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Sample records for qos provisioning recurrent

  1. A QoS Provisioning Recurrent Neural Network based Call Admission Control for beyond 3G Networks

    Directory of Open Access Journals (Sweden)

    Ramesh Babu H. S.

    2010-03-01

    Full Text Available The Call admission control (CAC is one of the Radio Resource Management (RRM techniques that plays influential role in ensuring the desired Quality of Service (QoS to the users and applications in next generation networks. This paper proposes a fuzzy neural approach for making the call admission control decision in multi class traffic based Next Generation Wireless Networks (NGWN. The proposed Fuzzy Neural call admission control (FNCAC scheme is an integrated CAC module that combines the linguistic control capabilities of the fuzzy logic controller and the learning capabilities of the neural networks. The model is based on recurrent radial basis function networks which have better learning and adaptability that can be used to develop intelligent system to handle the incoming traffic in an heterogeneous network environment. The simulation results are optimistic and indicates that the proposed FNCAC algorithm performs better than the other two methods and the call blocking probability is minimal when compared to other two methods.

  2. A QoS Provisioning Recurrent Neural Network based Call Admission Control for beyond 3G Networks

    CERN Document Server

    S., Ramesh Babu H; S, Satyanarayana P

    2010-01-01

    The Call admission control (CAC) is one of the Radio Resource Management (RRM) techniques that plays influential role in ensuring the desired Quality of Service (QoS) to the users and applications in next generation networks. This paper proposes a fuzzy neural approach for making the call admission control decision in multi class traffic based Next Generation Wireless Networks (NGWN). The proposed Fuzzy Neural call admission control (FNCAC) scheme is an integrated CAC module that combines the linguistic control capabilities of the fuzzy logic controller and the learning capabilities of the neural networks. The model is based on recurrent radial basis function networks which have better learning and adaptability that can be used to develop intelligent system to handle the incoming traffic in an heterogeneous network environment. The simulation results are optimistic and indicates that the proposed FNCAC algorithm performs better than the other two methods and the call blocking probability is minimal when compa...

  3. QoS mapping algorithm for ETE QoS provisioning

    Science.gov (United States)

    Wu, Jian J.; Foster, Gerry

    2002-08-01

    End-to-End (ETE) Quality of Service (QoS) is critical for next generation wireless multimedia communication systems. To meet the ETE QoS requirements, Universal Mobile Telecommunication System (UMTS) requires not only meeting the 3GPP QoS requirements [1-2] but also mapping external network QoS classes to UMTS QoS classes. There are four Quality of Services (QoS) classes in UMTS; they are Conversational, Streaming, Interactive and Background. There are eight QoS classes for LAN in IEEE 802.1 (one reserved). ATM has four QoS categories. They are Constant Bit Rate (CBR) - highest priority, short queue for strict Cell Delay Variation (CDV), Variable Bit Rate (VBR) - second highest priority, short queues for real time, longer queues for non-real time, Guaranteed Frame Rate (GFR)/ Unspecified Bit Rate (UBR) with Minimum Desired Cell Rate (MDCR) - intermediate priority, dependent on service provider UBR/ Available Bit Rate (ABR) - lowest priority, long queues, large delay variation. DiffServ (DS) has six-bit DS codepoint (DSCP) available to determine the datagram's priority relative to other datagrams and therefore, up to 64 QoS classes are available from the IPv4 and IPv6 DSCP. Different organisations have tried to solve the QoS issues from their own perspective. However, none of them has a full picture for end-to-end QoS classes and how to map them among all QoS classes. Therefore, a universal QoS needs to be created and a new set of QoS classes to enable end-to-end (ETE) QoS provisioning is required. In this paper, a new set of ETE QoS classes is proposed and a mappings algorithm for different QoS classes that are proposed by different organisations is given. With our proposal, ETE QoS mapping and control can be implemented.

  4. Performance analysis of IP QoS provision model

    Institute of Scientific and Technical Information of China (English)

    SUN Danning; Moonsik Kang

    2006-01-01

    The Performance of a heterogeneous IP QoS provision service model was analyzed. This model utilized RSVP technique to set up dynamic resource reservation interface between the user and the network, meanwhile, DiffServ technique was utilized to transmit class-based packets in different per hop behaviors. Furthermore, accordingly queue management and packets scheduling mechanisms were presented for end-to-end QoS guarantees and appropriate cooperation of network elements.

  5. SDN-based QoS Aware Network Service Provisioning

    DEFF Research Database (Denmark)

    Caba, Cosmin Marius; Soler, José

    2015-01-01

    One of the applicability areas of SDN is for creating services for dynamic provisioning of network resources with strict QoS requirements. The research available in this field focuses mainly on the service logic implemented over the functionality of the SDN Controller (SDNC). However, there is mu...

  6. Integration of QoS provisioning in home and access networks

    DEFF Research Database (Denmark)

    Popov, Mikhail; Gavler, A.; Sköldström, P.;

    2010-01-01

    Approaches for QoS provisioning using UPnP for home networks and GMPLS for access networks are described. A solution for interworking the UPnP and the GMPLS at the residential gateway is proposed.......Approaches for QoS provisioning using UPnP for home networks and GMPLS for access networks are described. A solution for interworking the UPnP and the GMPLS at the residential gateway is proposed....

  7. MAQF/MAC:A New QoS Provisioning MAC Mechanism for MANET

    Institute of Scientific and Technical Information of China (English)

    YAOYinxion; WANGHaoxing; WANXiang

    2003-01-01

    QoS provisioning is not an easy problem under the time varying and dynamic environment of MANET.Based on MANET Adaptive QoS Framework(MAQF)and through improving the scheme of MACA/PR,a new mechanism MAQF/MAC that can provide MAC layer QoS guarantees for MANET has been presented.MAQF/MAC can measure the variation of resource in real time,change the channel access policy and adapt the amount of resource captured by trafflc.In addition,this paper also concerns some key components of MAQF/MAC,including reservation table(RT),QoS routing,resource compression algorithm and etc.Simulation result show that MAQF/MAC ls superior to MACA/PR in the aspects of multi-level trafflc QoS provisioning and resource utilization.

  8. Performance Enhancements of UMTS networks using end-to-end QoS provisioning

    DEFF Research Database (Denmark)

    Wang, Haibo; Prasad, Devendra; Teyeb, Oumer;

    2005-01-01

    This paper investigates the end-to-end(E2E) quality of service(QoS) provisioning approaches for UMTS networks together with DiffServ IP network. The effort was put on QoS classes mapping from DiffServ to UMTS, Access Control(AC), buffering and scheduling optimization. The DiffServ Code Point (DSCP...... algorithm provide a fexible and effcient QoS guarantees for multiple UMTS classes....

  9. Cross Layer QoS Provisioning in Home Networks

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Brewka, Lukasz Jerzy; Ruepp, Sarah Renée

    2011-01-01

    Access (TDMA). By adopting OW MAC to the widely supported Universal Plug and Play – Quality of Service (UPnP-QoS) Architecture in the simulated home domain, algorithms for cross layer mapping QoS requirements are proposed. Compared to utilizing WLAN MAC, our scheme is able to provide guaranteed Qo...

  10. Satisfaction Equilibrium: A General Framework for QoS Provisioning in Self-Configuring Networks

    CERN Document Server

    Perlaza, Samir M; Lasaulce, Samson; Debbah, Merouane

    2010-01-01

    This paper is concerned with the concept of equilibrium and quality of service (QoS) provisioning in self-configuring wireless networks with non-cooperative radio devices (RD). In contrast with the Nash equilibrium (NE), where RDs are interested in selfishly maximizing its QoS, we present a concept of equilibrium, named satisfaction equilibrium (SE), where RDs are interested only in guaranteing a minimum QoS. We provide the conditions for the existence and the uniqueness of the SE. Later, in order to provide an equilibrium selection framework for the SE, we introduce the concept of effort or cost of satisfaction, for instance, in terms of transmit power levels, constellation sizes, etc. Using the idea of effort, the set of efficient SE (ESE) is defined. At the ESE, transmitters satisfy their minimum QoS incurring in the lowest effort. We prove that contrary to the (generalized) NE, at least one ESE always exists whenever the network is able to simultaneously support the individual QoS requests. Finally, we pr...

  11. QoS Provisioning Techniques for Future Fiber-Wireless (FiWi Access Networks

    Directory of Open Access Journals (Sweden)

    Martin Maier

    2010-04-01

    Full Text Available A plethora of enabling optical and wireless access-metro network technologies have been emerging that can be used to build future-proof bimodal fiber-wireless (FiWi networks. Hybrid FiWi networks aim at providing wired and wireless quad-play services over the same infrastructure simultaneously and hold great promise to mitigate the digital divide and change the way we live and work by replacing commuting with teleworking. After overviewing enabling optical and wireless network technologies and their QoS provisioning techniques, we elaborate on enabling radio-over-fiber (RoF and radio-and-fiber (R&F technologies. We describe and investigate new QoS provisioning techniques for future FiWi networks, ranging from traffic class mapping, scheduling, and resource management to advanced aggregation techniques, congestion control, and layer-2 path selection algorithms.

  12. An adaptive distributed admission approach in Bluetooth network with QoS provisions

    DEFF Research Database (Denmark)

    Son, L.T.; Schiøler, Henrik; Madsen, Ole Brun

    2002-01-01

    In this paper, a method of adaptive distributed admission with end-to-end Quality of Service (QoS) provisions for real time and non real time tra°cs in Blue-tooth networks is highlighted, its mathematic background is analyzed and a simulation with bursty tra°c sources, Interrupted Bernoulli Process...... (IBP), is carried out. The simulation results show that the performance of Bluetooth network is improved when applying the distributed admission method...

  13. Dynamic QoS Provisioning for Ethernet-based Networks

    Science.gov (United States)

    Angelopoulos, J.; Kanonakis, K.; Leligou, H. C.; Orfanoudakis, Th.; Katsigiannis, M.

    2008-11-01

    The evolution towards packet-based access networks and the importance of quality of experience brings the need for access networks that support the offer of a wide range of multimedia services not currently available to the desired extent. Legacy networks based on circuit switching used explicit signalling that travelled to all nodes along the path to book resources before the launce of the media stream. This approach does not scale well and is not in line with the philosophy of packet networks. Still, the need to reserve resources in advance remains since real-time services have limited if any means of adjusting their rates to the prevailing network conditions and to preserve customer satisfaction the traditional preventive approach that needs accurate estimates of resource needs for the duration of the session is the only option. The paper describes a possible CAC solution based on measuring flows and enriches the network with implicit admission control (without obviating explicit control if available) and can manage resource allocation to protect quality-demanding services from degradation. The basis is a flow measurement system, which will estimate the traffic load produced by the flow and activate admission control. However, because in most cases these initial indication may well be misleading, it will be cross checked against a database of previously recorded flows per customer interface which can provide long term data on the flows leaving only a few cases that have to be corrected on the fly. The overall product is a self-learning autonomic system that supports QoS in the access network for services that do not communicate with the network layer such as, for example, peer-to-peer real-time multimedia applications.

  14. Design and Implementation of Key Techniques for Mobile Ad hoc Network Adaptive QoS Provisioning Framework

    Institute of Scientific and Technical Information of China (English)

    YAOYinxiong; LIUJianxun; TANGXinhuai

    2004-01-01

    MAQF is a newly proposed adaptive QoS provisioning framework for Mobile Ad hoc network (MANET) by the authors. Through modifying the architecture of INSIGNIA and adding some components, MAQF overcomes many disadvantages appearing in related works and supports QoS guarantees for MANET. This paper focuses on the design and implementation of some key techniques in MAQF, including QoS routing, signaling in band, adaptive control mechanism, dynamic resource adaptation algorithm and, etc. Simulation results are presented and have verified the validity of MAQF.

  15. QoS Self-Provisioning and Interference Management for Co-Channel Deployed 3G Femtocells

    DEFF Research Database (Denmark)

    Kolding, Troels; Ochal, Pawel; Jørgensen, Niels T.K.

    2013-01-01

    A highly efficient self-provisioning interference management scheme is derived for 3G Home Node-Bs (HNB). The proposed scheme comprises self-adjustment of the HNB transmission parameters to meet the targeted QoS (quality of service) requirements in terms of downlink and uplink guaranteed minimum ...

  16. Adaptive QoS provision for IEEE 802.16e BWA networks based on cross-layer design

    Directory of Open Access Journals (Sweden)

    Kuo GS

    2011-01-01

    Full Text Available Abstract This article proposes an integrated framework for adaptive QoS provision in IEEE 802.16e broadband wireless access networks based on cross-layer design. On one hand, an efficient admission control (AC algorithm is proposed along with a semi-reservation scheme to guarantee the connection-level QoS. First, to guarantee the service continuity for handoff connections and resource efficiency, our semi-reservation scheme considers both users' handoff probability and average resource consumption together, which effectively avoids resource over-reservation and insufficient reservation. For AC, a new/handoff connection is accepted only when the target cell has enough resource to afford both instantaneous and average resource consumption to meet the average source rate request. On the other hand, a joint resource allocation and packet scheduling scheme is designed to provide packet-level QoS guarantee in term of "QoS rate", which can ensure fairness for the services with identical priority level in case of bandwidth shortage. Particularly, an enhanced bandwidth request scheme is designed to reduce unnecessary BR delay and redundant signaling overhead caused by the existing one in IEEE 802.16e, which further improves the packet-level QoS performance and resource efficiency for uplink transmission. Simulation results show that the proposed approach not only balances the tradeoff among connection blocking rate, connection dropping rate, and connection failure rate, but also achieves low mean packet dropping rate (PDR, small deviation of PDR, and low QoS outage rate. Moreover, high resource efficiency is ensured.

  17. A Toolkit For Storage Qos Provisioning For Data-Intensive Applications

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    Renata Słota

    2012-01-01

    Full Text Available This paper describes a programming toolkit developed in the PL-Grid project, named QStorMan, which supports storage QoS provisioning for data-intensive applications in distributed environments. QStorMan exploits knowledge-oriented methods for matching storage resources to non-functional requirements, which are defined for a data-intensive application. In order to support various usage scenarios, QStorMan provides two interfaces, such as programming libraries or a web portal. The interfaces allow to define the requirements either directly in an application source code or by using an intuitive graphical interface. The first way provides finer granularity, e.g., each portion of data processed by an application can define a different set of requirements. The second method is aimed at legacy applications support, which source code can not be modified. The toolkit has been evaluated using synthetic benchmarks and the production infrastructure of PL-Grid, in particular its storage infrastructure, which utilizes the Lustre file system.

  18. Provisioning QoS Guarantee by Multipath Routing and Reservation in Ad Hoc Networks

    Institute of Scientific and Technical Information of China (English)

    Yan-Tai Shu; Guang-Hong Wang; Lei Wang; Oliver W. W. Yang; Yong-Jie Fan

    2004-01-01

    In this paper, a QoS multipath source routing protocol (QoS-MSR) is proposed for ad hoc networks.It can collect QoS information through route discovery mechanism of multipath source routing (MSR) and establish QoS route with reserved bandwidth. In order to reserve bandwidth efficiently, a bandwidth reservation approach called the multipath bandwidth splitting reservation (MBSR) is presented, under which the overall bandwidth request is split into several smaller bandwidth requests among multiple paths. In simulations, the anthors introduce Insignia, an in-bind signaling system that supports QoS in ad hoc networks, and extend it to multipath Insignia (M-Insignia) with QoS-MSR and MBSR. The results show that QoS-MSR routing protocol with the MBSR algorithm can improve the call admission ratio of QoS traffic, the packet delivery ratio, and the end-to-end delay of both best-effort traffic and QoS traffic. Therefore, QoS-MSR with MBSR is an efficient mechanism that supports QoS for ad hoc networks.

  19. A New Resources Provisioning Method Based on QoS Differentiation and VM Resizing in IaaS

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    Rongdong Hu

    2015-01-01

    Full Text Available In order to improve the host energy efficiency in IaaS, we proposed an adaptive host resource provisioning method, CoST, which is based on QoS differentiation and VM resizing. The control model can adaptively adjust control parameters according to real time application performance, in order to cope with changes in load. CoST takes advantage of the fact that different types of applications have different sensitivity degrees to performance and cost. It places two different types of VMs on the same host and dynamically adjusts their sizes based on the load forecasting and QoS feedback. It not only guarantees the performance defined in SLA, but also keeps the host running in energy-efficient state. Real Google cluster trace and host power data are used to evaluate the proposed method. Experimental results show that CoST can provide performance-sensitive application with a steady QoS and simultaneously speed up the overall processing of performance-tolerant application by 20~66%. The host energy efficiency is significantly improved by 7~23%.

  20. QoS Provisioning for Multimedia Transmission in Cognitive Radio Networks

    CERN Document Server

    Yu, F Richard; Krishnamurthy, Vikram; Ali, Saqib

    2011-01-01

    In cognitive radio (CR) networks, the perceived reduction of application layer quality of service (QoS), such as multimedia distortion, by secondary users may impede the success of CR technologies. Most previous work in CR networks ignores application layer QoS. In this paper we take an integrated design approach to jointly optimize multimedia intra refreshing rate, an application layer parameter, together with access strategy, and spectrum sensing for multimedia transmission in a CR system with time varying wireless channels. Primary network usage and channel gain are modeled as a finite state Markov process. With channel sensing and channel state information errors, the system state cannot be directly observed. We formulate the QoS optimization problem as a partially observable Markov decision process (POMDP). A low complexity dynamic programming framework is presented to obtain the optimal policy. Simulation results show the effectiveness of the proposed scheme.

  1. 基于公平性和 QoS 保障的 OFDMA-WLAN 系统资源分配%Resource allocation based on fairness and QoS provisioning for OFDMA-WLAN system

    Institute of Scientific and Technical Information of China (English)

    鲍楠; 夏玮玮; 沈连丰

    2014-01-01

    为了满足 OFDMA-WLAN 系统下行通信中多用户的不同业务需求,提出一种基于公平性和 QoS 服务保障的资源分配算法。不同的 QoS 要求被转换成不同的速率要求来计算 QoS 满意等级;优化目标被修改为公平性驱动的优化函数以提供公平性保障;复杂的资源分配问题被划分为信道分配和功率分配问题,并通过二分图匹配和注水法得到分配结果。与其他算法相比,所提出的算法牺牲了较少的数据速率换取更高的公平性和 QoS 满意度。仿真结果表明所提算法具有保障 QoS 和公平性的能力,且在 QoS、公平性和速率之间权衡折中时表现更好。%To satisfy different service requirements of multiple users in the orthogo nal frequency division multiple access wireless local area network OFDMA-WLAN system downlink transmission a resource allocation algorithm based on fairness and quality of service QoS provisioning is proposed. Different QoS requirements are converted into different rate requirements to calculate the QoSs atisfaction level.The optimization object is revised as a fairness-driven resource optimization function to provide fairness. The complex resource allocation problem is divided into channel allocation and power assignment sub-problems. The sub-problems are solved by the bipartite graph matching and water-filling based method.Compared with other algorithms the proposed algorithm sacrifices less data rate for higher fairnes and QoS satisfaction.The sim ulation results show that the proposed algorithm is capableo fp rovi ding QoS and fairness and performs better in a tradeoff among QoS fairness and data rate.

  2. A Professional QoS Provisioning in the Intra Cluster Packet Level Resource Allowance for Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    K.Senthamil Selvan

    2013-04-01

    Full Text Available Wireless mesh networking has transpired as a gifted technology for potential broadband wireless access.In a communication network, wireless mesh network plays a vital role in transmission and are structured ina mesh topology. The coordination of mesh routers and mesh clients forms the wireless mesh networkswhich are routed through the gateways. Wireless mesh networks uses IEEE 802.11 standards and has itswide applications broadband home networking and enterprise networking deployment such as Microsoftwireless mesh and MIT etc. A professional Qos provisioning in intra cluster packet level resourceallocation for WMN approach takes power allocation, sub carrier allocation and packet scheduling. Thisapproach combines the merits of a Karush-Kuhn-Tucker (KKT algorithm and a genetic algorithm (GAbased approach. The KKT algorithm uses uniform power allocation over all the subcarriers, based on theoptimal allocation criterion. The genetic algorithm is used to generate useful solutions to optimization andsearch problems and it is also used for search problems. By combining the intrinsic worth of both theapproaches, it facilitates effective QOS provisioning at the packet level. It is concluded that, this approachachieves a preferred stability between system implementation and computational convolution.

  3. Automatic provisioning of end-to-end QoS into the home

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Skoldström, Pontus; Nelis, Jelle;

    2011-01-01

    Due to a growing number of high bandwidth applications today (such as HDTV), and an increasing amount of network and cloud based applications, service providers need to pay attention to QoS in their networks. We believe there is a need for an end-to-end approach reaching into the home as well....... The Home Gateway (HG) as a key component of the home network is crucial for enabling the end-to-end solutions. UPnP-QoS has been proposed as an inhome solution for resource reservations. In this paper we assess a solution for automatic QoS reservations, on behalf of non-UPnP-QoS aware applications....... Additionally we focus on an integrated end-to-end solution, combining GMPLS-based reservations in e.g., access/metro and UPnP-QoS based reservation in the home network....

  4. A game theoretical approach for QoS provisioning in heterogeneous networks

    Directory of Open Access Journals (Sweden)

    A.S.M. Zadid Shifat

    2015-09-01

    Full Text Available With the proliferation of mobile phone users, interference management is a big concern in this neoteric years. To cope with this problem along with ensuring better Quality of Service (QoS, femtocell plays an imperious preamble in heterogeneous networks (HetNets for some of its noteworthy characteristics. In this paper, we propose a game theoretic algorithm along with dynamic channel allocation and hybrid access mechanism with self-organizing power control scheme. With a view to resolving prioritized access issue, the concept of primary and secondary users is applied. Existence of pure strategy Nash equilibrium (NE has been investigated and comes to a perfection that our proposed scheme can be adopted both increasing capacity and increasing revenue of operators considering optimal price for consumers.

  5. On The Selection Of Qos Provisioned Routing Protocol Through Realistic Channel For Vanet

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    Aarja Kaur

    2015-07-01

    Full Text Available Abstract Vehicular Ad-Hoc Network VANET is a new communication paradigm creating a network on wheels. Communication between the vehicles provides for various safety and comfort applications. VANET is characterized by features like number of nodes varying topology constrained and high speed movement of nodes. All these features make routing in VANETs a crucial issue. This paper compares popular proactive reactive and hybrid protocols in infrastructure less environments as availability of an infrastructure is not ubiquitous. Intensive simulations are carried out using IEEE 802.11p standard in the presence of realistic propagation model. Behaviour of protocols is studied in different situations by measuring performance in terms of QoS metrics like throughput Packet delivery ratio PDR routing load and end to end delay.

  6. Network evolution and QOS provisioning for integrated femtocell/macrocell networks

    CERN Document Server

    Chowdhury, Mostafa Zaman; Haas, Zygmunt J

    2010-01-01

    Integrated femtocell/macrocell networks, comprising a conventional cellular network overlaid with femtocells, offer an economically appealing way to improve coverage, quality of service, and access network capacity. The key element to successful femtocells/macrocell integration lies in its self-organizing capability. Provisioning of quality of service is the main technical challenge of the femtocell/macrocell integrated networks, while the main administrative challenge is the choice of the proper evolutionary path from the existing macrocellular networks to the integrated network. In this article, we introduce three integrated network architectures which, while increasing the access capacity, they also reduce the deployment and operational costs. Then, we discuss a number of technical issues, which are key to making such integration a reality, and we offer possible approaches to their solution. These issues include efficient frequency and interference management, quality of service provisioning of the xDSL-ba...

  7. Adaptive Traffic Route Control in QoS Provisioning for Cognitive Radio Technology with Heterogeneous Wireless Systems

    Science.gov (United States)

    Yamamoto, Toshiaki; Ueda, Tetsuro; Obana, Sadao

    As one of the dynamic spectrum access technologies, “cognitive radio technology,” which aims to improve the spectrum efficiency, has been studied. In cognitive radio networks, each node recognizes radio conditions, and according to them, optimizes its wireless communication routes. Cognitive radio systems integrate the heterogeneous wireless systems not only by switching over them but also aggregating and utilizing them simultaneously. The adaptive control of switchover use and concurrent use of various wireless systems will offer a stable and flexible wireless communication. In this paper, we propose the adaptive traffic route control scheme that provides high quality of service (QoS) for cognitive radio technology, and examine the performance of the proposed scheme through the field trials and computer simulations. The results of field trials show that the adaptive route control according to the radio conditions improves the user IP throughput by more than 20% and reduce the one-way delay to less than 1/6 with the concurrent use of IEEE802.16 and IEEE802.11 wireless media. Moreover, the simulation results assuming hundreds of mobile terminals reveal that the number of users receiving the required QoS of voice over IP (VoIP) service and the total network throughput of FTP users increase by more than twice at the same time with the proposed algorithm. The proposed adaptive traffic route control scheme can enhance the performances of the cognitive radio technologies by providing the appropriate communication routes for various applications to satisfy their required QoS.

  8. Limited sharing with traffic prediction for dynamic bandwidth allocation and QoS provisioning over Ethernet passive optical networks

    Science.gov (United States)

    Luo, Yuanqiu; Ansari, Nirwan

    2005-09-01

    Feature Issue on Optical Access Networks (OAN) As an inexpensive, simple, and scalable solution for broadband access, Ethernet passive optical networks (EPONs) have the capability of delivering integrated broadband services to the end users. A critical issue of EPONs is the utility of a shared upstream channel among the local users, and thus an efficient bandwidth allocation mechanism is required to facilitate statistical multiplexing among the local network traffic. In this paper we propose a dynamic bandwidth allocation scheme, i.e., limited sharing with traffic prediction (LSTP), for upstream channel sharing over EPONs. LSTP enables dynamic bandwidth negotiation between the optical line terminal (OLT) and its associated optical network units (ONUs), alleviates data delay by predicting the traffic arrived during the waiting time and prereserving a portion of bandwidth for delivery, and avoids the aggressive bandwidth competition by upper bounding the allocated bandwidth to each ONU. Theoretical analysis and simulation results verify the feasibility of LSTP by showing that LSTP outperforms other existing schemes with respect to QoS metrics of data delay and data loss.

  9. Signaling performance of UPnP QoS architecture

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Wessing, Henrik; Dittmann, Lars

    2009-01-01

    Provisioning QoS within home networks becomes a common requirement. This paper evaluates one of the candidates for home network control and management protocol suites, namely UPnP. Using network modeling tools we identify highlights and drawbacks of UPnP QoS Architecture.......Provisioning QoS within home networks becomes a common requirement. This paper evaluates one of the candidates for home network control and management protocol suites, namely UPnP. Using network modeling tools we identify highlights and drawbacks of UPnP QoS Architecture....

  10. UPnP QoS Architecture and Lightweight Preemption Algorithms

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Wessing, Henrik; Dittmann, Lars

    2011-01-01

    Providing QoS in home networks seems to be more and more important in triple and quadruple play service scenarios. This paper focuses on the analysis of certain aspects of UPnP QoS Architecture designed to provision QoS in home networks. Basic signaling performance is discussed and preemption...

  11. Novel Adaptive QoS Framework for Integrated UMTS/WLAN Environment

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    T. Shuminoski

    2013-06-01

    Full Text Available Since Quality of Service (QoS provisioning for multimedia traffic in integrated Wireless and Mobile Networks is becoming an increasingly important objective, in this paper we introduce a novel concept of an adaptive QoS cross-layer framework. The Adaptive QoS framework is proven via novel simulation results in integrated environment with UMTS and IEEE 802.11 networks. The aim of our novel framework is presenting a new module that shall provide the best QoS and lower cost for a given service using one or more wireless technologies in a given time. The analysis of simulation results has shown superior performances with a high level of QoS provisioning in a variety of network conditions. The performance of Adaptive QoS algorithm is evaluated using ns-miracle augmented with our dual-mode Mobile Equipments (MEs and using statistical analysis.

  12. ETOM PROCESS TO MANITOR AND CORELAT IPTV QOS IN IMS

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    M.Bellafkih

    2011-06-01

    Full Text Available As the network convergence with services for both static and mobile networks has been the principal object of the next generation networks, the recent research focus is converging in the direction of standardizing common infrastructure based on all-IP networks. IMS is a recent initiative. Moreover, designing and deploying a standard QoS provisioning mechanisms in large networks is not a trivial matter. IPTV services are considered between the important IMS flow, the actual QoS management mechanisms proposed by 3GPP allow providing the IMS network components control and efficient service delivery, however the 3GPP approach focuses entirely on the step of providing the service, but there is no mechanism for monitoring Qos dynamically. This paper discusses the issues, design and analysis related to on demand dynamic QoS control in these next generation networks and fuss both Quality of Service (QoS information signaling and IPTV traffic engineering options that may serve as key components of IPTV service specific QoS policies, which are designed to accommodate with customer requirements and resource availability by using the eTOM process to monitor the Qos values and to propose optimal solution to provide the quality of delivered content. The eTOM process interact with implemented marking entities which execute an algorithm to marking IPTV packets, this cooperation must improve the quality of service of the IPTV traffic

  13. Evaluation of Lightweight Preemption Algorithms for UPnP QoS

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Wessing, Henrik; Dittmann, Lars

    2010-01-01

    Preemption is a common approach for QoS provisioning in multiservice and multiuser networks where the network resources are exhausted. This paper focuses on the analysis of the lightweight algorithms for the UPnP QoS Architecture where the decision about preemption is made by computation power...

  14. Adaptive Radio Resource Allocation in Hierarchical QoS Scheduling for IEEE 802.16 Systems

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2007-01-01

    Future mobile communication systems such as IEEE 802.16 are expected to deliver a variety of multimedia services with diverse QoS requirements. To guarantee the QoS provision, appropriate scheduler architecture and scheduling algorithms have to be carefully designed. In this paper, we propose...

  15. Proposal of QoS enabled GMPLS controlled XG-PON

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Gavler, Anders; Wessing, Henrik

    2011-01-01

    End-to-end QoS provisioning is still a challenging task despite many years of research and development in this area. Considering GMPLS based core/metro network and RSVP capable Home Gateways it is the access part of the network where QoS signaling is bridged. In this paper we propose strategies...... for GMPLS control over next emerging PON standard i.e., XGPON. Node management, resource allocation approaches are discussed and possible issues are raised. The analysis show that consideration of XG-PON as GMPLS controlled domain is valid and may advance end-to-end QoS provisioning for PON based customers....

  16. Extended QoS modelling based on multi-application environment in network on chip

    Science.gov (United States)

    Saadaoui, Abdelkader; Nasri, Salem

    2015-01-01

    Until now, there is no standard method of the quality of service (QoS) measurement and fewer techniques have been used to provide its definition. Therefore, researchers are looking for a projection of QoS on quantifiable space, since it is qualitative, subjective and not measurable. However, a few tentatives have studied QoS parameter estimation. Many applications in network on chip (NoC) present variable QoS parameters such as packet loss rate (PLR), end-to-end delay (EED) and throughput (Thp). However, there are a few papers that have developed different methods to modelise QoS in NoC. Their QoS presentation does not provide a multi-application parameter arbiter. Independently of the approach used, an important challenge associated with QoS provision is the development of an efficient and flexible way to monitor QoS. The originality of our approach is based on a proposition of a QoS-intellectual property module in NoC architecture to improve network performances. We implement an extended approach of QoS metrics modelling for NoC on multi-parameter and multi-application environment. The QoS metrics model is based on QoS parameters such as PLR, EED and Thp for different applications. To validate this work, a dynamic routing simulation for 4 × 4 mesh NoC behaviour under three different applications, namely transmission control protocol, variable bit rate and constant bit rate, is considered. To achieve an ideal network behaviour, load balancing on NoC with multiple concurrent applications is improved using QoS metrics measurement based on dynamic routing. The results have shown that extended QoS modelling approach is easy and cheap to implement in hardware-software quantifiable representation. Thus, implementing a quantifiable representation of QoS can be used to provide a NoC services arbiter. QoS arbiter interacts with other routers to ensure flit flow and QoS modelling to provide a QoS value.

  17. QoS over Internet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The integrated services and differentiated services architectures that can be used to support Quality of Service (QoS) guarantees over Internet are analysed. Specifically, how they can interwork in the pursuit of end-to-end QoS is discussed.

  18. QoS Aware Wavelength Assignment in Wavelength Division Multiplexing Based Optical Networks

    Directory of Open Access Journals (Sweden)

    U. Mahmud

    2015-01-01

    Full Text Available Wavelength Division Multiplexing (WDM is used in optical networks to implement data circuits. These circuits allow exchange of information as a measure of wavelength in optical domain. Quality of Service (QoS provisioning is one of the issues in WDM optical networks. This paper discusses different QoS aware Routing and Wavelength Assignment (RWA algorithms. Some unaddressed issues are identified that include the effects of degraded performance, traffic patterns and type of QoS service for users. A software module is proposed that calculates a ‘D’ factor facilitating in the wavelength assignment for QoS provisioning. This module is designed to work in conjunction with existing RWA algorithms.

  19. UPnP QoS and queuing in home networks

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Wessing, Henrik; Dittmann, Lars

    2010-01-01

    The QoS provisioning in home networks is being more often considered for future use cases, where mulitple high bandwidth flows are accomodated in the home environment. This paper investigates chosen characteristics of one of the home network control and management protocol suites, namely UPn......P. Using network modeling tools, we evaluate UPnP QoS architecture and its resource management influence on the end-to-end packet delay characteristics for different scheduling approaches....

  20. Minimum QOS Parameter Set in Transport Layer

    Institute of Scientific and Technical Information of China (English)

    汪芸; 顾冠群

    1997-01-01

    QOS(Quality Of Service)parameter definitions are the basis of further QOS control.But QOS parameters defined by organizations such as ISO and ITU are incoherent and incompatible.It leads to the imefficiency of QOS controls.Based on the analysis of QOS parameters defined by ISO and ITU,this paper first promotes Minimum QOS Parameter Set in transport layer.It demonstrates that the parameters defined by ISO and ITU can be represented b parameters or a combination of parameters of the Set.The paper also expounds that the Set is open and manageable and it can be the potential unified base for QOS parameters.

  1. QoS Enabled Resource Allocation Over an UPnP-QoS - GMPLS Controlled Edge

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Sköldström, Pontus; Gavler, Anders;

    2011-01-01

    This paper focuses on the problem of coherent resource allocation within home and access networks. The interdomain QoS signaling discussed here enables the initiation of the QoS provisioning in the home and access from the end device in users home. The home network considered in this paper is UPn......P-QoS enabled while the access network is GMPLS based. We propose and implement an interface between aforementioned network segments allowing for end-to-end QoS establishment. We present the QoS parameters and mechanisms in both UPnP-QoS and GMPLS and how they can be matched to create a coherent Qo...

  2. QOS-Enabled Networks Tools and Foundations

    CERN Document Server

    Barreiros, Miguel

    2011-01-01

    This book discusses the theory of Quality of Service (QoS) mechanisms in packet networks and shows how to apply them in practice. QOS-Enabled Networks: Tools and Foundations provides an understanding of the theory of QOS mechanisms in packet networks and how to apply them in practice. It explains QOS management features found in modern routers used by Internet Service Providers (ISP) and large companies.  The goal of this book is to provide the background and tools to help network managers and engineers configure production networks for providing services with quality of service (QOS) guarante

  3. Network QoS Management in Cyber-Physical Systems

    CERN Document Server

    Xia, Feng; Dong, Jinxiang; Sun, Youxian

    2008-01-01

    Technical advances in ubiquitous sensing, embedded computing, and wireless communication are leading to a new generation of engineered systems called cyber-physical systems (CPS). CPS promises to transform the way we interact with the physical world just as the Internet transformed how we interact with one another. Before this vision becomes a reality, however, a large number of challenges have to be addressed. Network quality of service (QoS) management in this new realm is among those issues that deserve extensive research efforts. It is envisioned that wireless sensor/actuator networks (WSANs) will play an essential role in CPS. This paper examines the main characteristics of WSANs and the requirements of QoS provisioning in the context of cyber-physical computing. Several research topics and challenges are identified. As a sample solution, a feedback scheduling framework is proposed to tackle some of the identified challenges. A simple example is also presented that illustrates the effectiveness of the pr...

  4. Framework for analysis of guaranteed QOS systems

    Science.gov (United States)

    Chaudhry, Shailender; Choudhary, Alok

    1997-01-01

    Multimedia data is isochronous in nature and entails managing and delivering high volumes of data. Multiprocessors with their large processing power, vast memory, and fast interconnects, are an ideal candidate for the implementation of multimedia applications. Initially, multiprocessors were designed to execute scientific programs and thus their architecture was optimized to provide low message latency and efficiently support regular communication patterns. Hence, they have a regular network topology and most use wormhole routing. The design offers the benefits of a simple router, small buffer size, and network latency that is almost independent of path length. Among the various multimedia applications, video on demand (VOD) server is well-suited for implementation using parallel multiprocessors. Logical models for VOD servers are presently mapped onto multiprocessors. Our paper provides a framework for calculating bounds on utilization of system resources with which QoS parameters for each isochronous stream can be guaranteed. Effects of the architecture of multiprocessors, and efficiency of various local models and mapping on particular architectures can be investigated within our framework. Our framework is based on rigorous proofs and provides tight bounds. The results obtained may be used as the basis for admission control tests. To illustrate the versatility of our framework, we provide bounds on utilization for various logical models applied to mesh connected architectures for a video on demand server. Our results show that worm hole routing can lead to packets waiting for transmission of other packets that apparently share no common resources. This situation is analogous to head-of-the-line blocking. We find that the provision of multiple VCs per link and multiple flit buffers improves utilization (even under guaranteed QoS parameters). This analogous to parallel iterative matching.

  5. QoS Routing in Smart Grid

    CERN Document Server

    Li, Husheng

    2010-01-01

    Smart grid is an emerging technology which is able to control the power load via price signaling. The communication between the power supplier and power customers is a key issue in smart grid. Performance degradation like delay or outage may cause significant impact on the stability of the pricing based control and thus the reward of smart grid. Therefore, a QoS mechanism is proposed for the communication system in smart grid, which incorporates the derivation of QoS requirement and applies QoS routing in the communication network. For deriving the QoS requirement, the dynamics of power load and the load-price mapping are studied. The corresponding impacts of different QoS metrics like delay are analyzed. Then, the QoS is derived via an optimization problem that maximizes the total revenue. Based on the derived QoS requirement, a simple greedy QoS routing algorithm is proposed for the requirement of high speed routing in smart grid. It is also proven that the proposed greedy algorithm is a $K$-approximation. ...

  6. Ontology Based Qos Driven Web Service Discovery

    Directory of Open Access Journals (Sweden)

    R Suganyakala

    2011-07-01

    Full Text Available In today's scenario web services have become a grand vision to implement the business process functionalities. With increase in number of similar web services, one of the essential challenges is to discover relevant web service with regard to user specification. Relevancy of web service discovery can be improved by augmenting semantics through expressive formats like OWL. QoS based service selection will play a significant role in meeting the non-functional user requirements. Hence QoS and semantics has been used as finer search constraints to discover the most relevant service. In this paper, we describe a QoS framework for ontology based web service discovery. The QoS factors taken into consideration are execution time, response time, throughput, scalability, reputation, accessibility and availability. The behavior of each web service at various instances is observed over a period of time and their QoS based performance is analyzed.

  7. QoS management of web services

    CERN Document Server

    Zheng, Zibin

    2013-01-01

    Quality-of-Service (QoS) is normally used to describe the non-functional characteristics of Web services and as a criterion for evaluating different Web services. QoS Management of Web Services presents an innovative QoS evaluation framework for these services. Moreover, three QoS prediction methods and two methods for creating fault-tolerant Web services are also proposed in this book. It not only provides the latest research findings, but also presents an excellent overview of the QoS management of Web services, making it a valuable resource for researchers and graduate students in service computing.   Zibin Zheng is an associate research fellow at the Shenzhen Research Institute, the Chinese University of Hong Kong, China. Professor Michael R. Lyu also works at the same institute.

  8. Qos Failover Routing In Tethernet

    Directory of Open Access Journals (Sweden)

    Ankita Goswami

    2015-07-01

    Full Text Available Abstarct Tethering is a concept of sharing of internet of a device with other devices. Its a low-cost short-distance wireless technology which employs the frequency hopping practice in the globally available ISM band to keep away from interference. In the tethering to form a network there is a concept of piconet containing master and slaves. These piconets are connected together to establish a big network called scatternet. There are several aspects on which scatternet working depends like the piconets numbers and bridges the bridge role etc. Already established routes consume much more energy for the maintenance hence instead of this routes can be created on-demand. Thus consumption can be altered and routes flexibility will inclined. Failover is an another concept that I have included. Its about transferring ones control to the other device whenever first device is failed. In this thesis I have proposed a QoS failover routing that will proficiently form the routes with the QoS desires and will prevent the stoppage of transmission if the transmitting node fails. It will pass its control to another node and allow it to transmit instead of it.

  9. Multiple QoS modeling and algorithm in computational grid

    Institute of Scientific and Technical Information of China (English)

    Li Chunlin; Feng Meilai; Li Layuan

    2007-01-01

    Multiple QoS modeling and algorithm in grid system is considered.Grid QoS requirements can be formulated as a utility function for each task as a weighted sum of its each dimensional QoS utility functions.Multiple QoS constraint resource scheduling optimization in computational grid is distributed to two subproblems: optimization of grid user and grid resource provider.Grid QoS scheduling can be achieved by solving sub problems via an iterative algorithm.

  10. NEW ARCHITECTURE OF IP QOS MANAGEMENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Jiao Li; Cui Yidong; Lin Yu; Wang Wendong; Cheng Shiduan

    2006-01-01

    Based on the analysis of current Quality of Service (QoS) management on IP network, new generation of QoS architecture QoSAF is proposed. QoSAF is divided into three layers: resource control layer, network service layer and business layer. QoS management is accomplished by interactivity of layers. In this architecture, mechanism of feedback control enhances the functions of resource management and system monitoring. The principle of design and logical architecture of system is discussed in detail.

  11. 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.

  12. Implementing a Session Aware Policy Based Mechanism for QoS Control in LTE

    Directory of Open Access Journals (Sweden)

    Zouhair Bazzal

    2017-01-01

    Full Text Available Quality of Service (QoS provisioning has become significant with the widely growth of multimedia applications and high increase in the number of users in both wireless and wired networks. In this paper, we implemented a session-aware policy based mechanism for QoS provisioning and control in LTE (Long Term Evolution networks. Policies are a set of rules identifying the QoS parameters for users. Implementation included DiffServ (Differentiated Services configuration and setting policies inside the PCRF (Policy Charging Rules Function which is the brain entity in LTE, then mapping from QCI (QoS Class ID to DiffServ. Moreover, the dialogue between PCEF (Policy Charging Enforcement Function and PCRF was implemented. Simulations on four different traffic application types: VoIP (voice over IP, video, web, and ftp (file transfer protocol were performed under the network simulator (ns2. Results showed that applying PCEF over the different traffic applications has a great effect in controlling these applications and specifically UDP (User Datagram Protocol based applications such as video.

  13. 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.

  14. Extending CORBA with specialised protocols for QoS provisioning

    NARCIS (Netherlands)

    Halteren, van A.T.; Noutash, A.; Nieuwenhuis, L.J.M.; Wegdam, M.

