper attempts to construct a resilient sensor network model with an example of space weather forecasting. The proposed model is based on a dynamic relational network. Space weather forecasting is vital for a satellite operation because an operational team needs to make a decision for providing its satellite service. The proposed model is resilient to failures of sensors or missing data due to the satellite operation. In the proposed model, the missing data of a sensor is interpolated by other sensors associated. This paper demonstrates two examples of space weather forecasting that involves the missing observations in some test cases. In these examples, the sensor network for space weather forecasting continues a diagnosis by replacing faulted sensors with virtual ones. The demonstrations showed that the proposed model is resilient against sensor failures due to suspension of hardware failures or technical reasons.

  5. IndigoVision IP video keeps watch over remote gas facilities in Amazon rainforest

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-07-15

    In Brazil, IndigoVision's complete IP video security technology is being used to remotely monitor automated gas facilities in the Amazon rainforest. Twelve compounds containing millions of dollars of process automation, telemetry, and telecom equipment are spread across many thousands of miles of forest and centrally monitored in Rio de Janeiro using Control Center, the company's Security Management software. The security surveillance project uses a hybrid IP network comprising satellite, fibre optic, and wireless links. In addition to advanced compression technology and bandwidth tuning tools, the IP video system uses Activity Controlled Framerate (ACF), which controls the frame rate of the camera video stream based on the amount of motion in a scene. In the absence of activity, the video is streamed at a minimum framerate, but the moment activity is detected the framerate jumps to the configured maximum. This significantly reduces the amount of bandwidth needed. At each remote facility, fixed analog cameras are connected to transmitter nodules that convert the feed to high-quality digital video for transmission over the IP network. The system also integrates alarms with video surveillance. PIR intruder detectors are connected to the system via digital inputs on the transmitters. Advanced alarm-handling features in the Control Center software process the PIR detector alarms and alert operators to potential intrusions. This improves operator efficiency and incident response. 1 fig.

  6. A New Damage Assessment Method by Means of Neural Network and Multi-Sensor Satellite Data

    Directory of Open Access Journals (Sweden)

    Alessandro Piscini

    2017-08-01

    Full Text Available Artificial Neural Network (ANN is a valuable and well-established inversion technique for the estimation of geophysical parameters from satellite images. After training, ANNs are able to generate very fast products for several types of applications. Satellite remote sensing is an efficient way to detect and map strong earthquake damage for contributing to post-disaster activities during emergency phases. This work aims at presenting an application of the ANN inversion technique addressed to the evaluation of building collapse ratio (CR, defined as the number of collapsed buildings with respect to the total number of buildings in a city block, by employing optical and SAR satellite data. This is done in order to directly relate changes in images with damage that has occurred during strong earthquakes. Furthermore, once they have been trained, neural networks can be used rapidly at application stage. The goal was to obtain a general tool suitable for re-use in different scenarios. An ANN has been implemented in order to emulate a regression model and to estimate the CR as a continuous function. The adopted ANN has been trained using some features obtained from optical and Synthetic Aperture Radar (SAR images, as inputs, and the corresponding values of collapse ratio obtained from the survey of the 2010 M7 Haiti Earthquake, i.e., as target output. As regards the optical data, we selected three change parameters: the Normalized Difference Index (NDI, the Kullback–Leibler divergence (KLD, and Mutual Information (MI. Concerning the SAR images, the Intensity Correlation Difference (ICD and the KLD parameters have been considered. Exploiting an object-oriented approach, a segmentation of the study area into several regions has been performed. In particular, damage maps have been generated by considering a set of polygons (in which satellite parameters have been calculated extracted from the open source Open Street Map (OSM geo-database. The trained

  7. Voice over IP Security

    CERN Document Server

    Keromytis, Angelos D

    2011-01-01

    Voice over IP (VoIP) and Internet Multimedia Subsystem technologies (IMS) are rapidly being adopted by consumers, enterprises, governments and militaries. These technologies offer higher flexibility and more features than traditional telephony (PSTN) infrastructures, as well as the potential for lower cost through equipment consolidation and, for the consumer market, new business models. However, VoIP systems also represent a higher complexity in terms of architecture, protocols and implementation, with a corresponding increase in the potential for misuse. In this book, the authors examine the

  8. Neural Network Change Detection Model for Satellite Images Using Textural and Spectral Characteristics

    Directory of Open Access Journals (Sweden)

    A. K. Helmy

    2010-01-01

    Full Text Available Problem statement: Change detection is the process of identifying difference of the state of an object or phenomena by observing it at different time. Essentially, it involves the ability to quantify temporal effects using multi-temporal data sets. Information about change is necessary for evaluating land cover and the management of natural resources. Approach: A neural network model based on both spectral and textural analysis is developed. Change detection system in this study is presented using modified version of back-propagation-training algorithm with dynamic learning rate and momentum. Through proposed model, the two images at different dates are fed into the input layer of neural network, in addition with Variance, Skewness and Eculedian for each image that represent different texture measure. This leads to better discrimination process. Results: The results showed that the trained network with texture measures achieve 23% higher accuracy than that without textural parameters. Conclusion: Adding textural parameters of satellite images through training phase increases the efficiently of change detection process also, it provides adequate information about the type of changes. It also found, when using dynamic momentum and learning rate, time and effort needed to select their appropriate value is reduced.

  9. A FD/DAMA network architecture for the first generation land mobile satellite services

    Science.gov (United States)

    Yan, T.-Y.; Wang, C.; Cheng, U.; Dessouky, K.; Rafferty, W.

    1989-01-01

    A frequency division/demand assigned multiple access (FD/DAMA) network architecture for the first-generation land mobile satellite services is presented. Rationales and technical approaches are described. In this architecture, each mobile subscriber must follow a channel access protocol to make a service request to the network management center before transmission for either open-end or closed-end services. Open-end service requests will be processed on a blocked call cleared basis, while closed-end requests will be processed on a first-come-first-served basis. Two channel access protocols are investigated, namely, a recently proposed multiple channel collision resolution scheme which provides a significantly higher useful throughput, and the traditional slotted Aloha scheme. The number of channels allocated for either open-end or closed-end services can be adaptively changed according to aggregated traffic requests. Both theoretical and simulation results are presented. Theoretical results have been verified by simulation on the JPL network testbed.

  10. Quantum communication for satellite-to-ground networks with partially entangled states

    Institute of Scientific and Technical Information of China (English)

    陈娜; 权东晓; 裴昌幸; 杨宏

    2015-01-01

    To realize practical wide-area quantum communication, a satellite-to-ground network with partially entangled states is developed in this paper. For efficiency and security reasons, the existing method of quantum communication in distributed wireless quantum networks with partially entangled states cannot be applied directly to the proposed quantum network. Based on this point, an efficient and secure quantum communication scheme with partially entangled states is presented. In our scheme, the source node performs teleportation only after an end-to-end entangled state has been established by entanglement swapping with partially entangled states. Thus, security of quantum communication is guaranteed. The destination node recovers the transmitted quantum bit with the help of auxiliary quantum bit and specially defined unitary matrices. Detailed calculations and simulation analyses show that in the presented scheme, the probability of successfully transferring a quantum bit is high. In addition, the auxiliary quantum bit provides a heralded mechanism for successful communication. Based on these critical components presented in this article, an efficient, secure, and practical wide-area quantum communication can be achieved.