    1999-01-01

    The CORBA layer in a distributed system hides the heterogeneity of the underlying computer network. The interactions of objects located at different computing systems are described in terms of IDL specifications and the ORB takes care of the actual transfer of messages along the wire. In fact, an ob

  15. Optimized QoS Routing Algorithm

    Institute of Scientific and Technical Information of China (English)

    石明洪; 王思兵; 白英彩

    2004-01-01

    QoS routing is one of the key technologies for providing guaranteed service in IP networks. The paper focuses on the optimization problem for bandwidth constrained QoS routing, and proposes an optimal algorithm based on the global optimization of path bandwidth and hop counts. The main goal of the algorithm is to minimize the consumption of network resource, and at the same time to minimize the network congestion caused by irrational path selection. The simulation results show that our algorithm has lower call blocking rate and higher throughput than traditional algorithms.

  16. SLA-aware differentiated QoS in elastic optical networks

    Science.gov (United States)

    Agrawal, Anuj; Vyas, Upama; Bhatia, Vimal; Prakash, Shashi

    2017-07-01

    The quality of service (QoS) offered by optical networks can be improved by accurate provisioning of service level specifications (SLSs) included in the service level agreement (SLA). A large number of users coexisting in the network require different services. Thus, a pragmatic network needs to offer a differentiated QoS to a variety of users according to the SLA contracted for different services at varying costs. In conventional wavelength division multiplexed (WDM) optical networks, service differentiation is feasible only for a limited number of users because of its fixed-grid structure. Newly introduced flex-grid based elastic optical networks (EONs) are more adaptive to traffic requirements as compared to the WDM networks because of the flexibility in their grid structure. Thus, we propose an efficient SLA provisioning algorithm with improved QoS for these flex-grid EONs empowered by optical orthogonal frequency division multiplexing (O-OFDM). The proposed algorithm, called SLA-aware differentiated QoS (SADQ), employs differentiation at the level of routing, spectrum allocation, and connection survivability. The proposed SADQ aims to accurately provision the SLA using such multilevel differentiation with an objective to improve the spectrum utilization from the network operator's perspective. SADQ is evaluated for three different CoSs under various traffic demand patterns and for different ratios of the number of requests belonging to the three considered CoSs. We propose two new SLA metrics for the improvement of functional QoS requirements, namely, security, confidentiality and survivability of high class of service (CoS) traffic. Since, to the best of our knowledge, the proposed SADQ is the first scheme in optical networks to employ exhaustive differentiation at the levels of routing, spectrum allocation, and survivability in a single algorithm, we first compare the performance of SADQ in EON and currently deployed WDM networks to assess the

  17. 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.

  18. A QoS Management and Control Architecture for Intranet

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the appearance of application, such as VoIP and VOD, traditional best-effort service of network cant meet the needs of these applications. This paper proposes a QoS management and control architecture for Intranet, through which guaranteed services of network can be implemented in Intranet. In this architecture, there is a QoS control server, which is responsible for QoS control and management,while the router forwards packets according to the command from it.

  19. Providing QoS for Networked Peers in Distributed Haptic Virtual Environments

    Directory of Open Access Journals (Sweden)

    Alan Marshall

    2008-01-01

    Full Text Available Haptic information originates from a different human sense (touch, therefore the quality of service (QoS required to support haptic traffic is significantly different from that used to support conventional real-time traffic such as voice or video. Each type of network impairment has different (and severe impacts on the user's haptic experience. There has been no specific provision of QoS parameters for haptic interaction. Previous research into distributed haptic virtual environments (DHVEs have concentrated on synchronization of positions (haptic device or virtual objects, and are based on client-server architectures. We present a new peer-to-peer DHVE architecture that further extends this to enable force interactions between two users whereby force data are sent to the remote peer in addition to positional information. The work presented involves both simulation and practical experimentation where multimodal data is transmitted over a QoS-enabled IP network. Both forms of experiment produce consistent results which show that the use of specific QoS classes for haptic traffic will reduce network delay and jitter, leading to improvements in users' haptic experiences with these types of applications.

  20. QoS Analysis of a Storage System with Self-similar Input

    Institute of Scientific and Technical Information of China (English)

    RAOYunhua; ZOUXuecheng

    2004-01-01

    Packet delay, jitter and loss rate of a storage system with self-similar traffic input is analyzed, which is related to QoS (Quality of service). At first, the storage model with First in first out (FIFO) service discipline and Fractional autoregressive integrated moving average(FARIMA) traffic input which comprises Long-range dependence (LRD) and Short-range dependence (SRD) simultaneity is proposed. Then based on large deviation technique, analytic overflow probability formula of this storage model is obtained, which is related to traffic time scale. Meanwhile, packet delay and jitter analytic formulas are also obtained. Studies show that both SRD and LRD traffic will influence QoS parameters. The effect of traffic SRD on system performance at small time scales is related to storage system parameters. And when the time scale of aggregated traffic is large enough, LRD character of traffic begins to dominate the impaction on system QoS.Monte-Carlo simulations confirm the validity of the above results. Because of self-similarity in network traffic, the performance of storage system can be influenced greatly,which is quite different from that of Markov model and must be considered in network QoS provision.

  1. OPTIMISATION OF BUFFER SIZE FOR ENHANCING QOS OF VIDEO TRAFFIC USING CROSS LAYERED HYBRID TRANSPORT LAYER PROTOCOL APPROACH

    Directory of Open Access Journals (Sweden)

    S. Matilda

    2011-03-01

    Full Text Available Video streaming is gaining importance, with the wide popularity of multimedia rich applications in the Internet. Video streams are delay sensitive and require seamless flow for continuous visualization. Properly designed buffers offer a solution to queuing delay. The diagonally opposite QoS metrics associated with video traffic poses an optimization problem, in the design of buffers. This paper is a continuation of our previous work [1] and deals with the design of buffers. It aims at finding the optimum buffer size for enhancing QoS offered to video traffic. Network-centric QoS provisioning approach, along with hybrid transport layer protocol approach is adopted, to arrive at an optimum size which is independent of RTT. In this combinational approach, buffers of routers and end devices are designed to satisfy the various QoS parameters at the transport layer. OPNET Modeler is used to simulate environments for testing the design. Based on the results of simulation it is evident that the hybrid transport layer protocol approach is best suited for transmitting video traffic as it supports the economical design.

  2. Improved competitive guarantees for QoS buffering

    NARCIS (Netherlands)

    Kesselman, A.; Mansour, Y.; Stee, R. van

    2003-01-01

    We consider a network providing Differentiated Services (Diffserv), which allow Internet Service Providers (ISP s) to offer different levels of Quality of Service (QoS) to different traffic streams. We study two types of buffering policies that are used in network switches supporting QoS. In the FIF

  3. QoS Management Structure for Mobile IPv6

    Institute of Scientific and Technical Information of China (English)

    QU Zhao-wei; L(U) Ting-jie

    2005-01-01

    It has become very significant to enhance Quality of Service (QoS) capabilities of real-time data transmission in the Next Generation Internet. The Resource Reservation Protocol (RSVP) provides a signaling mechanism for end-to-end QoS. Multi-Protocol Label Switching (MPLS) is a fast label-based switching technique that can offer new QoS capabilities for large scale IP networks. Management of QoS in wireless networks is more complex than in wired networks because of frequent mobility of mobile users. In this paper, a novel scheme that improves the efficiency using a Mobile Agents Flat Structure (MAFS) based on the definition of new option called QoS Object Option (QOO) over MPLS is proposed. Mobile agents are required to manage QOO, resource reservation and other mobility related tasks on behalf of mobile hosts. This scheme is based on Mobile IPv6.

  4. A Review of QoS in Mobility Phillic Communication

    Directory of Open Access Journals (Sweden)

    Sumit Joshi

    2012-01-01

    Full Text Available This particular outlook represents, in brief the recent upcoming issues associated with QoS guarantee mobility in communications. Moreover it also presents a brief context of QoS attributes handling techniques thereby. Even more, it covers aspects of QoS fundamentals in deployment of mobility led approaches. There are different kinds of systems that facilitate different QoS attributes for variable classes of services. This review represents different types of approaches involved in the process of modern communication networks with respect to the QoS offered by a particular service. Moreover the parameters such as: delay, bandwidth, jitter etc. are system specific along with being service specific too. All the system types are actually a broad classification which involves different service primitives. In this review we focus mainly on mobility aspects of computing in the modern arena.

  5. A SCHEDULING TECHNIQUE FOR QOS SENSITIVE JOBS IN CLOUD

    Directory of Open Access Journals (Sweden)

    S.P.Jeno Lovesum

    2014-07-01

    Full Text Available The aim of this paper is to introduce a new algorithm for QOS based resource scheduling. Cloud is a type of parallel and distributed system consisting of a collection of inter-connected and virtualized computers that are dynamically provisioned and presented as one or more unified computing resources based on service-level agreements established through negotiation between the service provider and consumers. Resource scheduling, which is a part of resource management is an important process that takes place in storage cloud which falls under IaaS cloud, so that the available resources may be properly allocated to the requesting tasks in a best fit manner so that no resources are wasted. In this paper a new algorithm is designed for task scheduling to minimize memory wastage since our task is to store some files in the storage cloud, task completion time and task response time. The task manager checks all the virtual machine and assigns the task to proper virtual machine which will have least memory wastage.

  6. Providing QoS guarantee in 3G wireless networks

    Science.gov (United States)

    Chuah, MooiChoo; Huang, Min; Kumar, Suresh

    2001-07-01

    The third generation networks and services present opportunities to offer multimedia applications and services that meet end-to-end quality of service requirements. In this article, we present UMTS QoS architecture and its requirements. This includes the definition of QoS parameters, traffic classes, the end-to-end data delivery model, and the mapping of end-to-end services to the services provided by the network elements of the UMTS. End-to-end QoS of a user flow is achieved by the combination of the QoS control over UMTS Domain and the IP core Network. In the Third Generation Wireless network, UMTS bearer service manager is responsible to manage radio and transport resources to QoS-enabled applications. The UMTS bearer service consists of the Radio Access Bearer Service between Mobile Terminal and SGSN and Core Network bearer service between SGSN and GGSN. The Radio Access Bearer Service is further realized by the Radio Bearer Service (mostly air interface) and Iu bearer service. For the 3G air interface, one can provide differentiated QoS via intelligent burst allocation scheme, adaptive spreading factor control and weighted fair queueing scheduling algorithms. Next, we discuss the requirements for the transport technologies in the radio access network to provide differentiated QoS to multiple classes of traffic. We discuss both ATM based and IP based transport solutions. Last but not least, we discuss how QoS mechanism is provided in the core network to ensure e2e quality of service requirements. We discuss how mobile terminals that use RSVP as QoS signaling mechanisms can be are supported in the 3G network which may implement only IETF diffserv mechanism. . We discuss how one can map UMTS QoS classes with IETF diffserv code points. We also discuss 2G/3G handover scenarios and how the 2G/3G QoS parameters can be mapped.

  7. Edge QoS study of RPR equipment

    Science.gov (United States)

    Wang, Xiaoling; Huang, Benxiong; Yu, Xin; Zhang, Fan

    2004-05-01

    The IEEE 802.17 Working Group has taken another step forward in providing standards to Resilient Packet Ring (RPR) architectures by approving draft 2.4 of the RPR standard. Some companies have already had their RPR equipments for good market perspectives before the final standardization of RPR specifications. These equipments can supply services such as Ethernet Private Line (EPL), Transparent LAN Service (TLS), Ethernet Line Aggregation (ELA) and so on. Quality of Service (QoS) is an important part implemented in these equipments. Only when there is promise of QoS for RPR equipment, can commercial clients put their key applications to its network. Both the edge and the ring of RPR equipment need take QoS into effect to get QoS guarantees. This paper mainly deals with edge QoS study of RPR equipment. Policing, classification, shaping, and scheduling that are used for edge QoS process are introduced in the paper. And a QoS process method for traffic across rings is discussed at the same time.

  8. A Heuristic Algorithm for QoS Multicast Routing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In recent years, QoS multicast routing has continued to be a very important research topic in the areas of net-works. This paper presents a heuristic algorithm for the QoS multicast routing (HAQMR). This heuristic algorithmdeals with delay and bandwidth constraints and has low cost. The HAQMR attempts to significantly reduce the overheadfor constructing a multicast tree. the proof for correctness of the HAQMR is given, and the performance of the HAQMRis evaluated by simulations. The study shows that HAQMR provides an available approach to QoS multicast routing.

  9. QoS Negotiation and Renegotiation Based on Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shi-bing; ZHANG Deng-yin

    2006-01-01

    The Quality of Service (QoS) has received more and more attention since QoS becomes increasingly important in the Internet development. Mobile software agents represent a valid alternative to the implementation of strategies for the negotiation. In this paper, a QoS negotiation and renegotiation system architecture based on mobile agents is proposed. The agents perform the task in the whole process. Therefore, such a system can reduce the network load, overcome latency, and avoid frequent exchange information between clients and server. The simulation results show that the proposed system could improve the network resource utility about 10%.

  10. Design and implementation of a differentiated service based qos model for real-time interactive traffic on constrained bandwidth ip networks

    CERN Document Server

    Chaudhuri, Sruti Gan

    2012-01-01

    In this thesis work, a QoS model for real-time interactive traffic on a real network with constrained bandwidth and real-time traffic has been proposed. The model supports tight guarantees of QoS to real-time interactive traffic without over provisioning of bandwidth. A dynamic scheduling model which is adaptive to input data rate of traffic has been proposed. In this model, A Differentiated Service (DiffServ) based approach is proposed for QoS provisioning. The packets are classified and distributed among finite number of queues with limited buffer based on different priorities and total available bandwidth. The model proposes a mechanism to derive the weighted service rates and queue length distribution so as to meet the requirement of low packet loss and delay for real time interactive traffic in the QoS engineered network. An adaptive queuing strategy is proposed so that minimum bandwidth in used for real time traffic. This ensures maximizing availability to best effort traffic. The model assumes constrai...

  11. SIMULATED ANNEALING BASED POLYNOMIAL TIME QOS ROUTING ALGORITHM FOR MANETS

    Institute of Scientific and Technical Information of China (English)

    Liu Lianggui; Feng Guangzeng

    2006-01-01

    Multi-constrained Quality-of-Service (QoS) routing is a big challenge for Mobile Ad hoc Networks (MANETs) where the topology may change constantly. In this paper a novel QoS Routing Algorithm based on Simulated Annealing (SA_RA) is proposed. This algorithm first uses an energy function to translate multiple QoS weights into a single mixed metric and then seeks to find a feasible path by simulated annealing. The paper outlines simulated annealing algorithm and analyzes the problems met when we apply it to Qos Routing (QoSR) in MANETs. Theoretical analysis and experiment results demonstrate that the proposed method is an effective approximation algorithms showing better performance than the other pertinent algorithm in seeking the (approximate) optimal configuration within a period of polynomial time.

  12. Nontrivial QoS. Switching the web to the grid

    Directory of Open Access Journals (Sweden)

    Mircea Mare

    2011-12-01

    Full Text Available The Internet provides no QoS, and from the looks of it, never will. We turn to the grid for a solution. In terms of QoS, existing grid technologies can bring a refreshing feel to the way we use the Web. The Internet evolved by interconnecting existing equipment (telephone lines while quality and security measures were later added to it's agenda, after the issues occurred. Grid architecture is being designed in a more proactive mindset. Grids have started being used not only for scientific purposes but also for communication, collaboration and transferring data. Switching to a grid-based Web and adding nontrivial QoS to the equation is a natural step forward. The paper compares the evolution of the Internet in parallel to the evolution of grids, providing Grid QoS solutions and arguing in favor of the switch to a grid-based Web.

  13. QOS-BASED MULTICAST ROUTING OPTIMIZATION ALGORITHMS FOR INTERNET

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Most of the multimedia applications require strict Quality-of-Service (QoS) guarantee during the communication between a single source and multiple destinations. The paper mainly presents a QoS Multicast Routing algorithms based on Genetic Algorithm (QMRGA). Simulation results demonstrate that the algorithm is capable of discovering a set of QoS-based near optimized, non-dominated multicast routes within a few iterations, even for the networks environment with uncertain parameters.

  14. 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...

  15. Interactive Web service choice-making based on extended QoS model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Quality of Service (QoS) is a key factor in Web service advertising, choosing and runtime monitoring. Web service QoS is multi-faceted, fuzzy and dynamic. Current researches focus on implementation level performance assurance, ignoring domain specific or application level metrics which are also very important to service users. Industry Web service standards lack QoS expression. The support for QoS based service choice-making is very limited. We proposed an extended Web service QoS model based on configurable fuzzy synthetic evaluation system. Web service QoS is evaluated dynamically according to the service context. A QoS requirement description model is also given for service QoS requirement definition. An interactive Web service choice-making process is described, which takes QoS as a key factor when choosing from functionally equivalent services.

  16. Cross-Layer Optimization of Two-Way Relaying for Statistical QoS Guarantees

    CERN Document Server

    lin, Cen; Tao, Meixia

    2012-01-01

    Two-way relaying promises considerable improvements on spectral efficiency in wireless relay networks. While most existing works focus on physical layer approaches to exploit its capacity gain, the benefits of two-way relaying on upper layers are much less investigated. In this paper, we study the cross-layer design and optimization for delay quality-of-service (QoS) provisioning in two-way relay systems. Our goal is to find the optimal transmission policy to maximize the weighted sum throughput of the two users in the physical layer while guaranteeing the individual statistical delay-QoS requirement for each user in the datalink layer. This statistical delay-QoS requirement is characterized by the QoS exponent. By integrating the concept of effective capacity, the cross-layer optimization problem is equivalent to a weighted sum effective capacity maximization problem. We derive the jointly optimal power and rate adaptation policies for both three-phase and two-phase two-way relay protocols. Numerical results...

  17. QoS Based Capacity Enhancement for WCDMA Network with Coding Scheme

    Directory of Open Access Journals (Sweden)

    K.AYYAPPAN

    2010-03-01

    Full Text Available The wide-band code division multiple access (WCDMA based 3G and beyond cellular mobile wirelessnetworks are expected to provide a diverse range of multimedia services to mobile users withguaranteed quality of service (QoS. To serve diverse quality of service requirements of these networksit necessitates new radio resource management strategies for effective utilization of network resourceswith coding schemes. Call admission control (CAC is a significant component in wireless networks toguarantee quality of service requirements and also to enhance the network resilience. In this papercapacity enhancement for WCDMA network with convolutional coding scheme is discussed andcompared with block code and without coding scheme to achieve a better balance between resourceutilization and quality of service provisioning. The model of this network is valid for the real-time (RTand non-real-time (NRT services having different data rate. Simulation results demonstrate theeffectiveness of the network using convolutional code in terms of capacity enhancement and QoS of thevoice and video services.

  18. An Multiple Pheromone Algorithm for Cloud Scheduling With Various QoS Requirements

    Directory of Open Access Journals (Sweden)

    Mr.R.Gogulan

    2012-05-01

    Full Text Available The Cloud computing is one of the rapidly improving technologies. Cloud computing is a new promising paradigm in distributed and parallel computing. As cloud-based services become more dynamic, resource provisioning becomes more challenging. One of the critical problems in cloud computing is job scheduling because it increases with the size of the grid and becomes difficult to solve effectively. This paper introduces a new algorithm called Multiple Pheromone Algorithm which is belongs to Ant Colony Optimization Algorithm. The objective of MPA algorithm is to dynamically generate an optimal schedule so as to complete the task in minimum period of time as well as utilizing the resources in an efficient way. In this paper three different Quality of Service (QoS makespan, cost and reliability constraints are considered as performance measure for scheduling. This algorithm is compared with normal Ant colony algorithm, Genetic Algorithm. With the implementation of this approach, the Multiple Pheromone Algorithm (MPA Algorithm reaches optimal solution as well as obtains the better QoS than ACO and GA.

  19. Resource Provisioning in SLA-Based Cluster Computing

    Science.gov (United States)

    Xiong, Kaiqi; Suh, Sang

    Cluster computing is excellent for parallel computation. It has become increasingly popular. In cluster computing, a service level agreement (SLA) is a set of quality of services (QoS) and a fee agreed between a customer and an application service provider. It plays an important role in an e-business application. An application service provider uses a set of cluster computing resources to support e-business applications subject to an SLA. In this paper, the QoS includes percentile response time and cluster utilization. We present an approach for resource provisioning in such an environment that minimizes the total cost of cluster computing resources used by an application service provider for an e-business application that often requires parallel computation for high service performance, availability, and reliability while satisfying a QoS and a fee negotiated between a customer and the application service provider. Simulation experiments demonstrate the applicability of the approach.

  20. QoS prediction for Web service in Mobile Internet environment

    Science.gov (United States)

    Sun, Qibo; Wang, Lubao; Wang, Shangguang; Ma, You; Hsu, Ching-Hsien

    2016-07-01

    Quality of Services (QoS) prediction plays an important role in Web service recommendation. Many existing Web service QoS prediction approaches are highly accurate and useful in Internet environments. However, the QoS data of Web service in Mobile Internet are notably more volatile, which makes these approaches fail in making accurate QoS predictions of Web services. In this paper, by weakening the volatility of QoS data, we propose an accurate Web service QoS prediction approach based on the collaborative filtering algorithm. This approach contains three processes, that is, QoS preprocessing, user similarity computing and QoS predicting. We have implemented our proposed approach with an experiment based on real-world and synthetic datasets. The results demonstrate that our approach outperforms other approaches in Mobile Internet.

  1. QoS Routing using OLSR with Optimization for Flooding

    CERN Document Server

    Banik, Suman; Dey, Parthi; Chaki, Nabendu; Sanyal, Sugata

    2011-01-01

    Mobile Ad-hoc Network (MANET) is the self organizing collection of mobile nodes. The communication in MANET is done via a wireless media. Ad hoc wireless networks have massive commercial and military potential because of their mobility support. Due to demanding real time multimedia applications, Quality of Services (QoS) support in such infrastructure less networks have become essential. QoS routing in mobile Ad-Hoc networks is challenging due to rapid change in network topology. Consequently, the available state information for routing is inherently imprecise. QoS routing may suffer badly due to several factors including radio interference on available bandwidth, and inefficient flooding of information to the adjacent nodes. As a result the performance of the network degrades substantially. This paper aims at the solution for energy efficient QoS routing by best utilization of network resources such as energy and bandwidth. A comparative study shows that despite the overhead due to QoS management, this solut...

  2. QoS Metrics for Cloud Computing Services Evaluation

    Directory of Open Access Journals (Sweden)

    Amid Khatibi Bardsiri

    2014-11-01

    Full Text Available Cloud systems are transforming the Information Technology trade by facultative the companies to provide admission to their structure and also software products to the membership foundation. Because of the vast range within the delivered Cloud solutions, from the customer’s perspective of an aspect, it's emerged as troublesome to decide whose providers they need to utilize and then what's the thought of his or her option. Especially, employing suitable metrics is vital in assessing practices. Nevertheless, to the most popular of our knowledge, there's no methodical explanation relating to metrics for estimating Cloud products and services. QoS (Quality of Service metrics playing an important role in selecting Cloud providers and also optimizing resource utilization efficiency. While many reports have got to devote to exploitation QoS metrics, relatively not much equipment supports the remark and investigation of QoS metrics of Cloud programs. To guarantee a specialized product is published, describing metrics for assessing the QoS might be an essential necessity. So, this text suggests various QoS metrics for service vendors, especially thinking about the consumer’s worry. This article provides the metrics list may stand to help the future study and also assessment within the field of Cloud service's evaluation.

  3. On Designing Thermal-Aware Localized QoS Routing Protocol for in-vivo Sensor Nodes in Wireless Body Area Networks.

    Science.gov (United States)

    Monowar, Muhammad Mostafa; Bajaber, Fuad

    2015-06-15

    In this paper, we address the thermal rise and Quality-of-Service (QoS) provisioning issue for an intra-body Wireless Body Area Network (WBAN) having in-vivo sensor nodes. We propose a thermal-aware QoS routing protocol, called TLQoS, that facilitates the system in achieving desired QoS in terms of delay and reliability for diverse traffic types, as well as avoids the formation of highly heated nodes known as hotspot(s), and keeps the temperature rise along the network to an acceptable level. TLQoS exploits modular architecture wherein different modules perform integrated operations in providing multiple QoS service with lower temperature rise. To address the challenges of highly dynamic wireless environment inside the human body. TLQoS implements potential-based localized routing that requires only local neighborhood information. TLQoS avoids routing loop formation as well as reduces the number of hop traversal exploiting hybrid potential, and tuning a configurable parameter. We perform extensive simulations of TLQoS, and the results show that TLQoS has significant performance improvements over state-of-the-art approaches.

  4. On Designing Thermal-Aware Localized QoS Routing Protocol for in-vivo Sensor Nodes in Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Muhammad Mostafa Monowar

    2015-06-01

    Full Text Available In this paper, we address the thermal rise and Quality-of-Service (QoS provisioning issue for an intra-body Wireless Body Area Network (WBAN having in-vivo sensor nodes. We propose a thermal-aware QoS routing protocol, called TLQoS, that facilitates the system in achieving desired QoS in terms of delay and reliability for diverse traffic types, as well as avoids the formation of highly heated nodes known as hotspot(s, and keeps the temperature rise along the network to an acceptable level. TLQoS exploits modular architecture wherein different modules perform integrated operations in providing multiple QoS service with lower temperature rise. To address the challenges of highly dynamic wireless environment inside the human body. TLQoS implements potential-based localized routing that requires only local neighborhood information. TLQoS avoids routing loop formation as well as reduces the number of hop traversal exploiting hybrid potential, and tuning a configurable parameter. We perform extensive simulations of TLQoS, and the results show that TLQoS has significant performance improvements over state-of-the-art approaches.

  5. QoS Based Capacity Enhancement for WCDMA Network with Coding Scheme

    CERN Document Server

    Ayyappan, K; 10.5121/vlsic.2010.1102

    2010-01-01

    The wide-band code division multiple access (WCDMA) based 3G and beyond cellular mobile wireless networks are expected to provide a diverse range of multimedia services to mobile users with guaranteed quality of service (QoS). To serve diverse quality of service requirements of these networks it necessitates new radio resource management strategies for effective utilization of network resources with coding schemes. Call admission control (CAC) is a significant component in wireless networks to guarantee quality of service requirements and also to enhance the network resilience. In this paper capacity enhancement for WCDMA network with convolutional coding scheme is discussed and compared with block code and without coding scheme to achieve a better balance between resource utilization and quality of service provisioning. The model of this network is valid for the real-time (RT) and non-real-time (NRT) services having different data rate. Simulation results demonstrate the effectiveness of the network using co...

  6. Providing QoS guarantees for self-similar traffic flows

    Institute of Scientific and Technical Information of China (English)

    Wen Jun; Zhang Rui; Lu Xianliang

    2005-01-01

    Provisioning network resource to meet the quality of Service (QoS) demand isa key issue for future network services. Such functions may be realized by an admission control algorithm, which determines whether or not a new traffic flow can be admitted into the network. It is widely accepted that many traffic flows have self-similar character that has detrimental influence on network performance. This characteristic has made old mathematical models invalid, and a new model must work with self-similar fractal instead. This paper applies Fractional Brownian Motion(FBM) model and integrates it into the comprehensive admission control scheme, which takes account of aggregated traffic behavior to get the statistical multiplexing performance gain. Experiment verifies that FBM model can be used to realistically describe packet traffic in modern packet networks and accurately predict their performance.

  7. QoS Requirement Generation and Algorithm Selection for Composite Service Based on Reference Vector

    Institute of Scientific and Technical Information of China (English)

    Bang-Yu Wu; Chi-Hung Chi; Shi-Jie Xu; Ming Gu; Jia-Guang Sun

    2009-01-01

    Under SOA (Service-Oriented Architecture), composite service is formed by aggregating multiple component services together in a given workflow. One key criterion of this research topic is QoS composition. Most work on service composition mainly focuses on the algorithms about how to compose services according to assumed QoS, without considering where the required QoS comes from and the selection of user preferred composition algorithm among those with different computational cost and different selection results. In this paper, we propose to strengthen current service composition mechanism by generation of QoS requirement and its algorithm selection based on the QoS reference vectors which are calculated optimally from the existing individual services' QoS by registry to represent QoS overview about the best QoS,the worst (or most economical) QoS, or the average QoS of all composite services. To implement QoS requirement, which is determined according to QoS overview, this paper introduces two selection algorithms as two kinds of experiment examples,one aiming at the most accurate service selection and the other chasing for trade-off between selection cost and result.Experimental results show our mechanism can help the requester achieve his expected composite service with appropriate QoS requirement and customized selection algorithm.

  8. Web service reputation evaluation based on QoS measurement.

    Science.gov (United States)

    Zhang, Haiteng; Shao, Zhiqing; Zheng, Hong; Zhai, Jie

    2014-01-01

    In the early service transactions, quality of service (QoS) information was published by service provider which was not always true and credible. For better verification the trust of the QoS information was provided by the Web service. In this paper, the factual QoS running data are collected by our WS-QoS measurement tool; based on these objectivity data, an algorithm compares the difference of the offered and measured quality data of the service and gives the similarity, and then a reputation evaluation method computes the reputation level of the Web service based on the similarity. The initial implementation and experiment with three Web services' example show that this approach is feasible and these values can act as the references for subsequent consumers to select the service.

  9. Mobile intelligent agent entity model towards QoS guarantee

    Institute of Scientific and Technical Information of China (English)

    LI Jie; WANG Ru-chuan; BIAN Zhen-gai

    2006-01-01

    Implementing a flexible configuration of the QoS parameter in a distributed computing network has become a problem due to the weak scalability of current approaches.In an effort to solve this problem,an inner basic model of an intelligent agent (IA) is presented.The IA functionality was extended by introducing a primarily mobile agent.A QoS guarantee scheme was subsequently designed and implemented based on the model as well.By utilizing the proposed scheme,the IA can sense,predict and configure the data flow traffic.Since the communicating ability was considered and provided,the competition among different devices could be eliminated effectively and the global traffic can be optimized.The results of the simulations have shown that the proposed model can provide a QoS guarantee.

  10. Improvement on QoS of VoIP

    Institute of Scientific and Technical Information of China (English)

    HUANGYongfeng; LIXing; RUANFang

    2003-01-01

    This paper first introduces some factors affecting QoS of VoIP System, and presents some strategies to improve VoIP speech quality. Studies are concentrated on an adaptive algorithms based on IP telephony gateway, which includes adopting buffer to smooth the jitter, low bit rate redundancy packet sending mechanism to recover the packet loss, a delay and loss measurement mechanism based on RTP (Real-time transmit protocol), and an adaptive scheme algorithm according to the loss ratio and end to end delay. Finally, the results of testing have denoted that these adaptive mechanisms applied in gateway can improve greatly QoS of VoIP.

  11. Ant Colony Algorithm for Solving QoS Routing Problem

    Institute of Scientific and Technical Information of China (English)

    SUN Li-juan; WANG Liang-jun; WANG Ru-chuan

    2004-01-01

    Based on the state transition rule, the local updating rule and the global updating rule of ant colony algorithm, we propose an improved ant colony algorithm of the least-cost quality of service (QoS) unicast routing. The algorithm is used for solving the routing problem with delay, delay jitter, bandwidth, and packet loss-constrained. In the simulation, about 52.33% ants find the successful QoS routing , and converge to the best. It is proved that the algorithm is efficient and effective.

  12. A Fuzzy Directed Graph-Based QoS Model for Service Composition

    Institute of Scientific and Technical Information of China (English)

    GUO Sanjun; DOU Wanchun; FAN Shaokun

    2007-01-01

    Web service composition lets developers create applications on top of service-oriented computing and its native description, discovery, and communication capabilities. This paper mainly focuses on the QoS when the concrete composition structure is unknown. A QoS model of service composition is presented based on the fuzzy directed graph theory. According to the model,a recursive algorithm is also described for calculating such kind of QoS. And, the feasibility of this QoS model and the recursive algorithm is verified by a case study. The proposed approach enables customers to get a possible value of the QoS before they achieve the service.

  13. Design and implementation of a QoS measurement and monitoring framework for Diff-Serv network

    Science.gov (United States)

    Ge, Fei; Cao, Yang

    2004-04-01

    The QoS measurement and monitoring framework proposed for Diff-Serv consists of three conceptual modules, the QoS data acquisition agent, the Qos data correlating agent and the QoS data analysis agent. The Common Object Request Broker Architecture (CORBA) is used when implementing the frame. The constructing of the measurement package, the transmitting rule of active measurement packages and path measurement is studied. A abbreviated QoS data correlating and analyzing is introduced.

  14. Survey on Horizontal QoS Mapping Strategy and Technology over Wireless Heterogeneous Networks%泛在异构网络水平QoS映射方案和技术综述

    Institute of Scientific and Technical Information of China (English)

    王再见; 董育宁; 张晖; 孙刚友; 杜盼盼

    2012-01-01

    不同网络的QoS机制存在差异,各种应用的QoS需求也不同,给泛在异构网络QoS保证带来挑战.为了满足异构网络QoS需求,最大化利用网络资源,最小化操作代价,应建立一种能够保证异构网络QoS的机制.QoS映射是有效的解决方案,它可以完成不同网络QoS之间的自动翻译,有利于降低问题的复杂度,能保证异构网络的QoS需求.因此,本文对现有的异构网络水平QoS映射方案和技术进行综述和比较,重点介绍了AQCM - ASM映射策略和FAbS模型,并给出了今后的研究方向.%End-to-end QoS provisioning in heterogeneous networks is a challenging research issue,since QoS mechanisms in various networks are different and with the requirement to support a variety of user applications of different characteristics. To maximize network resources utilization and minimize operational costs,proper QoS mechanism that can supply heterogeneous networks QoS assurance should be established. QoS mapping seems to be an effective solution, which can perform automatic translation of QoS classes between different networks, relieve the problem complexity and support QoS over heterogeneous networks. This paper surveys current horizontal QoS mapping strategies and architectures for heterogeneous networks,and introduces AQCM-ASM mapping scheme and FAbS model. Comparisons of different QoS mapping strategies and possible future research directions are given at the end of the paper.

  15. QOS based user driven scheduler for grid environment

    CERN Document Server

    Patel, Sanjay

    2011-01-01

    As grids are in essence heterogeneous, dynamic, shared and distributed environments, managing these kinds of platforms efficiently is extremely complex. A promising scalable approach to deal with these intricacies is the design of self-managing of autonomic applications. Autonomic applications adapt their execution accordingly by considering knowledge about their own behaviour and environmental conditions.QoS based User Driven scheduling for grid that provides the self-optimizing ability in autonomic applications. Computational grids to provide a user to solve large scale problem by spreading a single large computation across multiple machines of physical location. QoS based User Driven scheduler for grid also provides reliability of the grid systems and increase the performance of the grid to reducing the execution time of job by applying scheduling policies defined by the user. The main aim of this paper is to distribute the computational load among the available grid nodes and to developed a QoS based sche...

  16. Mapping QoS Classes in Loose Coupling Heterogeneous Networks

    Directory of Open Access Journals (Sweden)

    Firas Ousta

    2014-10-01

    Full Text Available One of the main objectives of Heterogeneous Wireless Access Networks (HWAN is to integrate the different wireless access technologies, such as Universal Mobile Telecommunication System (UMTS, Worldwide Interoperability for Microwave Access (WiMAX and Wireless Local Area Network (WLAN, with a common IP-based network in order to offer mobile users continuous and unified service in a transparent way. However, one of the major issues is to support end-to-end Quality of Service (QoS across all these technologies at all stages of the service from set-up to handoff. We present, in this study, a novel method of mapping QoS of UMTS and WiMAX over a loose coupling environment across Internet Protocol/Differentiated Service (IP/DiffServ network.

  17. Dynamic Routing of IP Traffic Based on QOS Parameters

    Directory of Open Access Journals (Sweden)

    Martin Kriška

    2014-07-01

    Full Text Available The article looks into the current state of the art of dynamic routing protocols with respect to their possibilities to react to changes in the Quality of Service when selecting the best route towards a destination network. New options that could leverage information about the ever changing QoS parameters for data communication are analysed and a Cisco Performance Routing solution is described more in detail. The practical part of this work focuses on a design and implementation of a test bed that provides ascalable laboratory architecture to manipulate QoS parameters of different data communications flowing through it. The test bed is used in various use cases that were used to evaluate Cisco Performance Routing optimization capabilities in different scenarios.

  18. QoS INVESTIGATION ON MOODLE’S VIDEO CONFERENCE

    Directory of Open Access Journals (Sweden)

    LINAWATI LINAWATI

    2011-06-01

    Full Text Available Learning Management System (LMS supports e-learning as a distant learning. Moodle is one of open source LMS applications that allow embedding multimedia into learning activity in a course, such as video conference session. The paper investigates quality of service (QoS of video conference session embedded in Moodle, i.e. end-to-end delay, jitter, throughput, packet loss and PSNR. Three scenarios were implemented in the experiment. The scenarios were applied on both wire and wireless transmission, and p2p and p2m connections. The investigation results show that the QoS of video conference session meets the standards issued by ITU-T G.1010 and G.114, for minimum bandwidth of 128 kbps. Thus the application of video conferencing that is integrated in Moodle can run well with minimum bandwidth of 128 Kbps. 

  19. A Network-Attached Storage System Supporting Guaranteed QoS

    Institute of Scientific and Technical Information of China (English)

    KONG Hua-feng; YU Sheng-sheng; LU Hong-wei

    2005-01-01

    We propose a network-attached storage system that can support guaranteed Quality of Service (QoS), called POPNet Storage. The special policy of date access and disk scheduling is enable users to access files quickly and directly with guaranteed QoS in the POPNet Storage. The POPNet Storage implements a measurement-based admission control algorithm (PSMBAC) to determine whether to admit a new data access request stream and admit as many requests as possible while meeting the QoS guarantees to its clients. The data reconstruction algorithms in the POPNet Storage also put more emphasis on data availability and guaranteed QoS, thus it is designed to complete the data recovery as soon as possible and at the same time provide the guaranteed QoS for high-priority data access. The experiment results show that the POPNet Storage can provide more significant performance, reliability, and guaranteed QoS than conventional storage systems.

  20. Distributed Reservation Protocol and QoS Method in WR-OBS System

    Institute of Scientific and Technical Information of China (English)

    LAN Zhou; GUO Hong-xiang; WU Jian; LIN Jin-tong

    2005-01-01

    Starting from centralized control model used in wavelength routed optical burst switching network, a distributed control model and correspondent wavelength resource reservation protocol are proposed in this paper. Two Quality-of-Service (QoS) methods, Based on the resource reservation protocol, are discussed. Also, computer simulation is implemented to investigate the performance of the newly proposed reservation protocol and QoS methods. Simulation results demonstrate that the QoS methods can efficiently provide different level service quality to traffic with different priorities. Furthermore, performances of the two QoS methods are compared concerning the QoS distinguished level, burst lost probability and implementation difficulty. It has been shown that the newly propose reservation protocol and QoS methods is a high qualified candidate for the future OBS networks.

  1. Analysis QoS Parameters for MANETs Routing Protocols

    Directory of Open Access Journals (Sweden)

    S. R. Biradar

    2010-05-01

    Full Text Available A Mobile Ad-Hoc Network (MANET is a decentralized network of autonomous mobile nodes able to communicate with each other over wireless links. We selected three routing protocols DSDV, DSR and AODVfor measuring QoS parameters. We have used the network simulator ns-2 for simulating routing protocols using group mobility model, and present the results of simulations of networks of 40 wireless mobile nodes.

  2. Fairness as a QoS Measure for Web Services

    CERN Document Server

    Bistarelli, Stefano; 10.4204/EPTCS.2.9

    2009-01-01

    Service Oriented Architectures (SOAs) are component-based architectures, characterized by reusability, modularization and composition, usually offered by HTTP (web services) and often equipped with a Quality of Services (QoS) measure. In order to guarantee the fairness property to each client requesting a service, we propose a fair version of the (Soft) Concurrent Constraint language to deal with the negotiation phases of the Service Level Agreement (SLA) protocol.

  3. GUARANTEEING QoS IN BLUETOOTH SCATTERNET SENSOR NETWORK

    Directory of Open Access Journals (Sweden)

    R. Dhaya

    2011-03-01

    Full Text Available Bluetooth is a low power and cost-effective short range wireless network technology working in 2.4GHz ISM band. Bluetooth can be implemented either in piconet or Scatternet. In piconet the devices can communicate with each other forming a network with maximum of 8 nodes (1 master and 7 slaves. Two or more piconets can be connected through a common Bluetooth device (a gateway or bridge to form a Scatternet. But the difficult thing is to achieve Quality of service (QoS in Bluetooth particularly in the Scatternet. Quality of service refers to the efficient management of system resources, which includes the parameters like bandwidth, delay, jitter etc. This paper addresses guaranteed QoS in a Bluetooth scatternet by considering mainly two constraints namely Packet Loss and Waiting time .The above two constraints are met in a Bluetooth scatternet under high traffic congestion, which increases packet delay and causes channel wastage thereby affecting QoS. In the existing First In First Out (FIFO scheme the slaves are served by the master in accordance with the arrival of the request offered by respective slaves in the form of ‘first come first serve’ technique. So a proposal to simulate a new priority based scheduling scheme like DST (Dynamic Scheduling Technique has been implemented, which overcomes the pitfalls like packet loss, waiting time, and high congestion in the FIFO scheduling scheme. The results shows that the proposed DST scheduling that carries dynamic priorities for the requesting slaves by employing dynamic scheduling technique, which assures and guaranties the QoS parameters.

  4. Quality of Service in Wireless Sensor Networks (QOS in WSN)

    Science.gov (United States)

    Zolhavarieh, Seyedjamal; Barati, Molood

    2013-03-01

    In this paper, we discuss about concept of Quality of Service (QoS) in Wireless Sensor Networks (WSN) and different methods to improve data security network. The most useful methods for network traffic control are Differentiated Services (DS), Integrated Services, Multi-Protocol Labeled Switching (MPLS), Resource Reservation Protocol (RSVP) and Traffic Engineering. Quality of Service is responsible for data transfer between different parts of the network and it guarantees some series of transport properties on the network [14].

  5. Recurrent recurrent gallstone ileus.

    Science.gov (United States)

    Hussain, Z; Ahmed, M S; Alexander, D J; Miller, G V; Chintapatla, S

    2010-07-01

    We describe the second reported case of three consecutive episodes of gallstone ileus and ask the question whether recurrent gallstone ileus justifies definitive surgery to the fistula itself or can be safely managed by repeated enterotomies.

  6. NOC: QOS Metrics Modelling And Analysis Based On Dynamic Routing

    Directory of Open Access Journals (Sweden)

    Abdelkader SAADAOUI

    2012-04-01

    Full Text Available Increasing heterogeneous software and hardware blocks constitute complex ICs known as System on Chip (SoC. These blocks are conceived as intellectual property (IP cores. Designers are developing SoCs by using IP cores reuse, which include interconnection architecture and interface to peripheral devices.Because of the SoC growing complexity, some researchers tend to concentrate more on the communication rather than the computation aspect. This area of research has leading to the Network on Chip (NoC Concepts.The research domain of NoC has many applications needing high communication performances. Therefore NoC offers attractive solutions to these applications.One of the goals of NoC technology is to maintain a required Quality of Service (QoS, defined in terms of acceptable parameters values.This paper proposes a presentation of QoS metrics model based on QoS parameters such as Endto-End Delays (EED and throughputs (Thp, for different applications. This study is based on dynamic routing simulation of a 4x4 mesh NoC behaviour under three communications processes namely TCP, VBR and CBR.

  7. QoS multicast routing algorithm based on GA

    Institute of Scientific and Technical Information of China (English)

    李腊元; 李春林

    2004-01-01

    The multicast routing problem with multiple QoS constraints in networks with uncertain parameters is discussed, and a network model that is suitable to research such QoS multicast routing problem is described. The QMRGA,a multicast routing policy for Internet, mobile network or other high-performance networks is mainly presented, which is based on the genetic algorithm(GA), and can provide QoS-sensitive paths in a scalable and flexible way in the network environment with uncertain parameters. The QMRGA can also optimize the network resources such as bandwidth and delay, and can converge to the optimal or near-optimal solution within few iterations, even for the network environment with uncertain parameters. The incremental rate of computational cost can be close to a polynomial and is less than exponential rate. The performance measures of the QMRGA are evaluated by using simulations. The results show that QMRGA provides an available approach to QoS multicast routing in network environment with uncertain parameters.

  8. Analyzing Comprehensive QoS with Security Constraints for Services Composition Applications in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Naixue Xiong

    2014-12-01

    Full Text Available Services composition is fundamental to software development in multi-service wireless sensor networks (WSNs. The quality of service (QoS of services composition applications (SCAs are confronted with severe challenges due to the open, dynamic, and complex natures of WSNs. Most previous research separated various QoS indices into different fields and studied them individually due to the computational complexity. This approach ignores the mutual influence between these QoS indices, and leads to a non-comprehensive and inaccurate analysis result. The universal generating function (UGF shows the speediness and precision in QoS analysis. However, only one QoS index at a time can be analyzed by the classic UGF. In order to efficiently analyze the comprehensive QoS of SCAs, this paper proposes an improved UGF technique—vector universal generating function (VUGF—which considers the relationship between multiple QoS indices, including security, and can simultaneously analyze multiple QoS indices. The numerical examples demonstrate that it can be used for the evaluation of the comprehensive QoS of SCAs subjected to the security constraint in WSNs. Therefore, it can be effectively applied to the optimal design of multi-service WSNs.

  9. FUZZY REQUIREMENT BASED STRATEGY OF QoS SERVICE FOR BROADBAND TELECOMMUNICATION NETWORKS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A fuzzy requirement based strategy for QoS service in broadband networks was presented. With the analysis of QoS service in ATM networks and broadband IP networks, it gave a requirement-based strategy for QoS service application with Fuzzy language evaluation principles. The requirement parameters are chosen according to the WANT/COST rule, and a fuzzy set is constructed to realize the fuzzy determinant. The simulation results show that it is useful to evaluate the QoS service in broadband networks, and to effectively simplify the access protocols and solve the billing issues in broadband networks.

  10. Analyzing comprehensive QoS with security constraints for services composition applications in wireless sensor networks.

    Science.gov (United States)

    Xiong, Naixue; Wu, Zhao; Huang, Yannong; Xu, Degang

    2014-12-01

    Services composition is fundamental to software development in multi-service wireless sensor networks (WSNs). The quality of service (QoS) of services composition applications (SCAs) are confronted with severe challenges due to the open, dynamic, and complex natures of WSNs. Most previous research separated various QoS indices into different fields and studied them individually due to the computational complexity. This approach ignores the mutual influence between these QoS indices, and leads to a non-comprehensive and inaccurate analysis result. The universal generating function (UGF) shows the speediness and precision in QoS analysis. However, only one QoS index at a time can be analyzed by the classic UGF. In order to efficiently analyze the comprehensive QoS of SCAs, this paper proposes an improved UGF technique-vector universal generating function (VUGF)-which considers the relationship between multiple QoS indices, including security, and can simultaneously analyze multiple QoS indices. The numerical examples demonstrate that it can be used for the evaluation of the comprehensive QoS of SCAs subjected to the security constraint in WSNs. Therefore, it can be effectively applied to the optimal design of multi-service WSNs.

  11. Device Centric Throughput and QoS Optimization for IoTsin a Smart Building Using CRN-Techniques

    Directory of Open Access Journals (Sweden)

    Saleem Aslam

    2016-10-01

    Full Text Available The Internet of Things (IoT has gained an incredible importance in the communication and networking industry due to its innovative solutions and advantages in diverse domains. The IoT’ network is a network of smart physical objects: devices, vehicles, buildings, etc. The IoT has a number of applications ranging from smart home, smart surveillance to smart healthcare systems. Since IoT consists of various heterogeneous devices that exhibit different traffic patterns and expect different quality of service (QoS in terms of data rate, bit error rate and the stability index of the channel, therefore, in this paper, we formulated an optimization problem to assign channels to heterogeneous IoT devices within a smart building for the provisioning of their desired QoS. To solve this problem, a novel particle swarm optimization-based algorithm is proposed. Then, exhaustive simulations are carried out to evaluate the performance of the proposed algorithm. Simulation results demonstrate the supremacy of our proposed algorithm over the existing ones in terms of throughput, bit error rate and the stability index of the channel.

  12. Device Centric Throughput and QoS Optimization for IoTsin a Smart Building Using CRN-Techniques

    Science.gov (United States)

    Aslam, Saleem; Hasan, Najam Ul; Shahid, Adnan; Jang, Ju Wook; Lee, Kyung-Geun

    2016-01-01

    The Internet of Things (IoT) has gained an incredible importance in the communication and networking industry due to its innovative solutions and advantages in diverse domains. The IoT’ network is a network of smart physical objects: devices, vehicles, buildings, etc. The IoT has a number of applications ranging from smart home, smart surveillance to smart healthcare systems. Since IoT consists of various heterogeneous devices that exhibit different traffic patterns and expect different quality of service (QoS) in terms of data rate, bit error rate and the stability index of the channel, therefore, in this paper, we formulated an optimization problem to assign channels to heterogeneous IoT devices within a smart building for the provisioning of their desired QoS. To solve this problem, a novel particle swarm optimization-based algorithm is proposed. Then, exhaustive simulations are carried out to evaluate the performance of the proposed algorithm. Simulation results demonstrate the supremacy of our proposed algorithm over the existing ones in terms of throughput, bit error rate and the stability index of the channel. PMID:27782057

  13. Device Centric Throughput and QoS Optimization for IoTsin a Smart Building Using CRN-Techniques.

    Science.gov (United States)

    Aslam, Saleem; Hasan, Najam Ul; Shahid, Adnan; Jang, Ju Wook; Lee, Kyung-Geun

    2016-10-06

    The Internet of Things (IoT) has gained an incredible importance in the communication and networking industry due to its innovative solutions and advantages in diverse domains. The IoT' network is a network of smart physical objects: devices, vehicles, buildings, etc. The IoT has a number of applications ranging from smart home, smart surveillance to smart healthcare systems. Since IoT consists of various heterogeneous devices that exhibit different traffic patterns and expect different quality of service (QoS) in terms of data rate, bit error rate and the stability index of the channel, therefore, in this paper, we formulated an optimization problem to assign channels to heterogeneous IoT devices within a smart building for the provisioning of their desired QoS. To solve this problem, a novel particle swarm optimization-based algorithm is proposed. Then, exhaustive simulations are carried out to evaluate the performance of the proposed algorithm. Simulation results demonstrate the supremacy of our proposed algorithm over the existing ones in terms of throughput, bit error rate and the stability index of the channel.

  14. Combined Admission Control and Scheduling for QoS Differentiation in LTE Uplink

    DEFF Research Database (Denmark)

    Anas, Mohmmad; Rosa, Claudio; Calabrese, Francesco Davide

    2008-01-01

    Long term evolution (LTE) architecture shall support end-to-end quality of service (QoS). For the QoS support and service differentiation it is important that the admission control and packet scheduling functionalities are QoS-aware. In this paper a combined admission control and a decoupled time...

  15. RMD-QOSM - The Resource Management in Diffserv QoS model

    NARCIS (Netherlands)

    Bader, Attila; Karagiannis, Georgios; Westberg, Lars; Kappler, Cornelia; Phelan, Tom; Bader, A.; Karagiannis, G.; Westberg, L.; Kappler, C.; Phelan, T.

    2006-01-01

    This document describes an NSIS QoS Model for networks that use the Resource Management in Diffserv (RMD) concept. RMD is a technique for adding admission control and preemption function to Differentiated Services (Diffserv) networks. The RMD QoS Model allows devices external to the RMD network to

  16. Semantic Service Composition with QoS End - to - End Constraints via AND/OR Graphs

    Directory of Open Access Journals (Sweden)

    Xhemal Zenuni

    2012-03-01

    Full Text Available In this paper we present AND/OR graphs as a unifying framework for semantic service composition that considers users QoS constraints. The main virtues of this representation among others are its ability to express semantic inference and to deal with QoS constraints from different perspectives. In addition it correctly handles multiple inputs/outputs of services, and allows high degree of automation. Once service dependencies and QoS features are formalized as AND/OR graph, we apply a search algorithm to discover composite services that considers user QoS end - to - end preferences. The implementation of a prototype system and the experimental results support our underlying hypothesis that AND/OR graphs are not only elegant and expressive formalism for addressing QoS - aware semantic service composition, but efficient as well.

  17. Distributed QoS multicast routing protocol in ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    Sun Baolin; Li Layuan

    2006-01-01

    Quality of service (QoS) routing and multicasting protocols in ad hoc networks are face with the challenge of delivering data to destinations through multihop routes in the presence of node movements and topology changes. The multicast routing problem with multiple QoS constraints is discussed, which may deal with the delay, bandwidth and cost metrics, and describes a network model for researching the ad hoc networks QoS multicast routing problem. It presents a distributed QoS multicast routing protocol (DQMRP). The proof of correctness and complexity analysis of the DQMRP are also given. Simulation results show that the multicast tree optimized by DQMRP is better than other protocols and is fitter for the network situations with frequently changed status and the real-time multimedia application. It is an available approach to multicast routing decision with ultiple QoS constraints.

  18. Appraisal and Analysis on Diversified Web Service Selection Techniques based on QoS Factors

    Directory of Open Access Journals (Sweden)

    N.Balaji

    Full Text Available Numerous monumental changes have been made in the existing web service selection to provide quality of services. The quality of service is a major bottle neck in the recent development. Hitherto various QoS based Web Service Selection Techniques exist. But these techniques lacks in functional and non-functional attributes. This paper consists with the following tasks; segregate various QoS based Web Service selection techniques with their respective merits and demerits, an extensive comparative study on different QoS aware service selection techniques with respect to the user requirements and multiple QoS properties and preferences. This paper also evaluates the performance of discussed techniques based on the strength of various QoS aware Web service selection functionalitiesusing a set of evaluation metrics.

  19. GRIDCC: A Real-Time Grid Workflow System with QoS

    Directory of Open Access Journals (Sweden)

    A. Stephen McGough

    2007-01-01

    Full Text Available The over-arching aim of Grid computing is to move computational resources from individual institutions where they can only be used for in-house work, to a more open vision of vast online ubiquitous `virtual computational' resources which support individuals and collaborative projects. A major step towards realizing this vision is the provision of instrumentation – such as telescopes, accelerators or electrical power stations – as Grid resources, and the tools to manage these resources online. The GRIDCC project attempts to satisfy these requirements by providing the following four co-dependent components; a flexible wrapper for publishing instruments as Grid resources; workflow support for the orchestration of multiple Grid resources in a timely manner; the machinery to make reservation agreements on Grid resources; and the facility to satisfy quality of service (QoS requirements on elements within workflows. In this paper we detail the set of services developed as part of the GRIDCC project to provide the last three of these components. We provide a detailed architecture for these services along with experimental results from load testing experiments. These services are currently deployed as a test-bed at a number of institutions across Europe, and are poised to provide a 'virtual lab' to production level applications.

  20. A QoS Control Approach in Differentiated Web Caching Service

    Directory of Open Access Journals (Sweden)

    Ang Gao

    2011-01-01

    Full Text Available As the heterogeneity ofWeb clients increasing, the differentiated service becomes an important issue especially for e-commerce Web site. Web caching as a key accelerator on the Internet plays an important role in alleviating the client-perceived delay. To meet the Service Level Agreement (SLA for clients without excessively over-provisioning resources, this paper proposes and evaluates a novel framework for enforcing Proportional Hit Rate. The framework combines the implement of Isolated Cache Model and the usage of control-theoretical approach for storage control. With system identification, the linear model is identified as well as the controller. At every sampling time, by dynamically reallocating storage spaces for different Web classes, the controller operates to guarantee the relationship of QoS metric among classes constant. The experimental results demonstrate the proposed approach achieves differentiated caching service with the enforcement of Greedy Dual Size Frequency (GDSF, Latest Recently Used (LRU and Latest Frequently Used (LFU cache replacement policies.

  1. Evaluation of QoS supported in Network Mobility NEMO environments

    Science.gov (United States)

    Hussien, L. F.; Abdalla, A. H.; Habaebi, M. H.; Khalifa, O. O.; Hassan, W. H.

    2013-12-01

    Network mobility basic support (NEMO BS) protocol is an entire network, roaming as a unit which changes its point of attachment to the Internet and consequently its reachability in the network topology. NEMO BS doesn't provide QoS guarantees to its users same as traditional Internet IP and Mobile IPv6 as well. Typically, all the users will have same level of services without considering about their application requirements. This poses a problem to real-time applications that required QoS guarantees. To gain more effective control of the network, incorporated QoS is needed. Within QoS-enabled network the traffic flow can be distributed to various priorities. Also, the network bandwidth and resources can be allocated to different applications and users. Internet Engineering Task Force (IETF) working group has proposed several QoS solutions for static network such as IntServ, DiffServ and MPLS. These QoS solutions are designed in the context of a static environment (i.e. fixed hosts and networks). However, they are not fully adapted to mobile environments. They essentially demands to be extended and adjusted to meet up various challenges involved in mobile environments. With existing QoS mechanisms many proposals have been developed to provide QoS for individual mobile nodes (i.e. host mobility). In contrary, research based on the movement of the whole mobile network in IPv6 is still undertaking by the IETF working groups (i.e. network mobility). Few researches have been done in the area of providing QoS for roaming networks. Therefore, this paper aims to review and investigate (previous /and current) related works that have been developed to provide QoS in mobile network. Consequently, a new proposed scheme will be introduced to enhance QoS within NEMO environment, achieving by which seamless mobility to users of mobile network node (MNN).

  2. Downlink Radio Resource Management for QoS Provisioning in OFDMA Systems

    DEFF Research Database (Denmark)

    Monghal, Guillaume Damien

    Orthogonal Frequency Division Multiple Access (OFDMA) is the preferred technology for future downlink mobile broadband access systems as the 3rd Generation Partnership Project Long Term Evolution (LTE) in downlink, where the diversification of the proposed services (Voice Over Internet Protocol...

  3. Context-aware QoS provisioning for an M-health service platform

    NARCIS (Netherlands)

    Wac, Katarzyna; Halteren, van Aart; Bults, Richard; Broens, Tom; Delgado Kloos, C.; Larrabeiti, D.; Lopez, A.M.

    2007-01-01

    Inevitably, healthcare goes mobile. Recently developed mobile healthcare (i.e., m-health) services allow healthcare professionals to monitor mobile patient's vital signs and provide feedback to this patient anywhere at any time. Due to the nature of current supporting mobile service platforms, m-hea

  4. Provision of QoS for Multimedia Services in IEEE 802.11 Wireless Network

    Science.gov (United States)

    2006-10-01

    order to ensure the adequate level of video transmission quality. From the simulation we can also learn that video rate adaptation mechanism should...INFORMATION SYSTEMS TECHNOLOGY PANEL SYMPOSIUM ON „DYNAMIC COMUNICATIONS MANAGEMENT” IST-062 October 9 - 10, 2006 Piotr Lubkowski, Jaroslaw Krygier

  5. QoS considerations in wireless sensor networks for telemedicine

    Science.gov (United States)

    Hu, Fei; Kumar, Sunil

    2003-11-01

    The integration of telemedicine with medical micro sensor technology (Mobile Sensor Networks for Telemedicine applications -- MSNT) provides a promising approach to improve the quality of people's lives. This type of network can truly implement the goal of providing health-care services anytime and anywhere. Our research in this field generates the following outcomes that are reported in this paper: (1) We propose a mobile sensor network infrastructure to support the third-generation telemedicine applications; (2) An energy-efficient query resolution mechanism in large-scale mobile sensor networks is used for critical medical data collections; (3) To provide the guaranteed mobile QoS for arriving multimedia calls, a new multi-class call admission control mechanism is proposed which is based on dynamically forming a reservation pool for handoff requests. We used discrete-event-based simulation model using OPNET to verify our scheme. The simulation results show that our system can satisfy the adaptive QoS requirements in large-scale telemedicine sensor networks.

  6. Cross Layer Adaptation for QoS in WSN

    Directory of Open Access Journals (Sweden)

    Sukumar Nandi

    2011-10-01

    Full Text Available In this paper, we propose QoS aware MAC protocol for Wire- less Sensor Networks and its cross layer extension to network layer for providing QoS in delay sensitive WSNscenarios. In WSNs, there can be two types of traffic one is event driven traffic which requires immedi- ate attention and another is periodic reporting. Event driven traffic is classified asClass I(delay sensitive traffic and periodic reporting is clas- sified as Class II(Best Effort Traffic. MAC layer adaptation can take place in terms of (i Dynamic contention window adjustment per class, (ii Reducing the delay suffered by difference in Sleep schedules(DSS of communicating nodes by dynamically adjusting Duty Cycle based on Utilization and DSS delay of class I traffic, (iii Different DIFS (DCF Inter Frame Spacing per class, (iv Adjusting all the three schemes pro- posed above simultaneously. Cross layer extension is also proposed, in which MAC layer uses network layer’s next hop information for better adaptation of duty cycle based on DSS delay. Routing protocols can uti- lize MAC layer parameter DSS delay to select the routes which offer least DSS delay latency, there by minimizing the overall end-to-end delay

  7. Cross Layer Adaptation for QoS in WSN

    CERN Document Server

    Nandi, Sukumar

    2011-01-01

    In this paper, we propose QoS aware MAC protocol for Wire- less Sensor Networks and its cross layer extension to network layer for providing QoS in delay sensitive WSN scenarios. In WSNs, there can be two types of traffic one is event driven traffic which requires immedi- ate attention and another is periodic reporting. Event driven traffic is classified as Class I(delay sensitive) traffic and periodic reporting is clas- sified as Class II(Best Effort) Traffic. MAC layer adaptation can take place in terms of (i) Dynamic contention window adjustment per class, (ii) Reducing the delay suffered by difference in Sleep schedules(DSS) of communicating nodes by dynamically adjusting Duty Cycle based on Utilization and DSS delay of class I traffic, (iii) Different DIFS (DCF Inter Frame Spacing) per class, (iv) Adjusting all the three schemes pro- posed above simultaneously. Cross layer extension is also proposed, in which MAC layer uses network layer's next hop information for better adaptation of duty cycle based on...

  8. Enhancing QOS and QOE in IMS enabled next generation networks

    CERN Document Server

    Lakhtaria, Kamaljit I

    2010-01-01

    Managing network complexity, accommodating greater numbers of subscribers, improving coverage to support data services (e.g. email, video, and music downloads), keeping up to speed with fast-changing technology, and driving maximum value from existing networks - all while reducing CapEX and OpEX and ensuring Quality of Service (QoS) for the network and Quality of Experience (QoE) for the user. These are just some of the pressing business issues faced by mobileservice providers, summarized by the demand to "achieve more, for less." The ultimate goal of optimization techniques at the network and application layer is to ensure End-user perceived QoS. The next generation networks (NGN), a composite environment of proven telecommunications and Internet-oriented mechanisms have become generally recognized as the telecommunications environment of the future. However, the nature of the NGN environment presents several complex issues regarding quality assurance that have not existed in the legacy environments (e.g., m...

  9. Recurrent varicocele

    Directory of Open Access Journals (Sweden)

    Katherine Rotker

    2016-01-01

    Full Text Available Varicocele recurrence is one of the most common complications associated with varicocele repair. A systematic review was performed to evaluate varicocele recurrence rates, anatomic causes of recurrence, and methods of management of recurrent varicoceles. The PubMed database was evaluated using keywords "recurrent" and "varicocele" as well as MESH criteria "recurrent" and "varicocele." Articles were not included that were not in English, represented single case reports, focused solely on subclinical varicocele, or focused solely on a pediatric population (age <18. Rates of recurrence vary with the technique of varicocele repair from 0% to 35%. Anatomy of recurrence can be defined by venography. Management of varicocele recurrence can be surgical or via embolization.

  10. Quality of Service Provisioning in Manet Using a Cross-Layer Approach for Routing

    CERN Document Server

    Goyal, Ruchita; Mishra, Manoj

    2011-01-01

    Deployment of multimedia applications warrants provisioning of Quality of Service (QoS) in MANET. However, limited battery power, other resource constraints and mobility of nodes make QoS provisioning difficult to achieve in MANET. This difficulty can be overcome by using a cross-layer approach for routing. In [1] Patil et al., proposed a cross-layer routing protocol named Cost Based Power Aware Cross Layer - AODV (CPACL-AODV) which overcomes the limitation of battery power of nodes. Though many similar energy efficient and cross-layer routing protocols have been proposed for MANET, none of them handles QoS. A novel MANET routing protocol, Type of Service, Power and Bandwidth Aware AODV (TSPBA-AODV), which overcomes resource constraints and simultaneously provides QoS guarantees using a cross-layer approach, is proposed in this paper. In addition the effect of variation in nodes' mobility on performance of TSPBA-AODV is compared with that of CPACL-AODV [1] for two different types of network traffic. As shown ...

  11. Network-State-Aware Quality of Service Provisioning for the Internet of Things

    Directory of Open Access Journals (Sweden)

    Shafique Ahmad Chaudhry

    2016-06-01

    Full Text Available The Internet of Things (IoT describes a diverse range of technologies to enable a diverse range of applications using diverse platforms for communication. IP-enabled Wireless Sensor Networks (6LoWPAN are an integral part of IoT realization because of their huge potential for sensing and communication. The provision of Quality of Service (QoS requirements in IoT is a challenging task because of device heterogeneity in terms of bandwidth, computing and communication capabilities of the diverse set of IoT nodes and networks. The sensor nodes in IoT, e.g., 6LoWPAN, exhibit low battery power, limited bandwidth and extremely constrained computing power. Additionally, these IP-based sensor networks are inherently dynamic in nature due to node failures and mobility. Introduction of modern delay-sensitive applications for such networks has made the QoS provisioning task even harder. In this paper, we present Network-State-Adaptive QoS provision algorithm for 6LoWPAN, which adapts with the changing network state to ensure that QoS requirements are met even with the dynamic network states. It is a policy-based mechanism, which collaborates with the underlying routing protocol to satisfy the QoS requirements specified in the high level policies. It is simple in its implementation yet minimizes the degradation of the best effort traffic at a considerable level. Our implementation results show that our protocol adjusts well in dynamic 6LoWPAN environment where multiple services are competing for available limited resources.

  12. QoS and QoE Aware N-Screen Multicast Service

    Directory of Open Access Journals (Sweden)

    Ghulam Sarwar

    2016-01-01

    Full Text Available The paper focuses on ensuring the quality-of-service (QoS and quality-of-experience (QoE requirements of users having heterogeneous devices in a multicast session. QoS parameters such as bit rate, delays, and packet losses are good indicators for optimizing network services but fall short in characterizing user perception (QoE. In N-Screen service, the users have different devices with heterogeneous attributes like screen size, resolution, and access network interface, and the users have different QoE on N-Screen devices with the same QoS parameters. We formulate the objective function of the N-Screen multicast grouping to ensure the minimum user’s QoE with smaller bandwidth requirement. We propose a dynamic user reassignment scheme to maintain and satisfy the QoE by adapting the user’s membership to the varying network conditions. The proposed schemes combine the available bandwidth and multimedia visual quality to ensure the QoS and QoE. In the network architecture, we introduce the functions of the QoS and QoE aware multicast group management and the estimation schemes for the QoS and QoE parameters. The simulation results show that the proposed multicast service ensures the network QoS and guarantees the QoE of users in the varying network conditions.

  13. A QoS aware services mashup model for cloud computing applications

    Directory of Open Access Journals (Sweden)

    Yee Ming Chen

    2012-12-01

    Full Text Available Purpose: With the popularity of cloud computing, cloud services have become to be application programming platform where users can create new applications mashup(composing the functionality offered byothers.By composing of distributed, cloud services dynamicallyto provide more complex tasks, services mashup provides an attractive way for building large-scale Internetapplications.Oneof the challenging issues of cloud services mashup is how to find service paths to route the service instances provider through whilemeeting the applications’ resource requirements so that the QoS constraints are satisfied. However, QoS aware service routing problem istypically NP-hard.The purpose of this paper is to propose a QoS Aware Services Mashup(QASM model to solve this problem more effectively.Design/methodology/approach: In this paper, we focus on the QoS aware services selection problem in cloud services mashup, for example, given the user service composition requirements and their QoS constraint descriptions, how to select the required serviceinstances and route the data flows through these instances so that the QoS requirements are satisfied. We design a heuristic algorithm to find service paths to route the data flows through whilemeeting the applications’ resource requirements and specific QoS constraints.Findings: This study propose a QoS Aware Services Mashup(QASM model to solve this problem more effectively. Simulations show that QASM can achieve desired QoS assurances as well as load balancing in cloud services environment.Originality/value: This paperpresent a QASM model for providing high performance distributedapplications in the cloud computing systems.

  14. Real-Time QoS Routing Protocols in Wireless Multimedia Sensor Networks: Study and Analysis.

    Science.gov (United States)

    Alanazi, Adwan; Elleithy, Khaled

    2015-09-02

    Many routing protocols have been proposed for wireless sensor networks. These routing protocols are almost always based on energy efficiency. However, recent advances in complementary metal-oxide semiconductor (CMOS) cameras and small microphones have led to the development of Wireless Multimedia Sensor Networks (WMSN) as a class of wireless sensor networks which pose additional challenges. The transmission of imaging and video data needs routing protocols with both energy efficiency and Quality of Service (QoS) characteristics in order to guarantee the efficient use of the sensor nodes and effective access to the collected data. Also, with integration of real time applications in Wireless Senor Networks (WSNs), the use of QoS routing protocols is not only becoming a significant topic, but is also gaining the attention of researchers. In designing an efficient QoS routing protocol, the reliability and guarantee of end-to-end delay are critical events while conserving energy. Thus, considerable research has been focused on designing energy efficient and robust QoS routing protocols. In this paper, we present a state of the art research work based on real-time QoS routing protocols for WMSNs that have already been proposed. This paper categorizes the real-time QoS routing protocols into probabilistic and deterministic protocols. In addition, both categories are classified into soft and hard real time protocols by highlighting the QoS issues including the limitations and features of each protocol. Furthermore, we have compared the performance of mobility-aware query based real-time QoS routing protocols from each category using Network Simulator-2 (NS2). This paper also focuses on the design challenges and future research directions as well as highlights the characteristics of each QoS routing protocol.

  15. QOS Aware Formalized Model for Semantic Web Service Selection

    Directory of Open Access Journals (Sweden)

    Divya Sachan

    2014-10-01

    Full Text Available Selecting the most relevant Web Service according to a client requirement is an onerous task, as innumerous number of functionally same Web Services(WS are listed in UDDI registry. WS are functionally same but their Quality and performance varies as per service providers. A web Service Selection Process involves two major points: Recommending the pertinent Web Service and avoiding unjustifiable web service. The deficiency in keyword based searching is that it doesn’t handle the client request accurately as keyword may have ambiguous meaning on different scenarios. UDDI and search engines all are based on keyword search, which are lagging behind on pertinent Web service selection. So the search mechanism must be incorporated with the Semantic behavior of Web Services. In order to strengthen this approach, the proposed model is incorporated with Quality of Services (QoS based Ranking of semantic web services.

  16. Modeling and performance analysis of QoS data

    Science.gov (United States)

    Strzeciwilk, Dariusz; Zuberek, Włodzimierz M.

    2016-09-01

    The article presents the results of modeling and analysis of data transmission performance on systems that support quality of service. Models are designed and tested, taking into account multiservice network architecture, i.e. supporting the transmission of data related to different classes of traffic. Studied were mechanisms of traffic shaping systems, which are based on the Priority Queuing with an integrated source of data and the various sources of data that is generated. Discussed were the basic problems of the architecture supporting QoS and queuing systems. Designed and built were models based on Petri nets, supported by temporal logics. The use of simulation tools was to verify the mechanisms of shaping traffic with the applied queuing algorithms. It is shown that temporal models of Petri nets can be effectively used in the modeling and analysis of the performance of computer networks.

  17. A QoS Routing Protocol based on Available Bandwidth Estimation for Wireless Ad Hoc Networks

    CERN Document Server

    Kaaniche, Heni; Frikha, Mounir; Kamoun, Farouk

    2011-01-01

    At the same time as the emergence of multimedia in mobile Ad hoc networks, research for the introduction of the quality of service (QoS) has received much attention. However, when designing a QoS solution, the estimation of the available resources still represents one of the main issues. This paper suggests an approach to estimate available resources on a node. This approach is based on the estimation of the busy ratio of the shared canal. We consider in our estimation the several constraints related to the Ad hoc transmission mode such as Interference phenomena. This approach is implemented on the AODV routing protocol. We call AODVwithQOS our new routing protocol. We also performed a performance evaluation by simulations using NS2 simulator. The results confirm that AODVwithQoS provides QoS support in ad hoc wireless networks with good performance and low overhead.

  18. Improvement of AODV Routing Protocol with QoS Support in Wireless Mesh Networks

    Science.gov (United States)

    Liu, Ling; Zhu, Lei; Lin, Long; Wu, Qihui

    The Wireless Mesh Network (WMN) is a newly developed wireless network which supports broadband and high speed multimedia service, so the Quality-of-Service (QoS) must be guaranteed by the network. In this paper, a new QoS-aware routing protocol based on AODV named QAODV (QoS- AODV) is proposed. Under the premise of the delay and available bandwidth meeting the QoS demands, the protocol defines a new route metric with the hop count and load rate so as to select the best route according to it. Simulation results show that, compared with AODV, the performance of QAODV is better on both network throughput and end-to-end delay with small increase of control overhead. As a whole, the protocol improves the QoS guarantee capability in the WMN.

  19. Using Kalman Filter to Guarantee QoS Robustness of Web Server

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The exponential growth of the Internet coupled with the increasing popularity of dynamically generated content on the World Wide Web, has created the need for more and faster Web servers capable of serving the over 100 million Internet users. To converge the control method has emerged as a promising technique to solve the Web QoS problem. In this paper, a model of adaptive session is presented and a session flow self-regulating algorism based on Kalman Filter are proposed towards Web Server. And a Web QoS self-regulating scheme is advanced. To attain the goal of on-line system identification, the optimized estimation of QoS parameters is fulfilled by utilizing Kalman Filter in full domain. The simulation results shows that the proposed scheme can guarantee the QoS with both robustness and stability .

  20. Network based control point for UPnP QoS architecture

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Wessing, Henrik; Rossello Busquet, Ana;

    2011-01-01

    Enabling coexistence of non-UPnP Devices in an UPnP QoS Architecture is an important issue that might have a major impact on the deployment and usability of UPnP in future home networks. The work presented here shows potential issues of placing non-UPnP Device in the network managed by UPnP QoS. We...... address this issue by extensions to the UPnP QoS Architecture that can prevent non-UPnP Devices from degrading the overall QoS level. The obtained results show that deploying Network Based Control Point service with efficient traffic classifier, improves significantly the end-to-end packet delay...

  1. Analysis of Energy Efficiency in Fading Channels under QoS Constraints

    CERN Document Server

    Gursoy, Mustafa Cenk; Velipasalar, Senem

    2008-01-01

    Energy efficiency in fading channels in the presence of Quality of Service (QoS) constraints is studied. Effective capacity, which provides the maximum arrival rate that a wireless channel can sustain while satisfying statistical QoS constraints, is considered. Spectral efficiency--bit energy tradeoff is analyzed in the low-power and wideband regimes by employing the effective capacity formulation, rather than the Shannon capacity. Through this analysis, energy requirements under QoS constraints are identified. The analysis is conducted under two assumptions: perfect channel side information (CSI) available only at the receiver and perfect CSI available at both the receiver and transmitter. In particular, it is shown in the low-power regime that the minimum bit energy required under QoS constraints is the same as that attained when there are no such limitations. However, this performance is achieved as the transmitted power vanishes. Through the wideband slope analysis, the increased energy requirements at lo...

  2. Providing end-to-end QoS for multimedia applications in 3G wireless networks

    Science.gov (United States)

    Guo, Katherine; Rangarajan, Samapth; Siddiqui, M. A.; Paul, Sanjoy

    2003-11-01

    As the usage of wireless packet data services increases, wireless carriers today are faced with the challenge of offering multimedia applications with QoS requirements within current 3G data networks. End-to-end QoS requires support at the application, network, link and medium access control (MAC) layers. We discuss existing CDMA2000 network architecture and show its shortcomings that prevent supporting multiple classes of traffic at the Radio Access Network (RAN). We then propose changes in RAN within the standards framework that enable support for multiple traffic classes. In addition, we discuss how Session Initiation Protocol (SIP) can be augmented with QoS signaling for supporting end-to-end QoS. We also review state of the art scheduling algorithms at the base station and provide possible extensions to these algorithms to support different classes of traffic as well as different classes of users.

  3. The application of packet classification and queue management in the web QOS system

    Science.gov (United States)

    Bai, Chun; Liu, Jin

    2011-10-01

    The control mechanisms and strategies of QoS are introduced and implemented in the Web server and system, to meet the growing demand of Web performance. And it provides service differentiation and performance guarantees for different types of user or request. And it is now a problems that urgent need to solve for Web development. The paper proposed a program that designs Web QoS software of the middleware to improve the server quality of the LAN Web server.

  4. An End-to-End QoS Control Model for Enhanced Internet

    Institute of Scientific and Technical Information of China (English)

    张尧学; 王晓春; 顾钧

    2000-01-01

    This paper describes an end-to-end QoS (Quality of Services) control model for distributed multimedia computing on enhanced Internet, and gives the design and implementation of this model including hosts and routers. The architecture, the mathematical definition about QoS parameters, and the mapping between Integrated Service (IS) and Differentiated Service (DS) are discussed in this paper.The simulation shows that this model can improve the performance of audio streams when it is used in IPhone system.

  5. ANCS: Achieving QoS through Dynamic Allocation of Network Resources in Virtualized Clouds

    OpenAIRE

    Cheol-Ho Hong; Kyungwoon Lee; Hyunchan Park; Chuck Yoo

    2016-01-01

    To meet the various requirements of cloud computing users, research on guaranteeing Quality of Service (QoS) is gaining widespread attention in the field of cloud computing. However, as cloud computing platforms adopt virtualization as an enabling technology, it becomes challenging to distribute system resources to each user according to the diverse requirements. Although ample research has been conducted in order to meet QoS requirements, the proposed solutions lack simultaneous support for ...

  6. 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.

  7. 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.

  8. A study of distributed QoS adapter in large-scale wireless networks

    CERN Document Server

    Hu, Xiaodong; Ganguly, Mitra

    2012-01-01

    Considering the comfortably establishing ad hoc networks, the use of this type of network is increasing day to day. On the other side, it is predicted that using multimedia applications will be more public in these network. As it is known, in contrary to best-effort flows, the transmission of multimedia flows in any network need support from QoS. However, the wireless ad hoc networks are severely affected by bandwidth, and establishing a QoS in these networks face problems. In this paper, we have proposed a thoroughly distributed algorithm to support the QoS in ad hoc networks. This algorithm guarantees the QoS of the real-time applications vis-a-vis each other and best-effort flows as well. The algorithm suggested in this paper dynamically regulates the Contention Window of the flows and serves the flows in terms of their requests QoS choosing the smallest CW in every node. This algorithm also uses the fixed and/or less stationary nodes for the transmission of real-time flows by increasing the QoS of the mul...

  9. Optimal Network QoS over the Internet of Vehicles for E-Health Applications

    Directory of Open Access Journals (Sweden)

    Di Lin

    2016-01-01

    Full Text Available Wireless technologies are pervasive to support ubiquitous healthcare applications. However, a critical issue of using wireless communications under a healthcare scenario is the electromagnetic interference (EMI caused by RF transmission, and a high level of EMI may lead to a critical malfunction of medical sensors. In consideration of EMI on medical sensors, we study the optimization of quality of service (QoS within the whole Internet of vehicles for E-health and propose a novel model to optimize the QoS by allocating the transmit power of each user. Our results show that the optimal power control policy depends on the objective of optimization problems: a greedy policy is optimal to maximize the summation of QoS of each user, whereas a fair policy is optimal to maximize the product of QoS of each user. Algorithms are taken to derive the optimal policies, and numerical results of optimizing QoS are presented for both objectives and QoS constraints.

  10. Characterization of User-Perceived Quality of Service (QOS in Mobile Devices Using Network Pairwise Comparisons

    Directory of Open Access Journals (Sweden)

    Carlos E. Otero

    2010-08-01

    Full Text Available This paper presents a user-centric and application-specific QoS assessment methodology for cellularcommunication networks. Specifically, it uses the Analytic Hierarchy Process (AHP to evaluate QoS as amulti-criteria decision problem that represents how well cellular networks’ data services are perceivedgiven particular sets of application classes and relative to other networks servicing in the same area. Aspart of the methodology, drive testing is performed to collect objective measurements associated withidentified QoS criteria for data services. Once drive testing is performed and data collected, multiplenetworks are compared to determine the network that provides higher QoS based on users’ perception ofquality. The selection of the best performing network is based on the output provided by the AHPapproach, which is used as unified measurement of the perceived QoS by users on different networks. Inorder to determine application-specific priorities, the approach presented uses three different applicationclasses, including Emergency, Business, and Personal. For each class, the relative importance of eachquality evaluation criteria is adjusted in the AHP procedure to reflect the priorities of the servicesexpected. Through several case studies, the approach is proven successful in providing a way foranalyzing user-centric QoS for application-specific scenarios.

  11. FP/FIFO scheduling: coexistence of deterministic and probabilistic QoS guarantees

    Directory of Open Access Journals (Sweden)

    Pascale Minet

    2007-01-01

    Full Text Available In this paper, we focus on applications having quantitative QoS (Quality of Service requirements on their end-to-end response time (or jitter. We propose a solution allowing the coexistence of two types of quantitative QoS garantees, deterministic and probabilistic, while providing a high resource utilization. Our solution combines the advantages of the deterministic approach and the probabilistic one. The deterministic approach is based on a worst case analysis. The probabilistic approach uses a mathematical model to obtain the probability that the response time exceeds a given value. We assume that flows are scheduled according to non-preemptive FP/FIFO. The packet with the highest fixed priority is scheduled first. If two packets share the same priority, the packet arrived first is scheduled first. We make no particular assumption concerning the flow priority and the nature of the QoS guarantee requested by the flow. An admission control derived from these results is then proposed, allowing each flow to receive a quantitative QoS guarantee adapted to its QoS requirements. An example illustrates the merits of the coexistence of deterministic and probabilistic QoS guarantees.

  12. Achieving QoS for Aeronautical Telecommunication Networks over Differentiated Services

    Science.gov (United States)

    Bai, Haowei; Atiquzzaman, Mohammed; Ivancic, William

    2001-01-01

    Aeronautical Telecommunication Network (ATN) has been developed by the International Civil Aviation Organization to integrate Air-Ground and Ground-Ground data communication for aeronautical applications into a single network serving Air Traffic Control and Aeronautical Operational Communications. To carry time critical information required for aeronautical applications, ATN provides different Quality of Services (QoS) to applications. ATN has therefore, been designed as a standalone network which implies building an expensive separate network for ATN. However, the cost of operating ATN can be reduced if it can be run over a public network such as the Internet. Although the current Internet does not provide QoS, the next generation Internet is expected to provide QoS to applications. The objective of this paper is to investigate the possibility of providing QoS to ATN applications when it is run over the next generation Internet. Differentiated Services (DiffServ), one of the protocols proposed for the next generation Internet, will allow network service providers to offer different QoS to customers. Our results show that it is possible to provide QoS to ATN applications when they run over a DiffServ backbone.

  13. QoS awared power and admission controls based on non-cooperative game theory in wireless networks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to better accommodate heterogeneous quality of service (QoS) in wireless networks, an algorithm called QeS-aware power and admission controls (QAPAC) is proposed. The system is modeled as u non- cooperative game where the users adjust their transmit powers to maximize the utility, thus restraining the interferences. By using adaptive utility functions and tunable pricing parameters according to QoS levels, this algorithm can well meet different QoS reqniremcnts and improve system capacity compared with those that ignore the QoS differ- ences.

  14. 一种异构网络多媒体业务QoS类弹性映射方法%An Elastic QoS Class Mapping Method for Multimedia Traffic in Heterogeneous Wireless Networks

    Institute of Scientific and Technical Information of China (English)

    王再见; 董育宁; 张晖; 赵海涛

    2013-01-01

      多媒体业务在异构网络传输过程中,由于现有的QoS(Quality of Service)类映射方法存在灵活性不足的问题,从而降低了系统端到端效能。针对这个问题,该文在深入分析当前的QoS类映射方法基础上,结合用户QoE (Quality of Experience)特点,借助于网络微积分理论,构建了QoS类映射的数学分析模型,并进行了理论分析。基于该数学分析模型,该文从用户QoE角度提出了具有弹性的QoS类映射方法(Elastic QoS Class Mapping Method, EQCMM),该方法根据当前网络资源的使用情况,通过灵活地调整QoS类映射,充分利用网络现有资源,提高了端到端带宽资源的利用率,改善了系统端到端的效能。最后,通过仿真验证了该方法的有效性。%To increase the end-to-end system efficiency with a flexible QoS (Quality of Service) class mapping scheme for transporting multimedia traffic over heterogeneous networks, by analyzing current QoS class mapping schemes which lack flexibility without considering user’s QoE (Quality of Experience), an analytical model is developed for end-to-end QoS provisioning based on network calculus theory. Based on this model, the paper derives an Elastic QoS Class Mapping Method (EQCMM) which considers user’s QoE. With EQCMM, the result of QoS class mapping can be adjusted elastically according to available network resources, in order to achieve higher end-to-end system efficiency. Finally, simulation results are given to demonstrate the effectiveness of the proposed method.

  15. QOS by Priority Routing in Internet of Things

    Directory of Open Access Journals (Sweden)

    G. Vithya

    2014-12-01

    Full Text Available The aim of this study is to present a system which uses a new layered network architecture approach for IOT. Sudden and unpredictable large-scale changes are commonly prevalent in Internet of Things (IoT. The images or video data captured from the remote places have to be routed without delay. This is a tumultuous task in large scale. By using an Agents in various wireless networks and the packets are routed depends on the priority. The scope of this study is to avoid delay, interference during transfer of data from various wireless networks. This study deals with (i congestion free data transfer under many cramped networks (ii low processing overhead (iii handling realistic failure scenarios, prioritized traffic in a flexible manner (iv robust to both topology failures and traffic variations. This study presents a QoS routing method, by setting a priority to the networks to differentiate eclectic sensing vicinities in the smart space between sender and receiver.