  11. Voice over IP

    OpenAIRE

    Mantula, Juha

    2006-01-01

    Tämä opinnäytetyö käsittelee Voice over Internet Protocol -tekniikkaa ja sen tuomia mahdollisuuksia yrityselämässä. Teoriaosa käsittelee VoIP:n kannalta tärkeitä pro-tokollia ja standardeja, VoIP:n ominaisuuksia sekä esittelee erilaisia puheohjelmia, jotka käyttävät VoIP-tekniikkaa hyväkseen. Empiirinen osuus tutkii Viestintä Ky Pitkärannan Skype-ohjelman käyttöä. Työn tarkoituksena on selvittää VoIP:n hyviä ja huonoja puolia ja sitä kuinka tek-niikkaa voidaan käyttää hyväksi päivittäisessä ...

  12. IP-STAR卫星跨点波束自动对星系统研究及应用展望%Study and Application Prospect of Automatic Tracking System Spanning the Spot Beam of IP-STAR Satellite’s Antenna

    Institute of Scientific and Technical Information of China (English)

    郑学东; 高云勇

    2015-01-01

    This paper made use of the locate function of GPS to determine the speciifc spot beam region of the mobile satellite application station in the IP-STAR satellite, the GIS map library kept in the CPU of the signal receiver and the spot beam database of the IP-STAR satellite; in addition it made use of the obtained information to which spot beam it had switched by means of the software of the user’s terminal computer to instruct the satellite antenna’s automatic tracking and the IP-STAR modem parameters’ automatic modiifcation, so that it realized the function of the automatic instruction of the IP-STAR modem’s access network. This paper achieved the automatic satellite-tracking and access network’s closed-loop control equipment and technique of the IP-STAR mobile satellite application station which were low-cost, simple to control, easy to operate, stable and high-precision.%利用GPS的定位功能,确定移动卫星应用站所在IP-STAR卫星的具体点波束区域,与储存在信号接收机内的CPU的GIS地图库及IP-STAR的点波束数据库,并能通过用户终端计算机安装的软件来获取跨到哪个点波束的信息,来指令卫星天线自动寻星完成及点波束的信息和自动修改IP-STAR调制解调器的参数,从而达到自动指令IP-STAR调制解调器完成入网的功能,实现了成本低廉、控制简单、便以操作、稳定性好、精度高的一种闭环IP-STAR移动卫星应用站的自动寻星和入网的控制装置及控制方法。

  13. Unlicensed Spectrum Sharing Game Between LEO Satellites and Terrestrial Cognitive Radio Networks

    Institute of Scientific and Technical Information of China (English)

    XIE Zhuochen; MA Lu; LIANG Xuwen

    2012-01-01

    By cognitive radio,the low Earth orbit (LEO) satellites may prefer to operate in the unlicensed spectrum which is open to all the users,and compete for the limited resources with terrestrial cognitive radio networks (CRNs).The competition can be regarded as a game and analyzed with game theory.This particular unlicensed spectrum sharing problem is modeled here,and the special properties of “spatially-distinguished-interference” and the short period of the interactions between satellites and terrestrial CRNs are explored.Then,the problem is formulated as a “partially-blind” finitely repeated prisoner's dilemma by game theory.Finally,we begin with two promising spectrum sharing schemes,which can be used to enforce the frequency reuse among the remotely located terrestrial CRN players as well as to overcome the observation noise.By analysis and comparison,it is proposed that the novel refreshing-contrite-tit-for-tat (R-CTFT) is the optimal spectrum sharing scheme.Simulation results verify that it can be used to utilize the spectrum most efficiently.

  14. A Topology Control Strategy with Reliability Assurance for Satellite Cluster Networks in Earth Observation

    Science.gov (United States)

    Chen, Qing; Zhang, Jinxiu; Hu, Ze

    2017-01-01

    This article investigates the dynamic topology control problem of satellite cluster networks (SCNs) in Earth observation (EO) missions by applying a novel metric of stability for inter-satellite links (ISLs). The properties of the periodicity and predictability of satellites’ relative position are involved in the link cost metric which is to give a selection criterion for choosing the most reliable data routing paths. Also, a cooperative work model with reliability is proposed for the situation of emergency EO missions. Based on the link cost metric and the proposed reliability model, a reliability assurance topology control algorithm and its corresponding dynamic topology control (RAT) strategy are established to maximize the stability of data transmission in the SCNs. The SCNs scenario is tested through some numeric simulations of the topology stability of average topology lifetime and average packet loss rate. Simulation results show that the proposed reliable strategy applied in SCNs significantly improves the data transmission performance and prolongs the average topology lifetime. PMID:28241474

  15. Adaptive Predistortions Based on Neural Networks Associated with Levenberg-Marquardt Algorithm for Satellite Down Links

    Directory of Open Access Journals (Sweden)

    Roviras Daniel

    2008-01-01

    Full Text Available Abstract This paper presents adaptive predistortion techniques based on a feed-forward neural network (NN to linearize power amplifiers such as those used in satellite communications. Indeed, it presents the suitable NN structures which give the best performances for three satellite down links. The first link is a stationary memoryless travelling wave tube amplifier (TWTA, the second one is a nonstationary memoryless TWT amplifier while the third is an amplifier with memory modeled by a memoryless amplifier followed by a linear filter. Equally important, it puts forward the studies concerning the application of different NN training algorithms in order to determine the most prefermant for adaptive predistortions. This comparison examined through computer simulation for 64 carriers and 16-QAM OFDM system, with a Saleh's TWT amplifier, is based on some quality measure (mean square error, the required training time to reach a particular quality level, and computation complexity. The chosen adaptive predistortions (NN structures associated with an adaptive algorithm have a low complexity, fast convergence, and best performance.

  16. Development of Cooperative Communication Techniques for a Network of Small Satellites and Cubesats in Deep Space

    Science.gov (United States)

    Babuscia, Alessandra; Cheung, Kar-Ming; Divsalar, Dariush; Lee, Charles

    2014-01-01

    This paper aims to address this problem by proposing cooperative communication approaches in which multiple CubeSats communicate cooperatively together to improve the link performance with respect to the case of a single satellite transmitting. Three approaches are proposed: a beam-forming approach, a coding approach, and a network approach. The approaches are applied to the specific case of a proposed constellation of CubeSats at the Lunar Lagrangian point L1 which aims to perform radio astronomy at very low frequencies (30 KHz -3 MHz). The paper describes the development of the approaches, the simulation and a graphical user interface developed in Matlab which allows to perform trade-offs across multiple constellation's configurations.

  17. A novel spectral index to automatically extract road networks from WorldView-2 satellite imagery

    Directory of Open Access Journals (Sweden)

    Kaveh Shahi

    2015-06-01

    Full Text Available This research develops a spectral index to automatically extract asphalt road networks named road extraction index (REI. This index uses WorldView-2 (WV-2 imagery, which has high spatial resolution and is multispectral. To determine the best bands for WV-2, field spectral data using a field spectroradiometer were collected. These data were then analyzed statistically. The bands were selected through the methodology of stepwise discriminant analysis. The appropriate WV-2 bands were distinguished from one another as per significant wavelengths. The proposed index is based on this classification. By applying REI to WV-2 imagery, we can extract asphalt roads accurately. Results demonstrate that REI is automated, transferable, and efficient in asphalt road extraction from high-resolution satellite imagery.

  18. Assimilation of Real-Time Satellite And Human Sensor Networks for Modeling Natural Disasters

    Science.gov (United States)

    Aulov, O.; Halem, M.; Lary, D. J.