  16. PROPOSED A HETEROGENEOUS CLUSTERING ALGORITHM TO IMPROVE QOS IN WSN

    Directory of Open Access Journals (Sweden)

    Mehran Mokhtari

    2016-07-01

    Full Text Available In this article it has presented leach extended hierarchical 3-level clustered heterogeneous and dynamics algorithm. On suggested protocol (LEH3LA with planning of selected auction cluster head, and alternative cluster head node, problem of delay on processing, processing of selecting members, decrease of expenses, and energy consumption, decrease of sending message, and receiving messages inside the clusters, selecting of cluster heads in large sensor networks were solved. This algorithm uses hierarchical heterogeneous network (3-levels, collective intelligence, and intra-cluster interaction for communications. Also it will solve the problems of sending data in Multi-BS mobile networks, expanding inter-cluster networks, overlap cluster, genesis orphan nodes, boundary change dynamically clusters, using backbone networks, cloud sensor. Using sleep/wake scheduling algorithm or TDMA-schedule alternative cluster head node provides redundancy, and fault tolerance. Local processing in cluster head nodes, and alternative cluster head, intra-cluster and inter-cluster communications such as Multi-HOP cause increase on processing speed, and sending data intra-cluster and inter-cluster. Decrease of overhead network, and increase the load balancing among cluster heads. Using encapsulation of data method, by cluster head nodes, energy consumption decrease during sending data. Also by improving quality of service (QoS in CBRP, LEACH, 802.15.4, decrease of energy consumption in sensors, cluster heads and alternative cluster head nodes, cause increase on lift time of sensor networks

  17. QoS Based User Driven Scheduler for Grid Environment

    Directory of Open Access Journals (Sweden)

    Sanjay Patel

    2011-05-01

    Full Text Available As grids are in essence heterogeneous, dynamic, shared and distributed environments, managing thesekinds of platforms efficiently is extremely complex. A promising scalable approach to deal with theseintricacies is the design of self-managing of autonomic applications. Autonomic applications adapt theirexecution accordingly by considering knowledge about their own behaviour and environmentalconditions.QoS based User Driven scheduling for grid that provides the self-optimizing ability inautonomic applications. Computational grids to provide a user to solve large scale problem by spreadinga single large computation across multiple machines of physical location.QoS based User Driven scheduler for grid also provides reliability of the grid systems and increase theperformance of the grid to reducing the execution time of job by applying scheduling policies defined bythe user. The main aim of this paper is to distribute the computational load among the available gridnodes and to developed a QoS based scheduling algorithm for grid and making grid more reliable.Gridcomputing system is different from conventional distributed computing systems by its focus on large scaleresource sharing, where processors and communication have significant inuence on Grid computingreliability. Reliability capabilities initiated by end users from within applications they submit to the gridfor execution. Reliability of infrastructure and management services that perform essential functionsnecessary for grid systems to operate, such as resource allocation and scheduling.

  18. A NOVEL QOS SCHEDULING FOR WIRELESS BROADBAND NETWORKS

    Directory of Open Access Journals (Sweden)

    D. David Neels Pon Kumar

    2010-09-01

    Full Text Available During the last few years, users all over the world have become more and more familiar to the availability of broadband access. When users want broadband Internet service, they are generally restricted to a DSL (Digital Subscribers Line, or cable-modem-based connection. Proponents are advocating worldwide interoperability for microwave access (WiMAX, a technology based on an evolving standard for point-to multipoint wireless networking. Scheduling algorithms that support Quality of Service (QoS differentiation and guarantees for wireless data networks are crucial to the deployment of broadband wireless networks. The performance affecting parameters like fairness, bandwidth allocation, throughput, latency are studied and found out that none of the conventional algorithms perform effectively for both fairness and bandwidth allocation simultaneously. Hence it is absolutely essential for an efficient scheduling algorithm with a better trade off for these two parameters. So we are proposing a novel Scheduling Algorithm using Fuzzy logic and Artificial neural networks that addresses these aspects simultaneously. The initial results show that a fair amount of fairness is attained while keeping the priority intact. Results also show that maximum channel utilization is achieved with a negligible increment in processing time.

  19. Enhancing QoS Through Dynamic and Fare AP Selection in a Wireless LAN

    Directory of Open Access Journals (Sweden)

    Fakhar Uddin Ahmed

    2014-01-01

    Full Text Available The IEEE 802.11 WLAN is primarily used for web browsing which belongs to the category of non-real time application. But the demand of real time applications like VOIP and video conferencing has become very much common to such WLAN. With IEEE 802.11e Mac protocol it is possible to improve the QoS for both real and non-real time traffic by service differentiation. To ensure efficient utilization of the radio resources and enhanced QoS the load imbalance should be resolved among APs from different BSSs. In large scale WLAN inter AP communication mechanism can be employed along side the current admission controller under EDCA. Beside service differentiation inter AP differentiation based QoS management can lead to efficient utilization of radio resources by moving STAs from heavily laded to a less loaded AP and ensure better QoS for all types of traffics. In this paper we propose a dynamic and fair AP selection mechanism to improve the QoS in a WLAN. The simulations have been carried out with NSv2.34.

  20. Autonomous QoS Management and Policing in Unmanaged Local Area Networks

    Directory of Open Access Journals (Sweden)

    Christopher Köhnen

    2015-01-01

    Full Text Available The high increase of bandwidth-intensive applications like high definition video streaming in home and small office environments leads to QoS challenges in hybrid wired/wireless local area networks. These networks are often not QoS aware and may contain bottlenecks in their topology. In addition, they often have a hybrid nature due to the used access technology consisting of, for example, Ethernet, wireless, and PowerLAN links. In this paper, we present the research work on a novel autonomous system for hybrid QoS in local area networks, called QoSiLAN, which does not rely on network infrastructure support but on host cooperation and works independently of the access technology. We present a new QoS Signalling Protocol, policing and admission control algorithms, and a new lightweight statistical bandwidth prediction algorithm for autonomous resource management in LANs. This new QoS framework enables link based, access-medium independent bandwidth management without network support. We provide evaluation results for the novel bandwidth prediction algorithm as well as for the QoSiLAN framework and its protocol, which highlight the features, robustness, and the effectiveness of the proposed system.

  1. Cross-Layer Algorithms for QoS Enhancement in Wireless Multimedia Sensor Networks

    Science.gov (United States)

    Saxena, Navrati; Roy, Abhishek; Shin, Jitae

    A lot of emerging applications like advanced telemedicine and surveillance systems, demand sensors to deliver multimedia content with precise level of QoS enhancement. Minimizing energy in sensor networks has been a much explored research area but guaranteeing QoS over sensor networks still remains an open issue. In this letter we propose a cross-layer approach combining Network and MAC layers, for QoS enhancement in wireless multimedia sensor networks. In the network layer a statistical estimate of sensory QoS parameters is performed and a nearoptimal genetic algorithmic solution is proposed to solve the NP-complete QoS-routing problem. On the other hand the objective of the proposed MAC algorithm is to perform the QoS-based packet classification and automatic adaptation of the contention window. Simulation results demonstrate that the proposed protocol is capable of providing lower delay and better throughput, at the cost of reasonable energy consumption, in comparison with other existing sensory QoS protocols.

  2. Challenges for Quality of Service (QoS in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    RAJSHREE S. DUBEY,

    2010-12-01

    Full Text Available A wireless sensor network is a special network with large numbers of nodes consisting embedded processors, sensors, and radios. These nodes cooperate to achieve a common goal or perform a common task such as environment monitoring or asset tracking. A lot of research has been done in the area of routing techniques and power consumption in sensor network but real-time communication with the Quality of Service (QoS concept in wireless sensor networks is still unexplored. Most protocols either ignore real time or simply attempt to process as fast as possible. QoS in wireless sensor networks can be characterized by reliability, timeliness, robustness, vailability, and security between all others. Recently, the design of sensor networks has become very important, due to several civil and military applications. Emerging sensor applications include habitat monitoring, pollution detection, weather forecasting, and monitoring disasters such as earthquakes, fires, and floods. In these new areas, similar to normal IP networks, there is real-time and non-real-timetraffic in the sensor networks. Each type of traffic requires a different treatment from the network to meet the objective QoS (Quality of Service. Queuing and scheduling have a direct impact on QoS characteristics. Many excellent protocols have already been developed for ad-hoc networks but providing QoS guarantees for real time traffic in sensor networks are still very immature.

  3. Optimizing on multiple constrained QoS multicast routing algorithms based on GA

    Institute of Scientific and Technical Information of China (English)

    孙宝林; 李腊元

    2004-01-01

    With the rapid development of Internet, mobile networks and high-performance networking technology,multiple constrained QoS multicast routing optimization in networks with uncertain parameters has become a very important research issue in the areas of networks and distributed systems. It is also a challenging and hard problem to the next generation Internet and high-performance networks, and has attracted the interests of many people. This paper discusses the multiple constrained QoS multicast routing problem, which may deal with the delay, delay jitter,bandwidth and packet loss metrics, and describes a network model for researching the routing problem. The paper mainly presents multiple constrained QoS multicast routing algorithm (MCQMRA), a QoS multicast routing policy for Internet,mobile network or other high-performance networks, which is based on the genetic algorithm (GA) and can provide QoS-sensitive paths in a scalable and flexible wayin the network environment with uncertain parameters. The MCQMRA can also optimize the network resources such as bandwidth, delay, packet loss metrics and can converge to the optimal or near-optimal solution within few iterations, even for the network environment with uncertain parameters. Simulation results show that MCQMRA is an available approach to QoS multicast routing decision.

  4. Delay aware Reactive Routing Protocols for QoS in MANETs: a Review

    Directory of Open Access Journals (Sweden)

    Saad M. Adam

    2013-12-01

    Full Text Available Mobile Ad Hoc Networks (MANETs are wireless networks, which do not require any infrastructure support for transferring data packets between mobile nodes. These nodes communicate in a multi-hop mode; each mobile node acting both as a host and router. The main function of Quality of Service (QoS routing in MANETs is to establish routes among different mobile nodes that satisfy QoS requirements such as bandwidth, end-to-end delay and to be able operate within the limited energy constraints. Efficient QoS routing protocols are required by most commercial, real-time and multimedia applications. Ad Hoc On-Demand Distance Vector (AODV and Dynamic Source Routing (DSR protocols are two of the most on-demand protocols used in MANETs. These protocols use shortest path as a main metric to establish routing between source and destination. However, they are designed primarily as best effort services and as such they do not fully heed QoS requirements as required by MANETs. This paper presents an overview of reactive routing protocols in QoS which use delay as a main metric.

  5. Modelling the guaranteed QoS for wireless sensor networks: a network calculus approach

    Directory of Open Access Journals (Sweden)

    Yu Jianping

    2011-01-01

    Full Text Available Abstract Wireless sensor networks (WSNs became one of the high technology domains during the last 10 years. Real-time applications for them make it necessary to provide the guaranteed quality of service (QoS. The main contributions of this article are a system skeleton and a guaranteed QoS model that are suitable for the WSNs. To do it, we develop a sensor node model based on virtual buffer sharing and present a two-layer scheduling model using the network calculus. With the system skeleton, we develop a guaranteed QoS model, such as the upper bounds on buffer queue length/delay/effective bandwidth, and single-hop/multi-hops delay/jitter/effective bandwidth. Numerical results show the system skeleton and the guaranteed QoS model are scalable for different types of flows, including the self-similar traffic flows, and the parameters of flow regulators and service curves of sensor nodes affect them. Our proposal leads to buffer dimensioning, guaranteed QoS support and control in the WSNs.

  6. Multiantenna relay beamforming design for QoS discrimination in two-way relay networks.

    Science.gov (United States)

    Xiong, Ke; Zhang, Yu; Li, Dandan; Chang, Chih-Yung; Zhong, Zhangdui

    2013-01-01

    This paper investigates the relay beamforming design for quality of service (QoS) discrimination in two-way relay networks. The purpose is to keep legitimate two-way relay users exchange their information via a helping multiantenna relay with QoS guarantee while avoiding the exchanged information overhearing by unauthorized receiver. To this end, we propose a physical layer method, where the relay beamforming is jointly designed with artificial noise (AN) which is used to interfere in the unauthorized user's reception. We formulate the joint beamforming and AN (BFA) design into an optimization problem such that the received signal-to-interference-ratio (SINR) at the two legitimate users is over a predefined QoS threshold while limiting the received SINR at the unauthorized user which is under a certain secure threshold. The objective of the optimization problem is to seek the optimal AN and beamforming vectors to minimize the total power consumed by the relay node. Since the optimization problem is nonconvex, we solve it by using semidefinite program (SDP) relaxation. For comparison, we also study the optimal relay beamforming without using AN (BFO) under the same QoS discrimination constraints. Simulation results show that both the proposed BFA and BFO can achieve the QoS discrimination of the two-way transmission. However, the proposed BFA yields significant power savings and lower infeasible rates compared with the BFO method.

  7. ALPHA: Proposal of Mapping QoS Parameters between UPnP Home Network and GMPLS Access

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Sköldström, Pontus; Gavler, Anders

    2011-01-01

    This paper is treating the interdomain QoS signaling between the home and access domains with a focus on applying it for providing QoS between a UPnP-QoS based home network and GMPLS based access network. The work presented here is defining a possible approach for an interface between UPn...

  8. QoS signaling across heterogeneous wired/wireless networks: resource management in diffserv using the NSIS protocol suite

    NARCIS (Netherlands)

    Bader, Attila; Karagiannis, Georgios; Westberg, Lars; Kappler, Cornelia; Phelan, Tom; Tschofenig, Hannes; Heijenk, Geert; Shen, S.

    2005-01-01

    Reservation-based Quality of Service (QoS) in a mixed wireless and wireline environment requires an end-to-end signaling protocol that is capable of adapting to the idiosyncrasies of the different networks. The QoS NSIS Signaling Protocol (QoSNSLP) has been created by the Next Steps In Signaling

  9. Recurrent vulvovaginitis.

    Science.gov (United States)

    Powell, Anna M; Nyirjesy, Paul

    2014-10-01

    Vulvovaginitis (VV) is one of the most commonly encountered problems by a gynecologist. Many women frequently self-treat with over-the-counter medications, and may present to their health-care provider after a treatment failure. Vulvovaginal candidiasis, bacterial vaginosis, and trichomoniasis may occur as discreet or recurrent episodes, and have been associated with significant treatment cost and morbidity. We present an update on diagnostic capabilities and treatment modalities that address recurrent and refractory episodes of VV.

  10. QoS Guarantee for IEEE 802.11a Based Mobile Ad Hoc Networks

    Institute of Scientific and Technical Information of China (English)

    YAOZhongbang; CAOZhigang

    2004-01-01

    In this paper, we propose a Distributed scheduling and optimization scheme (DSOQoS) for QoS guarantee in IEEE 802.11a based MANETs. In DSOQoS, for each station, the network layer takes different scheduling actions according to its local channel conditions estimated by the MAC layer, and the MAC layer takes different packet transmission actions based on the network load conditions estimated by the network layer. The optimizations are based on the following information sharing and interaction: traffic types, QoS parameters, network packet timeout periods, and predicted packet transmission periods. We evaluate the scheme under different network loads and different station moving speeds. The simulation results show that DSOQoS can guarantee the QoS requirements in terms of packet delivery ratio, packet delay and delay jitter.

  11. Secure Communication over Fading Channels with Statistical QoS Constraints

    CERN Document Server

    Qiao, Deli; Velipasalar, Senem

    2010-01-01

    In this paper, the secure transmission of information over an ergodic fading channel is investigated in the presence of statistical quality of service (QoS) constraints. We employ effective capacity, which provides the maximum constant arrival rate that a given process can support while satisfying statistical delay constraints, to measure the secure throughput of the system, i.e., effective secure throughput. We assume that the channel side information (CSI) of the main channel is available at the transmitter side. Depending on the availability of the CSI of the eavesdropper channel, we obtain the corresponding optimal power control policies that maximize the effective secure throughput. In particular, when the CSI of the eavesdropper channel is available at the transmitter, the transmitter can no longer wait for transmission when the main channel is much better than the eavesdropper channel due to the introduction of QoS constraints. Moreover, the CSI of the eavesdropper channel becomes useless as QoS constr...

  12. The Problems in QoS Routing%QoS中的路由问题

    Institute of Scientific and Technical Information of China (English)

    彭孜; 曾家智; 周明天

    2000-01-01

    The next-greneration high-speed networks are expected to suppot a wide range of delay-sensitive multimedia applications. They need a different routing algorithm from the conventional one. The goal of the new algorithm is twofold: (1)satisfying the QoS requirements for every admitted connections,and(2)achieving global efficiency in resource utilization. Thus,most of problems in QoS routing area have multiple constraints which make them NP-Hard. Until now,the generally effcient algorithm has not been found. In this paper,we pose two algorithms for PCPO problems common in QoS communication,and analyze respective characteristics and uses.

  13. A new burst assembly technique for supporting QoS in optical burst switching networks

    Institute of Scientific and Technical Information of China (English)

    Xiaolong Yang(阳小龙); Mingrui Dang(党明瑞); Youju Mao(毛幼菊); Lemin Li(李乐民)

    2003-01-01

    This letter proposes a new burst assembly technique for supporting QoS in optical burst switching (OBS)networks. It consists of the adaptive-threshold burst assembly mechanism and QoS-based random offset-time scheme. The assembly mechanism, which is fit well to multi-class burst assembly, not only matcheswith IP QoS mechanism based on packet classification, and also utilizes fairly and efficiently assemblycapacity. Based on token-bucket model and burst segment selective discard (BSSD), the offset-time schemecan smooth the traffic to support OBS QoS. The simulation results show that the technique can improvethe performance in terms of packet loss probability (PLP).

  14. Performance Analysis of QoS Multicast Routing in Mobile Ad Hoc Networks Using Directional Antennas

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2010-12-01

    Full Text Available in this paper, a quality of service (QoS multicast routing protocol in mobile ad hoc networks (MANETs by using directional antennas has been presented. Many important applications, such as audio/video conferencing, require the quality of service guarantee. Directional antenna technology provides the capability for considerable increase in spatial reuse, which increases the efficiency of communication. This paper studies TDMA-based timeslot allocation and directional antennas, and presents an effective algorithm for calculating bandwidth of a multicast tree. We also propose a novel on-demand QoS multicasting routing algorithm in TDMA-based mobile ad hoc networks using directional antennas. The simulation result shows the performance of this QoS multicast routing algorithm in TDMA-based mobile ad hoc networks using directional antennas.

  15. A dynamic access control method based on QoS requirement

    Science.gov (United States)

    Li, Chunquan; Wang, Yanwei; Yang, Baoye; Hu, Chunyang

    2013-03-01

    A dynamic access control method is put forward to ensure the security of the sharing service in Cloud Manufacturing, according to the application characteristics of cloud manufacturing collaborative task. The role-based access control (RBAC) model is extended according to the characteristics of cloud manufacturing in this method. The constraints are considered, which are from QoS requirement of the task context to access control, based on the traditional static authorization. The fuzzy policy rules are established about the weighted interval value of permissions. The access control authorities of executable service by users are dynamically adjusted through the fuzzy reasoning based on the QoS requirement of task. The main elements of the model are described. The fuzzy reasoning algorithm of weighted interval value based QoS requirement is studied. An effective method is provided to resolve the access control of cloud manufacturing.

  16. QoS Parameters Investigations and Load Intensity Analysis, (A Case for Reengineered DCN

    Directory of Open Access Journals (Sweden)

    Udeze Chidiebele. C, Prof. H. C Inyiama, Okafor Kennedy .C, Dr C. C. Okezie

    2012-05-01

    Full Text Available This paper presents the simulation results on Reengineered DCN model considering Quality of Service (QoS parameters in a homogeneous network for enterprise web application support. To make it feasible for the computer aided design (CAD tool, a complete and robust real performance assessment of simulation scenarios is considered. This paper deals with a performance measurement and evaluation of a number of homogeneous end-to-end (e2e DCN subnets taking into account a wide range of statistics. An active measurement approach of QoS parameters has been adopted for the studying of proprieties we called concise process model QoS. This paper validates the performance of the Reengineered DCN through simulations with MATLAB SimEvent which presents efficient performance metrics for its deployment. Considering the model hierarchy in context, the results shows that with the design model, a highly scalable DCN will be achieved.

  17. Parallel Switch System with QoS Guarantee for Real-Time Traffic

    Institute of Scientific and Technical Information of China (English)

    Wen-Jie Li; Bin Liu; Yang Xu; Heng Liao

    2006-01-01

    This paper studies the load-balancing algorithm and quality of service (QoS) control mechanism in a 320Gb/s switch system, which incorporates four packet-level parallel switch planes. Eight priorities for both unicast and multicast traffic are implemented, and the highest priority with strict QoS guarantee is designed for real-time traffic. Through performance analysis under multi-priority burst traffic, we demonstrate that the load-balancing algorithm is efficient, and the switch system not only provides excellent performance to real-time traffic, but also efficiently allocates bandwidth among other traffic of lower priorities. As a result, this parallel switch system is more scalable towards next generation core routers with QoS guarantee, as well as ensures in-order delivery of IP packets.

  18. Service allocation based on QoS evaluation in military organization cloud cooperation

    Institute of Scientific and Technical Information of China (English)

    An Zhang; Haiyang Sun; Yanxia Zhang

    2016-01-01

    The problem of cloud cooperation of military service providers (MSPs) is addressed for alocating limited resources to military service users (MSUs) that are geographicaly dis-tributed. The MSPs, also caled military organization clouds, are virtualized and encapsulated by the services they can offer and each of them contains different kinds of resources that MSU needs. The MSPs are also geographicaly dis-persed. They are required to alocate their resources to the MSU complying with the corresponding quality of service (QoS), so that each MSU gathers the services it needs to guarantee its task to be implemented. The outline of military organization cloud cooperation is discussed and the method of service optimal selection is proposed based on QoS evaluation. The QoS evaluation method based on exponential approximation is put forward to include the users’ will. Simulation results verify the effectiveness of the proposed algorithm.

  19. A Robust Service Selection Method Based on Uncertain QoS

    Directory of Open Access Journals (Sweden)

    Yanping Chen

    2016-01-01

    Full Text Available Nowadays, the number of Web services on the Internet is quickly increasing. Meanwhile, different service providers offer numerous services with the similar functions. Quality of Service (QoS has become an important factor used to select the most appropriate service for users. The most prominent QoS-based service selection models only take the certain attributes into account, which is an ideal assumption. In the real world, there are a large number of uncertain factors. In particular, at the runtime, QoS may become very poor or unacceptable. In order to solve the problem, a global service selection model based on uncertain QoS was proposed, including the corresponding normalization and aggregation functions, and then a robust optimization model adopted to transform the model. Experiment results show that the proposed method can effectively select services with high robustness and optimality.

  20. ALPHA: Proposal of Mapping QoS Parameters between UPnP Home Network and GMPLS Access

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Sköldström, Pontus; Gavler, Anders

    2011-01-01

    This paper is treating the interdomain QoS signaling between the home and access domains with a focus on applying it for providing QoS between a UPnP-QoS based home network and GMPLS based access network. The work presented here is defining a possible approach for an interface between UPnP-QoS an......P-QoS and GMPLS in order to move towards end-to-end QoS establishment as well as investigating the complexity of such a solution. We present the QoS parameters and mechanisms in both UPnP-QoS and GMPLS and how they can be matched to create a coherent QoS architecture....

  1. Achieving End-to-End QoS in the Next Generation Internet: Integrated Services over Differentiated Service Networks

    Science.gov (United States)

    Bai, Haowei; Atiquzzaman, Mohammed; Ivancic, William

    2001-01-01

    Currently there are two approaches to provide Quality of Service (QoS) in the next generation Internet: An early one is the Integrated Services (IntServ) with the goal of allowing end-to-end QoS to be provided to applications; the other one is the Differentiated Services (DiffServ) architecture providing QoS in the backbone. In this context, a DiffServ network may be viewed as a network element in the total end-to-end path. The objective of this paper is to investigate the possibility of providing end-to-end QoS when IntServ runs over DiffServ backbone in the next generation Internet. Our results show that the QoS requirements of IntServ applications can be successfully achieved when IntServ traffic is mapped to the DiffServ domain in next generation Internet.

  2. Studying on equilibriums between price and QoS in multi-provider overlay access networks

    Institute of Scientific and Technical Information of China (English)

    Wang Yufeng; Wang Wendong

    2006-01-01

    From the viewpoint of game theory, this paper proposes a model that combines QoS index with price factor in overlay access networks, and uses the multinomial logit (MNL) to model the choice behaviour of users. Each service class is considered an independent and competitive entity offered by each provider,which aims at maximizing its own utility. Based on noncooperative game, we prove the existence and uniqueness of equilibriums between QoS levels and prices among various service classes, and demonstrate the properties of equilibriums. Finally, these results are verified via numerical analysis.

  3. 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.

  4. A Real-Time Schedule Strategy with QoS Constraints

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhifei; QIU Zhengding

    2001-01-01

    A novel strategy for scheduling input packets queueing in three buffers with different quality of service constraints has been developed to improve the traffic QoS. By theoretical and simulation analysis, analytical formulas of the average circular time, return time, queue length and delay have been obtained and the impacts of k2, p2 on the average circular time, return time and delay have been investigated. It shows that the new schedule strategy can satisfy the QoS requirement by carefully selecting ki or pi with the arrival and departure rate of the packets being given.

  5. Assessing Measurements of QoS for global Cloud Computing Services

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, M. Tahir; Júnior, Joaquim Celestino

    2011-01-01

    -time streaming multimedia applications like online gaming and watching movies on a pay as you use basis hosted in a cloud computing environment. However, guaranteeing or even predicting QoS in global and diverse networks supporting complex hosting of application services is a very challenging issue that needs......, between servers placed in universities in Denmark, Poland, Brazil and Malaysia. The results show some correlation between latency and throughput, and between latency and jitter, even though the results are not completely consistent. As a side result, we were able to monitor the changes in QoS parameters...

  6. On the QoS of IPTV and Its Effects on Home Networks

    OpenAIRE

    2010-01-01

    In Internet Protocol Television (IPTV) systems, Quality-of-Service (QoS) is a critical factor for user satisfaction. In this paper, we first propose a queueing model for IPTV systems and discuss how to ensure the QoS of IPTV. We then use the model to analyze the effects of IPTV traffic on other applications in home networks. We find that TCP congestion control may not work well under this circumstance and propose a new approach to improve the performance of TCP. We also v...

  7. A Novel Adaptive Routing through Fitness Function Estimation Technique with Multiple QoS Parameters Compliance

    CERN Document Server

    Nair, T R Gopalakrishnan

    2011-01-01

    The paper presents a method which shows a significant improvement in discovering the path over the distance vector protocol. The proposed method is a multi-parameter QoS along with the fitness function which shows that it overcomes the limitation of DV like routing loops by spanning tree approach, count-to-infinity problem by decision attribute. The input considered is a topology satisfying the QoS parameters of size 1 to 64 nodes and it was shown that an optimal path selection was obtained efficiently over the classical distance vector algorithm

  8. Feedback threshold with guaranteed QoS in multiuser OFDM systems

    Institute of Scientific and Technical Information of China (English)

    YANG Rui-zhe; YUAN Chao-wei; TENG Ying-lei; ZHANG Yan-hua

    2009-01-01

    A threshold setting scheme is proposed based on the resource management and limited feedback theory in multiuser orthogonal frequency division multiplexing (OFDM) systems. In adaptive resource allocation, the factors denoting the quality of service (QoS) and fairness are both considered as the user weight. From the aspect of feedback outage probability, the proposed algorithm sets the threshold for each user related to its weight, which brings enough feedback to the user with greater weight. Analysis and simulation results show that, compared with the threshold ignoring weights, the proposed scheme has much lower feedback load while with better QoS.

  9. A novel QoS supported cooperative diversity algorithm for IEEE 802.11 WLAN

    Institute of Scientific and Technical Information of China (English)

    Li Yi; Ji Hong

    2008-01-01

    A new cooperative diversity algorithm with quality of service (QoS) awareness for wireless local area network (WLAN) is proposed. According to this protocol, cooperation is invoked only if a direct transmission cannot meet user-specific QoS requirements. If cooperation is implemented, partner choice depends on who can achieve the minimum data rate required to have a successful transmission. The closed-form expressions for the system throughput and the power consumption are provided. Theoretical analysis and simulation results indicate that the QoS-aware cooperative scheme can significantly improve the system performance in terms of throughput and energy efficiency by avoiding negative effect of unconditional cooperation.

  10. QoS Multicast Routing Based on Ant Algorithm in Internet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, based on ant-algorithm, we propose a QoS multicast routing scheme in Internet. We first describe ant-algorithm model and give ant-network model, then present an approach using ant-algorithm to optimize the multicast routes with QoS constaints. Finally, simulations has been made to show the efficiency of the approach in the environment of OPNET simulation software, and the simulation results show that the proposed approach can find the best optimal multicast routes which can satisfy the delay-bounded requirement and avoid congested nodes as soon as possible.

  11. Quantitative QoS Management Implement Mechanism in IP-DiffServ

    Institute of Scientific and Technical Information of China (English)

    Jin-Yu Zhang; Li Liu; Hong-Hui Li; Feng Liu

    2005-01-01

    In this paper, a quantitative QoS management implement mechanism in IP-DiffServ is presented. The approach has three merits: (1) it optimizes both the route selected for service class by traffic engineering in network layer and the service class selected for the user services by network plan in service layer, (2) it ensures quantitative QoS for the user service in DiffServ, (3) it achieves high resource utilization, and achieves better performance with less cost for the user service and selected route. Simulation has verified these merits.

  12. Evaluation of QoS differentiation mechanisms in asynchronous bufferless optical packet-switched networks

    DEFF Research Database (Denmark)

    Overby, H.; Stol, N.; Nord, Martin

    2006-01-01

    Existing quality of service differentiation schemes for today's IP over point-to-point optical WDM networks take advantage of electronic RAM to implement traffic management algorithms in order to isolate the service classes. Since practical optical RAM is not available, these techniques...... are not suitable for a future all-optical network. Hence, new schemes are needed to support QoS differentiation in optical packet-switched (OPS) networks. In this article we first present an overview of existing QoS differentiation mechanisms suitable for asynchronous bufferless OPS. We then compare...

  13. Quality-Of-Service Provisioning in Decentralized Networks: A Satisfaction Equilibrium Approach

    CERN Document Server

    Perlaza, Samir M; Lasaulce, Samson; Debbah, Mérouane

    2011-01-01

    This paper introduces a particular game formulation and its corresponding notion of equilibrium, namely the satisfaction form (SF) and the satisfaction equilibrium (SE). A game in SF models the case where players are uniquely interested in the satisfaction of some individual performance constraints, instead of individual performance optimization. Under this formulation, the notion of equilibrium corresponds to the situation where all players can simultaneously satisfy their individual constraints. The notion of SE, models the problem of QoS provisioning in decentralized self-configuring networks. Here, radio devices are satisfied if they are able to provide the requested QoS. Within this framework, the concept of SE is formalized for both pure and mixed strategies considering finite sets of players and actions. In both cases, sufficient conditions for the existence and uniqueness of the SE are presented. When multiple SE exist, we introduce the idea of effort or cost of satisfaction and we propose a refinemen...

  14. Strategy of Ethernet Services Carried in ONU and QOS%ONU上行以太业务承载方式及QOS

    Institute of Scientific and Technical Information of China (English)

    于路; 黄地龙; 郝园

    2010-01-01

    介绍了GPON系统中ONU承栽上行以太业务的方式,提出了四种承载以太业务的分类策略,以及根据分类的方式在ONU的T-CONT上承载以太业务和调度策略用以保证QOS.对实际应用有一定参考价值.

  15. Recurrent fevers.

    Science.gov (United States)

    Isaacs, David; Kesson, Alison; Lester-Smith, David; Chaitow, Jeffrey

    2013-03-01

    An 11-year-old girl had four episodes of fever in a year, lasting 7-10 days and associated with headache and neck stiffness. She had a long history of recurrent urticaria, usually preceding the fevers. There was also a history of vague pains in her knees and in the small joints of her hands. Her serum C-reactive protein was moderately raised at 41 g/L (normal <8). Her rheumatologist felt the association of recurrent fevers that lasted 7 or more days with headaches, arthralgia and recurrent urticaria suggested one of the periodic fever syndromes. Genetic testing confirmed she had a gene mutation consistent with one of tumour necrosis factor receptor-associated periodic syndrome.

  16. A QoS scheme for a congestion core network based on dissimilar QoS structures in smart-phone environments.

    Science.gov (United States)

    Hong, Sung-Ryong; Na, Wonshik; Kang, Jang-Mook

    2010-01-01

    This study suggests an approach to effective transmission of multimedia content in a rapidly changing Internet environment including smart-phones. Guaranteeing QoS in networks is currently an important research topic. When transmitting Assured Forwarding (AF) packets in a Multi-DiffServ network environment, network A may assign priority in an order AF1, AF2, AF3 and AF4; on the other hand, network B may reverse the order to a priority AF4, AF3, AF2 and AF1. In this case, the AF1 packets that received the best quality of service in network A will receive the lowest in network B, which may result in dropping of packets in network B and vice versa. This study suggests a way to guarantee QoS between hosts by minimizing the loss of AF packet class when one network transmits AF class packets to another network with differing principles. It is expected that QoS guarantees and their experimental value may be utilized as principles which can be applied to various mobile-web environments based on smart-phones.

  17. RPOA Model-Based Optimal Resource Provisioning

    Directory of Open Access Journals (Sweden)

    Noha El. Attar

    2014-01-01

    Full Text Available Optimal utilization of resources is the core of the provisioning process in the cloud computing. Sometimes the local resources of a data center are not adequate to satisfy the users’ requirements. So, the providers need to create several data centers at different geographical area around the world and spread the users’ applications on these resources to satisfy both service providers and customers QoS requirements. By considering the expansion of the resources and applications, the transmission cost and time have to be concerned as significant factors in the allocation process. According to the work of our previous paper, a Resource Provision Optimal Algorithm (RPOA based on Particle Swarm Optimization (PSO has been introduced to find the near optimal resource utilization with considering the customer budget and suitable for deadline time. This paper is considered an enhancement to RPOA algorithm to find the near optimal resource utilization with considering the data transfer time and cost, in addition to the customer budget and deadline time, in the performance measurement.

  18. A Novel Prioritization Scheme to Improve QoS in IEEE 802.11e Networks

    Directory of Open Access Journals (Sweden)

    Navid Tadayon

    2010-01-01

    Full Text Available IEEE 802.11 WLAN utilizes a distributed function at its MAC layer, namely, DCF to access the wireless medium. Due to its distributed nature, DCF is able to guarantee working stability in a wireless medium while maintaining the assembling and maintenance cost in a low level. However, DCF is inefficient in dealing with real-time traffics due to its incapability on providing QoS. IEEE 802.11e was introduced as a supplementary standard to cope with this problem. This standard introduces an Enhanced Distributed Coordination Function (EDCF that works based on diff-Serve model and can serve multiple classes of traffics (by using different prioritizations schemes. With the emergence of new time-sensitive applications, EDCF has proved to be yet inefficient in dealing with these kinds of traffics because it could not provide network with well-differentiated QoS. In this study, we propose a novel prioritization scheme to improve QoS level in IEEE 802.11e network. In this scheme, we replace Uniform PDF with Gamma PDF, which has salient differentiating properties. We investigate the suitability and superiority of this scheme on furnishing network with well-differentiated QoS using probabilistic analysis. We strengthen our claims by extensive simulation runs.

  19. Fuzzy Logic Control Based QoS Management in Wireless Sensor/Actuator Networks

    CERN Document Server

    Xia, Feng; Sun, Youxian; Tian, Yu-Chu

    2008-01-01

    Wireless sensor/actuator networks (WSANs) are emerging rapidly as a new generation of sensor networks. Despite intensive research in wireless sensor networks (WSNs), limited work has been found in the open literature in the field of WSANs. In particular, quality-of-service (QoS) management in WSANs remains an important issue yet to be investigated. As an attempt in this direction, this paper develops a fuzzy logic control based QoS management (FLC-QM) scheme for WSANs with constrained resources and in dynamic and unpredictable environments. Taking advantage of the feedback control technology, this scheme deals with the impact of unpredictable changes in traffic load on the QoS of WSANs. It utilizes a fuzzy logic controller inside each source sensor node to adapt sampling period to the deadline miss ratio associated with data transmission from the sensor to the actuator. The deadline miss ratio is maintained at a pre-determined desired level so that the required QoS can be achieved. The FLC-QM has the advantag...

  20. Protected Core Networking (PCN): PCN QoS and SLA definition

    NARCIS (Netherlands)

    Schutz, R.; McLaughlin, S.; Daeleman, T.; Luoma, M.; Peuhkuri, M.; Carlen, P.; Haines, J.

    2013-01-01

    The aim of this paper is to share the early results available from IST-103 regarding QoS (Quality of Service) and SLA (Service Level Agreement) definition. This paper is a position paper addressing how PCN WG sees Quality of Service Management & Service Level Agreement Management. The paper will

  1. Protected Core Networking (PCN): PCN QoS and SLA definition

    NARCIS (Netherlands)

    Schutz, R.; McLaughlin, S.; Daeleman, T.; Luoma, M.; Peuhkuri, M.; Carlen, P.; Haines, J.

    2013-01-01

    The aim of this paper is to share the early results available from IST-103 regarding QoS (Quality of Service) and SLA (Service Level Agreement) definition. This paper is a position paper addressing how PCN WG sees Quality of Service Management & Service Level Agreement Management. The paper will add

  2. Using latency as a QoS indicator for global cloud computing services

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Tahir; Dubalski, Bozydar

    2013-01-01

    Many globally distributed cloud computing (CC) applications and services running over the Internet, between globally dispersed clients and servers, will require certain levels of QoS in order to deliver and give a sufficiently smooth user experience. This would be essential for real-time streamin...

  3. Cross-layer QoS Support for Multimedia Delivery over Wireless Internet

    Directory of Open Access Journals (Sweden)

    Zhang Qian

    2005-01-01

    Full Text Available Delivering multimedia over wireless Internet is a very challenging task. Multimedia delivery inherently has strict quality of service (QoS requirement on bandwidth, delay, and delay jitter. However, the current Internet can only support best-effort service, which imposes varying network conditions during multimedia delivery. The advent of wireless networks further exacerbates the variance of network conditions and brings greater challenges for multimedia delivery. To improve perceived media quality by end users over wireless Internet, QoS supports can be addressed in different layers, including application layer, transport layer, link layer, and so forth. This paper presents a framework, which provides QoS support, for multimedia delivery over wireless Internet, across different layers. To provide efficient QoS support for different types of media over the best-effort networks, we first propose a cross-layer architecture, which combines the application-level, transport-layer, as well as link-layer controls, and then review recent advances in each individual component. Specifically, dynamic estimation of varying channel and network, adaptive and energy-efficient application and link-level error control, efficient congestion control, header compression, adaptive automatic repeat request (ARQ and priority-based scheduling, as well as QoS-adaptive proxy caching technologies are explicitly reviewed in this paper.

  4. An Analysis of QoS in ZigBee Network Based on Deviated Node Priority

    Directory of Open Access Journals (Sweden)

    Md. Jaminul Haque Biddut

    2016-01-01

    Full Text Available ZigBee is an IEEE 802.15.4 standardized communication protocol. It forms a flawless Wireless Sensor Network (WSN standard for interoperability at all levels of the network, particularly the application level which most closely touches the user. A large number of devices from different vendors can work seamlessly. These devices act as a network and send huge data traffic to the Coordinator. End devices at different zones have different roles in communication with each other. There has been a lack in executing their requests in a synchronized way based on task priority. This lack leads to massive data traffic loss and degrades the Quality of Service (QoS. One of the challenges is to analyze the QoS parameters in ZigBee network that help to detect the overall network performance. The contribution of this paper is twofold; first, a ZigBee Network is implemented based on node priority. It demonstrates a method to generate a new priority of devices with respect to their existing priority and zones’ priority as well. Second, the QoS is analyzed based on the new priority status for tasks preference purposes. The outcome of this paper shows that the QoS of the network is more conspicuous than non-priority based network.

  5. Transmission Algorithm with QoS Considerations for a Sustainable MPEG Streaming Service

    Directory of Open Access Journals (Sweden)

    Sang-Hyong Kim

    2017-03-01

    Full Text Available With the proliferation of heterogeneous networks, there is a need to provide multimedia stream services in a sustainable manner. It is especially critical to maintain the Quality of Service (QoS standards. Existing multimedia streaming services have been studied to guarantee QoS on the receiving side. QoS has not been ensured due to the fact that the loss of streaming data to be transmitted has not been considered in network conditions. With an algorithm that considers the QoS and can reduce the overhead of the network, it will be possible to reduce the transmission error and wastage of communication network resources. In this paper, we propose a scheme that improves the reliability of multimedia transmissions by using an adaptive algorithm that switches between UDP (User Datagram Protocol and TCP (Transmission Control Protocol based on the size of the data. In addition, we present a method that retransmits essential portions of the multimedia data, thus improving transmission efficiency. We simulate an MPEG (Moving Picture Experts Group stream service and evaluate the performance of the proposed adaptive MPEG stream service.

  6. Modeling on Guaranteed QoS for Wireless Sensor Networks: A Network Calculus Method

    CERN Document Server

    Zhang, Lianming; Deng, Xiaoheng

    2011-01-01

    Wireless sensor networks (WSNs) became one of the high-technology domains during the last years. Real-time applications for them make it necessary to provide the guaranteed Quality of Service (QoS). The main contributions of the paper are a service framework and a guaranteed QoS model that are suitable for the WSNs with some characteristics of the distribution, multi-hop, etc. To do it, we develop a sensor node model based on virtual buffer sharing and present a two-layer scheduling model by arrival curves and service curves in the network calculus. With this service framework, we develop a guaranteed QoS model, such as the upper bounds on buffer queue length, buffer queue delay, end-to-end delay/jitter and end-to-end effective bandwidth. Numerical results show that the service framework and guaranteed QoS model are highly scalable for different types of input flows, including the self-similar input flows, and they are only affected by the parameters of service curves and flow regulators. Our proposal leads t...

  7. Integrating QoS and security functions in an IP-VPN gateway

    Science.gov (United States)

    Fan, Kuo-Pao; Chang, Shu-Hsin; Lin, Kuan-Ming; Pen, Mau-Jy

    2001-10-01

    IP-based Virtual Private Network becomes more and more popular. It can not only reduce the enterprise communication cost but also increase the revenue of the service provider. The common IP-VPN application types include Intranet VPN, Extranet VPN, and remote access VPN. For the large IP-VPN market, some vendors develop dedicated IP-VPN devices; while some vendors add the VPN functions into their existing network equipment such as router, access gateway, etc. The functions in the IP-VPN device include security, QoS, and management. The common security functions supported are IPSec (IP Security), IKE (Internet Key Exchange), and Firewall. The QoS functions include bandwidth control and packet scheduling. In the management component, policy-based network management is under standardization in IETF. In this paper, we discuss issues on how to integrate the QoS and security functions in an IP-VPN Gateway. We propose three approaches to do this. They are (1) perform Qos first (2) perform IPSec first and (3) reserve fixed bandwidth for IPSec. We also compare the advantages and disadvantages of the three proposed approaches.