    2011-12-01

    We describe the development of underlying technologies needed to address the merging of a web of real time satellite sensor Web (SSW) and Human Sensor Web (HSW) needed to augment the US response to extreme events. As an initial prototyping step and use case scenario, we consider the development of two major system tools that can be transitioned from research to the responding operational agency for mitigating coastal oil spills. These tools consist of the capture of Situation Aware (SA) Social Media (SM) Data, and assimilation of the processed information into forecasting models to provide incident decision managers with interactive virtual spatial temporal animations superimposed with probabilistic data estimates. The system methodologies are equally applicable to the wider class of extreme events such as plume dispersions from volcanoes or massive fires, major floods, hurricane impacts, radioactive isotope dispersions from nuclear accidents, etc. A successful feasibility demonstration of this technology has been shown in the case of the Deepwater Horizon Oil Spill where Human Sensor Networks have been combined with a geophysical model to perform parameter assessments. Flickr images of beached oil were mined from the spill area, geolocated and timestamped and converted into geophysical data. This data was incorporated into General NOAA Operational Modeling Environment (GNOME), a Lagrangian forecast model that uses near real-time surface winds, ocean currents, and satellite shape profiles of oil to generate a forecast of plume movement. As a result, improved estimates of diffusive coefficients and rates of oil spill were determined. Current approaches for providing satellite derived oil distributions are collected from a satellite sensor web of operational and research sensors from many countries, and a manual analysis is performed by NESDIS. A real time SA HSW processing system based on geolocated SM data from sources such as Twitter, Flickr, YouTube etc., greatly

  19. Coupling of ground biosensor networks for water monitoring with satellite observations in assessing Leptospirosis

    Science.gov (United States)

    Skouloudis, A. N.; Rickerby, D. G.

    2012-12-01

    Leptospirosis became recently a major public-health problem that is closely related with the environment (Nature review Oct 2009, Vol 7, pp 736-747). This disease originates from zoonotic pathogens associated with asymptomatic rodent carriers. Unfortunately, it effects human populations via various direct and indirect routes. This disease can claim many victims with large outbreaks during natural disasters or floods occurring during seasonal conditions. The severity of the illness ranges from subclinical infection to a fulminating fatal disease. Improved water quality monitoring techniques based on biosensor, optical, micro-fluidic and information technologies are leading to radical changes in our ability to perceive and monitor the aquatic environment. Biosensors are capable of providing specific, high spatial resolution information and allow unattended operation that will be particularly useful for water borne related diseases. Current research on biosensors is leading to solutions to problems for several contaminants that were previously irresolvable due to their high degree of complexity. Networking of the sensors enables sensitive monitoring systems allowing real-time monitoring of pollutants and facilitates data transmission between the measurement points and central control stations for continuous surveillance and to provide an early warning capability. The application of intelligent biosensor networks for water quality monitoring and detection of localized sources of pollution are discussed together with the setting up of a methodology that utilizes images from satellite coupled with in-situ sensors for anticipating the zones of potential evolution of this disease and assessing the population at risk. Environmental and climatic conditions that are associated the outbreaks are described and the rational of combining earth observations coupled with advanced in-situ biosensors is explained. The implementation of sensor networks for data collection and exposure

  20. 一种实时纠错的P2P模式网络立体电视播放系统%Real-time Correction IP-3DTV Player System Based on P2P Network

    Institute of Scientific and Technical Information of China (English)

    吴晨刚; 金志刚; 赵西满; 王佳

    2011-01-01

    随着宽带网络飞速发展,网络立体电视将成为未来视频主流业务.提出一种实时纠错的P2P模式网络立体电视播放系统的解决方案,该方案利用P2P技术进行视频传输,利用LDPC码进行纠错.经实验证明,在高斯噪声下,纠错后的立体视频与未纠错的相比,PSNR值平均提高约15dB.通过在CERNET2网络中测试,系统充分保证了立体视频的正常观看,同时系统配备认证功能,并且兼容IPv4和IPv6网络环境,能够为未来网络立体电视产业化发展提供有力支持.%With the rapid development of Broad-band network technology, 3DTV has become a research hotspot and IP-3DTV is to become a trend. This paper presents a solution to the real-time correction IP-3DTV player system based on P2P network, which a-dopts P2P and LDPC for video transmission and correction respectively. Experiment shows that with Gaussian noise, the average PSNR value of the corrected video increases by almost 15dB. We test the system in CERNET2, and find that the system runs normally. Meanwhile, the system is implemented with authentication, and can run in both IPV4 and IPV6 network, which provides strong support for the industrialized development of IP-3DTV in the future.

  1. 论数字网络广播IP流和TS流的异同%On the Similarities and Differences of IP Stream and TS Stream in Digital Network Broadcasting

    Institute of Scientific and Technical Information of China (English)

    吴志祥

    2016-01-01

    Mainly for digital IP flow network radio and digital TS stream function are introduced, IP network broadcasting inevitable five major disadvantages and TS flow broadcasting unique advantage at 6.In the final analysis the spirit sound intelligent emergency broadcasting system basic structure, forecasted its market vi-sion, be used for reference in the study of digital network broadcasting.%主要对数字IP流网络广播和数字TS流广播的功能进行了介绍,提出了IP网络广播不可避免的5大弊端以及TS流广播独有的6点优势。最后分析了灵声智能应急广播系统的基本结构,展望了其市场远景,对数字网络广播的研究起到借鉴作用。

  2. The utility of satellite fire product accuracy information - Perspectives and recommendations from the southern Africa fire network

    NARCIS (Netherlands)

    Roy, D.P.; Trigg, S.N.; Bhima, R.; Brockett, B.H.; Mutanga, O.; Virgilo, S.

    2006-01-01

    This correspondence gives Southern Africa Fire Network (SAFNet) perspectives on the utility of satellite fire product accuracy information, drawing on two main sources: insights gained during SAFNet's six years of working together, and relevant findings from a SAFNet focus group study that explored

  3. Destination directed packet switch architecture for a 30/20 GHz FDMA/TDM geostationary communication satellite network

    Science.gov (United States)

    Ivancic, William D.; Shalkhauser, Mary JO

    1991-01-01

    Emphasis is on a destination directed packet switching architecture for a 30/20 GHz frequency division multiplex access/time division multiplex (FDMA/TDM) geostationary satellite communication network. Critical subsystems and problem areas are identified and addressed. Efforts have concentrated heavily on the space segment; however, the ground segment was considered concurrently to ensure cost efficiency and realistic operational constraints.

  4. Circuit-switch architecture for a 30/20-GHz FDMA/TDM geostationary satellite communications network

    Science.gov (United States)

    Ivancic, William D.

    1992-01-01

    A circuit switching architecture is described for a 30/20 GHz frequency division, multiple access uplink/time division multiplexed downlink (FDMA/TDM) geostationary satellite communications network. Critical subsystems and problem areas are identified and addressed. Work was concentrated primarily on the space segment; however, the ground segment was considered concurrently to ensure cost efficiency and realistic operational constraints.

  5. Destination-directed, packet-switching architecture for 30/20-GHz FDMA/TDM geostationary communications satellite network

    Science.gov (United States)

    Ivancic, William D.; Shalkhauser, Mary JO

    1992-01-01

    A destination-directed packet switching architecture for a 30/20-GHz frequency division multiple access/time division multiplexed (FDMA/TDM) geostationary satellite communications network is discussed. Critical subsystems and problem areas are identified and addressed. Efforts have concentrated heavily on the space segment; however, the ground segment has been considered concurrently to ensure cost efficiency and realistic operational constraints.