  8. Desempeño de la calidad del servicio (QoS sobre IPv6

    Directory of Open Access Journals (Sweden)

    Octavio José Salcedo Parra

    2011-06-01

    Full Text Available New applications such as VoIP, e-commerce and video conferencing are sensitive to network performance, making the network capacity to provide quality of service is increasingly important. IPv6 was developed to solve some of the problems of IPv4, such as QoS, security and IP address exhaustion. Current IP networks provide better trafficdelivery effort, therefore, offer no guarantee of quality service. However, there are services, including voice, with stringent requirements for delay and delay variation (jitter, which makes it necessary to add functionality to IP networks based on this protocol are capable of supporting such services. For its part, IPv6 uses 2 fields that can be used to implement QoS, which are: Flow Label and Traffic Class. This article describes the mechanisms and architectures that are used to provide QoS on a network. Later, you specify the features that use both IPv4 and IPv6 to implement QoS. In the last sections present the results of the comparison of 2 scenarios, which are evaluated.

  9. Research on the business QoS and trustworthy and controllable strategies mechanism for energy internet

    Science.gov (United States)

    Zhang, Geng; Lu, Meiling; Zhang, Dahua; Zhou, Liang; Li, Likang

    2017-01-01

    Energy internet is a kind of power sharing network, which can realize the bidirectional flow of energy information on the basis of the existing power grid. It puts forward higher requirements for reliability and controllability of information communication, and all kinds of business QoS of the backbone network. So the research of business QoS and trustworthy and controllable strategies mechanism have an important significance for the development of energy internet. This paper mainly studies how to use the software defined network (SDN) to achieve business QoS, and provide QoS support for all kinds of business of the energy internet. Combined with the current development situation of the energy internet in our country, this paper researches the trustworthy and controllable strategies mechanism for energy internet, and proposes the transition scheme of the IPv6 credible network architecture based on SDN. This coordinates the contradiction between the growing demand for energy internet applications and the limitations of the energy internet technology itself.

  10. QoS Guided Min-Min Heuristic for Grid Task Scheduling

    Institute of Scientific and Technical Information of China (English)

    HE XiaoShan(何晓珊); SUN XianHe(孙贤和); Gregor von Laszewski

    2003-01-01

    Task scheduling is an integrated component of computing. With the emergence of Grid and ubiquitous computing, new challenges appear in task scheduling based on properties such as security, quality of service, and lack of central control within distributed administrative domains. A Grid task scheduling framework must be able to deal with these issues. One of the goals of Grid task scheduling is to achieve high system throughput while matching applications with the available computing resources. This matching of resources in a non-deterministically shared heterogeneous environment leads to concerns over Quality of Service (QoS). In this paper a novel QoS guided task scheduling algorithm for Grid computing is introduced. The proposed novel algorithm is based on a general adaptive scheduling heuristics that includes QoS guidance.The algorithm is evaluated within a simulated Grid environment. The experimental results show that the new QoS guided Min-Min heuristic can lead to significant performance gain for a variety of applications. The approach is compared with others based on the quality of the prediction formulated by inaccurate information.

  11. QoS multicast routin8 protocol in hierarchical wireless MANET

    Institute of Scientific and Technical Information of China (English)

    LI LaYuan; LI ChunLin

    2008-01-01

    A wireless MANET is s self-configurable network in which mobile, battery-powered devices dynamically create and change the network topology without relying on any intrastructure or administrative support. It offers unique benefits for certain environments, but there are still several open issues to be resolved before realizing these benefits, including QoS routing, multicasting, and mobility management. Specifically, an efficient QoS multicast routing protocol is needed. This paper pre-sents a hierarchical QoS multicast routing protocol (QMRP) for mobile ad hoc networks, it can provide QoS-sensitive routes in a scalable and flexible way, in the network environment with mobility. In the proposed QMRP scheme, each local node only needs to maintain local multicast routing information and/or summary infor-mation of other clusters (or domains) but does not require any global ad hoc net-work states to be maintained. The QMRP also allows any ad hoc group member to join/leave the muIticast group dynamically and supports multiple QoS constraints. This paper presents formal description and main procedures for realizing routing decision process of the QMRP and the proof of correctness and complexity analy-sis of the protocol. The performance measures of QMRP are evaluated using simulation. The simulation results verify the efficiency and availability of QMRP.

  12. A framework for QoS & mobility in the Internet next generation

    NARCIS (Netherlands)

    Rexhepi, Vlora; Karagiannis, Georgios; Heijenk, Geert; Pras, Aiko

    2000-01-01

    It is expected that the Internet next generation architecture will support applications with different quality of service requirements, independently of whether their location is fixed or mobile. However, enabling QoS in Internet is a tough challenge, and it gets even tougher when the mobile

  13. Fuzzy Logic QoS Dynamic Source Routing for Mobile Ad Hoc Networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xu; CHENG Sheng; FENG Mei-yu; DING Wei

    2004-01-01

    Considering the characters of dynamic topology and the imprecise state information in mobile ad hoc network,we propose a Fuzzy Logic QoS Dynamic Source Routing (FLQDSR) algorithm based on Dynamic Source Routing (DSR)protocol while adopting fuzzy logic to select the appropriate QoS routing in multiple paths which are searched in parallel.This scheme considers not only the bandwidth and end-to-end delay of routing, but also the cost of the path. On the other hand the merit of using fuzzy logic is that it can be implemented by hardware. This makes the realization of the scheme easier and faster. However our algorithm is based on DSR, the maximal hop count should be less than 10, i.e., the scale of mobile ad hoc network should not be very large. Simulation results show that FLQDSR can tolerate a high degree of information imprecision by adding the fuzzy logic module which integrates the QoS requirements of application and the routing QoS parameters to determine the most qualified one in every node.

  14. Fuzzy Logic Control Based QoS Management in Wireless Sensor/Actuator Networks

    Directory of Open Access Journals (Sweden)

    Yu-Chu Tian

    2007-12-01

    Full Text Available Wireless sensor/actuator networks (WSANs are emerging rapidly as a newgeneration of sensor networks. Despite intensive research in wireless sensor networks(WSNs, limited work has been found in the open literature in the field of WSANs. Inparticular, quality-of-service (QoS management in WSANs remains an important issue yetto be investigated. As an attempt in this direction, this paper develops a fuzzy logic controlbased QoS management (FLC-QM scheme for WSANs with constrained resources and indynamic and unpredictable environments. Taking advantage of the feedback controltechnology, this scheme deals with the impact of unpredictable changes in traffic load on theQoS of WSANs. It utilizes a fuzzy logic controller inside each source sensor node to adaptsampling period to the deadline miss ratio associated with data transmission from the sensorto the actuator. The deadline miss ratio is maintained at a pre-determined desired level sothat the required QoS can be achieved. The FLC-QM has the advantages of generality,scalability, and simplicity. Simulation results show that the FLC-QM can provide WSANswith QoS support.

  15. QoS Support Polling Scheme for Multimedia Traffic in Wireless LAN MAC Protocol

    Institute of Scientific and Technical Information of China (English)

    YANG Zhijun; ZHAO Dongfeng

    2008-01-01

    Quality of service (QoS) support is a key attribute for multimedia traffic including video, voice, and data in wireless local area networks (LANs) but is limited in 802.11-based wireless LANs. A polling-based scheme called the point coordination function (PCF) was developed for 802.11 LANs to support the trans-mission of multimedia traffic. However, the PCF is not able to meet the desired practical traffic differentiation requirements for real-time data. This paper describes a QoS support polling scheme based on the IEEE 802.11 medium access control (MAC) protocol. The scheme uses a two-level polling mechanism with the QoS classes differentiated by two different access policies. Stations with higher priority traffic such as key or real-time data form the first level and can access the common channel through an exhaustive access policy. Other stations with lower priority traffic form the second level and can access the channel through a gated access policy. A system model based on imbedded Markov chain theory and a generation function were setup to explicitly analyze the mean information packet waiting time of the two-level polling scheme. Theo-retical and simulation results show that the new scheme efficiently differentiates services to guarantee better QoS and system stability.

  16. Distribution QoS scheme for a novel of hybrid optical wireless network

    Science.gov (United States)

    Wang, Shiwei; Li, Hui; Ji, Yuefeng

    2007-11-01

    The paper presents a novel WDM-PON architecture with converged TDM-PON and WIMAX to provide wired and wireless services at a uniform platform. The QoS map mechanism at isomerous network with theory and simulation comparison is given. As a novel of network architecture, this paper presents the basical survivability and reliability evaluation.

  17. Assessing Measurements of QoS for global Cloud Computing Services

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, M. Tahir; Júnior, Joaquim Celestino;

    2011-01-01

    -time streaming multimedia applications like online gaming and watching movies on a pay as you use basis hosted in a cloud computing environment. However, guaranteeing or even predicting QoS in global and diverse networks supporting complex hosting of application services is a very challenging issue that needs...

  18. Optimizing Network Routing by Deducing a QoS Metric Using Rough Sets

    Directory of Open Access Journals (Sweden)

    Ali.A.Sakr,

    2010-07-01

    Full Text Available The routing within networks, must satisfy the QoS metrics. In traditional data networks, routing is concerned on connectivity or cost. Routing protocols usually characterize the network with one or more metric(s. However, in order to support a wide range of QoS requirements, routing protocols need to have a more complex model. Thenetwork is characterized with multiple metrics such as bandwidth, delay, jitters, loss rate, authentication, security,…etc. This complex model necessitates a long time to proceed. The Rough Set Theory (RST is applied to reduce these metrics successfully and decide the most effective ones. In this paper, RST is applied to reduce the online metrics that are reported by Routing Information Protocols (RIP. The paper represents information about network elements (links, or nodes to obtain the Quality of Service (QoS core [1]. ROSETTA software is applied to deduce a QoS metric as a substitution for all routing metrics. This metric is used to select the optimal routes. The results confirm that the proposed metric is adequately suit for selecting the proper routes.

  19. QoS awared power and admission controls based on non-cooperative game theory in wireless networks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to better accommodate heterogeneous quality of service (QoS) in wireless networks, an algorithm called QoS-aware power and admission controls (QAPAC) is proposed. The system is modeled as a non-cooperative game where the users adjust their transmit powers to maximize the utility, thus restraining the interferences. By using adaptive utility functions and tunable pricing parameters according to QoS levels, this algorithm can well meet different QoS requirements and improve system capacity compared w...

  20. Cross-layer resource allocation for QoS guarantee with finite queue constraint in multirate OFDMA wireless networks

    Institute of Scientific and Technical Information of China (English)

    XU Hai-bo; TIAN Hui; FENG Yuan

    2008-01-01

    Efficient radio resource allocation is essential to provide quality of service (QoS) for wireless networks. In this article, a cross-layer resource allocation scheme is presented with the objective of maximizing system throughput, while providing guaranteed QoS for users. With the assumption of a finite queue for arrival packets, the proposed scheme dynamically allocates radio resources based on user's channel characteristic and QoS metrics derived from a queuing model, which considers a packet arrival process modeled by discrete Markov modulated Poisson process (dMMPP), and a multirate transmission scheme achieved through adaptive modulation. The cross-layer resource allocation scheme operates over two steps. Specifically, the amount of bandwidth allocated to each user is first derived from a queuing analytical model, and then the algorithm finds the best subcarrier assignment for users. Simulation results show that the proposed scheme maximizes the system throughput while guaranteeing QoS for users.

  1. A Cooperative QoS Management Scheme Based on DiffServ Network for Real-Time Service

    Institute of Scientific and Technical Information of China (English)

    ZHAO Dong-ping; ZHANG De-yun; ZHANG Jun; AN Zhi-ping

    2004-01-01

    In this paper, an improved scheme based on DiffServ network is proposed to provide a decentralized cooperative QoS management for real-time services' admission control and resources' monitoring. The proposed scheme consists of a QoS Control Server (QoSCS), a Service Management Server (SMS), a Network Management Server (NMS) and routers in the concerned management domain. When an application asks for a service with specific QoS requirements, a series of cooperation are initiated among these components by means of a suit of signaling protocol. Once a service is admitted, it can provide required QoS services more effectively than original Di ffServ network. Monitoring per-flow states are moved from edge routers to the QoSCS server. The prototype implementation and experimental results show that this scheme can provide enhanced manageability and scalability for providing per-flow management in such a distributed way.

  2. OPNET Modeler Simulation Testing of the New Model Used to Cooperation Between QoS and Security Mechanisms

    Directory of Open Access Journals (Sweden)

    Jan Papaj

    2012-01-01

    Full Text Available In this article the performance analysis of the new model, used to integration between QoS and Security, is introduced. OPNET modeler simulation testing of the new model with comparation with the standard model is presented. This new model enables the process of cooperation between QoS and Security in MANET. The introduction how the model is implemented to the simulation OPNET modeler is also showed. Model provides possibilities to integration and cooperation of QoS and security by the cross layer design (CLD with modified security service vector (SSV. An overview of the simulation tested of the new model, comparative study in mobile ad-hoc networks, describe requirements and directions for adapted solutions are presented. Main idea of the testing is to show how QoS and Security related services could be provided simultaneously with using minimal interfering with each service.

  3. 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

  4. A Headway to QoS on Traffic Prediction over VANETs using RRSCM Statistical Classifier

    Directory of Open Access Journals (Sweden)

    ISHTIAQUE MAHMOOD

    2016-07-01

    Full Text Available In this paper, a novel throughput measurement forecast model is recommended for VANETs. The model is based on a statistical technique adopted and deployed over a high speed IP network traffic. Network traffic would always experience more QoS (Quality of Service issues such as jitter, delay, packet loss and degradation due to very low bit rate codification too. Despite of all such dictated issues the traffic throughput is to be predicted with at most accuracy using a proposed multivariate analysis scheme represented as a RRSCM (Refined Regression Statistical Classifier Model that optimizes parting parameters. Henceforth, the focus is towards the measurement methodology that estimates the traffic parameters that triggers to predict the accurate traffic and extemporize the QoS for the end-users. Finally, the proposed RRSCM classification model?s end-results are compared with the ANN (Artificial Neural Network classification model to showcase its better act on the projected model

  5. A simulation based QoS review of multipath routing protocols for MANET

    Directory of Open Access Journals (Sweden)

    P.Periyasamy

    2012-11-01

    Full Text Available A MANET is an interconnection of mobile devices by wireless links forming a dynamic topology without much physical network infrastructure such as routers, servers, access points/cables or centralized administration. The multipath routing protocols establish efficient communication within the network by discovering multiple routes between a pair of source and destination in order to have load balancing to satisfy Quality of Service (QoS requirements. In this paper, the QoS comparison of three multipath routing protocols are carried out in terms of five scenario patterns such as RWM, RPGM, MGM, GMM, and PMM in two different traffic patterns such as CBR and TCP using NS2 and Bonn Motion. The multipath routing protocols AOMDV, OLSR and ZRP have been selected for simulation due to their edges over other protocols in various aspects.

  6. Research on Application of Perceived QoS Guarantee through Infrastructure Specific Traffic Parameter Optimization

    Directory of Open Access Journals (Sweden)

    Vikram Jeet Singh

    2014-02-01

    Full Text Available The technological developments in the fields of multimedia clinical applications and communication networks require a specific analysis to increase the efficiency of network based healthcare services. In this work, we computed the optimum transmission parameter (data packet size for applications needed to guarantee the perceived quality of service in the proposed ubiquitous healthcare network. This has been carried out through NS2 based simulation of a state wide area network infrastructure implemented in Himachal Pradesh, a state with diverse geographical terrain situated in the Western Himalayan region of India. The various types of healthcare applications and services have been classified into different classes according to their perceived QOS requirements as per the guidelines in ITU report on network performance objectives. The infrastructure specific optimum values of data packet size for these QoS classes have been computed. Network based healthcare applications and services running on both TCP and UDP type of traffic have been presented in this paper.

  7. A Simple Network Management Architecture for Supporting Network Administrator and QoS Requirements

    CERN Document Server

    Phonphoem, Anan

    2011-01-01

    In this paper, a simple network management architecture for supporting both QoS requirements and organization network management policies is purposed. By grouping the traffic flows according to the QoS requirements or certain network management policies, the network resources are effectively controlled. The purposed architecture is easy to deploy; the gateway is the only equipment that needs installation, leaving the rest of the system untouched. The architecture has not significantly degraded the overall system utilization when applying it to the outgoing bound of the gateway. The architecture can also be implemented on the wireless LAN at the access point because the architecture is designed in such the way that it is independent to both the lower and upper protocol layers.

  8. AN APPROACH TO OPTIMIZE QOS ROUTING PROTOCOL USING GENETIC ALGORITHM IN MANET

    Directory of Open Access Journals (Sweden)

    Vikas Siwach

    2012-09-01

    Full Text Available Quality of Service support for Mobile Ad hoc Networks is an exigenttask due to dynamic topology and limited resource. To support QoS,the link state information such as delay, bandwidth, jitter, cost, errorrate and node energy in the network should be available andmanageable. QOS is one the basic requirement of a network andwhen we talk about the Mobile Network this is the highly constraintrequirement of a user. To improve the quality of service we usedifferent changes in MANET protocols, its parameter, routingalgorithm etc. The proposed work is to define a genetic based routingapproach to optimize the routing in MANETs. The genetic approachwill generate an optimized path on the basic of congestion over thenetwork. The result path will improve the data delivery over thenetwork. The focus of the paper is to study about MANET, QOS andtries to develop a network on which genetic algorithm is applied togenerate an optimized path.

  9. Intelligent Bees for QoS Routing in Networks-on-Chip

    CERN Document Server

    Xie, Peibo

    2011-01-01

    Networks-on-Chip (NoCs) for future many-core processor platforms integrate more and more heterogeneous components of different types and many real-time and latency-sensitive applications can run on a single chip concurrently. The reconfigurable FPGA and reconfigurable NoCs have emerged for the purpose of reusability. Those types' traffics within NoCs exhibit diverse, burst, and unpredictable communication patterns. QoS guaranteed mechanisms are necessary to provide guaranteed throughput (GT) or guaranteed bandwidth (GB) performance for NoCs. In this paper, we propose a QoS routing algorithm inspired by bees' foraging behaviors to provide guaranteed bandwidth performance. Virtual circuits and Spatial Division Multiplexing are employed to maintain available paths for different type's traffics.

  10. Transmission Strategies in Multiple Access Fading Channels with Statistical QoS Constraints

    CERN Document Server

    Qiao, Deli; Velipasalar, Senem

    2010-01-01

    Effective capacity, which provides the maximum constant arrival rate that a given service process can support while satisfying statistical delay constraints, is analyzed in a multiuser scenario. In particular, the effective capacity region of fading multiple access channels (MAC) in the presence of quality of service (QoS) constraints is studied. Perfect channel side information (CSI) is assumed to be available at both the transmitters and the receiver. It is initially assumed the transmitters send the information at a fixed power level and hence do not employ power control policies. Under this assumption, the performance achieved by superposition coding with successive decoding techniques is investigated. It is shown that varying the decoding order with respect to the channel states can significantly increase the achievable throughput region. In the two-user case, the optimal decoding strategy is determined for the scenario in which the users have the same QoS constraints. The performance of orthogonal trans...

  11. Enhancement of QoS in Mobile Network through Channel Allocation using Software Agents

    Directory of Open Access Journals (Sweden)

    Nitin Muchhal

    2011-05-01

    Full Text Available In the last two decades the demand for mobile hosts is increasing rapidly. One of the biggest challenges in cellular systems is to fulfill the mobile user demand under the constraint of the limited spectrum. Some of the most common methods to increase the channel allocation and utilization are resource allocation schemes. Various channel allocation schemes have been proposed to provide Quality of Service (QoS and efficient channel utilization in cellular networks. This paper proposes architecture of Multi-agent system consisting of software agents to implement distributed dynamic channel allocation strategy. The strategy is based on the channel reassignment within the cell boundary and chained channel borrowing in neighboring cell areas. The QoS parameters analyzed are Call dropping probability and Call blocking probability.

  12. Delivering audiovisual content with MPEG-21-enabled cross-layer QoS adaptation

    Institute of Scientific and Technical Information of China (English)

    AHMED Toufik; DJAMA Ismail

    2006-01-01

    Future multimedia communication systems have to support the user's needs, the terminal capabilities, the content specification and the underlying networking technologies. The related protocols and applications must be designed from this integration perspective in a cross-layer centric manner. In this paper, we propose an implementation of a streaming service (e.g.,Television over IP service) with a unified QoS management concept that enables an IP driven integration of different system components (terminal, user, content, and network). The MPEG-21 framework is used to provide a common support for implementing and managing the end-to-end QoS. The main focus of this paper is on the architecture design, protocols specification and implementation evaluation. Performance evaluations using PSNR and SSIM objective video quality metrics show the benefit of the proposed MPEG-21-enabled cross-layer adaptation.

  13. Efficient Qos Based Resource Scheduling Using PAPRIKA Method for Cloud Computing

    Directory of Open Access Journals (Sweden)

    Hilda Lawrance

    2013-03-01

    Full Text Available Cloud computing is increasingly been used in enterprises and business markets for serving demanding jobs. The performance of resource scheduling in cloud computing is important due to the increase in number of users, services and type of services. Resource scheduling is influenced by many factors such as CPU speed, memory, bandwidth etc. Therefore resource scheduling can be modeled as a multi criteria decision making problem. This study proposes an efficient QoS based resource scheduling algorithm using potentially all pair-wise rankings of all possible alternatives (PAPRIKA. The tasks are arranged based on the QoS parameters and the resources are allocated to the appropriate tasks based on PAPRIKA method and user satisfaction. The scheduling algorithm was simulated with cloudsim tool package. The experiment shows that, the algorithm reduces task completion time and improves resource utility rate.

  14. QOS BASED SELECTION AND COMPOSITION OF WEB SERVICES-A FUZZY APPROACH

    Directory of Open Access Journals (Sweden)

    N. Hema Priya

    2014-01-01

    Full Text Available Web Services are emerging technologies which satisfy users’ requests on the Web. Selecting appropriate services to suit the needs is a huge task. There are a huge number of service providers who offer same type of service, with differences in functional and non functional qualities. A few users may need multiple services at the same moment. So composition of services also becomes important. Moreover the consumers get confused in selecting apt services, which leads to the necessity of an automated service selection mechanism based on QoS metrics. It is tedious to find the service with the composite of QoS parameters along with the consumer vague perception. We take these constraints into account and implement a fuzzy rule based algorithm for selection and composition. The open source environment is preferred for a number of reasons. The simulation results show that this setup works well in Service oriented environments.

  15. A new composite assembly mechanism for supporting QoS in OBS networks

    Science.gov (United States)

    Guan, Ai-hong; Hu, Fang; Li, Wan-chong

    2014-01-01

    To provide the differential quality of service (QoS) for different classes of packets and reduce the packet loss probability (PLP), a novel priority-based composite assembly scheme for optical burst switching (OBS) networks is proposed. The low and high packet classes are aggregated into a single burst simultaneously, and the highest-priority packets are placed in the middle, while the low-priority packets are at the tail and head of the burst. The priority is lowered gradually from the middle to the ends. Simulation results demonstrate that the proposed assembly strategy not only guarantees the integrity of the high-priority bursts, but also significantly reduces the average end-to-end delay of the bursts and the PLP of network. So it can adapt to the flexible network with QoS requirement.

  16. Performance Evaluation of QoS Parameters in Dynamic Spectrum Sharing for Heterogeneous Wireless Communication Networks

    Directory of Open Access Journals (Sweden)

    R.Kaniezhil

    2012-01-01

    Full Text Available Cognitive radio nodes have been proposed as means to improve the spectrum utilization. It reuses the spectrum of a primary service provider under the condition that the primary service provider services are not harmfully interrupted. A cognitive radio can sense its operating environment's conditions and it is able to reconfigure itself and to communicate with other counterparts based on the status of the environment and also the requirements of the user to meet the optimal communication conditions and to keep quality of service (QoS as high as possible. The efficiency of spectrum sharing can be improved by minimizing the interference. The Utility function that captures the cooperative behavior to minimize the interference and the satisfaction to improve the throughput is investigated. The dynamic spectrum sharing algorithm can maintain the quality of service (QoS of each network while the effective spectrum utilisation is improved under a fluctuation traffic environment when the available spectrum is limited.

  17. A review of Fuzzy Based QoS Web Service Discovery

    Directory of Open Access Journals (Sweden)

    R.Buvanesvari

    2013-03-01

    Full Text Available Recently, web service has become an important issue for developers. Selecting a specific service is a crucial task. Some approaches develop extensive description and publication mechanisms while others use syntactic, semantic, and structural reviews of Web service specifications. It is very crucial for finding the most suitable web service from a large collection of web services for successful execution of applications. In many cases, the value of a QoS property may not be precisely defined. Recently, fuzzy is considered as the dominant approaches in Web services which can deal with fuzzy constraints have been proposed. Therefore fuzzy logic can be applied to support for representing such imprecise QoS constraints. In this paper, we will present an overview which focus on developing fuzzy-based approach for Web service discovery. This paper also describes the web service challenges on fuzzy mechanism that summarized and analyzed in order to assess their benefits and limitations.

  18. Multiple constraints QoS multicast routing optimization algorithm in MANET based on GA

    Institute of Scientific and Technical Information of China (English)

    Baolin Sun; Shangchao Pi; Chao Gui; Yue Zeng; Bing Yan; Wenxiang Wang; Qianqing Qin

    2008-01-01

    Usually multiple quality of service (QoS) guarantees are required in most multicast applications. This paper presents a multiple constraints algorithm for multicast traffic engineering in mobile ad hoc networks (MANET). The proposed algorithm is a new version of multiple constraints QoS multicast routing optimization algorithm in MANET based on genetic algorithm (MQMGA). The proposed MQMGA can optimize the maximum link utilization, the cost of the multicast tree, the selection of the long-life path, the average delay and the maximum end-to-end delay. Experimental result shows that the approach is efficient, has promising performance in multicast traffic engineering and for evaluating the route stability in dynamic mobile networks.

  19. Calidad de servicio (QoS en procesos: Escenarios de procesamiento con aspectos

    Directory of Open Access Journals (Sweden)

    Hector Manuel Soto Pérez

    2016-12-01

    En resumen el presente trabajo estudia conceptos básicos de calidad de servicio y algunos de sus marcos de aplicación siguiendo un enfoque aspectual. Planteando posibles casos de uso genéricos para aplicar mejoras en la prestación de la QoS mediante aspectos en la planificación y gestión de recursos de aplicaciones tradicionales.

  20. Utilizing Network QoS for Dependability of Adaptive Smart Grid Control

    OpenAIRE

    Madsen, Jacob Theilgaard; Kristensen, Thomas le Fevre; Olsen, Rasmus Løvenstein; Schwefel, Hans-Peter; Totu, Luminita Cristiana

    2014-01-01

    A smart grid is a complex system consisting of awide range of electric grid components, entities controlling powerdistribution, generation and consumption, and a communicationnetwork supporting data exchange. This paper focuses on theinfluence of imperfect network conditions on smart grid con-trollers, and how this can be counteracted by utilizing Qualityof Service (QoS) information from the communication network.Such an interface between grid controller and network QoSis particularly relevan...

  1. Enhancing fault management performance of two-step QoS routing algorithms in GMPLS networks

    OpenAIRE

    Calle Ortega, Eusebi; Marzo i Lázaro, Josep Lluís; Urra i Fàbregas, Anna; Fàbrega i Soler, Lluís

    2004-01-01

    In this paper a novel methodology aimed at minimizing the probability of network failure and the failure impact (in terms of QoS degradation) while optimizing the resource consumption is introduced. A detailed study of MPLS recovery techniques and their GMPLS extensions are also presented. In this scenario, some features for reducing the failure impact and offering minimum failure probabilities at the same time are also analyzed. Novel two-step routing algorithms using this methodology are pr...

  2. Efficient multi-field packet classification for QoS purposes

    OpenAIRE

    Borg, Niklas; Svanberg, Emil; Schelén, Olov

    1999-01-01

    Mechanisms for service differentiation in datagram networks, such as the Internet, rely on packet classification in routers to provide appropriate service. Classification involves matching multiple packet header fields against a possibly large set of filters identifying the different service classes. In this paper, we describe a packet classifier based on tries and binomial trees and we investigate its scaling properties in three QoS scenarios that are likely to occur in the Internet. One sce...

  3. Using Pre-Estimate with Feedback for Adaptation Web Server QoS Guarantee

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The heterogeneity in the communicating terminals needs to be handled through software-supported adaptation. The real-time dynamical adaptation brings the system more time cost unavoidably. In this paper, we propose QoS pre-estimation for user admission control and system load control. Feedback acts as adjuster of the input parameters of the pre-estimate module. We present tests results to evaluate our approach. The test results show that our service quality control mechanism is effective.

  4. Ephedrine QoS: An Antidote to Slow, Congested, Bufferless NoCs

    OpenAIRE

    Juan Fang; Zhicheng Yao; Xiufeng Sui; Yungang Bao

    2014-01-01

    Datacenters consolidate diverse applications to improve utilization. However when multiple applications are colocated on such platforms, contention for shared resources like networks-on-chip (NoCs) can degrade the performance of latency-critical online services (high-priority applications). Recently proposed bufferless NoCs (Nychis et al.) have the advantages of requiring less area and power, but they pose challenges in quality-of-service (QoS) support, which usually relies on buffer-based vi...

  5. Polynomial time algorithm for hop-constrained QoS routing

    Science.gov (United States)

    Verma, Shekhar; Saxena, Anil K.

    2003-08-01

    The basis of a QoS-based routing algorithm is a dynamic network dependent cost function that is used to find the optimal or at least a feasible route across the network. However, all QoS-based routing algorithms suffer from a major drawback. The cost function at the core of the algorithms identifies segments of the network where resources are ample and exploits them to the benefit of connections that would otherwise cross a congested portion of the network. Thus, the algorithms consume more resources than Minimum Hop routing would do when the network traffic is non-stationary and heavy. QoS-based routing, thus, wastes resources and performs poorly compared with Minimum Hop routing in the event of congestion. The crux of the discussion is that whatever is gained at low or medium network loads, is offset at high network loads. What is required is a resilient algorithm that either allows the migration of a QoS-based routing algorithm to a Minimum Hop algorithm at high loads or an algorithm that merges Minimum Hop and QoS characteristics. The study opts for the latter approach and proposes and exhibits a hop constrained QoS routing algorithm that outperforms traditional QoS routing algorithms during simulation. This routing technique is based on an approximation algorithm that solves the hop constrained routing problem. The algorithm is derived from a dynamic programming FPAS scheme and finds the shortest walk for a single source destination pair in a graph with restricted number of hops when all the edge costs are non-negative. Simulated results demonstrate that routing technique based on the algorithm is robust to changes in the traffic pattern and consistently outperforms other QoS based routing techniques under heavy load conditions.

  6. Secure Communication over Fading Channels with Statistical QoS Constraints

    OpenAIRE

    Qiao, Deli; Gursoy, Mustafa Cenk; Velipasalar, Senem

    2010-01-01

    In this paper, the secure transmission of information over an ergodic fading channel is investigated in the presence of statistical quality of service (QoS) constraints. We employ effective capacity, which provides the maximum constant arrival rate that a given process can support while satisfying statistical delay constraints, to measure the secure throughput of the system, i.e., effective secure throughput. We assume that the channel side information (CSI) of the main channel is available a...

  7. Impact of VoIP and QoS on Open and Distance Learning

    Directory of Open Access Journals (Sweden)

    Sanjay JASOLA

    2006-07-01

    Full Text Available Voice over Internet Protocol (VoIP is becoming a reality in many organizations. The potential for mobility in voice over wi-fi networks will derive demand for the technology. Wireless VoIP is poised to rival VoIP as an alternative telephony tool. Internet has been used to transport data in the form of packet. In the past, Internet did not support any kind of sophisticated quality of service (QoS mechanism. Although the type of service (TOS field in the Internet protocol (IP header has been existing and has been allowing the differentiated treatment of packets, it was never really used on a large scale. The voice is sensitive to delay and jitter so bandwidth must be guaranteed while transporting it. With the extensive use of Internet for carrying voice, there is a need to add QoS functionality in it. QoS with reference to VoIP has been discussed in the paper. Limited bandwidth and network latency are the issues which need to be considered while using wireless LAN for packetized voice data. Efforts of standards like 802.11e which will take care of these issues, have also been explored. The impact of these technologies on distance education has also been explored in the paper.

  8. A QoS guaranteeing MAC layer protocol for the "underdog" traffic

    Directory of Open Access Journals (Sweden)

    Paolini Christopher

    2011-01-01

    Full Text Available Abstract With the tremendous boom in the wireless local area network arena, there has been a phenomenal spike in the web traffic which has been triggered by the growing popularity of real-time multimedia applications. Towards this end, the IEEE 802.11e medium access control (MAC standard specifies a set of quality-of-service (QoS enhancement features to ensure QoS for these delay sensitive multimedia applications. Most of these features are unfair and inefficient from the perspective of low priority (non-real time traffic flows as they tend to starve the non-real time flows depriving them of appropriate channel access, hence throughput. To that extent, this article proposes a MAC protocol that ensures fairness in the overall network performance by still providing QoS for real-time traffic without starving the "underdog" or non-real-time flows. The article first presents analytical expressions supported by Matlab simulation results which highlight the performance drawbacks of biased protocols such as 802.11e. It then evaluates the efficiency of the proposed "fair MAC protocol" through extensive simulations conducted on the QualNet simulation platform. The simulation results validate the fairness aspect of the proposed scheme.

  9. A hybrid ACO/PSO based algorithm for QoS multicast routing problem

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Patel

    2014-03-01

    Full Text Available Many Internet multicast applications such as videoconferencing, distance education, and online simulation require to send information from a source to some selected destinations. These applications have stringent Quality-of-Service (QoS requirements that include delay, loss rate, bandwidth, and delay jitter. This leads to the problem of routing multicast traffic satisfying QoS requirements. The above mentioned problem is known as the QoS constrained multicast routing problem and is NP Complete. In this paper, we present a swarming agent based intelligent algorithm using a hybrid Ant Colony Optimization (ACO/Particle Swarm Optimization (PSO technique to optimize the multicast tree. The algorithm starts with generating a large amount of mobile agents in the search space. The ACO algorithm guides the agents’ movement by pheromones in the shared environment locally, and the global maximum of the attribute values are obtained through the random interaction between the agents using PSO algorithm. The performance of the proposed algorithm is evaluated through simulation. The simulation results reveal that our algorithm performs better than the existing algorithms.

  10. Power Aware QoS Multipath Routing Protocol for Disaster Recovery Networks

    Directory of Open Access Journals (Sweden)

    S.Santhi

    2012-01-01

    Full Text Available Mobile communication plays an important role in disaster recovery management during emergency situations. It is helpful in situations where the system has less robust and less flexible fixed infrastructure. The Disaster recovery management systems require timely interaction and coordination in order to save lives and property. Energy consumption in heterogeneous network is a major issue , whether they operate within a base station infrastructure , fixed network or in a free-standing Mobile Ad Hoc Network (MANET. The lifetime of network will be improved by suitably reducing the requirement of power for connections. There is a challenge to provide Quality of Service (QoS solutions to wired cum wireless domains and maintain end-to-end QoS in ad hoc network. In this paper we propose a new protocol Power Aware QoS Multipath Routing protocol (PAQMR for disaster recovery network. This protocol is the enhanced protocol of Ad-Hoc On Demand Multipath Distance Vector protocol (AOMDV. This routing protocol is used to avoid the loop formation in network so that it reduces congestion in the channel. The Network Simulator (NS-2.34 tool is utilized to measure the performance of AODV, AOMDV and PAQMR protocols in hybrid environment. The metrics for the simulation are energy consumption, average end to end delay and packet delivery ratio by varying the traffic load and pause time in the network. The results shows that the proposed protocol minimize the power, delay, congestion and maximize the packet delivery ratio.

  11. Information Centric Networking based Handover Support for QoS Maintenance in Cooperative Heterogeneous Wireless Networks

    CERN Document Server

    Saleem, Muhammad Shoaib; Zeghlache, Djamal

    2011-01-01

    Network of Information (NetInf) is a term coined for networks which unlike contemporary network are not node centric. As the name indicates, information supersedes nodes in the network. In this report, we propose an architecture of mobile node for NetInf. We call it NetInf Mobile Node. It is an extension of the basic node architecture proposed for NetInf. It is compatible to NetInf and TCP/IP based networks. The Virtual Node Layer modules in the architecture provide support for managing mobility, power consumption of the node as well data relaying/storing services. In- ner/Outer Locator Construction Routers (I/O LCTR) are two functions introduced in NetInf mobile nodes to operate between NetInf and non- NetInf sites. The basic purpose of NetInf mobile node is to maintain the QoS during mobility events. The handoff/handover are critical situations during mobility where chances of QoS degradation of an ongoing session are high. This report presents one such scenario in which QoS of an appli- cation is maintaine...

  12. QoS & QoE MANAGEMENT IN WIRELESS COMMUNICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Dinesh Sharma,

    2011-03-01

    Full Text Available Now a day, Wireless communication systems are popular due to its wide advantages. In the customer’s point of view, we can say the most of the customer requirements related to communication from one placeto another place are fulfilled up to the most extent using these systems. The initiation to these wireless communication systems started to satisfy the minimum requirements of the customers herefore the first generation (1G mobiles are came into the picture, there after according to customer satisfaction the requirements are increased and therefore the evolution started from 1G and now it is reaching 4G. In this evolution we take care about the quality of service (QoS and quality of end user experience (QoE which customer requires is important. By maintaining QoS as well as QoE we can maintain the level of customer satisfaction, so the QoS & QoE anagement in wireless communication systems is significant particularly in the design part of the system.

  13. Priority Queues with Fractional Service for Tiered Delay QoS

    Directory of Open Access Journals (Sweden)

    Gary Chang

    2015-12-01

    Full Text Available Packet scheduling is key to quality of service (QoS capabilities of broadband wired and wireless networks. In a heterogeneous traffic environment, a comprehensive QoS packet scheduler must strike a balance between flow fairness and access delay. Many advanced packet scheduling solutions have targeted fair bandwidth allocation while protecting delay-constrained traffic by adding priority queue(s on top of a fair bandwidth scheduler. Priority queues are known to cause performance uncertainties and, thus, various modifications have been proposed. In this paper, we present a packet queueing engine dubbed Fractional Service Buffer (FSB, which, when coupled with a configurable flow scheduler, can achieve desired QoS objectives, such as fair throughputs and differentiated delay guarantees. Key performance metrics, such as delay limit and probability of delay limit violation, are derived as a function of key FSB parameters for each delay class in the packet queueing engine using diffusion approximations. OPNET simulations verify these analytical results.

  14. QoS Support in TDMA-Based Mobile Ad Hoc Networks

    Institute of Scientific and Technical Information of China (English)

    Imad Jawhar; Jie Wu

    2005-01-01

    Mobile ad hoc networks (MANETs) are gaining a lot of attention in research lately due to their importance in enabling mobile wireless nodes to communicate without any existing wired or predetermined infrastructures. Furthermore,in order to support the growing need for multimedia and realtime applications, quality of service (QoS) support by the networking protocol is required. Several important QoS parameters that are needed by such applications can be identified.They include bandwidth, end-to-end delay, delay jitter, and bit error rate. A good amount of research has been developed in this area covering different issues and challenges such as developing routing protocols that support bandwidth reservation and delay management. In this paper, the current state of research for QoS support in TDMA-based MANETs at different layers of the networking model is presented and categorized. In addition, the current issues and future challenges involved in this exciting area of research are also included.

  15. Existence and uniqueness of the Nash equilibrium in the non-cooperative QoS routing

    Science.gov (United States)

    Conforto, Paolo; Delli Priscoli, Francesco; Facchinei, Francisco

    2010-04-01

    Researchers dealing with game theoretic issues are well aware that the definition of a model capturing some physical behaviours such as the routing, the pricing, the flow and congestion control, the admission control just to mention some examples in the telecommunication field, is a difficult task, but it is only half of the overall effort. As a matter of fact, a key aspect is the analysis of the equilibrium (or equilibria) towards which the game will (hopefully) converge. The existence, the uniqueness, the efficiency and the structure of the equilibrium are some of the typical properties which are investigated. In this article, we propose a game theoretic model for quality of service (QoS) routing in networks implementing a Differentiated Service model for the QoS support. In particular, we focus on a parallel link network model and we consider a non-cooperative joint problem of QoS routing and dynamic capacity allocation. For this model, we demonstrate that the Nash equilibrium exists, so overcoming a typical problem in the existence proofs appeared in many papers in the area of routing game since 1990s, and we explicitly obtain a suitable set of relations characterising its structure. Moreover, we prove that Nash equilibrium uniqueness cannot be guaranteed in general.

  16. Optimizing Multiple QoS for Workflow Applications using PSO and Min-Max Strategy

    Science.gov (United States)

    Umar Ambursa, Faruku; Latip, Rohaya; Abdullah, Azizol; Subramaniam, Shamala

    2017-08-01

    Workflow scheduling under multiple QoS constraints is a complicated optimization problem. Metaheuristic techniques are excellent approaches used in dealing with such problem. Many metaheuristic based algorithms have been proposed, that considers various economic and trustworthy QoS dimensions. However, most of these approaches lead to high violation of user-defined QoS requirements in tight situation. Recently, a new Particle Swarm Optimization (PSO)-based QoS-aware workflow scheduling strategy (LAPSO) is proposed to improve performance in such situations. LAPSO algorithm is designed based on synergy between a violation handling method and a hybrid of PSO and min-max heuristic. Simulation results showed a great potential of LAPSO algorithm to handling user requirements even in tight situations. In this paper, the performance of the algorithm is anlysed further. Specifically, the impact of the min-max strategy on the performance of the algorithm is revealed. This is achieved by removing the violation handling from the operation of the algorithm. The results show that LAPSO based on only the min-max method still outperforms the benchmark, even though the LAPSO with the violation handling performs more significantly better.

  17. An Effective Randomized QoS Routing Algorithm on Networks with Inaccurate Parameters

    Institute of Scientific and Technical Information of China (English)

    WANG Jianxin(王建新); CHEN Jian'er(陈建二); CHEN Songqiao(陈松乔)

    2002-01-01

    This paper develops an effective randomized on-demand QoS routing algorithm on networks with inaccurate link-state information. Several new techniques are proposed in the algorithm. First, the maximum safety rate and the minimum delay for each node in the network are pre-computed, which simplify the network complexity and provide the routing process with useful information. The routing process is dynamically directed by the safety rate and delay of the partial routing path developed so far and by the maximum safety rate and the minimum delay of the next node. Randomness is used at the link level and depends dynamically on the routing configuration. This provides great flexibility for the routing process, prevents the routing process from overusing certain fixed routing paths, and adequately balances the safety rate and delay of the routing path. A network testing environment has been established and five parameters are introduced to measure the performance of QoS routing algorithms.Experimental results demonstrate that in terms of the proposed parameters, the algorithm outperforms existing QoS algorithms appearing in the literature.

  18. A novel bandwidth allocation scheme for QoS routing in mobile ad hoc networks

    Science.gov (United States)

    Wu, Bin; Kuo, Geng-Sheng

    2004-09-01

    The main purpose of this paper is to propose a novel bandwidth allocation scheme for facilitating quality of service (QoS) routing in mobile ad hoc networks (MANETs). In a MANET using time division multiple access (TDMA), each node communicates with its neighbors in the same time slot. In general, finding a route with the maximum end-to-end bandwidth subject to the constraint of collision-free transmission is an NP-complete problem. This paper proposed a sub-optimal solution to this problem. The solution is based on a centrally controlled bandwidth allocation scheme to properly assign the available time slots to each intermediate link. The advantage of our proposed scheme is that the resource utilization of MANET is maximized and the end-to-end QoS is guaranteed during the route establishment period. Performance analyses show that when using the proposed scheme with AODV to perform QoS routing, it achieves about 25% throughput higher than its best-effort counterpart if the node is moving at 5mps speed.

  19. ANCS: Achieving QoS through Dynamic Allocation of Network Resources in Virtualized Clouds

    Directory of Open Access Journals (Sweden)

    Cheol-Ho Hong

    2016-01-01

    Full Text Available To meet the various requirements of cloud computing users, research on guaranteeing Quality of Service (QoS is gaining widespread attention in the field of cloud computing. However, as cloud computing platforms adopt virtualization as an enabling technology, it becomes challenging to distribute system resources to each user according to the diverse requirements. Although ample research has been conducted in order to meet QoS requirements, the proposed solutions lack simultaneous support for multiple policies, degrade the aggregated throughput of network resources, and incur CPU overhead. In this paper, we propose a new mechanism, called ANCS (Advanced Network Credit Scheduler, to guarantee QoS through dynamic allocation of network resources in virtualization. To meet the various network demands of cloud users, ANCS aims to concurrently provide multiple performance policies; these include weight-based proportional sharing, minimum bandwidth reservation, and maximum bandwidth limitation. In addition, ANCS develops an efficient work-conserving scheduling method for maximizing network resource utilization. Finally, ANCS can achieve low CPU overhead via its lightweight design, which is important for practical deployment.

  20. Análisis de la QoS en redes inalámbricas

    Directory of Open Access Journals (Sweden)

    Yosuan Crespo García

    2013-03-01

    Full Text Available Las comunicaciones inalámbricas en sus diferentes variantes están tomando cada vez más auge en la vida de los diferentes usuarios y con ello la necesidad de soportar las mismas aplicaciones que en las redes cableadas. Ante las necesidades crecientes de aplicaciones sobre redes que presentan limitaciones de ancho de banda como es el caso de las inalámbricas se impone la necesidad de brindar calidad de servicio (QoS, Quality of Service. En este trabajo se realiza un estudio de la calidad de servicio en entornos inalámbricos haciendo énfasis en dos tecnologías fundamentales como la wifi y la 802.16. En este análisis se describen los parámetros de calidad de servicios, la necesidad de la QoS en entornos inalámbricos así como los métodos que se emplean en las tecnologías mencionadas para obtener dicha QoS.

  1. On the Achievable Throughput Region of Multiple-Access Fading Channels with QoS Constraints

    CERN Document Server

    Qiao, Deli; Velipasalar, Senem

    2009-01-01

    Effective capacity, which provides the maximum constant arrival rate that a given service process can support while satisfying statistical delay constraints, is analyzed in a multiuser scenario. In particular, we study the achievable effective capacity region of the users in multiaccess fading channels (MAC) in the presence of quality of service (QoS) constraints. We assume that channel side information (CSI) is available at both the transmitters and the receiver, and superposition coding technique with successive decoding is used. When the power is fixed at the transmitters, we show that varying the decoding order with respect to the channel state can significantly increase the achievable throughput region. For a two-user case, we obtain the optimal decoding strategy when the users have the same QoS constraints. Meanwhile, it is shown that time-division multiple-access (TDMA) can achieve better performance than superposition coding with fixed successive decoding order at the receiver side for certain QoS con...

  2. EVM as generic QoS trigger for heterogeneous wieless overlay network

    CERN Document Server

    Kumar, Rajender; 10.5121/ijwmn.2010.2315

    2010-01-01

    Fourth Generation (4G) Wireless System will integrate heterogeneous wireless overlay systems i.e. interworking of WLAN/ GSM/ CDMA/ WiMAX/ LTE/ etc with guaranteed Quality of Service (QoS) and Experience (QoE).QoS(E) vary from network to network and is application sensitive. User needs an optimal mobility solution while roaming in Overlaid wireless environment i.e. user could seamlessly transfer his session/ call to a best available network bearing guaranteed Quality of Experience. And If this Seamless transfer of session is executed between two networks having different access standards then it is called Vertical Handover (VHO). Contemporary VHO decision algorithms are based on generic QoS metrics viz. SNR, bandwidth, jitter, BER and delay. In this paper, Error Vector Magnitude (EVM) is proposed to be a generic QoS trigger for VHO execution. EVM is defined as the deviation of inphase/ quadrature (I/Q) values from ideal signal states and thus provides a measure of signal quality. In 4G Interoperable environmen...

  3. Traffic Agents for Improving QoS in Mixed Infrastructure and Ad Hoc Modes Wireless LAN

    Directory of Open Access Journals (Sweden)

    Yuan Hai-Feng

    2006-01-01

    Full Text Available As an important complement to infrastructured wireless networks, mobile ad hoc networks (MANET are more flexible in providing wireless access services, but more difficult in meeting different quality of service (QoS requirements for mobile customers. Both infrastructure and ad hoc network structures are supported in wireless local area networks (WLAN, which can offer high data-rate wireless multimedia services to the mobile stations (MSs in a limited geographical area. For those out-of-coverage MSs, how to effectively connect them to the access point (AP and provide QoS support is a challenging issue. By mixing the infrastructure and the ad hoc modes in WLAN, we propose in this paper a new coverage improvement scheme that can identify suitable idle MSs in good service zones as traffic agents (TAs to relay traffic from those out-of-coverage MSs to the AP. The service coverage area of WLAN is then expanded. The QoS requirements (e.g., bandwidth of those MSs are considered in the selection process of corresponding TAs. Mathematical analysis, verified by computer simulations, shows that the proposed TA scheme can effectively reduce blocking probability when traffic load is light.

  4. Simulation Model to Improve QoS Performance over Fixed WiMAX using OPNET

    Directory of Open Access Journals (Sweden)

    Ibrahim A. Lawal

    2013-09-01

    Full Text Available Worldwide Interoperability for Microwave Access (WiMAX Technology is one of the most interesting solutions for broadband wireless access, that provide multimedia traffic and applications through an appropriate QoS management for fixed and mobile devices. In this regard, we attempt to introduce a new distributed model to improve the performance of QoS over fixed WiMAX with respect to parameters including throughput, delay and application response time, to enhance the services that are provided to the end users by minimizing delay, application response time and increasing throughput. A Model was developed based on the proposed new distributed model (Master-Slave, the first scenario comprised of 3 Base Stations (BS and thirty Subscriber Station (SS with one Master BS selected by the designed algorithm (Nearest Neighborhood Algorithms. Simulations run while increasing the number of BSs, SSs and master BSs using point-to-multipoint connection with multicast transmission based on Orthogonal Frequency Division Multiplexing (OFDM. The design has been evaluated using the simulation tool OPNET modeler 16.0. The results obtained from the three Scenarios shows significant increase in the network throughput and drastic decrease in network delay and application response time. Furthermore, with help of the distributed Master BSs, the coverage area of WiMAX has been increased. Thus greatly enhances the performance of Quality of service (QoS.

  5. The Effect of Path Loss on QoS at NPL

    Directory of Open Access Journals (Sweden)

    Dinesh Sharma,

    2010-07-01

    Full Text Available Radio communication or radio propagation is important for growing technologies with proper design, development and management strategies for any wireless network. Radio propagation is specific about the site and varies extensively depending on terrains, frequency of operation, velocity of mobile terminal, interface sources and other parameters. exact description of radio channel through basic parameters and using the mathematical models are important to predict the signal coverage, attainable data rate explicit performance quality of substitute signaling and reception schemes. This paper shows the quality of service (QoS parameters and its possible realization at network planning level on the basis of path loss. Here we analyze the QoS in terms of received signal strength. To achieve this purpose we have taken the field data and calculated the path loss at 900 and 1800 MHz frequency and compared graphically with existing path loss models. After observing the results we conclude the QoS in urban area decreases rapidly as we move away from the transmitter with compared to sub urban and rural areas.

  6. 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.

  7. Presentation New Method to Increase Network QOS using OSPF's Link Weight

    Directory of Open Access Journals (Sweden)

    Ali Abulhallaj

    2013-08-01

    Full Text Available Nowadays, the internet is used various functions such as Radio, Television, and Telephone. Forappropriate usage, we need network solutions that aim to provide end-users with Quality of Service(QoS support. The networking research community proposed distinct QoS aware architectures andspecific traffic control mechanisms that provide distinct service levels to networkedapplications(Wang,2001.Accordingly, Internet Service Providers (ISPs must have Service Level Agreements (SLAs (Liu et al,2005 with their clients and with other ISPs. If neglected, must pay financial penalties. To achieve that,administrators must do some important configuration in their networks to assure that correct resourceprovisioning is achieved in the ISP domain. For example, these configurations may vary based on ISPsbecause The QoS solutions are different. Also it may includes distinct tasks such as, specifying theforwarding treatment given at each network nodes (e.g. the per-hop-behaviors(Davie et al, 2002(Wroclawski et al,1999 of DiffServ (Blake,1998 . defining traffic classification and packet markingrules at network edges, configuring admission control based mechanisms(Tsuchiya,2003, configuringrouting algorithms(Slattery et al,2008 or finer-grain QoS solutions, enabling signaling protocols allowper flow resource reservation(Zhang et al,1997. In addition, there is more than one solution to achieveQoS aware network infrastructure. In general, any solutions require number of components workingtogether.

  8. End to End Inter-domain Quality of Service Provisioning

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy

    This thesis addresses selected topics of Quality of Service (QoS) provisioning in heterogeneous data networks that construct the communication environment of today's Internet. In the vast range of protocols available in different domains of network infrastructures, a few chosen ones are discussed......, the general UPnPQoS performance was assessed analytically and confirmed by simulations results. The results validate the usability of UPnP-QoS, but some open issues in the specication were identified. As a result of addressing mentioned shortcomings of UPnP-QoS, a few pre-emption algorithms for home gateway...... were designed and compared. Similarly as for general UPnP-QoS assessment, analysis and intensive simulations were used for verification of proposed pre-emption techniques. The other proposed extension for UPnP-QoS was an integration of trac auto-classication within UPnP-QoS Architecture. Simulation...

  9. Efficient Resources Provisioning Based on Load Forecasting in Cloud

    Directory of Open Access Journals (Sweden)

    Rongdong Hu

    2014-01-01

    Full Text Available Cloud providers should ensure QoS while maximizing resources utilization. One optimal strategy is to timely allocate resources in a fine-grained mode according to application’s actual resources demand. The necessary precondition of this strategy is obtaining future load information in advance. We propose a multi-step-ahead load forecasting method, KSwSVR, based on statistical learning theory which is suitable for the complex and dynamic characteristics of the cloud computing environment. It integrates an improved support vector regression algorithm and Kalman smoother. Public trace data taken from multitypes of resources were used to verify its prediction accuracy, stability, and adaptability, comparing with AR, BPNN, and standard SVR. Subsequently, based on the predicted results, a simple and efficient strategy is proposed for resource provisioning. CPU allocation experiment indicated it can effectively reduce resources consumption while meeting service level agreements requirements.

  10. Efficient resources provisioning based on load forecasting in cloud.

    Science.gov (United States)

    Hu, Rongdong; Jiang, Jingfei; Liu, Guangming; Wang, Lixin

    2014-01-01

    Cloud providers should ensure QoS while maximizing resources utilization. One optimal strategy is to timely allocate resources in a fine-grained mode according to application's actual resources demand. The necessary precondition of this strategy is obtaining future load information in advance. We propose a multi-step-ahead load forecasting method, KSwSVR, based on statistical learning theory which is suitable for the complex and dynamic characteristics of the cloud computing environment. It integrates an improved support vector regression algorithm and Kalman smoother. Public trace data taken from multitypes of resources were used to verify its prediction accuracy, stability, and adaptability, comparing with AR, BPNN, and standard SVR. Subsequently, based on the predicted results, a simple and efficient strategy is proposed for resource provisioning. CPU allocation experiment indicated it can effectively reduce resources consumption while meeting service level agreements requirements.

  11. GEMSS: grid-infrastructure for medical service provision.

    Science.gov (United States)

    Benkner, S; Berti, G; Engelbrecht, G; Fingberg, J; Kohring, G; Middleton, S E; Schmidt, R

    2005-01-01

    The European GEMSS Project is concerned with the creation of medical Grid service prototypes and their evaluation in a secure service-oriented infrastructure for distributed on demand/supercomputing. Key aspects of the GEMSS Grid middleware include negotiable QoS support for time-critical service provision, flexible support for business models, and security at all levels in order to ensure privacy of patient data as well as compliance to EU law. The GEMSS Grid infrastructure is based on a service-oriented architecture and is being built on top of existing standard Grid and Web technologies. The GEMSS infrastructure offers a generic Grid service provision framework that hides the complexity of transforming existing applications into Grid services. For the development of client-side applications or portals, a pluggable component framework has been developed, providing developers with full control over business processes, service discovery, QoS negotiation, and workflow, while keeping their underlying implementation hidden from view. A first version of the GEMSS Grid infrastructure is operational and has been used for the set-up of a Grid test-bed deploying six medical Grid service prototypes including maxillo-facial surgery simulation, neuro-surgery support, radio-surgery planning, inhaled drug-delivery simulation, cardiovascular simulation and advanced image reconstruction. The GEMSS Grid infrastructure is based on standard Web Services technology with an anticipated future transition path towards the OGSA standard proposed by the Global Grid Forum. GEMSS demonstrates that the Grid can be used to provide medical practitioners and researchers with access to advanced simulation and image processing services for improved preoperative planning and near real-time surgical support.

  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. Two-Level Cross-Talked Admission Control Mechanism for QoS Guarantee in 802.11e EDCA

    Institute of Scientific and Technical Information of China (English)

    NIU Zhisheng; LIU Jing

    2008-01-01

    This paper describes a two-level cross-talked admission control mechanism that guarantees qual-ity of service (QoS) requirements for multimedia applications over wireless local area networks (WLANs). An enhanced distributed channel access analytical model is used to compute the maximum number of admitted users according to the QoS requirements and the packet arrival characters. Then, some channel resources are reserved for handoff calls based on the maximum number of admitted users and the call-level traffic model. The channel utilization ratio is also measured to reflect the current system traffic load. The maximum number of admitted users and the channel utilization ratio are used for admission control for applications with QoS requirements in the call level and for rate control of best effort applications in the packet level using the p-nonacknowledgement scheme. Thus, the QoS requirements are statistically guaranteed while the system is efficiently utilized. Simulations validate the effectiveness of this mechanism to guarantee the QoS and bandwidth utilization.

  14. Mapping of multiple parameter m-health scenarios to mobile WiMAX QoS variables.

    Science.gov (United States)

    Alinejad, Ali; Philip, N; Istepanian, R S H

    2011-01-01

    Multiparameter m-health scenarios with bandwidth demanding requirements will be one of key applications in future 4 G mobile communication systems. These applications will potentially require specific spectrum allocations with higher quality of service requirements. Furthermore, one of the key 4 G technologies targeting m-health will be medical applications based on WiMAX systems. Hence, it is timely to evaluate such multiple parametric m-health scenarios over mobile WiMAX networks. In this paper, we address the preliminary performance analysis of mobile WiMAX network for multiparametric telemedical scenarios. In particular, we map the medical QoS to typical WiMAX QoS parameters to optimise the performance of these parameters in typical m-health scenario. Preliminary performance analyses of the proposed multiparametric scenarios are evaluated to provide essential information for future medical QoS requirements and constraints in these telemedical network environments.

  15. 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).

  16. Performance Evaluation of Different QoS Models for Connecting Telephone Exchange Centers over Metro Ethernet Networks

    Directory of Open Access Journals (Sweden)

    Ghasem Mirjalily

    2009-12-01

    Full Text Available Recent large deployment of high-speed metro Ethernet networks creates opportunity to connect legacy telephone exchange centers and cellular telephone base stations to the core telephony network. The success of data and legacy voice services convergence shall depend on whether it can provide the customer with the required QoS or not. Packet-base telephony service requires stringent bounds on end-to-end packet delay, jitter, and loss. New protocols such as MPLS and Diffserv are realized due to the major advantages associated with them such as QoS. This paper studies the performance of connecting telephone exchange centers over a metro Ethernet network using MPLS and DiffServ QoS model. We will implement some simulations to evaluate the performance in terms of delay, jitter and loss.

  17. Analisa Horizontal Handover Terhadap Qos Layanan Streaming Multimedia E-Learning Pada Jaringan WLAN 802.11

    Directory of Open Access Journals (Sweden)

    I M.O. Widyantara

    2015-06-01

    Full Text Available In this globalization era, the state of the user who no longer occupies in a single place, but always moving, it is necessary to continuity of communication that will cause a handover. This paper intends to analyze the effect of 802.11 WLAN horizontal handover to the QoS of streaming e-learning. Methods of data collection process using the Cisco 3500 series access point that supports handover with existing network systems, ad-hoc network and type of hard handover. The results of the data analysis showed that the handover process is able to improve the QoS by gradually restored gradually, to get back to normal QoS

  18. QoS Adaptive Topology Configuration in Synchronous Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    杨挺; 武娇雯; 李昂; 张志东

    2010-01-01

    By using hyper-graph theory,this paper proposes a QoS adaptive topology configuration(QATC) algorithm to effectively control large-scale topology and achieve robust data transmitting in synchronous wireless sensor networks.Firstly,a concise hyper-graph model is abstracted to analyze the large-scale and high-connectivity network.Secondly,based on the control theory of biologic "Cell Mergence",a novel self-adaptive topology configuration algorithm is used to build homologous perceptive data logic sub-network ...

  19. Network on Chip: a New Approach of QoS Metric Modeling Based on Calculus Theory

    Directory of Open Access Journals (Sweden)

    Salem NASRI

    2011-10-01

    Full Text Available According to ITRS, in 2018, ICs will be able to integrate billions of transistors, with feature sizes around 18 nm and clock frequencies near to 10 GHz. In this context, Network on Chip (NoC appears as an attractive solution to implement future high performance networks and more QoS management. A NoC is composed by IP cores (Intellectual Propriety and switches connected among themselves by communicationchannels. End-to-End Delay (EED communication is accomplished by the exchange of data among IP cores.Often, the structure of particular messages is not adequate for the communication purposes. This leads to the concept of packet switching. In the context of NoCs, packets are composed by header, payload, and trailer. Packets are divided into small pieces called Flits. It appears of importance, to meet the required performance in NoC hardware resources. It should be specified in an earlier step of the system design. The main attention should be given to the choice of some network parameters such as the physical buffer size in the node. The EED and packet loss are some of the critical QoS metrics. Some real-time and multimedia applications bound up these parameters and require specific hardware resources and particular management approaches in the NoC switch.A traffic contract (SLA, Service Level Agreement specifies the ability of a network or protocol to give guaranteed performance, throughput or latency bounds based on mutually agreed measures, usually by prioritizing traffic. A defined Quality of Service (QoS may be required for some types of network real time traffic or multimedia applications. The main goal of this paper is, using the Network on Chip modeling architecture, to define a QoS metric. We focus on the network delay bound and packet losses. This approach is based on the Network Calculus theory, a mathematical model to represent the data flows behavior between IPs interconnected over NoC.We propose an approach of QoS-metric based on Qo

  20. Web Caching:A Way to Improve Web QoS

    Institute of Scientific and Technical Information of China (English)

    Ming-Kuan Liu; Fei-Yue Wang; Daniel Dajun Zeng

    2004-01-01

    As the Internet and World Wide Web grow at a fast pace, it is essential that the Web's performance should keep up with increased demand and expectations. Web Caching technology has.been widely accepted as one of the effective approaches to alleviating Web traffic and increase the Web Quality of Service (QoS). This paper provides an up-to-date survey of the rapidly expanding Web Caching literature. It discusses the state-of-the-art web caching schemes and techniques, with emphasis on the recent developments in Web Caching technology such as the differentiated Web services, heterogeneous caching network structures, and dynamic content caching.

  1. Performance Analysis of QoS in PMP Mode WiMax Networks

    CERN Document Server

    kamboj, Maninder Singh

    2010-01-01

    IEEE 802.16 standard supports two different topologies: point to multipoint (PMP) and Mesh. In this paper, a QoS mechanism for point to multipoint of IEEE 802.16 and BS scheduler for PMP Mode is proposed. This paper also describes quality of service over WiMAX networks. Average WiMAX delay, Average WiMAX load and Average WiMAX throughput at base station is analyzed and compared by applying different scheduler at Base station and at fixed nodes.

  2. Impact of Mobility On QoS of Mobile WiMax Network With CBR Application

    CERN Document Server

    Bala, Kranti

    2011-01-01

    The issue of mobility is important in wireless network because internet connectivity can only be effective if it's available during the movement of node. To enhance mobility, wireless access systems are designed such as IEEE 802.16e to operate on the move without any disruption of services. In this paper we are analyzing the impact of mobility on the QoS parameters (Throughput, Average Jitter and Average end to end Delay) of a mobile WiMAX network (IEEE 802.16e) with CBR application.

  3. Secure Broadcasting over Fading Channels with Statistical QoS Constraints

    CERN Document Server

    Qiao, Deli; Velipasalar, Senem

    2010-01-01

    In this paper, the fading broadcast channel with confidential messages is studied in the presence of statistical quality of service (QoS) constraints in the form of limitations on the buffer length. We employ the effective capacity formulation to measure the throughput of the confidential and common messages. We assume that the channel side information (CSI) is available at both the transmitter and the receivers. Assuming average power constraints at the transmitter side, we first define the effective secure throughput region, and prove that the throughput region is convex. Then, we obtain the optimal power control policies that achieve the boundary points of the effective secure throughput region.

  4. Applying Hopfield neural network to QoS routing in communication network

    Institute of Scientific and Technical Information of China (English)

    WANG Li; SHEN Jin-yuan; CHANG Sheng-jiang; ZHANG Yan-xin

    2005-01-01

    The main goal of routing solutions is to satisfy the requirements of the Quality of Service (QoS) for every admitted connection as well as to achieve a global efficiency in resource utilization.In this paper proposes a solution based on Hopfield neural network (HNN) to deal with one of representative routing problems in uni-cast routing,i.e.the multi-constrained(MC) routing problem.Computer simulation shows that we can obtain the optimal path very rapidly with our new Lyapunov energy functions.

  5. Estimation of trust metrics for MANET using QoS parameter and source routing algorithms

    CSIR Research Space (South Africa)

    Umuhoza, D

    2007-08-01

    Full Text Available for MANET Using QoS Parameter and Source Routing Algorithms D. Umuhoza1, J.I. Agbinya2, C.W. Omlin3 1Meraka Institute, PO Box 395, Pretoria 0001, South Africa; (dumuhoza@csir.co.za); 2Information and Communication Technology Group, University... trust models incorporated in MANET routing protocols. The new metrics of trust are presented in section 3. Different probabilities for detecting anomalies are computed in section4. Section 5 presents results of experiments and section 6 concludes...

  6. Mobile Agent as an Approach to Improve QoS in Vehicular Ad Hoc Network

    CERN Document Server

    Kumar, Rakesh

    2011-01-01

    Vehicular traffic is a foremost problem in modern cities. Huge amount of time and resources are wasted while traveling due to traffic congestion. With the introduction of sophisticated traffic management systems, such as those incorporating dynamic traffic assignments, more stringent demands are being placed upon the available real time traffic data. In this paper we have proposed mobile agent as a mechanism to handle the traffic problem on road. Mobile software agents can be used to provide the better QoS (Quality of Service) in vehicular ad hoc network to improve the safety application and driver comfort.

  7. Research on user-aware QoS based Web services composition

    Institute of Scientific and Technical Information of China (English)

    LIU Feng; LEI Zhen-ming

    2009-01-01

    To improve user experience of composite Web services, a user-aware quality of service (QoS) based Web services composition model is proposed. Under such model, a Web services selection method based on quantum genetic algorithm is proposed. This algorithm uses quantum bit encoding, dynamic step-length quantum gate angle adjustment, neighborhood service search and dynamic punishment strategy to expand search scope and speed up convergence. Simulation experiment shows that this algorithm is more efficient than other existing algorithms in Web services selection.

  8. Packet QoS level classifier based on optical binary priority comparison.

    Science.gov (United States)

    Song, Seoksu; Nguyen, Vancanh; Park, Jinwoo

    2010-07-19

    Next generation High-Speed optical packet switching networks require components capable of classifying incoming packet into the appropriate priority queue according to the service class of the packet. For the first time, we proposed an all-optical packet QoS (Quality of Service) level classifier employing a sequential binary packet priority comparator, which is implemented using the SOA-based optical logic gates. The performance of the optical binary packet priority comparator was verified experimentally at 1 Gbit/s showing that the proposed scheme can operate higher data rates. These packet level classifier structures are attractive for all-optical network and applications.

  9. QoS and security in Link State Routing protocols for MANETs

    OpenAIRE

    Cervera, Gimer; Barbeau, Michel; Garcia-Alfaro, Joaquin; Kranakis, Evangelos

    2013-01-01

    International audience; We study security issues in the Optimized Link State Routing (OLSR) protocol with Quality-of-Service (QoS). We propose the function k-robust-QANS, to construct a Quality Advertisement Neighbor Set (QANS). Given a node v, the one-hop nodes selected as part of its QANS generate routing information to advertise, when possible, a set with k+1 links to reach any two-hop neighbor. Several approaches have been proposed to construct a QANS. However, none of them guarantees tha...

  10. A QoS Aware Service Composition Protocol in Mobile Ad Hoc Networks

    Institute of Scientific and Technical Information of China (English)

    HAN Song-qiao; ZHANG Shen-sheng; ZHANG Yong; CAO Jian

    2008-01-01

    A novel decentralized service composition protocol was presented based on quality of service (QoS) for mobile ad hoc networks (MANETs). A service composition in MANETs is considered as a service path discovery in a service network. Based on the concept of source routing, the protocol integrates route discovery, service discovery and service composition and utilizes a constrained flooding approach to discover the optimal service path. A service path maintenance mechanism was exploited to recover broken service paths. Simulation experiments demonstrate that the proposed protocol outperforms existing service composition protocols.

  11. Asynchronous Object Storage with QoS for Scientific and Commercial Big Data

    Energy Technology Data Exchange (ETDEWEB)

    Brim, Michael J [ORNL; Dillow, David A [ORNL; Oral, H Sarp [ORNL; Settlemyer, Bradley W [ORNL; Wang, Feiyi [ORNL

    2013-01-01

    This paper presents our design for an asynchronous object storage system intended for use in scientific and commercial big data workloads. Use cases from the target workload do- mains are used to motivate the key abstractions used in the application programming interface (API). The architecture of the Scalable Object Store (SOS), a prototype object stor- age system that supports the API s facilities, is presented. The SOS serves as a vehicle for future research into scalable and resilient big data object storage. We briefly review our research into providing efficient storage servers capable of providing quality of service (QoS) contracts relevant for big data use cases.

  12. Adaptive QoS Mechanism on the Next Generation Network%下一代网络自适应QoS研究

    Institute of Scientific and Technical Information of China (English)

    罗军; 袁满; 胡建平; 阚志刚; 马健

    2003-01-01

    With the development of Internet technology, especially the conditions of wireless and mobility be migrated, more user's tasks with different QoS requirement will be implemented in Internet, this will make current network-level QoS guarantee not meeting future user's needs. However, adaptive QoS is the best way that solves future user's quality needs in wireless mobile environments. In this paper, for the future network conditions with heterogeneity, mobility, more covered links, more covered services and so on, based on the original object of QoS, which it guarantees use's personality need, we propose the concepts such as network-level, application-level and userlevel, and then discuss future user demands characteristics, and detail adaptive QoS conception, studying ranges and basic architecture. Finally, we show our future work direction.

  13. An intelligent inter-domain routing scheme under the consideration of diffserv QoS and energy saving in multi-domain software-defined flexible optical networks

    Science.gov (United States)

    Zhao, Jijun; Li, Fengyun; Ren, Danping; Hu, Jinhua; Yao, Qiuyan; Li, Wei

    2016-05-01

    Large scale multi-domain software-defined optical networks (SDON) provisioning has become a key area with increased scalable bandwidth services across wider network regions. Although distributed schemes could achieve lightpath routing by the ergodic process of domain boundary nodes, it increases the complexity of the signaling procedure and deployment of the interface. Moreover, the physical impairments are always the main factor of the infrastructure layer in SDON, which affect the transmission quality of the signal. Meanwhile, with increasing energy consumption of the Internet, it is imperative to design energy-efficient networks. To address the above issues, in this paper, an intelligent inter-domain routing scheme, which is supported by hierarchical control plane architecture, is presented based on sub-topology graph under the consideration of diffserv quality-of-service (QoS) and energy saving. The proposed scheme could achieve multi-domain quality of transmission (QoT), energy aware routing and spectrum assignment (RSA). We explore the scenarios where the multi-domain SDON achieve energy efficiency on the basis of meeting the QoT requirement. The blocking, energy consumption and average set up delay performances of the proposed schemes are estimated. The results indicate that the introduction of sub-topology in multi-domain RSA scheme has the better performance comparing with the distributed scheme.

  14. Taxonomy for QoS Parameters%服务质量(QoS)的分类学

    Institute of Scientific and Technical Information of China (English)

    郭乐深; 刘锦德; 张乃靖; 郭乐群

    2000-01-01

    In order to design a comprehensive QoS-driven distributed system where heterogeneous applications can compete for heterogeneous resources,we have developed a QoS taxonomy that captures,in a generic fashion,the various facets of QoS.The primary categories within this taxonomy are metrics and policies.Metrics specifies quantifiable QoS parameters.Metrics can be further grouped into the following classifications:performance specifications,security levels,and relative importance.Policies are divided into service guarantees,and management policies.

  15. Fault-tolerant and QoS based Network Layer for Security Management

    Directory of Open Access Journals (Sweden)

    Mohamed Naceur Abdelkrim

    2013-07-01

    Full Text Available Wireless sensor networks have profound effects on many application fields like security management which need an immediate, fast and energy efficient route. In this paper, we define a fault-tolerant and QoS based network layer for security management of chemical products warehouse which can be classified as real-time and mission critical application. This application generate routine data packets and alert packets caused by unusual events which need a high reliability, short end to end delay and low packet loss rate constraints. After each node compute his hop count and build his neighbors table in the initialization phase, packets can be routed to the sink. We use FELGossiping protocol for routine data packets and node-disjoint multipath routing protocol for alert packets. Furthermore, we utilize the information gathering phase of FELGossiping to update the neighbors table and detect the failed nodes, and we adapt the network topology changes by rerun the initialization phase when chemical units were added or removed from the warehouse. Analysis shows that the network layer is energy efficient and can meet the QoS constraints of unusual events packets.

  16. Power-efficient distributed resource allocation under goodput QoS constraints for heterogeneous networks

    Science.gov (United States)

    Andreotti, Riccardo; Del Fiorentino, Paolo; Giannetti, Filippo; Lottici, Vincenzo

    2016-12-01

    This work proposes a distributed resource allocation (RA) algorithm for packet bit-interleaved coded OFDM transmissions in the uplink of heterogeneous networks (HetNets), characterized by small cells deployed over a macrocell area and sharing the same band. Every user allocates its transmission resources, i.e., bits per active subcarrier, coding rate, and power per subcarrier, to minimize the power consumption while both guaranteeing a target quality of service (QoS) and accounting for the interference inflicted by other users transmitting over the same band. The QoS consists of the number of information bits delivered in error-free packets per unit of time, or goodput (GP), estimated at the transmitter by resorting to an efficient effective SNR mapping technique. First, the RA problem is solved in the point-to-point case, thus deriving an approximate yet accurate closed-form expression for the power allocation (PA). Then, the interference-limited HetNet case is examined, where the RA problem is described as a non-cooperative game, providing a solution in terms of generalized Nash equilibrium. Thanks to the closed-form of the PA, the solution analysis is based on the best response concept. Hence, sufficient conditions for existence and uniqueness of the solution are analytically derived, along with a distributed algorithm capable of reaching the game equilibrium.

  17. Providing data transfer with QoS as agreement-based service.

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.; Keahey, K.; Allcock, W.; Mathematics and Computer Science; Univ. of Illinois

    2004-01-01

    Over the last decade, grids have become a successful tool for providing distributed environments for secure and coordinated execution of applications. The successful deployment of many realistic applications in such environments on a large scale has motivated their use in experimental science [L. C. Pearlman et al., (2004), K. Keahey et al. (2004)] where grid-based computations are used to assist in ongoing experiments. In such scenarios, quality of service (QoS) guarantees on execution as well as data transfer is desirable. The recently proposed WS-Agreement model [K. Czajkowski et al. K. Keahey et al. (2004)] provides an infrastructure within which such quality of service can be negotiated and obtained. We have designed and implemented a data transfer service that exposes an interface based on this model and defines agreements which guarantee that, within a certain confidence level, file transfer can be completed under a specified time. The data transfer service accepts a client's request for data transfer and makes an agreement with the client based on QoS metrics (such as the transfer time and confidence level with which the service can be provided). In our approach we use prediction as a base for formulating an agreement with the client, and we combine prediction and rate limiting to adoptively ensure that the agreement is met.

  18. QoS Measurement of Workflow-Based Web Service Compositions Using Colored Petri Net

    Science.gov (United States)

    Nematzadeh, Hossein; Motameni, Homayun; Nematzadeh, Zahra

    2014-01-01

    Workflow-based web service compositions (WB-WSCs) is one of the main composition categories in service oriented architecture (SOA). Eflow, polymorphic process model (PPM), and business process execution language (BPEL) are the main techniques of the category of WB-WSCs. Due to maturity of web services, measuring the quality of composite web services being developed by different techniques becomes one of the most important challenges in today's web environments. Business should try to provide good quality regarding the customers' requirements to a composed web service. Thus, quality of service (QoS) which refers to nonfunctional parameters is important to be measured since the quality degree of a certain web service composition could be achieved. This paper tried to find a deterministic analytical method for dependability and performance measurement using Colored Petri net (CPN) with explicit routing constructs and application of theory of probability. A computer tool called WSET was also developed for modeling and supporting QoS measurement through simulation. PMID:25110748

  19. Analysis and solutions of QoS issue in Ethernet PON

    Science.gov (United States)

    Zhang, Ao; He, Yan; Shi, Lei

    2004-04-01

    Ethernet Passive Optical Network (EPON) aims at providing full services to end users over a single platform, which combines the low cost Ethernet equipment and economic fiber infrastructure, appears to be the best candidate for the future broad access network. Due to Ethernet has a seamless connection with modern IP network, EPON has shown excellent performance when transmitting data service. However, a key technical challenge for EPON vendors lies in enhancing Ethernet"s capabilities to support real-time services, such as VoIP, live video and other TDM services, e .g. POTS and T1/E1. In order to guarantee the required QoS, many new technologies are introduced, either common to all IP based network or dedicated to EPON network. Firstly, a short overview of EPON technology is given. Then, two prevailing QoS architectures, Intserv and Diffserv, are presented in detail. Both their advantages and disadvantages are also discussed. Subsequently, the light is turned to a certain DBA algorithm, which is more efficient in EPON. Both the features of the algorithm and the main ideas are described in particular. At last, reserving bandwidth for TDM service, which is simple but not very efficient, is also proposed.

  20. QoS Supported IPTV Service Architecture over Hybrid-Tree-Based Explicit Routed Multicast Network

    Directory of Open Access Journals (Sweden)

    Chih-Chao Wen

    2012-01-01

    Full Text Available With the rapid advance in multimedia streaming and multicast transport technology, current IP multicast protocols, especially PIM-SM, become the major channel delivery mechanism for IPTV system over Internet. The goals for IPTV service are to provide two-way interactive services for viewers to select popular program channel with high quality for watching during fast channel surfing period. However, existing IP multicast protocol cannot meet above QoS requirements for IPTV applications between media server and subscribers. Therefore, we propose a cooperative scheme of hybrid-tree based on explicit routed multicast, called as HT-ERM to combine the advantages of shared tree and source tree for QoS-supported IPTV service. To increase network utilization, the constrained shortest path first (CSPF routing algorithm is designed for construction of hybrid tree to deliver the high-quality video stream over watching channel and standard quality over surfing channel. Furthermore, the Resource Reservation Protocol- Traffic Engineering (RSVP-TE is used as signaling mechanism to set up QoS path for multicast channel admission control. Our simulation results demonstrated that the proposed HT-ERM scheme outperforms other multicast QoS-based delivery scheme in terms of channel switching delay, resource utilization, and blocking ratio for IPTV service.

  1. An Improved QoS Multipath Routing Using Bandwidth Estimation and Rate Adaptation

    Directory of Open Access Journals (Sweden)

    S. Suganya

    2014-06-01

    Full Text Available Mobile Adhoc Networks (MANETs are composed of nodes which communicate with one another without network infrastructure. Their advantage being that they can be used in isolation or along with wired infrastructure, usually via a gateway node to ensure traffic relay for both networks. Quality of Service (QoS is harder to ensure in ad hoc networks than in other network types, as wireless bandwidth is shared by adjacent nodes with network topology changing as nodes move. Most QoS protocols are implemented for specific scenarios and consider parameters such as network topologies, bandwidth, mobility, security and so on. This work proposes a novel multipath routing protocol which is an extension of AOMDV by discovering routes based on available bandwidth and rate adaptation. The method with Hello message box is used to calculate available bandwidth for a route. Relative Fairness and Optimized Throughput is an approach for rate adaptation in this paper which is to ensure fairness and allow nodes to adapt transmission rates and contention windows to channel quality. In sequence this is determined by calculating the access probability of a channel for each node in a distributed manner approximating successful and failed transmissions.

  2. QoS Measurement of Workflow-Based Web Service Compositions Using Colored Petri Net

    Directory of Open Access Journals (Sweden)

    Hossein Nematzadeh

    2014-01-01

    Full Text Available Workflow-based web service compositions (WB-WSCs is one of the main composition categories in service oriented architecture (SOA. Eflow, polymorphic process model (PPM, and business process execution language (BPEL are the main techniques of the category of WB-WSCs. Due to maturity of web services, measuring the quality of composite web services being developed by different techniques becomes one of the most important challenges in today’s web environments. Business should try to provide good quality regarding the customers’ requirements to a composed web service. Thus, quality of service (QoS which refers to nonfunctional parameters is important to be measured since the quality degree of a certain web service composition could be achieved. This paper tried to find a deterministic analytical method for dependability and performance measurement using Colored Petri net (CPN with explicit routing constructs and application of theory of probability. A computer tool called WSET was also developed for modeling and supporting QoS measurement through simulation.

  3. Trust-Enhanced Cloud Service Selection Model Based on QoS Analysis.

    Science.gov (United States)

    Pan, Yuchen; Ding, Shuai; Fan, Wenjuan; Li, Jing; Yang, Shanlin

    2015-01-01

    Cloud computing technology plays a very important role in many areas, such as in the construction and development of the smart city. Meanwhile, numerous cloud services appear on the cloud-based platform. Therefore how to how to select trustworthy cloud services remains a significant problem in such platforms, and extensively investigated owing to the ever-growing needs of users. However, trust relationship in social network has not been taken into account in existing methods of cloud service selection and recommendation. In this paper, we propose a cloud service selection model based on the trust-enhanced similarity. Firstly, the direct, indirect, and hybrid trust degrees are measured based on the interaction frequencies among users. Secondly, we estimate the overall similarity by combining the experience usability measured based on Jaccard's Coefficient and the numerical distance computed by Pearson Correlation Coefficient. Then through using the trust degree to modify the basic similarity, we obtain a trust-enhanced similarity. Finally, we utilize the trust-enhanced similarity to find similar trusted neighbors and predict the missing QoS values as the basis of cloud service selection and recommendation. The experimental results show that our approach is able to obtain optimal results via adjusting parameters and exhibits high effectiveness. The cloud services ranking by our model also have better QoS properties than other methods in the comparison experiments.

  4. 320-Gb/s switch system to guarantee QoS of real-time traffic

    Science.gov (United States)

    Li, Wenjie; Liu, Bin; Xu, Yang

    2003-08-01

    To provide QoS control for real time traffic in core routers, this paper designs and evaluates a 320 Gb/s switch system, which supports 16 line cards, each operating at OC192c line rate (10 Gb/s). This switch system contains a high performance switch fabric and supports variable-length IP packet interface. These two characters provide advantages over traditional switch fabrics with a cell interface. This switch system supports eight priorities to both unicast and multicast traffic. The highest priority with strict QoS guarantee is for real time traffic, and other seven lower priorities with weighted round-robin (WRR) service discipline are for other common data traffic. Through simulation under multi-priority burst traffic model, we demonstrate this switch system not only can provide excellent performance for real time traffic, but also can efficiently allocate bandwidth among all kinds of traffic. As a result, this switch system can serve as a key node in high-speed networks, and it can also meet the challenge of multimedia traffic to the next generation Internet.

  5. QoS measurement of workflow-based web service compositions using Colored Petri net.

    Science.gov (United States)

    Nematzadeh, Hossein; Motameni, Homayun; Mohamad, Radziah; Nematzadeh, Zahra

    2014-01-01

    Workflow-based web service compositions (WB-WSCs) is one of the main composition categories in service oriented architecture (SOA). Eflow, polymorphic process model (PPM), and business process execution language (BPEL) are the main techniques of the category of WB-WSCs. Due to maturity of web services, measuring the quality of composite web services being developed by different techniques becomes one of the most important challenges in today's web environments. Business should try to provide good quality regarding the customers' requirements to a composed web service. Thus, quality of service (QoS) which refers to nonfunctional parameters is important to be measured since the quality degree of a certain web service composition could be achieved. This paper tried to find a deterministic analytical method for dependability and performance measurement using Colored Petri net (CPN) with explicit routing constructs and application of theory of probability. A computer tool called WSET was also developed for modeling and supporting QoS measurement through simulation.

  6. QoS Modeling for End-to-End Performance Evaluation over Networks with Wireless Access

    Directory of Open Access Journals (Sweden)

    Gerardo Gómez

    2010-01-01

    Full Text Available This paper presents an end-to-end Quality of Service (QoS model for assessing the performance of data services over networks with wireless access. The proposed model deals with performance degradation across protocol layers using a bottom-up strategy, starting with the physical layer and moving on up to the application layer. This approach makes it possible to analytically assess performance at different layers, thereby facilitating a possible end-to-end optimization process. As a representative case, a scenario where a set of mobile terminals connected to a streaming server through an IP access node has been studied. UDP, TCP, and the new TCP-Friendly Rate Control (TFRC protocols were analyzed at the transport layer. The radio interface consisted of a variable-rate multiuser and multichannel subsystem, including retransmissions and adaptive modulation and coding. The proposed analytical QoS model was validated on a real-time emulator of an end-to-end network with wireless access and proved to be very useful for the purposes of service performance estimation and optimization.

  7. Enhancing QoS and QoE in IMS Enabled Next Generation Networks

    CERN Document Server

    Lakhtaria, Kamaljit I

    2010-01-01

    Managing network complexity, accommodating greater numbers of subscribers, improving coverage to support data services (e.g. email, video, and music downloads), keeping up to speed with fast-changing technology, and driving maximum value from existing networks - all while reducing CapEX and OpEX and ensuring Quality of Service (QoS) for the network and Quality of Experience (QoE) for the user. These are just some of the pressing business issues faced by mobileservice providers, summarized by the demand to "achieve more, for less." The ultimate goal of optimization techniques at the network and application layer is to ensure End-user perceived QoS. The next generation networks (NGN), a composite environment of proven telecommunications and Internet-oriented mechanisms have become generally recognized as the telecommunications environment of the future. However, the nature of the NGN environment presents several complex issues regarding quality assurance that have not existed in the legacy environments (e.g., m...