  6. Presence in the IP Multimedia Subsystem

    Directory of Open Access Journals (Sweden)

    Ling Lin

    2007-01-01

    Full Text Available With an ever increasing penetration of Internet Protocol (IP technologies, the wireless industry is evolving the mobile core network towards all-IP network. The IP Multimedia Subsystem (IMS is a standardised Next Generation Network (NGN architectural framework defined by the 3rd Generation Partnership Project (3GPP to bridge the gap between circuit-switched and packet-switched networks and consolidate both sides into on single all-IP network for all services. In this paper, we provide an insight into the limitation of the presence service, one of the fundamental building blocks of the IMS. Our prototype-based study is unique of its kind and helps identifying the factors which limit the scalability of the current version of the presence service (3GPP TS 23.141 version 7.2.0 Release 7 [1], which will in turn dramatically limit the performance of advanced IMS services. We argue that the client-server paradigm behind the current IMS architecture does not suite the requirements of the IMS system, which defies the very purpose of its introduction. We finally elaborate on possible avenues for addressing this problem.

  7. An overview of neural network applications for soil moisture retrieval from radar satellite sensors

    Science.gov (United States)

    Santi, E.; Paloscia, S.; Pettinato, S.

    2014-10-01

    Frequent and spatially distributed measurements of soil moisture (SMC), at different spatial scales, are advisable for all applications related to the environmental disciplines, such as climatology, meteorology, hydrology and agriculture. Satellite sensors operating in the low part of microwave spectrum are very suitable for this purpose, and their signals can be directly related to the moisture content of the observed surfaces, provided that all the contributions from soil and vegetation to the measured signal are properly accounted for. Among the algorithms used for the retrieval of SMC from both active (i.e. Synthetic Aperture Radar, SAR or real aperture radars) and passive (radiometers) microwave sensors, the artificial neural networks (ANN) represent the best compromise between accuracy and computation speed. ANN based algorithms have been developed at IFAC, and adapted to several radar and radiometric satellite sensors, in order to generate SMC products at different spatial resolutions, varying from hundreds of meters to tens of kilometers. These algorithms, which use the ANN techniques for inverting theoretical and semi-empirical models, such as Advanced Integral Equation (AIEM), Oh models, and Radiative transfer Theory (RTT), have been adapted to the C-band acquisitions from SAR (Envisat/ASAR) and real aperture radar (ASCAT) and to the X-band SAR acquisitions of Cosmo-SkyMed and TerraSAR-X. Moreover, a specific ANN algorithm has also been implemented for the L-band active and passive acquisitions of the incoming SMAP mission. The latter satellite will carry onboard simultaneously one radar and one radiometer operating at the same frequency, but with different spatial resolutions (3 and 40 km, respectively). Large datasets of co-located satellite acquisitions and direct SMC measurements on several test sites located worldwide have been used along with simulations derived from forward electromagnetic models for setting up, training and validating these

  8. ATM QoS Experiments Using TCP Applications: Performance of TCP/IP Over ATM in a Variety of Errored Links

    Science.gov (United States)

    Frantz, Brian D.; Ivancic, William D.

    2001-01-01

    Asynchronous Transfer Mode (ATM) Quality of Service (QoS) experiments using the Transmission Control Protocol/Internet Protocol (TCP/IP) were performed for various link delays. The link delay was set to emulate a Wide Area Network (WAN) and a Satellite Link. The purpose of these experiments was to evaluate the ATM QoS requirements for applications that utilize advance TCP/IP protocols implemented with large windows and Selective ACKnowledgements (SACK). The effects of cell error, cell loss, and random bit errors on throughput were reported. The detailed test plan and test results are presented herein.

  9. Implementation of direct routing mobile IP for solving triangular routing

    Science.gov (United States)

    Jang, Jongwook; Jang, SeongHo; Park, Miri; Lee, Dae-bong

    2001-10-01

    Mobility support on the network layer is of special importance, as the network layer holds together the huge Internet with common protocol IP. Although based on possibility different wireless or wired technologies, all nodes of the network should be able to communicate. Therefore, mobile IP(an extension of the classical IP) has been designed which enablemobility in the Internet without changing existing wired systems. However, mobile IP leaves some points unsolved. Especially, if it comes to security, efficiency of the packet flow that is called triangular routing. Especially triangular routing can cause unnecessary overhead for the network. Furthermore latency can increase dramatically. This is particularly unfortunate if two communicating hosts are separated by transatlantic links. In order to this problem, many methods like IPv6 and ROMIP are proposed. But these methods have limitation. In other words, they have not compatibility because of needing modification of original IP scheme. Especially ROMIP is very complex and the overhead of control message and processing are serious. The problem of inconsistency of Binding caches may occur too. We therefore propose and analyze the performance of the DRMIP (Direct Routing Mobile IP) which do not modify IP source needed in the sender, is compatible with IP and Mobile IP.

  10. Design and performance evaluation of direct routing mobile IP

    Science.gov (United States)

    Jang, Jongwook; Jang, SeongHo; Kim, Kilyeun; Lee, Jung-Tae

    2001-07-01

    Mobility support on the network layer is of special importance, as the network layer holds together the huge Internet with common protocol IP. Although based on possibility different wireless or wired technologies, all nodes of the network should be able to communicate. Therefore, mobile IP (an extension of the classical IP) has been designed which enables mobility in the Internet without changing existing wired systems. However, mobile IP leaves some points unsolved. Especially, if it comes to security, efficient of the packet flow that is called triangular routing. Especially triangular routing can cause unnecessary overhead for the network. Furthermore latency can increase dramatically. This is particularly unfortunate if two communicating hosts are separated by transatlantic links. In order to this problem, many methods like IPv6 and ROMIP are proposed. But these methods have limitation. In other words, they have not compatibility because of needing modification or original IP scheme. Especially ROMIP is very complex and the overhead of control message and processing are serious. The problem of inconsistency of Binding caches may occur tool. We therefore propose and analyze the DRMIP (Direct Routing Mobile IP) which do not modify IP source needed in the sender, is compatible with IP and Mobile IP.

  11. 全IP网络中的分层移动管理结构%The Hierarchical Mobility Management in All IP Networks

    Institute of Scientific and Technical Information of China (English)

    何晓英; 雷振明

    2002-01-01

    该文首先简要介绍目前IP网上的移动管理方案Mobile IP,然后重点分析讨论对Mobile IP进行的改进和扩展,最后提出一种基于Mobile IP的适于未来全IP网络的分层移动管理结构.

  12. Impact of the codec and various QoS methods on the final quality of the transferred voice in an IP network

    Science.gov (United States)

    Slavata, Oldřich; Holub, Jan

    2015-02-01

    This paper deals with an analysis of the relation between the codec that is used, the QoS method, and the final voice transmission quality. The Cisco 2811 router is used for adjusting QoS. VoIP client Linphone is used for adjusting the codec. The criterion for transmission quality is the MOS parameter investigated with the ITU-T P.862 PESQ and P.863 POLQA algorithms.

  13. Secure Networks for First Responders and Special Forces

    Science.gov (United States)

    2005-01-01

    When NASA needed help better securing its communications with orbiting satellites, the Agency called on Western DataCom Co., Inc., to help develop a prototype Internet Protocol (IP) router. Westlake, Ohio-based Western DataCom designs, develops, and manufactures hardware that secures voice, video, and data transmissions over any IP-based network. The technology that it jointly developed with NASA is now serving as a communications solution in military and first-response situations.

  14. Integrated Services Digital Network (ISDN) status and opportunities for satellite systems

    Science.gov (United States)

    Casas, J. M.; Burke, W. R.

    1987-05-01

    The driving force behind the proposed Integrated Digital Services Network (ISDN) is identified as PTT's and industry. It is doubtful whether ISDN can satisfy business user requirements. For residential users, the prospects are even more uncertain, since the costs associated with the implementation of subscriber loops seem to be out of all proportion to the added value offered to end users in terms of new services. The evolution of IDN in Europe is such that it will leave substantial areas without digital connectivity for many years; morever, the transition from IDN to ISDN still requires the solution of many important problems at different levels of the network. Although ISDN can be expected to be offered gradually at national level in several countries in the coming years, access on a European scale will not be possible to any significant degree before the year 2000 and it will continue to remain unclear whether this offer will correspond to a real demand. It is shown that satellites could be of considerable help in solving Europe's communications problems. By providing instant coverage of the entire West European region, they can offer the benefits of ISDN wherever they are required.

  15. Delay analysis of an integrated voice and data access protocol with collision detection for multimedia satellite networks

    Science.gov (United States)

    Poon, Charles C. K.; Suda, Tatsuya

    1992-03-01

    The novel multiple-access scheme for multimedia satellite networks presented is based on a combination of FDMA and TDMA, integrating both circuit and packet-switching techniques. While the circuit-switching method is used to transmit such stream-type traffic as real-time voice communications, packet-switching is used to transmit such 'bursty' traffic as interactive data. A ground radio network is assumed for control signaling; the tone sense multiple access/partial collision detection scheme is implemented on this network to enhance the integrated access scheme's performance.

  16. Industry leading satellite based GNSS (Global Navigation Satellite System) positioning and monitoring solutions with real-time CORS (Continuously Operating Reference Station) networks

    Science.gov (United States)

    Janousek, Martin

    2010-05-01

    Real-Time CORS (Continuously Operating Reference Station Networks) today are typically GNSS networks for positioning and monitoring purposes. Real-Time networks can consist of a few stations for a local network up to nation- or continental wide networks with several hundred CORS stations. Such networks use wide area modeling of GNSS error sources including ionospheric, tropospheric and satellite orbit correction parameters to produce highest precision and efficiency method of positioning using GNSS. In 1998 Trimble Navigation Ltd. introduced a method of surveying with a non-physical or computed base station, called VRS (Virtual Reference Station). It is the most widely supported method of producing a network solution for precise carrier phase positioning in the industry. Surveying historically required one base as the fixed point of reference, and one or multiple rovers using that point of reference to compute their location by processing a vector result, either in real-time or in a postprocessed sense. Real-time survey is often referred to as RTK, short for real-time kinematic, and as the name suggests the results are in real time and you can move. The power of VRS is in the ability to compute a real-time wide-area solution to the factors that cause single base methods to degrade with distance. Namely, ionospheric and tropospheric modeling, and satellite orbit corrections. This is achieved by the reference network of CORS. A wide scattering of CORS across a state, typically 50-70km in mid-latitudes, creates a ground based sampling which significantly reduces the distance dependent errors that accumulate in the single base-rover relationship described early. Furthermore, GNSS networks can be used for real-time monitoring purposes at various distance range. Trimble Integrity Manager software provides a suite of motion engines designed to detect and quantify any movement in a range of scales from slow, creeping movement like subsidence, through sudden events such as

  17. S@tMax—A space-based system enabling mobile IP applications in vehicles

    Science.gov (United States)

    Arcioni, Marco; Daehler, Erik; Mueller, Robert P.; van der Meulen, Wencke

    2009-06-01

    As personal mobility increases, people spend more time in their vehicles. Furthermore, a large segment of today's workforce is part of a growing mobile service industry. This mobile society creates opportunities to increase productivity which do not yet exist. Today's commuting time could be better utilized and mobile business transactions could be more efficiently conducted, by integrating mobile IP wireless services in vehicles. By means of a direct to mobile user Internet access, and total IP services, integrated into automobiles, S@tMax services can empower the mobile business movement therefore improving productivity. This paper presents a commercial system architecture that will deliver an optimized solution for direct to mobile user Internet access, through an integration of a ground based network infrastructure, use of existing communications satellites and the development of a proprietary satellite system. As a result of a detailed systems engineering process, the architectures of the space, ground and infrastructures segments will be presented. Furthermore, the benefits of on-orbit servicing were examined in the S@tMax context. The approach proposed is considered as an important step towards enforcing main roadway IP coverage in the US, for near-continuous communications and services.

  18. Swarm Utilisation Analysis: LEO satellite observations for the ESA's SSA Space Weather network

    Science.gov (United States)

    Kervalishvili, Guram; Stolle, Claudia; Rauberg, Jan; Olsen, Nils; Vennerstrøm, Susanne; Gullikstad Johnsen, Magnar; Hall, Chris

    2017-04-01

    ESA's (European Space Agency) constellation mission Swarm was successfully launched on 22 November 2013. The three satellites achieved their final constellation on 17 April 2014 and since then Swarm-A and Swarm-C orbiting the Earth at about 470 km (flying side-by-side) and Swarm-B at about 520 km altitude. Each of Swarm satellite carries instruments with high precision to measure magnetic and electric fields, neutral and plasma densities, and TEC (Total Electron Content) for which a dual frequency GPS receiver is used. SUA (Swarm Utilisation Analysis) is a project of the ESA's SSA (Space Situational Awareness) SWE (Space Weather) program. Within this framework GFZ (German Research Centre for Geosciences, Potsdam, Germany) and DTU (National Space Institute, Kongens Lyngby, Denmark) have developed two new Swarm products ROT (Rate Of change of TEC) and PEJ (Location and intensity level of Polar Electrojets), respectively. ROT is derived as the first time derivative from the Swarm measurements of TEC at 1 Hz sampling. ROT is highly relevant for users in navigation and communications: strong plasma gradients cause GPS signal degradation or even loss of GPS signal. Also, ROT is a relevant space weather asset irrespective of geomagnetic activity, e.g., high amplitude values of ROT occur during all geomagnetic conditions. PEJ is derived from the Swarm measurements of the magnetic field strength at 1 Hz sampling. PEJ has a high-level importance for power grid companies since the polar electrojet is a major cause for ground-induced currents. ROT and PEJ together with five existing Swarm products TEC, electron density, IBI (Ionospheric Bubble Index), FAC (Field-Aligned Current), and vector magnetic field build the SUA service prototype. This prototype will be integrated into ESA's SSA Space Weather network as a federated service and will be available soon from ESA's SSA SWE Ionospheric Weather and Geomagnetic Conditions Expert Service Centres (ESCs).

  19. Attack Methods and Security Strategies of TCP/IP Network%TCP/IP网络的攻击方式与安全策略

    Institute of Scientific and Technical Information of China (English)

    颜世峰; 栾贵兴; 李莉

    2001-01-01

    网络安全一直是困扰Internet应用发展的重大问题.针对Internet所使用协议的目前版本IPv4,本文首先介绍了几种TCP/IP网络的几种攻击方式,然后详细分析了几种TCP/IP---尤其是TCP攻击的原理,最后给出了TCP/IP网络安全的几种解决方案.