  8. Dynamic Pricing Strategy of Provider with Different QoS Levels in Web Service

    Directory of Open Access Journals (Sweden)

    Wei Pan

    2009-06-01

    Full Text Available In order to improve the service provider profit, the pricing strategies in service network have been studied, but primarily in static pricing setting without considering different quality of service (QoS levels. However, in real situation, providers usually dynamically adjust their prices and offer multiple class services to meet different customers. Moreover, because service provider will satisfy demands of customers on a specific future date, customers may cancel order. In this paper, we establish a new dynamic pricing model to consider order cancellation ration and different QoS levels for maximizing provider revenue. The analytical results from this new model reveal that the optimal capacity and prices are derived via closed-form solutions. Finally, a numerical example is presented to illustrate that the proposed method is effective for determining the optimal capacity and prices. In addition, sensitivity analysis of the optimal capacity and profit with respect to some important parameters are also conducted to illustrate the optimal decision characteristics.

  9. Model checking and evaluating QoS of batteries in MPSoC dataflow applications via hybrid automata

    NARCIS (Netherlands)

    Ahmad, Waheed; Jongerden, Marijn; Stoelinga, Mariëlle; Pol, van de Jaco

    2016-01-01

    System lifetime is a major design constraint for attery-powered mobile embedded systems. The increasing gap between the energy demand of portable devices and their battery capacities is further limiting durability of mobile devices. Thus, the guarantees over Quality of Service (QoS) of battery-const

  10. QoS Differential Scheduling in Cognitive-Radio-Based Smart Grid Networks: An Adaptive Dynamic Programming Approach.

    Science.gov (United States)

    Yu, Rong; Zhong, Weifeng; Xie, Shengli; Zhang, Yan; Zhang, Yun

    2016-02-01

    As the next-generation power grid, smart grid will be integrated with a variety of novel communication technologies to support the explosive data traffic and the diverse requirements of quality of service (QoS). Cognitive radio (CR), which has the favorable ability to improve the spectrum utilization, provides an efficient and reliable solution for smart grid communications networks. In this paper, we study the QoS differential scheduling problem in the CR-based smart grid communications networks. The scheduler is responsible for managing the spectrum resources and arranging the data transmissions of smart grid users (SGUs). To guarantee the differential QoS, the SGUs are assigned to have different priorities according to their roles and their current situations in the smart grid. Based on the QoS-aware priority policy, the scheduler adjusts the channels allocation to minimize the transmission delay of SGUs. The entire transmission scheduling problem is formulated as a semi-Markov decision process and solved by the methodology of adaptive dynamic programming. A heuristic dynamic programming (HDP) architecture is established for the scheduling problem. By the online network training, the HDP can learn from the activities of primary users and SGUs, and adjust the scheduling decision to achieve the purpose of transmission delay minimization. Simulation results illustrate that the proposed priority policy ensures the low transmission delay of high priority SGUs. In addition, the emergency data transmission delay is also reduced to a significantly low level, guaranteeing the differential QoS in smart grid.

  11. Cooperative Optimization QoS Cloud Routing Protocol Based on Bacterial Opportunistic Foraging and Chemotaxis Perception for Mobile Internet

    Directory of Open Access Journals (Sweden)

    Shujuan Wang

    2015-01-01

    Full Text Available In order to strengthen the mobile Internet mobility management and cloud platform resources utilization, optimizing the cloud routing efficiency is established, based on opportunistic bacterial foraging bionics, and puts forward a chemotaxis perception of collaborative optimization QoS (Quality of Services cloud routing mechanism. The cloud routing mechanism is based on bacterial opportunity to feed and bacterial motility and to establish the data transmission and forwarding of the bacterial population behavior characteristics. This mechanism is based on the characteristics of drug resistance of bacteria and the structure of the field, and through many iterations of the individual behavior and population behavior the bacteria can be spread to the food gathering area with a certain probability. Finally, QoS cloud routing path would be selected and optimized based on bacterial bionic optimization and hedge mapping relationship between mobile Internet node and bacterial population evolution iterations. Experimental results show that, compared with the standard dynamic routing schemes, the proposed scheme has shorter transmission delay, lower packet error ratio, QoS cloud routing loading, and QoS cloud route request overhead.

  12. Downlink resource management for QoS scheduling in IEEE 802.16 WiMAX networks

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2010-01-01

    IEEE 802.16, also known as WiMAX, has received much attention recently for its capability to support multiple types of applications with diverse Quality-of-Service (QoS) requirements. Beyond what the standard has defined, radio resource management (RRM) still remains an open issue, which plays...

  13. Resource management framework for QoS scheduling in IEEE 802.16 WiMAX networks

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2009-01-01

    IEEE 802.16, also known as WiMAX, has received much attention recently for its capability to support multiple types of applications with diverse Quality-of-Service (QoS) requirements. Beyond what the standard has defined, radio resource management (RRM) still remains an open issue, which plays...

  14. Resource management framework for QoS scheduling in IEEE 802.16 WiMAX networks

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2009-01-01

    IEEE 802.16, also known as WiMAX, has received much attention recently for its capability to support multiple types of applications with diverse Quality-of-Service (QoS) requirements. Beyond what the standard has defined, radio resource management (RRM) still remains an open issue, which plays...

  15. A Revenue Maximization Approach for Provisioning Services in Clouds

    Directory of Open Access Journals (Sweden)

    Li Pan

    2015-01-01

    Full Text Available With the increased reliability, security, and reduced cost of cloud services, more and more users are attracted to having their jobs and applications outsourced into IAAS data centers. For a cloud provider, deciding how to provision services to clients is far from trivial. The objective of this decision is maximizing the provider’s revenue, while fulfilling its IAAS resource constraints. The above problem is defined as IAAS cloud provider revenue maximization (ICPRM problem in this paper. We formulate a service provision approach to help a cloud provider to determine which combination of clients to admit and in what Quality-of-Service (QoS levels and to maximize provider’s revenue given its available resources. We show that the overall problem is a nondeterministic polynomial- (NP- hard one and develop metaheuristic solutions based on the genetic algorithm to achieve revenue maximization. The experimental simulations and numerical results show that the proposed approach is both effective and efficient in solving ICPRM problems.

  16. Fuzzy recurrence plots

    Science.gov (United States)

    Pham, T. D.

    2016-12-01

    Recurrence plots display binary texture of time series from dynamical systems with single dots and line structures. Using fuzzy recurrence plots, recurrences of the phase-space states can be visualized as grayscale texture, which is more informative for pattern analysis. The proposed method replaces the crucial similarity threshold required by symmetrical recurrence plots with the number of cluster centers, where the estimate of the latter parameter is less critical than the estimate of the former.

  17. Recurrent zosteriform herpes simplex

    Directory of Open Access Journals (Sweden)

    Inamadar Arun

    1992-01-01

    Full Text Available A 25-year-old man had recurrent zosteriform herpes simplex for past 6 years. The attacks were precipitated by prolonged exposure to sunlight. Pain was mild and lesions used to subside each time in about 7 days. Clinical features which help in differentiating recurrent herpes simplex from recurrent herpes zoster are summarized.

  18. Optimal Resource Allocation under Fair QoS in Multi-tier Server Systems

    Science.gov (United States)

    Akai, Hirokazu; Ushio, Toshimitsu; Hayashi, Naoki

    Recent development of network technology realizes multi-tier server systems, where several tiers perform functionally different processing requested by clients. It is an important issue to allocate resources of the systems to clients dynamically based on their current requests. On the other hand, Q-RAM has been proposed for resource allocation in real-time systems. In the server systems, it is important that execution results of all applications requested by clients are the same QoS(quality of service) level. In this paper, we extend Q-RAM to multi-tier server systems and propose a method for optimal resource allocation with fairness of the QoS levels of clients’ requests. We also consider an assignment problem of physical machines to be sleep in each tier sothat the energy consumption is minimized.

  19. AN ADVANCED QOS ANALYSIS AND EVALUATION METHOD FOR MOBILE INTERNET ACCESS

    Directory of Open Access Journals (Sweden)

    F. Beritelli1

    2016-06-01

    Full Text Available The paper proposes a new method for the analysis and evaluation of the Quality of Service (QoS in a mobile Internet access scenario. In particular, the paper proposes a throughput evaluation method based on PathChirp algorithm. The end-to-end bandwidth was estimated by means of the Self Loading of Periodic Streams (SloPS technique. The obtained measurements were then analyzed by estimating the degree of correlation with other parameters that characterize the data transmission such as power, round trip time, etc. Finally, in order to have greater spatial resolution performance guaranteed by an Internet service provider, a 3D reconstruction method based on using drones is proposed and some preliminary results are discussed.

  20. 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.

  1. An Adaptive QoS Routing Solution for MANET Based Multimedia Communications in Emergency Cases

    Science.gov (United States)

    Ramrekha, Tipu Arvind; Politis, Christos

    The Mobile Ad hoc Networks (MANET) is a wireless network deprived of any fixed central authoritative routing entity. It relies entirely on collaborating nodes forwarding packets from source to destination. This paper describes the design, implementation and performance evaluation of CHAMELEON, an adaptive Quality of Service (QoS) routing solution, with improved delay and jitter performances, enabling multimedia communication for MANETs in extreme emergency situations such as forest fire and terrorist attacks as defined in the PEACE project. CHAMELEON is designed to adapt its routing behaviour according to the size of a MANET. The reactive Ad Hoc on-Demand Distance Vector Routing (AODV) and proactive Optimized Link State Routing (OLSR) protocols are deemed appropriate for CHAMELEON through their performance evaluation in terms of delay and jitter for different MANET sizes in a building fire emergency scenario. CHAMELEON is then implemented in NS-2 and evaluated similarly. The paper concludes with a summary of findings so far and intended future work.

  2. SLA Establishment with Guaranteed QoS in the Interdomain Network: A Stock Model

    CERN Document Server

    Barth, Dominique; Mautor, Thierry; 10.5121/ijcnc.2011.3413

    2011-01-01

    The new model that we present in this paper is introduced in the context of guaranteed QoS and resources management in the inter-domain routing framework. This model, called the stock model, is based on a reverse cascade approach and is applied in a distributed context. So transit providers have to learn the right capacities to buy and to stock and, therefore learning theory is applied through an iterative process. We show that transit providers manage to learn how to strategically choose their capacities on each route in order to maximize their benefits, despite the very incomplete information. Finally, we provide and analyse some simulation results given by the application of the model in a simple case where the model quickly converges to a stable state.

  3. Trust Based Scheme for QoS Assurance in Mobile Ad-Hoc Networks

    CERN Document Server

    Subramanian, Sridhar

    2012-01-01

    A mobile ad-hoc network (MANET) is a peer-to-peer wireless network where nodes can communicate with each other without the use of infrastructure such as access points or base stations. These networks are self-configuring, capable of self-directed operation and hastily deployable. Nodes cooperate to provide connectivity, operates without centralized administration. Nodes are itinerant, topology can be very dynamic and nodes must be able to relay traffic since communicating nodes might be out of range. The dynamic nature of MANET makes network open to attacks and unreliability. Routing is always the most significant part for any networks. Each node should not only work for itself, but should be cooperative with other nodes. Node misbehaviour due to selfish or malicious intention could significantly degrade the performance of MANET. The Qos parameters like PDR, throughput and delay are affected directly due to such misbehaving nodes. We focus on trust management framework, which is intended to cope with misbehav...

  4. QTDMAC: MAC protocol for QoS support in MANET using smart antennas

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying-chao; GUAN Li-li

    2009-01-01

    Unlike directional antennas, smart antennas offer MANET (Mobile Ad hoc Net works) potential increases in their achievable throughput and capacity. Based on the development of smart antenna technology, we studied the MAC protocol for QoS support was studied, which becomes the hot issue in multimedia services. The protocol divides the channel into the data channel and the control channel, node sends forecast guarantee to compete the channel. And after completing the RTS / CTS handshake appointment, node is reserved for data transmission. Node can send Busy Tones to prevent the problem of the deafness nodes and hidden terminal. At last if the direct link between the sender and receiver has low quality and low rate, data packets may be delivered faster through a relay node. Through the analytical results, QTDMAC with the protocol IEEE802.1 and DMAC were compared. The QTDMAC protocol is proved the superiority in throughput and the real-time delay business.

  5. Efficient congestion control scheme for providing QoS to I-VPN

    Science.gov (United States)

    De Marco, Martino; Trabucchi, Sara

    1998-12-01

    In this paper we outline an overall network architecture for the Internet Service Providers who want offer an Internet- Virtual Private Network service with QoS guarantees and, at the same time, with a high-level of efficiency in the network resource usage. The proposed approach is based on the negotiation of a service level agreement, which includes the definition of profile of traffic the user is allowed to emit. The ingress nodes perform an adaptive shaping of the user traffic entering the network, driven by a fast congestion notification scheme. In this scenario, the adoption of a service architecture based on a class-of- service concept enables the Internet Service Provider to offer different level of network performance according to the customer needs.

  6. QoS Adaptive Topology Configuration in Synchronous Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    YANG Ting; WU Jiaowen; LI Ang; ZHANG Zhidong

    2010-01-01

    By using hyper-graph theory,this paper proposes a QoS adaptive topology configuration(QATC)algorithm to effectively control large-scale topology and achieve robust data transmitting in synchronous wireless sensor networks.Firstly,a concise hyper-graph model is abstracted to analyze the large-scale and high-connectivity network.Secondly,based on the control theory of biologic "Cell Mergence",a novel self-adaptive topology configuration algorithm is used to build homologous perceptive data logic sub-network for data aggregation.Compared with Flooding,Directed Diffusion,and Energy Aware Directed Diffusion protocols,the simulation proved that QATC algorithm can save more energy,e.g.,about 23.7% in a large size network,and has less delay than the other algorithms.In dynamic experiments,QATC keeps a robust transmitting quality with 10%,20% and 30% random failure nodes.

  7. An Improvement on Algorithm of Grid-Workflow Based on QoS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-feng; GE Wei

    2004-01-01

    With the emergence of grid computing, new challenges have arisen in workflow tasks scheduling.The goal of grid-workflow task scheduling is to achieve high system throughput and to match the application needs with the available computing resources.This matching of resources in a non-deterministically share heterogeneous environment leads to concerns on quality of service (QoS).Grid concept is presented in this paper, coupled with the QoS requirement of workflow task and an improved algorithm-ILGSS algorithm, has been brought out.The complexity of the improved scheduling algorithm has been analyzed.The experiment results show that the improved algorithm can lead to significant performance gain in various applications.An important research domain-adaptive workflow transaction in grid computing environment, has been explored and a new solution for the scheduling of distribute workflow has been bring forward in grid environment.

  8. SELFLESS DISTRIBUTED CREDIT BASED SCHEDULING FOR IMPROVED QOS IN IEEE 802.16 WBA NETWORKS

    Directory of Open Access Journals (Sweden)

    C.Kalyana Chakravarthy

    2009-11-01

    Full Text Available Packet and flow scheduling algorithms for WiMAX has been a topic of interest for a long time since the very inception of WiMAX networks. WiMAX offers advantages particularly in terms of Quality of service it offers over a longer range at the MAC level. In our paper, we propose two credit based scheduling schemes one in which completed flows distributes the left over credits equally to all higher priority flows(FDCBSS and another in which completed flows give away all the excess credits to the highest priority uncompleted flow(SDCBSS. Both the schemes are compatible with 802.16 MAC protocol and can efficiently serve real time bursty traffic with reduced latency and hence improved QOS for real time flows. We compare the two proposed schemes for their latency, bandwidth utilization and throughput for real time burst flows with the basic Deficit Round Robin scheduling scheme.

  9. SLA ESTABLISHMENT WITH GUARANTEED QOS IN THE INTERDOMAIN NETWORK: A STOCK MODEL

    Directory of Open Access Journals (Sweden)

    Dominique Barth

    2011-08-01

    Full Text Available The new model that we present in this paper is introduced in the context of guaranteed QoS andresources management in the inter-domain routing framework. This model, called the stock model, isbased on a reverse cascade approach and is applied in a distributed context. So transit providers have tolearn the right capacities to buy and to stock and, therefore learning theory is applied through aniterative process. We show that transit providers manage to learn how to strategically choose theircapacities on each route in order to maximize their benefits, despite the very incomplete information.Finally, we provide and analyse some simulation results given by the application of the model in a simplecase where the model quickly converges to a stable state.

  10. Scalable video object coding & QoS control for next generation space internet

    Institute of Scientific and Technical Information of China (English)

    TU GuoFang; ZHANG Can; HEINRICH Nimann; XU Jie; WU WeiRen

    2008-01-01

    The next generation space internet (NGSI) is based on all-IP-based mobile network that merges land-based network, sea-based network, sky-based network, space-based network, deep space-based network together using existing assess network technologies. There are high signal propagation delays, high error rate, bandwidth variation and time-variety in NGSI. In order to adapt to various space communica-tion environment constraints and bandwidth variation, we propose a reduced di-mension scalable video coding scheme based on CCSDS IDCS algorithm and quality of service (QoS) control method by cross layer design (CLD). The experi-mental result shows that this new method has better performance than that of ex-isting algorithms, and can be adaptive to the bandwidth variation dynamically.

  11. Performance Analysis of Cognitive Radio Systems under QoS Constraints and Channel Uncertainty

    CERN Document Server

    Akin, Sami

    2010-01-01

    In this paper, performance of cognitive transmission over time-selective flat fading channels is studied under quality of service (QoS) constraints and channel uncertainty. Cognitive secondary users (SUs) are assumed to initially perform channel sensing to detect the activities of the primary users, and then attempt to estimate the channel fading coefficients through training. Energy detection is employed for channel sensing, and different minimum mean-square-error (MMSE) estimation methods are considered for channel estimation. In both channel sensing and estimation, erroneous decisions can be made, and hence, channel uncertainty is not completely eliminated. In this setting, performance is studied and interactions between channel sensing and estimation are investigated. Following the channel sensing and estimation tasks, SUs engage in data transmission. Transmitter, being unaware of the channel fading coefficients, is assumed to send the data at fixed power and rate levels that depend on the channel sensing...

  12. NoC Design Flow for TDMA and QoS Management in a GALS Context

    Directory of Open Access Journals (Sweden)

    Houzet Dominique

    2006-01-01

    Full Text Available This paper proposes a new approach dealing with the tedious problem of NoC guaranteed traffics according to GALS constraints impelled by the upcoming large System-on-Chips with multiclock domains. Our solution has been designed to adjust a tradeoff between synchronous and clockless asynchronous techniques. By means of smart interfaces between synchronous sub-NoCs, Quality-of-Service (QoS for guaranteed traffic is assured over the entire chip despite clock heterogeneity. This methodology can be easily integrated in the usual NoC design flow as an extension to traditional NoC synchronous design flows. We present real implementation obtained with our tool for a 4G telecom scheme.

  13. NoC Design Flow for TDMA and QoS Management in a GALS Context

    Directory of Open Access Journals (Sweden)

    Dominique Houzet

    2006-10-01

    Full Text Available This paper proposes a new approach dealing with the tedious problem of NoC guaranteed traffics according to GALS constraints impelled by the upcoming large System-on-Chips with multiclock domains. Our solution has been designed to adjust a tradeoff between synchronous and clockless asynchronous techniques. By means of smart interfaces between synchronous sub-NoCs, Quality-of-Service (QoS for guaranteed traffic is assured over the entire chip despite clock heterogeneity. This methodology can be easily integrated in the usual NoC design flow as an extension to traditional NoC synchronous design flows. We present real implementation obtained with our tool for a 4G telecom scheme.

  14. An Improved Framework for Enhancing QoS in MIPv6

    Directory of Open Access Journals (Sweden)

    Shilpy Gupta

    2011-02-01

    Full Text Available With the advent of technology, a large number of wireless and mobile devices are being connected to the internet increasingly giving the users access to the internet while on move. This mobility has been supported through the Internet Protocol known as Mobile IP, allowing the users with mobile devices to have continuous network connectivity to the internet without changing their IP addresses when moving from one network to another. Mobility is supported in both versions of IP, using MIPv4 in IPv4 network, and MIPv6 in IPv6 network. The framework of MIP moves around the core concepts like throughput, delay handover latency and packet loss. These concepts are the metrics of the quality of service (QoS that must be efficient in providing consistent, predictable data delivery service over the networks. While on move, the Mobile Node (MN undergoes a handover process, in which a MN is disconnected from one network and connected to another. The time period of disconnection during the handover process is known as the handover latency and it may cause a major problem of real–timepacket loss, i.e., a number of packets may not reach their estination. The major delay in handover is due to the duplicate-address detection (DAD process. Several solutions have been proposed to overcome these problems in MIPv6. However, no solution seems to be the optimum. The framework in this paper suggests the removal of DAD procedure and configuration of a new Care of Address for the MN by theNAR (New Access Router and the use of efficient buffer management mechanism for improving the two metrics of, and enhancing the QoS in MIPv6.

  15. Simulasi dan Analisis QoS Video Conference Melalui Jaringan Interworking IMS - UMTS Menggunakan Opnet

    Directory of Open Access Journals (Sweden)

    Dadiek Pranindito

    2017-02-01

    Full Text Available Next Generation Network (NGN merupakan salah satu teknologi masa depan yang memberikan layanan berupa voice, data, multimedia, dan internet yang mengacu pada konvergensi layanan berbasis IP. Sebuah teknologi yang mendukung konsep konvergensi berbasis IP adalah IP Multimedia Subsystem (IMS. UMTS merupakan salah satu teknologi bergerak seluler generasi ke tiga (3G yang sebagian besar masyarakat gunakan karena rata-rata masyarakat sudah menggunakan gadget yang mendukung jaringan 3G. Dengan menggunakan jaringan 3G, masyarakat dapat melakukan komunikasi video conference. Video conference merupakan salah satu komunikasi jarak jauh yang bersifat real time sebagai pengganti tatap muka. Namun, layanan video conference pada jaringan IMS – UMTS perlu diketahui kelayakannya. Video conference merupakan layanan yang sensitif terhadap delay sehingga perlu dilakukan analisis QoS. Pada penelitian ini dilakukan simulasi dan analisis QoS video conference pada jaringan IMS – UMTS. Simulasi ini akan dibuat dengan menggunakan software OPNET modeler 14.5. Skenario yang digunakan adalah skenario Integrated Service (IntServ untuk mengamati jaringan IMS dan Differentiated Service (DiffServ untuk mengamati hubungan antara IMS dengan UMTS. Penelitian ini menggunakan jumlah user yang berbeda-beda yaitu 4 user, 8 user, dan 12 user dengan waktu simulasi yang berbeda, yaitu 100 detik, 200 detik, dan 300 detik. Dari hasil penelitian yang didapat, pada skenario Intserv dihasilkan nilai rata-rata terbesar untuk throughput adalah 26.643 Mbit/s, end-to-end delay sebesar 233.069 ms, dan jitter  sebesar 0.073 ms. Untuk skenario Diffserv dihasilkan nilai rata-rata terbesar untuk throughput adalah 8.484 Mbit/s, end-to-end delay sebesar 164.138 ms, dan jitter sebesar 0.488 ms. Untuk nilai packet loss ke dua skenario menghasilkan nilai kurang dari 1%. Jika dilihat dari standar ITU-T G-114, rata-rata nilai parameter pada ke dua skenario termasuk dalam kategori baik

  16. Cross-layer protocol design for QoS optimization in real-time wireless sensor networks

    Science.gov (United States)

    Hortos, William S.

    2010-04-01

    The metrics of quality of service (QoS) for each sensor type in a wireless sensor network can be associated with metrics for multimedia that describe the quality of fused information, e.g., throughput, delay, jitter, packet error rate, information correlation, etc. These QoS metrics are typically set at the highest, or application, layer of the protocol stack to ensure that performance requirements for each type of sensor data are satisfied. Application-layer metrics, in turn, depend on the support of the lower protocol layers: session, transport, network, data link (MAC), and physical. The dependencies of the QoS metrics on the performance of the higher layers of the Open System Interconnection (OSI) reference model of the WSN protocol, together with that of the lower three layers, are the basis for a comprehensive approach to QoS optimization for multiple sensor types in a general WSN model. The cross-layer design accounts for the distributed power consumption along energy-constrained routes and their constituent nodes. Following the author's previous work, the cross-layer interactions in the WSN protocol are represented by a set of concatenated protocol parameters and enabling resource levels. The "best" cross-layer designs to achieve optimal QoS are established by applying the general theory of martingale representations to the parameterized multivariate point processes (MVPPs) for discrete random events occurring in the WSN. Adaptive control of network behavior through the cross-layer design is realized through the parametric factorization of the stochastic conditional rates of the MVPPs. The cross-layer protocol parameters for optimal QoS are determined in terms of solutions to stochastic dynamic programming conditions derived from models of transient flows for heterogeneous sensor data and aggregate information over a finite time horizon. Markov state processes, embedded within the complex combinatorial history of WSN events, are more computationally

  17. QoS Management Mechanisms and Prototype System of VoIP%VoIP服务质量管理机制及原型系统

    Institute of Scientific and Technical Information of China (English)

    陈秀忠; 王春峰; 黄晓潞

    2003-01-01

    In this paper, we briefly introduce the architecture of VoIP application at the beginning. Then we focus on discussing QoS management mechanisms in data plane and control plane in detail. We explore the implementation of QoS management system by describing the prototype system QNet. At last, we discuss their future trends and present several issues remained to be studied by combining the experiences of our research.

  18. 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.

  19. Application-Level and User-Level QoS Assessment of Audio-Video IP Transmission over Cross-Layer Designed Wireless Ad Hoc Networks

    Science.gov (United States)

    Nunome, Toshiro; Tasaka, Shuji; Nakaoka, Ken

    This paper performs application-level QoS and user-level QoS assessment of audio-video streaming in cross-layer designed wireless ad hoc networks. In order to achieve high QoS at the user-level, we employ link quality-based routing in the network layer and media synchronization control in the application layer. We adopt three link quality-based routing protocols: OLSR-SS (Signal Strength), AODV-SS, and LQHR (Link Quality-Based Hybrid Routing). OLSR-SS is a proactive routing protocol, while AODV-SS is a reactive one. LQHR is a hybrid protocol, which is a combination of proactive and reactive routing protocols. For applicationlevel QoS assessment, we performed computer simulation with ns-2 where an IEEE 802.11b mesh topology network with 24 nodes was assumed. We also assessed user-level QoS by a subjective experiment with 30 assessors. From the assessment results, we find AODV-SS the best for networks with long inter-node distances, while LQHR outperforms AODV-SS for short inter-node distances. In addition, we also examine characteristics of the three schemes with respect to the application-level QoS in random topology networks.

  20. A synthesizing control model of networked control systems to guarantee QoP and QoS

    Institute of Scientific and Technical Information of China (English)

    Jun KANG; Guanzhong DAI

    2008-01-01

    The whole performance of the networked control system(NCSs)depends on two interaction factors.namely the quality of control performance(QoP)and quality of network service(QoS).So,to optimize the whole performance of NCSs,the problem of guaranteeing QoP and QoS plays an important role in the design of NCSs.However,up to now,little work has been done in this field.In this paper, a synthesizing control model of NCSs to guarantee QoP and QoS is proposed,and a feasible condition of optimizing whole performance of NCSs is also suggested.Finally,the simulation results show that the proposed model is effective.

  1. A Network QoS Framework for Real-time Event Systems in highly Mobile Ad-hoc Environments

    Directory of Open Access Journals (Sweden)

    H.A. Duran-Limon

    2014-06-01

    Full Text Available A new class of applications can now be envisaged with the emergence of both mobile ad hoc computing and ubiquitous computing, which imposes a number of new unsolved challenges. Examples of such applications include automatic car control systems and air traffic control systems. Applications of such kind have real-time constraints and are characterised by being highly mobile and proactive, i.e. able to operate without human intervention. Moreover, this kind of applications requires multiple-source multicasting. However, current approaches mainly focus on offering support for continuous flows in low mobile environments where single-source multicasting is assumed. In this paper, we present the QoSMMANET (QoS Management in Mobile Ad hoc Networks framework, which offers QoS support for real-time event systems in highly mobile ad hoc environments. Our approach is validated by a number of experiments carried out in the ns-2 network simulator.

  2. Simulation of the new MANET integration model of QoS and security as a one parameter in OPNET

    Directory of Open Access Journals (Sweden)

    PAPAJ Ján

    2010-10-01

    Full Text Available In mobile ad hoc network (MANET, theQoS and Security are essentials to satisfy thecommunication constraints and requirements. Currenttrends in the field of providing new services require theproviding of services with QoS and security together.In this article, the simulation studies of the newdesigned model, which is used to integration of QoSand security as a one parameter in MANET, isdiscussed. Main parts of our model are modifiedsecurity service vector and cross layer design model.These two elements are used to interaction betweenuser and system and also to provide interactionbetween system´s elements. The new model enables thecooperation between QoS and security mechanisms.The OPNET modeler simulator is used to simulation ofthe new designed model.

  3. Late recurrence of medulloblastoma.

    Science.gov (United States)

    Stevens, Brittney; Razzaqi, Faisal; Yu, Lolie; Craver, Randall

    2008-01-01

    We present a child with a cerebellar medulloblastoma, diagnosed at age three, treated with near total surgical resection, radiotherapy, and chemotherapy, that recurred 13 years after the initial diagnosis. This late recurrence exceeds the typical 10-year survival statistics that are in common use, and exceeds the Collins rule. Continued follow-up of these children is justified to increase the likelihood of detecting these late recurrences early and to learn more about these late recurrences.

  4. A Distributed Continua AHD System with ZigBee/PAN-IF Gateway and Continua QoS Control Mechanism

    Directory of Open Access Journals (Sweden)

    William T. Lin

    2012-07-01

    Full Text Available In a residential or nursing home environment, using ZigBee/802.15.4 wireless network specifically to collect and gather various types of personal health data proves to be a feasible choice. The Continua Guidelines has defined both the sensor-LAN IF (sensor Local Area Network Interface PHD (Personal Health Device and PAN IF (Personal Area Network Interface PHD, but only a Continua certified sensor-LAN IF PHD with Zigbee HC (Health Care profile can connect with Continua AHD (Application Hosting Device through Zigbee/802.15.4 network and allows data communicating between AHD and PHDs. In this paper, we present a distributed Continua AHD system design that divides the AHD device containing Continua PAN IF into Continua AHD Host and Continua AHD Gateway with communication through ZigBee/802.15.4 network. Under this structure, a Continua PHD connects with a Continua AHD Host through Continua AHD Gateway within ZigBee/802.15.4 network. One immediate advantage of the proposed system is that both of the Continua sensor-LAN IF and PAN IF PHDs can connect with Continua AHD (Host through ZigBee/802.15.4 network. To further address the QoS (Quality of Service issue for Continua PAN IF message transmission in a ZigBee network, we present a software approach to automatically determine the types of packet transmitted and execute Continua QoS control. Together with the QoS mechanism in the enhanced ZigBee MAC Layer, this approach realizes a complete Continua QoS control mechanism for the distributed AHD system.

  5. QoS support for end users of I/O-intensive applications using shared storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Marion Kei [Los Alamos National Laboratory; Zhang, Xuechen [WAYNE STATE UNIV; Jiang, Song [WAYNE STATE UNIV.

    2011-01-19

    I/O-intensive applications are becoming increasingly common on today's high-performance computing systems. While performance of compute-bound applications can be effectively guaranteed with techniques such as space sharing or QoS-aware process scheduling, it remains a challenge to meet QoS requirements for end users of I/O-intensive applications using shared storage systems because it is difficult to differentiate I/O services for different applications with individual quality requirements. Furthermore, it is difficult for end users to accurately specify performance goals to the storage system using I/O-related metrics such as request latency or throughput. As access patterns, request rates, and the system workload change in time, a fixed I/O performance goal, such as bounds on throughput or latency, can be expensive to achieve and may not lead to a meaningful performance guarantees such as bounded program execution time. We propose a scheme supporting end-users QoS goals, specified in terms of program execution time, in shared storage environments. We automatically translate the users performance goals into instantaneous I/O throughput bounds using a machine learning technique, and use dynamically determined service time windows to efficiently meet the throughput bounds. We have implemented this scheme in the PVFS2 parallel file system and have conducted an extensive evaluation. Our results show that this scheme can satisfy realistic end-user QoS requirements by making highly efficient use of the I/O resources. The scheme seeks to balance programs attainment of QoS requirements, and saves as much of the remaining I/O capacity as possible for best-effort programs.

  6. Recurrent intracerebral hemorrhage

    Institute of Scientific and Technical Information of China (English)

    Shen jinsong; Lu jianhong

    2000-01-01

    Objective: In order to study the clinical manifestation and risk factor of recurrent intracerebral hemorrhage(ICH).Methods:The 256 patients were analysed who admitted to our hospital for intracerebral hemorrhage between 1995 and 1997.The 15(5 .86%)patients had a recurrent ICH.There were 9 men and 6 women and the mean age of the patients was 63.5 ± 6.4years at the first bleeding episode and 67.8± 8. 5 years at the second. The mean interval between the two bleeding episodes was 44.6 ± 12.5 months. The 73.3%patients were hypertensive .′The site of the first hemorrhage was ganglionic in 8 patients , ]ohar in six paients and brainstem in one .The recurrent hemorrhage occurred at a different location from the previous ICH.The most common pattern of recurrence was “ganglionic -ganglionic” (7 patients), lobar - ganglionic (3 patients), lobar-lobar(three patients), which was always observed in hypertensive patients. The outcome after the recurrent hemorrhage was usually poor. By comparison with 24 patients followed up to average 47.5± 18.7 months with isolated ICH without recurrence .Only lobar hematoma and a younger age were risk factors for recurrences whereas sex and previous hypertension were not. The mechanism of recurrence of ICH were multiple(hypertension, cerebral amyloid angiopathy).Contral of blood pressure and good living habit after the first hemorrhage may prevent ICH recurrences.

  7. Optimal Recurrence Grammars

    CERN Document Server

    Graben, Peter beim; Fröhlich, Flavio

    2015-01-01

    We optimally estimate the recurrence structure of a multivariate time series by Markov chains obtained from recurrence grammars. The goodness of fit is assessed with a utility function derived from the stochastic Markov transition matrix. It assumes a local maximum for the distance threshold of the optimal recurrence grammar. We validate our approach by means of the nonlinear Lorenz system and its linearized stochastic surrogates. Finally we apply our optimization procedure to the segmentation of neurophysiological time series obtained from anesthetized animals. We propose the number of optimal recurrence domains as a statistic for classifying an animals' state of consciousness.

  8. Recurrent Takotsubo Cardiomyopathy Related to Recurrent Thyrotoxicosis.

    Science.gov (United States)

    Patel, Keval; Griffing, George T; Hauptman, Paul J; Stolker, Joshua M

    2016-04-01

    Takotsubo cardiomyopathy, or transient left ventricular apical ballooning syndrome, is characterized by acute left ventricular dysfunction caused by transient wall-motion abnormalities of the left ventricular apex and mid ventricle in the absence of obstructive coronary artery disease. Recurrent episodes are rare but have been reported, and several cases of takotsubo cardiomyopathy have been described in the presence of hyperthyroidism. We report the case of a 55-year-old woman who had recurrent takotsubo cardiomyopathy, documented by repeat coronary angiography and evaluations of left ventricular function, in the presence of recurrent hyperthyroidism related to Graves disease. After both episodes, the patient's left ventricular function returned to normal when her thyroid function normalized. These findings suggest a possible role of thyroid-hormone excess in the pathophysiology of some patients who have takotsubo cardiomyopathy.

  9. Fairness Time-Slot Allocation and Scheduling with QoS Guarantees in Multihop WiMAX Mesh Networks

    Directory of Open Access Journals (Sweden)

    Chien-Yu Wu

    2013-01-01

    Full Text Available The WiMAX technology has been defined to provide high throughput over long distance communications and support the quality of service (QoS control applied on different applications. This paper studies the fairness time-slot allocation and scheduling problem for enhancing throughput and guaranteeing QoS in multihop WiMAX mesh networks. For allocating time slots to multiple subscribe stations (SSs, fairness is a key concern. The notion of max-min fairness is applied as our metric to define the QoS-based max-min fair scheduling problem for maximizing the minimum satisfaction ratio of each SS. We formulate an integer linear programming (ILP model to provide an optimal solution on small-scale networks. For large-scale networks, several heuristic algorithms are proposed for better running time and scalability. The performance of heuristic algorithms is compared with previous methods in the literatures. Experimental results show that the proposed algorithms are better in terms of QoS satisfaction ratio and throughput.

  10. The Impact of QoS Constraints on the Energy Efficiency of Fixed-Rate Wireless Transmissions

    CERN Document Server

    Qiao, Deli; Velipasalar, Senem

    2008-01-01

    Transmission over wireless fading channels under quality of service (QoS) constraints is studied when only the receiver has channel side information. Being unaware of the channel conditions, transmitter is assumed to send the information at a fixed rate. Under these assumptions, a two-state (ON-OFF) transmission model is adopted, where information is transmitted reliably at a fixed rate in the ON state while no reliable transmission occurs in the OFF state. QoS limitations are imposed as constraints on buffer violation probabilities, and effective capacity formulation is used to identify the maximum throughput that a wireless channel can sustain while satisfying statistical QoS constraints. Energy efficiency is investigated by obtaining the bit energy required at zero spectral efficiency and the wideband slope in both wideband and low-power regimes assuming that the receiver has perfect channel side information (CSI). In both wideband and low-power regimes, the increased energy requirements due to the presenc...

  11. Cross Layer QoS Support Architecture with Integrated CAC and Scheduling Algorithms for WiMAX BWA Networks

    CERN Document Server

    Chowdhury, Prasun; Sanyal, Salil K

    2012-01-01

    In this paper, a new technique for cross layer design, based on present Eb/N0 (bit energy per noise density) ratio of the connections and target values of the Quality of Service (QoS) information parameters from MAC layer, is proposed to dynamically select the Modulation and Coding Scheme (MCS) at the PHY layer for WiMAX Broadband Wireless Access (BWA) networks. The QoS information parameter includes New Connection Blocking Probability (NCBP), Hand off Connection Dropping Probability (HCDP) and Connection Outage Probability (COP). In addition, a Signal to Interference plus Noise Ratio (SINR) based Call Admission Control (CAC) algorithm and Queue based Scheduling algorithm are integrated for the cross layer design. An analytical model using the Continuous Time Markov Chain (CTMC) is developed for performance evaluation of the algorithms under various MCS. The effect of Eb/No is observed for QoS information parameters in order to determine its optimum range. Simulation results show that the integrated CAC and p...

  12. Context Aware Adaptive Service based Dynamic Channel Allocation Approach for Providing an Optimal QoS over MANET

    Directory of Open Access Journals (Sweden)

    A. Ayyasamy

    2014-07-01

    Full Text Available Large variations in network Quality of Service (QoS in terms of bandwidth, latency and jitter may occur during media transfer over mobile ad-hoc networks. Applications need to adapt their functionality according to dynamic change of their QoS update. This paper proposes an enhanced service based platform to provide adaptive network management services to higher level application layer components. The Context Aware Adaptive Service (COAAS is a middleware architecture for service adaptation based on ad hoc network and service awareness. COAAS is structured in such a way that it can provide QoS awareness to streaming applications as well manage dynamic ad hoc network resources using an adaptive channel allocation approach. The overall architecture of COAAS framework includes core components to connection establishment, connection monitor, connection controller and policy manager. Adaptive channel allocation defined as object based component helps in dynamic binding during run time implemented using JXTA and J2ME using CDC [15] toolkit to demonstrate the performance of a mobile setup as a conference application.

  13. Optimization of Quality of Service (QoS framework for highway based Vehicular Ad-hoc Networks (VANETs

    Directory of Open Access Journals (Sweden)

    Wajahat Hussain

    2016-02-01

    Full Text Available The Vehicular Ad-hoc Network is a novel technology. It has the property of higher node mobility. Vehicular Adhoc networks offer wireless communications between vehicles themselves (V2V and between vehicles to the roadside units (V2R. The VANET is an active research area, as it has great prospective to enhance the road and vehicle safety, efficiency of traffic. Vehicular Ad-hoc Network not only just provides the safety applications, but also provides communication to the users. The QoS support in VANET is a challenge when the existing routing paths become no longer are available as a result of changes in the velocity and position of node, and distance between the vehicular nodes or network topology. In this study we designed a framework which provides us the facility to enhance various Quality of Service parameters, such as End to End Delay, throughput and packet loss ratio etc. The proposed model uses layered approach, deep classification as existed QoS components are further broken down and provides Quality of Experience to the users. NCTUns is used as simulation tool to build up simulations. After getting the results of simulation we carried out the performance analysis of various routing protocols. The simulation results indicate that the proposed scheme provides much better performance in terms of various QoS parameters like End to End Delay, throughput and packet loss ratio.

  14. 云计算下负载均衡的多维 QoS 约束任务调度机制%Multi-dimensional QoS constrained scheduling mechanism based on load balancing for cloud computing

    Institute of Scientific and Technical Information of China (English)

    祝家钰; 肖丹; 王飞

    2013-01-01

    In cloud, the needs of the user’s QoS can be better met and the load balancing between physical hosts can be achieved depending on an efficient scheduling mechanism. The traditional scheduling mechanisms often concern only about the response time of tasks or security, and load balancing strategy is static. The overall performance of the cloud computing environ-ment needs to be improved. Based on the flexibility, virtualization and other new features of cloud computing, this paper proposes a task scheduling mechanism considering performance QoS and trust QoS of tasks. It uses virtual machine migration technology to achieve dynamic load balancing. Simulation by CloudSim2.1 shows the scheduling mechanism will not only improve satisfac-tion of customers but also achieve load balancing effectively.%  高效的任务调度机制能够更好地满足用户的 QoS 需求,实现各物理主机间的负载均衡,从而提高云计算环境的整体性能.而传统的任务调度往往只考虑任务的响应时间或安全性等,且负载均衡策略是静态的.根据云计算的弹性化和虚拟化等新特性,综合考虑任务的性能 QoS 和信任 QoS,提出一种在云计算环境下的任务调度机制,采用虚拟机迁移技术实现动态负载均衡.通过在 CloudSim2.1仿真环境下的分析和比较,该任务调度机制不但可以提高用户满意度,而且可以有效实现负载均衡.