  20. Contribution of MODIS Derived Snow Cover Satellite Data into Artificial Neural Network for Streamflow Estimation

    Science.gov (United States)

    Uysal, Gokcen; Arda Sorman, Ali; Sensoy, Aynur

    2014-05-01

    Contribution of snowmelt and correspondingly snow observations are highly important in mountainous basins for modelers who deal with conceptual, physical or soft computing models in terms of effective water resources management. Long term archived continuous data are needed for appropriate training and testing of data driven approaches like artificial neural networks (ANN). Data is scarce at the upper elevations due to the difficulty of installing sufficient automated SNOTEL stations; thus in literatures many attempts are made on the rainfall dominated basins for streamflow estimation studies. On the other hand, optical satellites can easily detect snow because of its high reflectance property. MODIS (Moderate Resolution Imaging Spectroradiometer) satellite that has two platforms (Terra and Aqua) provides daily and 8-daily snow images for different time periods since 2000, therefore snow cover data (SCA) may be useful as an input layer for ANN applications. In this study, a multi-layer perceptron (MLP) model is trained and tested with precipitation, temperature, radiation, previous day discharges as well as MODIS daily SCA data. The weights and biases are optimized with fastest and robust Levenberg-Marquardt backpropagation algorithm. MODIS snow cover images are removed from cloud coverage using certain filtering techniques. The Upper Euphrates River Basin in eastern part of Turkey (10 250 km2) is selected as the application area since it is fed by snowmelt approximately 2/3 of total annual volume during spring and early summer. Several input models and ANN structures are investigated to see the effect of the contributions using 10 years of data (2001-2010) for training and validation. The accuracy of the streamflow estimations is checked with statistical criteria (coefficient of determination, Nash-Sutcliffe model efficiency, root mean square error, mean absolute error) and the results seem to improve when SCA data is introduced. Furthermore, a forecast study is

  1. Digital signage sobre IP

    OpenAIRE

    Casademont Filella, Albert

    2012-01-01

    Projecte que versa sobre el disseny i la implementació d'un sistema de Digital Signage (Cartelleria Digital) sobre IP, creant un gestor que permeti controlar de forma remota tot un conjunt de petits dispositius connectats a pantalles que emeten continguts multimèdia com vídeos, imatges, feeds rss...

  2. Secure IP mobility management for VANET

    CERN Document Server

    Taha, Sanaa

    2013-01-01

    This brief presents the challenges and solutions for VANETs' security and privacy problems occurring in mobility management protocols including Mobile IPv6 (MIPv6), Proxy MIPv6 (PMIPv6), and Network Mobility (NEMO). The authors give an overview of the concept of the vehicular IP-address configurations as the prerequisite step to achieve mobility management for VANETs, and review the current security and privacy schemes applied in the three mobility management protocols. Throughout the brief, the authors propose new schemes and protocols to increase the security of IP addresses within VANETs in

  3. Comparison of global irradiance measurements of the official Spanish radiometric network for 2006 with satellite estimated data

    Directory of Open Access Journals (Sweden)

    J. M. Sancho

    2011-01-01

    Full Text Available The monthly average values of daily global irradiance measured in broadband at 40 stations of the National Radiometric Network of the Spanish Meteorological Agency have been compared with the monthly values of SIS (Surface Incoming Shortwave radiation of the Climate Monitoring-Satellite Application Facility for 2006. It is calculated by the data from the instrument Spinning Enhanced Visible and Infrared Imager of the Meteosat Second Generation satellite and of the Advanced Very High Resolution Radiometer of the NOAA polar satellites. The results show a great similarity between the data from both sources of information, and the discrepancies found are around 5%. The aim of such a comparison is to evaluate the suitability of the use of the SIS data for the elaboration of an atlas of solar irradiance available in Spain.

  4. Alternative packet switch architectures for a 30/20 GHz FDMA/TDMA geostationary communication satellite network

    Science.gov (United States)

    Stehle, Roy; Ogier, Richard G.

    1995-01-01

    This study has investigated alternatives for realizing a packet-based network switch for deployment on a communication satellite. The emphasis was on the avoidance of contention problems that can occur due to the simultaneous arrival of an excessive number of packets destined for the same downlink dwell. The study was to look ahead, beyond the current Advanced Communications Technology Satellite (ACTS) capability, to the next generation of satellites. The study has not been limited by currently available technology, but has used university and commercial research efforts as a basis for designs that can be readily constructed and launched within the next five years. Tradeoffs in memory requirement, power requirement, and architecture have been considered as a part of our study.

  5. Spatiotemporal interpolation of discharge across a river network by using synthetic SWOT satellite data

    Science.gov (United States)

    Paiva, Rodrigo C. D.; Durand, Michael T.; Hossain, Faisal

    2015-01-01

    Recent efforts have sought to estimate river discharge and other surface water-related quantities using spaceborne sensors, with better spatial coverage but worse temporal sampling as compared with in situ measurements. The Surface Water and Ocean Topography (SWOT) mission will provide river discharge estimates globally from space. However, questions on how to optimally use the spatially distributed but asynchronous satellite observations to generate continuous fields still exist. This paper presents a statistical model (River Kriging-RK), for estimating discharge time series in a river network in the context of the SWOT mission. RK uses discharge estimates at different locations and times to produce a continuous field using spatiotemporal kriging. A key component of RK is the space-time river discharge covariance, which was derived analytically from the diffusive wave approximation of Saint Venant's equations. The RK covariance also accounts for the loss of correlation at confluences. The model performed well in a case study on Ganges-Brahmaputra-Meghna (GBM) River system in Bangladesh using synthetic SWOT observations. The correlation model reproduced empirically derived values. RK (R2=0.83) outperformed other kriging-based methods (R2=0.80), as well as a simple time series linear interpolation (R2=0.72). RK was used to combine discharge from SWOT and in situ observations, improving estimates when the latter is included (R2=0.91). The proposed statistical concepts may eventually provide a feasible framework to estimate continuous discharge time series across a river network based on SWOT data, other altimetry missions, and/or in situ data.

  6. IP validation in remote microelectronics testing

    Science.gov (United States)

    Osseiran, Adam; Eshraghian, Kamran; Lachowicz, Stefan; Zhao, Xiaoli; Jeffery, Roger; Robins, Michael

    2004-03-01

    This paper presents the test and validation of FPGA based IP using the concept of remote testing. It demonstrates how a virtual tester environment based on a powerful, networked Integrated Circuit testing facility, aimed to complement the emerging Australian microelectronics based research and development, can be employed to perform the tasks beyond the standard IC test. IC testing in production consists in verifying the tested products and eliminating defective parts. Defects could have a number of different causes, including process defects, process migration and IP design and implementation errors. One of the challenges in semiconductor testing is that while current fault models are used to represent likely faults (stuck-at, delay, etc.) in a global context, they do not account for all possible defects. Research in this field keeps growing but the high cost of ATE is preventing a large community from accessing test and verification equipment to validate innovative IP designs. For these reasons a world class networked IC teletest facility has been established in Australia under the support of the Commonwealth government. The facility is based on a state-of-the-art semiconductor tester operating as a virtual centre spanning Australia and accessible internationally. Through a novel approach the teletest network provides virtual access to the tester on which the DUT has previously been placed. The tester software is then accessible as if the designer is sitting next to the tester. This paper presents the approach used to test and validate FPGA based IPs using this remote test approach.

  7. Using remote sensing satellite data and artificial neural network for prediction of potato yield in Bangladesh

    Science.gov (United States)

    Akhand, Kawsar; Nizamuddin, Mohammad; Roytman, Leonid; Kogan, Felix

    2016-09-01

    Potato is one of the staple foods and cash crops in Bangladesh. It is widely cultivated in all of the districts and ranks second after rice in production. Bangladesh is the fourth largest potato producer in Asia and is among the world's top 15 potato producing countries. The weather condition for potato cultivation is favorable during the sowing, growing and harvesting period. It is a winter crop and is cultivated during the period of November to March. Bangladesh is mainly an agricultural based country with respect to agriculture's contribution to GDP, employment and consumption. Potato is a prominent crop in consideration of production, its internal demand and economic value. Bangladesh has a big economic activities related to potato cultivation and marketing, especially the economic relations among farmers, traders, stockers and cold storage owners. Potato yield prediction before harvest is an important issue for the Government and the stakeholders in managing and controlling the potato market. Advanced very high resolution radiometer (AVHRR) based satellite data product vegetation health indices VCI (vegetation condition index) and TCI (temperature condition index) are used as predictors for early prediction. Artificial neural network (ANN) is used to develop a prediction model. The simulated result from this model is encouraging and the error of prediction is less than 10%.

  8. Learning Oriented Region-based Convolutional Neural Networks for Building Detection in Satellite Remote Sensing Images

    Science.gov (United States)

    Chen, C.; Gong, W.; Hu, Y.; Chen, Y.; Ding, Y.

    2017-05-01

    The automated building detection in aerial images is a fundamental problem encountered in aerial and satellite images analysis. Recently, thanks to the advances in feature descriptions, Region-based CNN model (R-CNN) for object detection is receiving an increasing attention. Despite the excellent performance in object detection, it is problematic to directly leverage the features of R-CNN model for building detection in single aerial image. As we know, the single aerial image is in vertical view and the buildings possess significant directional feature. However, in R-CNN model, direction of the building is ignored and the detection results are represented by horizontal rectangles. For this reason, the detection results with horizontal rectangle cannot describe the building precisely. To address this problem, in this paper, we proposed a novel model with a key feature related to orientation, namely, Oriented R-CNN (OR-CNN). Our contributions are mainly in the following two aspects: 1) Introducing a new oriented layer network for detecting the rotation angle of building on the basis of the successful VGG-net R-CNN model; 2) the oriented rectangle is proposed to leverage the powerful R-CNN for remote-sensing building detection. In experiments, we establish a complete and bran-new data set for training our oriented R-CNN model and comprehensively evaluate the proposed method on a publicly available building detection data set. We demonstrate State-of-the-art results compared with the previous baseline methods.

  9. AERONET-OC: Strengths and Weaknesses of a Network for the Validation of Satellite Coastal Radiometric Products

    Science.gov (United States)

    Zibordi, Giuseppe; Holben, Brent; Slutsker, Ilya; Giles, David; D'Alimonte, Davide; Melin, Frederic; Berthon, Jean-Francois; Vandemark, Doug; Feng, Hui; Schuster, Gregory; Fabbri, Bryan E.; Kaitala, Seppo; Seppala, Jukka

    2008-01-01

    The Ocean Color component of the Aerosol Robotic Network (AERONET-OC) has been implemented to support long-term satellite ocean color investigations through cross-site consistent and accurate measurements collected by autonomous radiometer systems deployed on offshore fixed platforms. The ultimate purpose of AERONET-OC is the production of standardized measurements performed at different sites with identical measuring systems and protocols, calibrated using a single reference source and method, and processed with the same code. The AERONET-OC primary data product is the normalized water leaving radiance determined at center-wavelengths of interest for satellite ocean color applications, with an uncertainty lower than 5% in the blue-green spectral regions and higher than 8% in the red. Measurements collected at 6 sites counting the northern Adriatic Sea, the Baltic Proper, the Gulf of Finland, the Persian Gulf, and, the northern and southern margins of the Middle Atlantic Bay, have shown the capability of producing quality assured data over a wide range of bio-optical conditions including Case-2 yellow substance- and sedimentdominated waters. This work briefly introduces network elements like: deployment sites, measurement method, instrument calibration, processing scheme, quality-assurance, uncertainties, data archive and products accessibility. Emphases is given to those elements which underline the network strengths (i.e., mostly standardization of any network element) and its weaknesses (i.e., the use of consolidated, but old-fashioned technology). The work also addresses the application of AERONET-OC data to the validation of primary satellite radiometric products over a variety of complex coastal waters and finally provides elements for the identification of new deployment sites most suitable to support satellite ocean color missions.

  10. Analysis of IDS and IPS Network Security In-depth Protection Strategy%浅析IDS及IPS网络安全深层防护策略

    Institute of Scientific and Technical Information of China (English)

    王秋华

    2005-01-01

    随着网络入侵事件的不断增加和黑客攻击水平的不断提高,传统的防火墙或入侵检测技术(IDS)已显得力不从心,这就需要引入一种全新的技术-入侵防护(Intrusion Prevention System,IPS).本文在分析IDS不足的基础上,探讨了IPS的工作原理和技术特征及其面临的挑战.并探讨了未来网络安全深层防护的策略.

  11. Robust adjustment of a geodetic network measured by satellite technology in the Dargovských Hrdinov suburb

    Directory of Open Access Journals (Sweden)

    Slavomír Labant

    2011-12-01

    Full Text Available This article addresses the adjustment of a 3D geodetic network in the Dargovských Hrdinov suburbs using Global Navigation SatelliteSystems (GNSS for the purposes of deformation analysis. The advantage of using the GNSS compared to other terrestrial technology is thatit is not influenced by unpredictability in the ground level atmosphere and individual visibilities between points in the observed network arenot necessary. This article also includes the planning of GNSS observations using Planning Open Source software from Trimble as well assubsequent observations at individual network points. The geodetic network is processing on the basis of the Gauss-Markov model usingthe least square method and robust adjustment. From robust methods, Huber’s Robust M-estimation and Hampel’s Robust M-estimationwere used. Individual adjustments were tested and subsequently the results of analysis were graphically visualised using absolute confidenceellipsoids.

  12. Measuring QoS in an Aeronautical Opportunistic Network Architecture with Limited Access to a Satellite Communications Backhaul

    Directory of Open Access Journals (Sweden)

    Rubén Martínez-Vidal

    2016-01-01

    Full Text Available We measure quality of service (QoS in a wireless network architecture of transoceanic aircraft. A distinguishing characteristic of the network scheme we analyze is that it mixes the concept of Delay Tolerant Networking (DTN through the exploitation of opportunistic contacts, together with direct satellite access in a limited number of the nodes. We provide a graph sparsification technique for deriving a network model that satisfies the key properties of a real aeronautical opportunistic network while enabling scalable simulation. This reduced model allows us to analyze the impact regarding QoS of introducing Internet-like traffic in the form of outgoing data from passengers. Promoting QoS in DTNs is usually really challenging due to their long delays and scarce resources. The availability of satellite communication links offers a chance to provide an improved degree of service regarding a pure opportunistic approach, and therefore it needs to be properly measured and quantified. Our analysis focuses on several QoS indicators such as delivery time, delivery ratio, and bandwidth allocation fairness. Obtained results show significant improvements in all metric indicators regarding QoS, not usually achievable on the field of DTNs.

  13. Research on a New Program of Satellite Network Security Certification%一种新型卫星网络安全认证方案的研究

    Institute of Scientific and Technical Information of China (English)

    高婧; 朱晨光

    2011-01-01

    在卫星网络通信中,卫星的安全防护是卫星通信系统建设的重要内容之一.结合卫星网络的特点,在对卫星网络的安全认证需求进行分析的基础上,提出了一种基于ELGamal数字签名的卫星网络安全双向认证方案,以解决卫星干扰、非法盗用卫星资源的问题;克服了传统认证方案中普遍存在的认证效率较低和认证过程较复杂等问题,如将该方案加以推广,可以广泛采用.%In the communication of satellite network, the security of satellite is an important content in the development of satellite communication system.Combining with the characteristics of satellite network and analyzing the safety certification requirements of satellite network, a two-way satellite network security certification program based on EIGamal digital signature is introduced to address the satellite interference, illegal use of satellite resources, and overcome the low efficiency and complex process certification existed in traditional common certification.This program can he widely adopted.

  14. Combined Geometric and Neural Network Approach to Generic Fault Diagnosis in Satellite Actuators and Sensors

    DEFF Research Database (Denmark)

    Baldi, P.; Blanke, Mogens; Castaldi, P.

    2016-01-01

    This paper presents a novel scheme for diagnosis of faults affecting the sensors measuring the satellite attitude, body angular velocity and flywheel spin rates as well as defects related to the control torques provided by satellite reaction wheels. A nonlinear geometric design is used to avoid...... on a detailed nonlinear satellite model with embedded disturbance description. The results document the efficacy of the proposed diagnosis scheme....

  15. A Methodology For Measuring Resilience in a Satellite-Based Communication Network

    Science.gov (United States)

    2014-03-27

    In the cyber realm, most satellite operators were in compliance with the National Security Agency’s (NSA) approved encryptions for transmissions...and more continue to meet compliance as new satellites are placed in orbit. Along with the encryptions , many 17 satellite operators utilize “deaf...nation at war may be of higher concern than the nation providing backdoor support which is higher than a neutral nation, and so on until a region not

  16. Towards Multi-Stage Intrusion Detection using IP Flow Records

    OpenAIRE

    Muhammad Fahad Umer; Muhammad Sher; Imran Khan

    2016-01-01

    Traditional network-based intrusion detection sys-tems using deep packet inspection are not feasible for modern high-speed networks due to slow processing and inability to read encrypted packet content. As an alternative to packet-based intrusion detection, researchers have focused on flow-based intrusion detection techniques. Flow-based intrusion detection systems analyze IP flow records for attack detection. IP flow records contain summarized traffic information. However, flow data is very ...

  17. Satellite/Terrestrial Networks: End-to-End Communication Interoperability Quality of Service Experiments

    Science.gov (United States)

    Ivancic, William D.

    1998-01-01

    Various issues associated with satellite/terrestrial end-to-end communication interoperability are presented in viewgraph form. Specific topics include: 1) Quality of service; 2) ATM performance characteristics; 3) MPEG-2 transport stream mapping to AAL-5; 4) Observation and discussion of compressed video tests over ATM; 5) Digital video over satellites status; 6) Satellite link configurations; 7) MPEG-2 over ATM with binomial errors; 8) MPEG-2 over ATM channel characteristics; 8) MPEG-2 over ATM over emulated satellites; 9) MPEG-2 transport stream with errors; and a 10) Dual decoder test.

  18. Controlling IP Falsifying Using Realistic Simulation

    Directory of Open Access Journals (Sweden)

    Govindavaram Madhusri

    2013-07-01

    Full Text Available The study of Internet-scale events such as worm proliferation, distributed denial-of-service attacks (DDoS,flash crowds, routing volatilities, and DNS attacks depend on the formation of all the networks thatgenerate or forward valid and malevolent traffic,The Distributed Denial of Services (DDoS attack is aserious threat to the valid use of the Internet. Forestalling mechanisms are disappointed by the ability ofattackers to steal, or spoof, the source addresses in IP packets. IP falsifying is still widespread in networkscanning and investigates, as well as denial of service floods.IDPFs can limit the falsifying capability ofattackers. Moreover, it works on a small number of candidate networks easily traceable, thus simplifyingthe reactive IP trace back process. However, this technique does not allow large number of networks,which is a common misapprehension for those unfamiliar with the practice. Current network simulatorscannot be used to study Internet-scale events. They are general-purpose, packet-level simulators thatreproduce too many details of network communication, which limits scalability. We propose to develop adistributed Internet simulator, with the following novel features. It will provide a built-in Internet model,including the topology, routing, link bandwidths and delays, Instead of being a general-purpose simulator,it will provide a common simulation core for traffic generation and message passing, on top of which wewill build separate modules that customize messages and level of simulation details for the event of interest.Customization modules will ensure that all and only the relevant details of the event of interest aresimulated, cutting down the simulation time. We will also provide an interface for new modulespecification, and for existing module modification, this will bring the Internet event simulation at thefingertips of all interested researchers. The simulator will promote research in worm detection and defense,IP

  19. Developing a new global network of river reaches from merged satellite-derived datasets

    Science.gov (United States)

    Lion, C.; Allen, G. H.; Beighley, E.; Pavelsky, T.

    2015-12-01

    In 2020, the Surface Water and Ocean Topography satellite (SWOT), a joint mission of NASA/CNES/CSA/UK will be launched. One of its major products will be the measurements of continental water extent, including the width, height, and slope of rivers and the surface area and elevations of lakes. The mission will improve the monitoring of continental water and also our understanding of the interactions between different hydrologic reservoirs. For rivers, SWOT measurements of slope must be carried out over predefined river reaches. As such, an a priori dataset for rivers is needed in order to facilitate analysis of the raw SWOT data. The information required to produce this dataset includes measurements of river width, elevation, slope, planform, river network topology, and flow accumulation. To produce this product, we have linked two existing global datasets: the Global River Widths from Landsat (GRWL) database, which contains river centerline locations, widths, and a braiding index derived from Landsat imagery, and a modified version of the HydroSHEDS hydrologically corrected digital elevation product, which contains heights and flow accumulation measurements for streams at 3 arcsecond spatial resolution. Merging these two datasets requires considerable care. The difficulties, among others, lie in the difference of resolution: 30m versus 3 arseconds, and the age of the datasets: 2000 versus ~2010 (some rivers have moved, the braided sections are different). As such, we have developed custom software to merge the two datasets, taking into account the spatial proximity of river channels in the two datasets and ensuring that flow accumulation in the final dataset always increases downstream. Here, we present our preliminary results for a portion of South America and demonstrate the strengths and weaknesses of the method.

  20. Integrating Satellite, Aircraft, and Ground-Based Observations to Improve a GHG Inventory Network

    Science.gov (United States)

    Midzik, M.; Abbate, J.; Raheja, G.

    2016-12-01

    Methane (CH4) is the second-most effective greenhouse gas, with a global warming potential up to 70 times that of carbon dioxide (CO2) over the span of 25 years. With a majority of these emissions attributed to livestock, landfill, and wastewater treatment, CH4 emissions are a concern for both urban and rural landscapes. Though Earth-observing satellites can effectively monitor mid-to-upper tropospheric CH4 on a global scale, current instrumentation is limited in its capacity to accurately measure near-surface CH4 on a local scale. The Bay Area Air Quality Management District (BAAQMD) regulates stationary sources of air pollution in the nine counties surrounding San Francisco Bay. BAAQMD traditionally estimates emissions using a bottom-up approach, combining emissions factor and activity data to estimate source emissions per sector. However, recent literature suggests that these bottom-up approaches are underestimating CH4 emissions by nearly 50% in many regions of California. In efforts to address the discrepancy, this project compares BAAQMD's current CH4 spatial emissions inventory with top-down sub-Planetary Boundary Layer aircraft measurements from the NASA Alpha Jet Atmospheric eXperiment (AJAX). Together, these different approaches were used to identify CH4 hot-spots in the San Francisco Bay Area. In addition, sources of high-CH4 anomalies were identified using USGS high resolution aerial imagery and trajectory analysis. Furthermore, this project used NASA Landsat 8 imagery and USGS orthoimagery to classify the types of indicated emissions and infer other points of interest not included in the current BAAQMD inventory. These findings help pinpoint specific sites for BAAQMD's upcoming Mobile GHG Measurement Network; furthermore, results from this project suggest future sites for coincident data collection between advancing bottom-up and top-down instruments.