  15. 基于“适应活性”的 QoS 组播路由算法%A QoS MULTICAST ROUTING ALGORITHM BASED ON ‘ADAPTIVE LIVING’

    Institute of Scientific and Technical Information of China (English)

    王帅; 朱磊; 俞璐; 林万里

    2016-01-01

    In special application scenarios such as the natural disasters and the wars,communication networks are difficult to provide stable services to users because it is prone to the effects of physical attacks and multi-constraints.Traditional QoS routing algorithms are based on steady network,they are no longer suitable under the condition of physical attacks and multi-constraints.Aiming at this problem,in the paper we put forward and calculate for the first time the ‘adaptive living’model to comprehensively measure the dynamic service performance of network nodes and their connecting links.Furthermore,by improving the ant colony optimisation algorithm we put forward an ‘adaptive living’-based QoS multicast routing algorithm.The algorithm can consider comprehensively the selection path of the link and the service performance of nodes in combination with the external environment,service requirements and network status,while inheriting the advantage of traditional ant colony optimisation,it solves the problem that the external environment affects the variation of node performance which in turn causes the path selection cannot reach QoS optimum.Result of simulation on MATLAB shows that the algorithm can keep away from low performance nodes when the networks performance varying,and can fast and effectively select QoS optimal path.%自然灾害、战争等特殊应用场景下通信网络易受到物理攻击和约束条件影响,难以为用户提供稳定服务。传统的 QoS 路由算法基于稳态网络,在物理攻击与多约束环境下难以适用。针对这一问题,首次提出并求解了“适应活性”模型以综合衡量节点及其相连链路的动态服务性能。进而通过改进蚁群算法,提出了基于“适应活性”的 QoS 组播路由算法。该算法能够结合外界环境、业务需求与网络状态,综合考虑链路与节点服务性能选择路径,在继承传统蚁群算法优点的同时,解决了外界环

  16. Recurrent Abdominal Pain

    Science.gov (United States)

    Banez, Gerard A.; Gallagher, Heather M.

    2006-01-01

    The purpose of this article is to provide an empirically informed but clinically oriented overview of behavioral treatment of recurrent abdominal pain. The epidemiology and scope of recurrent abdominal pain are presented. Referral process and procedures are discussed, and standardized approaches to assessment are summarized. Treatment protocols…

  17. The eternal recurrence today

    CERN Document Server

    Neves, J C S

    2015-01-01

    In this work we have carried out an approach between the nonsingular scientific cosmologies (without the initial singularity, the big bang), specially the cyclic models, and the Nietzsche's thought of the eternal recurrence. Moreover, we have pointed out reasons for the Nietzsche's search for scientific proofs about the eternal recurrence in the decade of 1880's.

  18. Recurrent aphthous stomatitis

    Directory of Open Access Journals (Sweden)

    L Preeti

    2011-01-01

    Full Text Available Recurrent aphthous ulcers are common painful mucosal conditions affecting the oral cavity. Despite their high prevalence, etiopathogenesis remains unclear. This review article summarizes the clinical presentation, diagnostic criteria, and recent trends in the management of recurrent apthous stomatitis.

  19. Acute recurrent polyhydramnios

    DEFF Research Database (Denmark)

    Rode, Line; Bundgaard, Anne; Skibsted, Lillian

    2007-01-01

    Acute recurrent polyhydramnios is a rare occurrence characterized by a poor fetal outcome. This is a case report describing a 34-year-old woman presenting with acute recurrent polyhydramnios. Treatment with non-steroidal anti-inflammatory drugs (NSAID) and therapeutic amniocenteses was initiated ...

  20. Ananalysis on Runtime Associated QOS-Based Proficient Web Services Discovery Optimization

    Directory of Open Access Journals (Sweden)

    A. Amirthasaravanan

    Full Text Available ABSTRACT In today's web world, Service-oriented architectures represent the main standard for IT infrastructures. Certainly, with the initiation of service oriented architecture, Web services have gained incredible growth. Web service discovery has become increasingly more significant as the existing use of web service. Discovering most appropriate web service from vast collection of web services is very decisive for successful execution of applications. In automation of web service discovery, there is always a need to deem Quality of Service (QoS attributes during matching. A study of literature concerning the evolution of different web service discovery optimization methods with unique prominence to quality motivated service discovery have been carried out in this work. This paper depicts Bio-inspired algorithms optimizing the discovery process for semantic web services. Bio-inspired algorithm is a metaheuristics method that mimics the nature in order to unravel optimization difficulty and evaluates the analysis of some popular bio-inspired optimization algorithm systematically. This paper also focused on the principle of each algorithm and their application with respect to run time oriented QoSattributes and from result the best suitable bio-inspired optimization algorithm is been deployed.

  1. Intelligent QoS routing algorithm based on improved AODV protocol for Ad Hoc networks

    Science.gov (United States)

    Huibin, Liu; Jun, Zhang

    2016-04-01

    Mobile Ad Hoc Networks were playing an increasingly important part in disaster reliefs, military battlefields and scientific explorations. However, networks routing difficulties are more and more outstanding due to inherent structures. This paper proposed an improved cuckoo searching-based Ad hoc On-Demand Distance Vector Routing protocol (CSAODV). It elaborately designs the calculation methods of optimal routing algorithm used by protocol and transmission mechanism of communication-package. In calculation of optimal routing algorithm by CS Algorithm, by increasing QoS constraint, the found optimal routing algorithm can conform to the requirements of specified bandwidth and time delay, and a certain balance can be obtained among computation spending, bandwidth and time delay. Take advantage of NS2 simulation software to take performance test on protocol in three circumstances and validate the feasibility and validity of CSAODV protocol. In results, CSAODV routing protocol is more adapt to the change of network topological structure than AODV protocol, which improves package delivery fraction of protocol effectively, reduce the transmission time delay of network, reduce the extra burden to network brought by controlling information, and improve the routing efficiency of network.

  2. QoS Differentiated and Fair Packet Scheduling in Broadband Wireless Access Networks

    Directory of Open Access Journals (Sweden)

    Zhang Yan

    2009-01-01

    Full Text Available This paper studies the packet scheduling problem in Broadband Wireless Access (BWA networks. The key difficulties of the BWA scheduling problem lie in the high variability of wireless channel capacity and the unknown model of packet arrival process. It is difficult for traditional heuristic scheduling algorithms to handle the situation and guarantee satisfying performance in BWA networks. In this paper, we introduce learning-based approach for a better solution. Specifically, we formulate the packet scheduling problem as an average cost Semi-Markov Decision Process (SMDP. Then, we solve the SMDP by using reinforcement learning. A feature-based linear approximation and the Temporal-Difference learning technique are employed to produce a near optimal solution of the corresponding SMDP problem. The proposed algorithm, called Reinforcement Learning Scheduling (RLS, has in-built capability of self-training. It is able to adaptively and timely regulate its scheduling policy according to the instantaneous network conditions. Simulation results indicate that RLS outperforms two classical scheduling algorithms and simultaneously considers: (i effective QoS differentiation, (ii high bandwidth utilization, and (iii both short-term and long-term fairness.

  3. Enabling Broadband as Commodity within Access Networks: A QoS Recipe

    Science.gov (United States)

    Areizaga, Enrique; Foglar, Andreas; Elizondo, Antonio J.; Geilhardt, Frank

    This paper describes the QoS features that will transform the access networks landscape in order to bring “Broadband” as a commodity while setting up the pillars of the “Future Media Internet”. Quality of Experience is obviously key for emerging and future services. Broadcasting services will first need to equal the QoE of their counterparts in the Open-air market (for IP-TV examples would be artifact-free, no picture freezing, fast zapping times) and offer new features often using interactivity (Time-shifted TV, access to more content, 3DTV with feeling of presence). The huge variety of communications alternatives will lead to different requirements per customer, whose needs will also be dependent on parameters like where the connection is made, the time of the day/day of the week/period of the year or even his/her mood. Today’s networks, designed for providing just Broadband connectivity, will not be enough to satisfy customer’s needs and will necessarily support the introduction of new and innovative services. The Networks of the future should learn from the way the users are communicating, what services they are using, where, when, and how, and adapt accordingly.

  4. Network on Chip: a New Approach of QoS Metric Modeling Based on Calculus Theory

    CERN Document Server

    Nasri, Salem

    2011-01-01

    A NoC is composed by IP cores (Intellectual Propriety) and switches connected among themselves by communication channels. End-to-End Delay (EED) communication is accomplished by the exchange of data among IP cores. Often, the structure of particular messages is not adequate for the communication purposes. This leads to the concept of packet switching. In the context of NoCs, packets are composed by header, payload, and trailer. Packets are divided into small pieces called Flits. It appears of importance, to meet the required performance in NoC hardware resources. It should be specified in an earlier step of the system design. The main attention should be given to the choice of some network parameters such as the physical buffer size in the node. The EED and packet loss are some of the critical QoS metrics. Some real-time and multimedia applications bound up these parameters and require specific hardware resources and particular management approaches in the NoC switch. A traffic contract (SLA, Service Level Ag...

  5. Data Sharing in a File Structured QoS Aware Peer-To-Peer System

    Directory of Open Access Journals (Sweden)

    A. Samydurai

    2014-05-01

    Full Text Available The Peer-to-Peer system has the potential capacity in building an efficient unified network structure for location based secure data transfer with information sharing and minimizing the failure factor. In this study we define the data transfer with certain futuristic characters that will provide data sharing strength for the users to understand the efficiency with which the data reaches the end node or users. For this purpose we have used specific QoS metric tools like, bandwidth, lookup time, delay, response time and trip time that will help in data sharing. This study concentrates on the search operation on the P2P network for data retrieval. Replication strategy is used in order to increase the probability of successful search. The lookup search employed in this regard uses two type of search namely ring and binary search. The efficiency aspect of data transfer in this study raises the importance of the system compared with the earlier system. The performance analysis will clearly chat out the quality of this system of data sharing and searching. Evaluations have shown a positive sign in the functioning of the proposed system.

  6. On QoS guarantee in MPLS network with software deadline awareness

    Science.gov (United States)

    Gao, Yu; Jin, Yaohui; Cheng, Hong; Yu, Yingdi; Sun, Weiqiang; Guo, Wei; Hu, Weisheng

    2007-11-01

    With the increasing number of internet users, more and more real-time services are added into the network, such as IPTV, online-video, Voice over IP, etc. As we know, throughput is a highly important performance criterion for scheduling algorithms of networks. Besides throughput, these growing real-time services are very sensitive to delay variance termed as jitter. Therefore, high performance scheduling algorithm should achieve good performance in terms of throughput, delay, jitter and fairness together. Scheduling algorithm with deadline-awareness employed in packet switching plays a key role in QoS guarantees. Although traditional hard-deadline can provide guarantee on in-node delay-deadline criteria, the end-to-end delay-deadline criteria cannot be guaranteed due to the characteristic of hard-deadline, while the delay-deadline guaranteed throughput is low. Thus, soft-deadline scheduling algorithm has been proposed. In this paper, we investigate and compare the classical hard-deadline and soft-deadline switching algorithm. A new scheme "Bonus System" is proposed in order to realize the idea of soft-deadline switching algorithm. Bonus System based on soft-deadline is compared with classical Early-Deadline First scheme based on hard-deadline, which shows that Bonus System has better performance in End-to-End deadline guarantee.

  7. Ephedrine QoS: An Antidote to Slow, Congested, Bufferless NoCs

    Directory of Open Access Journals (Sweden)

    Juan Fang

    2014-01-01

    Full Text Available Datacenters consolidate diverse applications to improve utilization. However when multiple applications are colocated on such platforms, contention for shared resources like networks-on-chip (NoCs can degrade the performance of latency-critical online services (high-priority applications. Recently proposed bufferless NoCs (Nychis et al. have the advantages of requiring less area and power, but they pose challenges in quality-of-service (QoS support, which usually relies on buffer-based virtual channels (VCs. We propose QBLESS, a QoS-aware bufferless NoC scheme for datacenters. QBLESS consists of two components: a routing mechanism (QBLESS-R that can substantially reduce flit deflection for high-priority applications and a congestion-control mechanism (QBLESS-CC that guarantees performance for high-priority applications and improves overall system throughput. We use trace-driven simulation to model a 64-core system, finding that, when compared to BLESS, a previous state-of-the-art bufferless NoC design, QBLESS, improves performance of high-priority applications by an average of 33.2% and reduces network-hops by an average of 42.8%.

  8. Ephedrine QoS: an antidote to slow, congested, bufferless NoCs.

    Science.gov (United States)

    Fang, Juan; Yao, Zhicheng; Sui, Xiufeng; Bao, Yungang

    2014-01-01

    Datacenters consolidate diverse applications to improve utilization. However when multiple applications are colocated on such platforms, contention for shared resources like networks-on-chip (NoCs) can degrade the performance of latency-critical online services (high-priority applications). Recently proposed bufferless NoCs (Nychis et al.) have the advantages of requiring less area and power, but they pose challenges in quality-of-service (QoS) support, which usually relies on buffer-based virtual channels (VCs). We propose QBLESS, a QoS-aware bufferless NoC scheme for datacenters. QBLESS consists of two components: a routing mechanism (QBLESS-R) that can substantially reduce flit deflection for high-priority applications and a congestion-control mechanism (QBLESS-CC) that guarantees performance for high-priority applications and improves overall system throughput. We use trace-driven simulation to model a 64-core system, finding that, when compared to BLESS, a previous state-of-the-art bufferless NoC design, QBLESS, improves performance of high-priority applications by an average of 33.2% and reduces network-hops by an average of 42.8%.

  9. Bandwidth constrained QoS routing scheme for MPLS traffic engineering

    Institute of Scientific and Technical Information of China (English)

    李震宇; 张中兆

    2004-01-01

    Traffic engineering has been essential to optimize the utilization of network resource and to provide for QoS,QoS routing is a basic component of traffic engineering in MPLS networks. Aiming at some shortages of certain existing routing algorithms, we propose an efficient bandwidth constrained QoS routing scheme with additional traffic engineering objectives. The objectives of traffic engineering considered in our algorithm are to reduce the blocking probability of requests and to evenly distribute the traffic load. Accordingly, the algorithm avoids using critical links as far as possible by assigning large weights to them as a function of their criticality. The critical links can be specified according to max-flow reduction weight, a new link weight introduced by the algorithm. Then, a new defined additive metric, path saturation,is used to select optimal path. Extensive simulations are carried out to evaluate the performance of the proposed algorithm in terms of call blocking probability and link resource utilization. Compared to other several routing algorithms, the simulation results show the new algorithm performs well.

  10. Unified study of Quality of Service (QoS) in OPS/OBS networks

    Science.gov (United States)

    Hailu, Dawit Hadush; Lema, Gebrehiwet Gebrekrstos; Yekun, Ephrem Admasu; Kebede, Samrawit Haylu

    2017-07-01

    With the growth of Internet traffic, an inevitable use of optical networks provide a large bandwidth, fast data transmission rates and Quality of Service (QoS) support. Currently, Optical Burst Switched (OBS)/Optical Packet Switched (OPS) networks are under study as future solutions for addressing the increase demand of Internet traffic. However, due to their high blocking probability in the intermediate nodes they have been delayed in the industries. Packet loss in OBS/OPS networks is mainly occur due to contention. Hence, the contribution of this study is to analyze the file loss ratio (FLR), packet overhead and number of disjoint paths, and processing delay over Coded Packet Transport (CPT) scheme for OBS/OPS network using simulation. The simulations show that CPT scheme reduces the FLR in OBS/OPS network for the evaluated scenarios since the data packets are chopped off into blocks of the data packet for transmission over a network. Simulation results for secrecy and survivability are verified with the help of the analytical model to define the operational range of CPT scheme.

  11. Modified Opportunistic Deficit Round Robin Scheduling for improved QOS in IEEE 802.16 WBA networks

    CERN Document Server

    Chakravarthy, C Kalyana

    2009-01-01

    Packet and flow scheduling algorithms for WiMAX has been a topic of interest for a long time since the very inception of WiMAX networks. WiMAX offers advantages particularly in terms of Quality of service it offers over a longer range at the MAC level. In our work, we propose two credit based scheduling schemes one in which completed flows distributes the left over credits equally to all higher priority uncompleted flows(ODRREDC) and another in which completed flows give away all the excess credits to the highest priority uncompleted flow(ODRRSDC). Both the schemes are compatible with 802.16 MAC protocol and can efficiently serve real time bursty traffic with reduced latency and hence improved QOS for real time flows. We compare the two proposed schemes for their latency, bandwidth utilization and throughput for real time burst flows with the opportunity based Deficit Round Robin scheduling scheme. While the ODRR scheduler focuses on reducing the credits for the flows with errors, our approach also distribute...

  12. Study of Network on Chip resources allocation for QoS Management

    Directory of Open Access Journals (Sweden)

    Abdelhamid HELALI

    2006-01-01

    Full Text Available The increasing complexity of integrated circuits and application requirements drive the research of new on-chip interconnection architectures. A network on chip draws on concepts inherited from distributed systems and computer networks subject areas to interconnect IP cores in a structured and scalable way. The main goal pursued is to achieve superior bandwidth when compared to conventional on-chip bus architectures. The complexity of Systems-on-Chip (SoC is growing; meeting real-time requirements is becoming increasingly difficult. Predictability for computation, memory and communication components are needed to build up real-time SoC. To achieve guaranteed throughput and bounded delivery delay, buffers in network interfaces (NIs must be dimensioned to hide round-trip latency and rate difference between computation and IPs communication.. It is crucial to shape these buffers according to the network requirements and to bring out the right specification before the design step to provide desired performances in the SoC. In this field this paper describes and presents a performance analyses of NoC shaped on mesh architecture. The goal of this work is to quantify buffering requirements in the NoC nodes by the analyze of some QoS metrics such as drop, compute latency, and throughput. This study presented in this paper is based on simulation approach of a mesh (4 x 4 NoC behavior under multimedia communication process with MPEG-4 (Moving Picture Experts Group flows.

  13. QoS measurement of Zigbee home automation network using various modulation schemes

    Directory of Open Access Journals (Sweden)

    Gurjit Kaur,

    2011-02-01

    Full Text Available Increased demands on implementation of wireless sensor networks in automation praxis resulted in relatively new wireless standard – Zigbee. The IEEE 802.15.4 standard specifies the multiple PHYs for 868, 915 and 2400 MHz three frequency bands. In this paper we presents the performance analysis of different modulation schemesat different frequency range like ASK, BPSK and QPSK at 868, 915 & 2400 MHz based on their effect on the quality of service parameter by using CBR application in Zigbee home automation network using static IEEE 802.15.4. The QoS parameters such as average end-to-end delay, jitter, and throughput are investigated as the performance metrics. The results show that even though ASK at 868 MHz gives the highest throughput of 100% which is highest amongst all five modulation schemes but still overall ASK at 915 MHz is the best suited modulation schemes for CBR application of Zigbee home automation since it produced lowest jitter value of 0.03s and lowest average end-to-end delay value of 3.30s which are both favorable conditions for better performance of CBR application of Zigbee home automation network.

  14. ACCOUNTING PROVISIONS FOR VACATION PAY

    Directory of Open Access Journals (Sweden)

    Anna CEBOTARI

    2016-09-01

    Full Text Available In the presented article are proposed for examination theoretical aspects related to the notion of provision. The authors describe the method of calculation and accounting for provisions regarding the payment of leave.

  15. Dialysis provision in Malaysia.

    Science.gov (United States)

    Lim, T O; Lee, D G; Zaki, M

    2000-06-01

    We determined the provision for dialysis treatment in Malaysia. There were 181 dialysis centres as at 1st June 1999 (161 Haemodialysis (HD) and 20 Continuous Ambulatory Peritoneal Dialysis (CAPD) centres), providing treatment for 5614 patients. This is equivalent to an estimated prevalence rate of 253 patients per million population (pmp) and new dialysis acceptance rate of 49 patients pmp. Dialysis facilities were widely distributed throughout the country though rather unevenly among states. Penang, Selangor/KL, Malacca led with number of dialysis patients pmp ranging from 417 to 480. Kelantan and Sabah had the lowest provision with 51 and 64 patients pmp respectively. There were more centres and HD capacity in the private sector while the Non-Government Organisation and public sectors had about the same capacity. However the public sector had more patients on account of availability of CAPD and home HD services, as well as low HD capacity to patient ratio. The number ofcentres, HD capacity and patients have increased rapidly especially since 1991; the estimated growth rates were 16.5 centres/year, 658 capacity/year, and 392 patients/year respectively. There was also a trend toward increasing over-capacity in the private and NGO sectors. In conclusion, the level of dialysis provision is increasing, indicating increasing accessibility of dialysis treatment in Malaysia. Over-capacity is a concern in the private and NGO sectors. Thus funding agencies should be encouraged to source provision from those sectors. The public sector still has the crucial role of providing for under-served areas in the country.

  16. RESNA Wheelchair Service Provision Guide

    Science.gov (United States)

    Arledge, Stan; Armstrong, William; Babinec, Mike; Dicianno, Brad E.; Digiovine, Carmen; Dyson-Hudson, Trevor; Pederson, Jessica; Piriano, Julie; Plummer, Teresa; Rosen, Lauren; Schmeler, Mark; Shea, Mary; Stogner, Jody

    2011-01-01

    The purpose of the Wheelchair Service Provision Guide is to provide an appropriate framework for identifying the essential steps in the provision of a wheelchair. It is designed for use by all participants in the provision process including consumers, family members, caregivers, social service and health care professionals, suppliers,…

  17. Predictors of Recurrent AKI.

    Science.gov (United States)

    Siew, Edward D; Parr, Sharidan K; Abdel-Kader, Khaled; Eden, Svetlana K; Peterson, Josh F; Bansal, Nisha; Hung, Adriana M; Fly, James; Speroff, Ted; Ikizler, T Alp; Matheny, Michael E

    2016-04-01

    Recurrent AKI is common among patients after hospitalized AKI and is associated with progressive CKD. In this study, we identified clinical risk factors for recurrent AKI present during index AKI hospitalizations that occurred between 2003 and 2010 using a regional Veterans Administration database in the United States. AKI was defined as a 0.3 mg/dl or 50% increase from a baseline creatinine measure. The primary outcome was hospitalization with recurrent AKI within 12 months of discharge from the index hospitalization. Time to recurrent AKI was examined using Cox regression analysis, and sensitivity analyses were performed using a competing risk approach. Among 11,683 qualifying AKI hospitalizations, 2954 patients (25%) were hospitalized with recurrent AKI within 12 months of discharge. Median time to recurrent AKI within 12 months was 64 (interquartile range 19-167) days. In addition to known demographic and comorbid risk factors for AKI, patients with longer AKI duration and those whose discharge diagnosis at index AKI hospitalization included congestive heart failure (primary diagnosis), decompensated advanced liver disease, cancer with or without chemotherapy, acute coronary syndrome, or volume depletion, were at highest risk for being hospitalized with recurrent AKI. Risk factors identified were similar when a competing risk model for death was applied. In conclusion, several inpatient conditions associated with AKI may increase the risk for recurrent AKI. These findings should facilitate risk stratification, guide appropriate patient referral after AKI, and help generate potential risk reduction strategies. Efforts to identify modifiable factors to prevent recurrent AKI in these patients are warranted. Copyright © 2016 by the American Society of Nephrology.

  18. Recurrent Intracerebral Hemorrhage

    DEFF Research Database (Denmark)

    Schmidt, Linnea Boegeskov; Goertz, Sanne; Wohlfahrt, Jan;

    2016-01-01

    the use of any of the investigated medicines with antithrombotic effect (ATT, SSRI's, NSAID's) and recurrent ICH. CONCLUSIONS: The substantial short-and long-term recurrence risks warrant aggressive management of hypertension following a primary ICH, particularly in patients treated surgically...... treatment and renal insufficiency were associated with increased recurrence risks (RR 1.64, 95% CI 1.39-1.93 and RR 1.72, 95% CI 1.34-2.17, respectively), whereas anti-hypertensive treatment was associated with a reduced risk (RR 0.82, 95% CI 0.74-0.91). We observed non-significant associations between...

  19. RECURRENT CROUP IN CHILDREN

    Directory of Open Access Journals (Sweden)

    S. L. Piskunova

    2014-01-01

    Full Text Available The article presents the results of examination of 1849 children, entering children's infectioushospitalofVladivostokwith the clinical picture of croup of viral etiology. The clinical features of primary and recurrent croup are described. Frequency of recurrent croup inVladivostokis 8%. Children with a recurrent croup had the burdened premorbid background, and also persistent herpetic infections (cytomegalic infection in 42,9% cases, cytomegalic infection in combination with the herpes simplex virus -1. Frequency of croups substantially rose in the period of epidemic of influenza.

  20. A Management Framework for Web Service QoS Based on WSDL%一种基于WSDL的Web服务QoS管理框架

    Institute of Scientific and Technical Information of China (English)

    李璐

    2014-01-01

    随着Internet的发展,Web服务得到广泛应用,如何选择满足用户非功能性需求的Web服务是其中的一个重要问题。基于此,提出一种基于WSDL的Web服务QoS管理框架,引入多维QoS对Web服务的QoS需求进行全面分析,定义Web服务的多维QoS属性,并在此基础上基于WSDL实现了Web服务的QoS管理框架。%With the development of Internet, web service is used widely. How to choose the web service which can satisfy the non-functional requirement of users is an important problem in web service. To address this problem, a management framework for web service QoS based on WSDL is presented. It introduces multi-dimension QoS to analyse the QoS requirement of web service and define multi-dimension QoS properties of web service. On the basis of this, this paper achieves a management frame-work for web service QoS based on WSDL.

  1. QoS Algorithms in Hierarchical IPv4 Network%层次型IPv4网络QoS算法

    Institute of Scientific and Technical Information of China (English)

    蒋建峰

    2014-01-01

    Hierarchical IPv4 networks put forward higher requirements for the quality of service. This paper analyzes the advantages, disadvantages and the application environment of the traditional QoS architecture based on business according to the second layer and the third layer of the OSI reference model. Then a QoS algorithm integrated differentiated service model with integrated service model is designed to enhance the QoS of a hierarchical network. The simulation results prove that the model can improve the network’s QoS in many aspects such as packet loss rate, transmission delay, delay jitter and network throughput.%网络服务质量 QoS 在层次型网络中要求更高.从 OSI 参考模型的第二层与第三层出发,分析了传统的QoS体系结构和三种QoS模型的工作原理、优缺点以及网络应用环境.设计了将IntServ与DiffServ模型相结合的互补算法来保证层次型网络的服务质量.仿真结果表明,此模型能够从传输延迟、丢包率、延时抖动和网络吞吐量等多个方面提升网络的QoS.

  2. Recurrent Breast Cancer

    Science.gov (United States)

    ... that can help you cope with distress include: Art therapy Dance or movement therapy Exercise Meditation Music ... mayoclinic.org/diseases-conditions/recurrent-breast-cancer/basics/definition/CON-20032432 . Mayo Clinic Footer Legal Conditions and ...

  3. Multifocal recurrent periostitis

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, K.; Anderson, R.; Tink, A.

    1981-11-01

    Two case reports of recurrent multifocal periostitis in two girls aged 15 and 16 are added to the eight cases already reported in the literature. The disease is characterised clinically by recurrent mesomelic swelling of the extremities and radiologically by periosteal thickening and sclerosis of underlying bone. Hyperglobulinaemia is the most constant biochemical finding. The bone biopsy shows no typical features. The possibility of a viral etiology is discussed.

  4. Recurrences of strange attractors

    Indian Academy of Sciences (India)

    E J Ngamga; A Nandi; R Ramaswamy; M C Romano; M Thiel; J Kurths

    2008-06-01

    The transitions from or to strange nonchaotic attractors are investigated by recurrence plot-based methods. The techniques used here take into account the recurrence times and the fact that trajectories on strange nonchaotic attractors (SNAs) synchronize. The performance of these techniques is shown for the Heagy-Hammel transition to SNAs and for the fractalization transition to SNAs for which other usual nonlinear analysis tools are not successful.

  5. Trust Based Scheme for QoS Assurance in Mobile Ad-Hoc Networks

    Directory of Open Access Journals (Sweden)

    Sridhar Subramanian

    2012-02-01

    Full Text Available A mobile ad-hoc network (MANET is a peer-to-peer wireless network where nodes can communicate with each other without the use of infrastructure such as access points or base stations. These networks are self-configuring, capable of self-directed operation and hastily deployable. Nodes cooperate to provide connectivity, operates without centralized administration. Nodes are itinerant, topology can be very dynamic and nodes must be able to relay traffic since communicating nodes might be out of range. The dynamic nature of MANET makes network open to attacks and unreliability. Routing is always the most significant part for any networks. Each node should not only work for itself, but should be cooperative with other nodes. Node misbehaviour due to selfish or malicious intention could significantly degrade the performance of MANET. The Qos parameters like PDR, throughput and delay are affected directly due to such misbehaving nodes. We focus on trust management framework, which is intended to cope with misbehaviour problem of node and increase the performance of MANETs. A trust-based system can be used to track this misbehaving of nodes, spot them and isolate them from routing and provide reliability. In this paper a Trust Based Reliable AODV [TBRAODV] protocol is presented which implements a trust value for each node. For every node trust value is calculated and based trust valuenodes are allowed to participate in routing or else identified to become a misbehaving node. This enhances reliability in AODV routing and results in increase of PDR, decrease in delay and throughput is maintained. This work is implemented and simulated on NS-2. Based on simulation results, the proposed protocol provides more consistent and reliable data transfer compared with general AODV, if there are misbehaving nodes in the MANET.

  6. QoS Assertion in MANET Routing based on Trusted AODV (ST-AODV

    Directory of Open Access Journals (Sweden)

    Sridhar Subramanian

    2012-06-01

    Full Text Available Mobile ad hoc network is a standalone network capab le of autonomous operation where nodes communicate with each other without the need of any existing infrastructure. They are self configuring , autonomous, quickly deployable and operate without infrastructure. Mobile ad hoc networks consist of nodes that cooperate to provide connectivity and ar e free to move and organize randomly. Every node is router or an end host, in general autonomous and sh ould be capable of routing traffic as destination nodes sometimes might be out of range. Nodes are mo bile since topology is very dynamic and they have limited energy and computing resources . These nodes are often vulnerable to failure thus m aking mobile ad hoc networks open to threats and attacks. Commun ication in MANET relies on mutual trust between the participating nodes but the features of MANET m ake this hard. Nodes sometimes fail to transmit and start dropping packets during the transmission. Suc h nodes are responsible for untrustworthy routing. A trust based scheme can be used to track these untru stworthy nodes and isolate them from routing, thus provide trustworthiness. In this paper a trusted AO DV (ST-AODV protocol is presented which assigns a trust value for each node. Nodes are allowed to par ticipate in routing based on their trust values. A threshold value is assigned and if the nodes trust value is greater than this value its marked as trustworthy node and allowed to participate in rout ing else the node is marked untrustworthy. The ST- AODV increases PDR and decreases delay thereby enha ncing the QoS metrics and trustworthiness in AODV based MANET routing. The work is implemented a nd simulated on NS-2. The simulation result shows the proposed ST-AODV provides more trustworth y routing compared with general AODV in presence of packet dropping nodes in MANET.

  7. QoS Analysis of the Integrated UMTS and WLAN Ad Hoc Network in different Security Schemes with Wormhole Attack under large Scalability for CBR Voice Interactive Traffic

    Directory of Open Access Journals (Sweden)

    Mr. Shashank Tripathi,

    2016-07-01

    Full Text Available The selection of security schemes against Wormhole Attack (WHA in next generation heterogeneous networks is based on major factors: authentication, confidentiality, and integrity and data availability. The effect of this active threat on Quality of Service (QoS of the Integrated Universal Mobile Telecommunications System (UMTS and Wireless Local Area Network (WLAN Ad Hoc network can be minimized by a suitable secure routing protocol. The aim of this work is to analyze QoS of the Integrated UMTS and WLAN network for Constant Bit-Rate (CBR voice messaging, interactive traffic under a secure distance vector routing protocol with various security schemes under WHA. This paper compares them on the basis of QoS metrics.

  8. 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.

  9. 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.

  10. Recurrent Fever in Children.

    Science.gov (United States)

    Torreggiani, Sofia; Filocamo, Giovanni; Esposito, Susanna

    2016-03-25

    Children presenting with recurrent fever may represent a diagnostic challenge. After excluding the most common etiologies, which include the consecutive occurrence of independent uncomplicated infections, a wide range of possible causes are considered. This article summarizes infectious and noninfectious causes of recurrent fever in pediatric patients. We highlight that, when investigating recurrent fever, it is important to consider age at onset, family history, duration of febrile episodes, length of interval between episodes, associated symptoms and response to treatment. Additionally, information regarding travel history and exposure to animals is helpful, especially with regard to infections. With the exclusion of repeated independent uncomplicated infections, many infective causes of recurrent fever are relatively rare in Western countries; therefore, clinicians should be attuned to suggestive case history data. It is important to rule out the possibility of an infectious process or a malignancy, in particular, if steroid therapy is being considered. After excluding an infectious or neoplastic etiology, immune-mediated and autoinflammatory diseases should be taken into consideration. Together with case history data, a careful physical exam during and between febrile episodes may give useful clues and guide laboratory investigations. However, despite a thorough evaluation, a recurrent fever may remain unexplained. A watchful follow-up is thus mandatory because new signs and symptoms may appear over time.

  11. Recurrent Fever in Children

    Directory of Open Access Journals (Sweden)

    Sofia Torreggiani

    2016-03-01

    Full Text Available Children presenting with recurrent fever may represent a diagnostic challenge. After excluding the most common etiologies, which include the consecutive occurrence of independent uncomplicated infections, a wide range of possible causes are considered. This article summarizes infectious and noninfectious causes of recurrent fever in pediatric patients. We highlight that, when investigating recurrent fever, it is important to consider age at onset, family history, duration of febrile episodes, length of interval between episodes, associated symptoms and response to treatment. Additionally, information regarding travel history and exposure to animals is helpful, especially with regard to infections. With the exclusion of repeated independent uncomplicated infections, many infective causes of recurrent fever are relatively rare in Western countries; therefore, clinicians should be attuned to suggestive case history data. It is important to rule out the possibility of an infectious process or a malignancy, in particular, if steroid therapy is being considered. After excluding an infectious or neoplastic etiology, immune-mediated and autoinflammatory diseases should be taken into consideration. Together with case history data, a careful physical exam during and between febrile episodes may give useful clues and guide laboratory investigations. However, despite a thorough evaluation, a recurrent fever may remain unexplained. A watchful follow-up is thus mandatory because new signs and symptoms may appear over time.

  12. Recurrent wheezing in children

    Science.gov (United States)

    Piazza, Michele; Piacentini, Giorgio

    2016-01-01

    Recurrent wheezing have a significant morbidity and it’s estimated that about one third of school-age children manifest the symptom during the first 5 years of life. Proper identification of children at risk of developing asthma at school age may predict long-term outcomes and improve treatment and preventive approach, but the possibility to identify these children at preschool age remains limited. For many years authors focused their studies to identify early children with recurrent wheezing at risk to develop asthma at school age. Different phenotypes have been proposed for a more precise characterization and a personalized plan of treatment. The main criticism concerns the inability to define stable phenotypes with the risk of overestimating or underestimating the characteristics of symptoms in these children. The aim of this review is to report the recent developments on the diagnosis and treatment of recurrent paediatric wheezing. PMID:26835404

  13. Recurrence of angular cheilitis.

    Science.gov (United States)

    Ohman, S C; Jontell, M; Dahlen, G

    1988-08-01

    The incidence of recurrence of angular cheilitis following a successful antimicrobial treatment was studied in 48 patients. Clinical assessments including a microbial examination were carried out 8 months and 5 yr after termination of treatment. Eighty percent of the patients reported recurrence of their angular cheilitis on one or more occasions during the observation period. Patients with cutaneous disorders associated with dry skin or intraoral leukoplakia had an increased incidence of recrudescence. Neither the presence of denture stomatitis nor the type of microorganisms isolated from the original lesions of angular cheilitis, i.e. Candida albicans and/or Staphylococcus aureus, were associated with the number of recurrences. The present observations indicate that treatment of the majority of patients with angular cheilitis should be considered in a longer perspective than previously supposed, due to the short lasting therapeutic effects of the antimicrobial therapy.

  14. Recurrent Novae - A Review

    CERN Document Server

    Mukai, Koji

    2014-01-01

    In recent years, recurrent nova eruptions are often observed very intensely in wide range of wavelengths from radio to optical to X-rays. Here I present selected highlights from recent multi-wavelength observations. The enigma of T Pyx is at the heart of this paper. While our current understanding of CV and symbiotic star evolution can explain why certain subset of recurrent novae have high accretion rate, that of T Pyx must be greatly elevated compared to the evolutionary mean. At the same time, we have extensive data to be able to estimate how the nova envelope was ejected in T Pyx, and it turns to be a rather complex tale. One suspects that envelope ejection in recurrent and classical novae in general is more complicated than the textbook descriptions. At the end of the review, I will speculate that these two may be connected.

  15. Evaluasi Kinerja IEEE 802.11e HCCA untuk Dukungan QoS pada WLAN Menggunakan NS-2

    Directory of Open Access Journals (Sweden)

    Amry Daulat Gultom

    2014-06-01

    Full Text Available Wireless Local Area Network (WLAN digunakan oleh trafik multimedia yang seharusnya memerlukan persyaratan jaringan yang lebih baik terhadap delay, jitter dan packet losses. IEEE 802.11 Task Group E memperkenalkan perbaikan protokol MAC 802.11, yaitu Hybrid Coordination Function (HCF, yang terdiri dari dua mekanisme akses: Enhanced Distributed Channel Access (EDCA dan HCF Controlled Channel Access (HCCA yang memberikan dukungan Kualitas Layanan/Quality of Service (QoS bagi trafik multimedia. Tujuan dari penelitian ini adalah untuk memahami algoritma protokol MAC IEEE 802.11e HCCA pada jaringan WLAN, dan menganalisis kinerja protokol MAC 802.11e HCCA pada aplikasi multimedia dengan menggunakan metode simulasi pada NS-2. Metrik kinerja yang diukur adalah jitter dan throughput-nya. Hasil penelitian ini menunjukkan bahwa protokol MAC HCCA dapat memberikan jaminan QoS dibanding protokol MAC DCF, dimana jitter HCCA lebih stabil dari pada jitter DCF. Begitupula dengan throughput HCCA yang tidak berubah selama trafik berlangsung, tidak seperti pada DCF yang masih mengalami fluktuasi yang besar.

  16. Designing area optimized application-specific network-on-chip architectures while providing hard QoS guarantees.

    Directory of Open Access Journals (Sweden)

    Sajid Gul Khawaja

    Full Text Available With the increase of transistors' density, popularity of System on Chip (SoC has increased exponentially. As a communication module for SoC, Network on Chip (NoC framework has been adapted as its backbone. In this paper, we propose a methodology for designing area-optimized application specific NoC while providing hard Quality of Service (QoS guarantees for real time flows. The novelty of the proposed system lies in derivation of a Mixed Integer Linear Programming model which is then used to generate a resource optimal Network on Chip (NoC topology and architecture while considering traffic and QoS requirements. We also present the micro-architectural design features used for enabling traffic and latency guarantees and discuss how the solution adapts for dynamic variations in the application traffic. The paper highlights the effectiveness of proposed method by generating resource efficient NoC solutions for both industrial and benchmark applications. The area-optimized results are generated in few seconds by proposed technique, without resorting to heuristics, even for an application with 48 traffic flows.

  17. Cost-Sensitive and Load-Balancing Gateway Placement in Wireless Mesh Networks with QoS Constraints

    Institute of Scientific and Technical Information of China (English)

    Feng Zeng; Zhi-Gang Chen

    2009-01-01

    In wireless mesh networks (WMNs), gateway placement is the key to network performance, QoS and construction cost. This paper focuses on the optimization of the cost and load balance in the gateway placement strategy, ensuring the QoS requirements. Firstly, we define a metric for load balance on the gateways, and address the minimum cost and load balancing gateway placement problem. Secondly, we propose two algorithms for gateway placement. One is a heuristic algorithm, which is sensitive to the cost, selects the gateway candidates according to the capacity/cost ratio of the nodes, and optimizes the load balance on the gateways through scanning and shifting methods. The other is a genetic algorithm, which can find the global optimal solution. The two algorithms differ in their computing complexity and the quality of the generated solutions, and thus provide a trade-off for WMN design. At last, simulation is done, and experimental results show that the two algorithms outperform the others. Compared with OPEN/CLOSE, the average cost of gateway placement generated by our algorithms is decreased by 8%~32%, and the load variance on the gateways decreased by 77%~86%. For the genetic algorithm, the performance improvement is at the price of the increase of the CPU execution time.

  18. PRM:A Resource Management Framework for Policy-driven QoS Control in Enhanced Internets

    Institute of Scientific and Technical Information of China (English)

    FU Xiaoming; ZHANG Yaoxue

    2001-01-01

    The Internet has evolved from a tra-ditional best-effort delivery data network into an en-hanced Internet that can provide a certain Qualityof Service(QoS) mechanisms for applications.How-ever,these QoS mechanisms usually do not take policyfactors into account such as priority and time-of-day.The paper presents a Resource Management Frame-work for Policy-driven QoS control (PRM) in en-hanced internets,which consists of four components:Domain Policy Controller(DPC) resides an adminis-trator domain,Border Resource Manager(BRM) re-sides between adjacent domains,Interior ResourceManagers(IRM) in each router between two BRMswithin the same domain,and Endsystem ResourceManager(ERM) in charge of end-node/host router re-sources.We first introduce challenges and demandsfacing the enhanced internets,then give a formalizeddefinition of policy and describe the functions and in-teraction of components of PRM.Specifically we takeQoS-pricing policy used in a Diff-Serv environmentas an example to illustrate the operational phases of PRM.

  19. Joint terminals and relay optimization for two-way power line information exchange systems with QoS constraints

    Science.gov (United States)

    Wu, Xiaolin; Rong, Yue

    2015-12-01

    The quality-of-service (QoS) criteria (measured in terms of the minimum capacity requirement in this paper) are very important to practical indoor power line communication (PLC) applications as they greatly affect the user experience. With a two-way multicarrier relay configuration, in this paper we investigate the joint terminals and relay power optimization for the indoor broadband PLC environment, where the relay node works in the amplify-and-forward (AF) mode. As the QoS-constrained power allocation problem is highly non-convex, the globally optimal solution is computationally intractable to obtain. To overcome this challenge, we propose an alternating optimization (AO) method to decompose this problem into three convex/quasi-convex sub-problems. Simulation results demonstrate the fast convergence of the proposed algorithm under practical PLC channel conditions. Compared with the conventional bidirectional direct transmission (BDT) system, the relay-assisted two-way information exchange (R2WX) scheme can meet the same QoS requirement with less total power consumption.

  20. Recurrent parotitis in children

    Directory of Open Access Journals (Sweden)

    Bhattarai M

    2006-01-01

    Full Text Available Recurrent parotitis is an uncommon condition in children. Its etiological factors have not been proved till date although causes due to genetic inheritance, local autoimmune manifestation, allergy, viral infection and immunodeficiency have been suggested. The exact management of this disorder is not yet standardized, but a conservative approach is preferred and all affected children should be screened for Sjogren′s syndrome and immune deficiency including human immunodeficiency virus. We report a 12 years female child who presented with 12 episodes of non-painful recurrent swellings of the bilateral parotid gland in the past 3 years.

  1. Tackling a recurrent pinealoblastoma.

    Science.gov (United States)

    Palled, Siddanna; Kalavagunta, Sruthi; Beerappa Gowda, Jaipal; Umesh, Kavita; Aal, Mahalaxmi; Abdul Razack, Tanvir Pasha Chitraduraga; Gowda, Veerabhadre; Viswanath, Lokesh

    2014-01-01

    Pineoblastomas are rare, malignant, pineal region lesions that account for <0.1% of all intracranial tumors and can metastasize along the neuroaxis. Pineoblastomas are more common in children than in adults and adults account for <10% of patients. The management of pinealoblastoma is multimodality approach, surgery followed with radiation and chemotherapy. In view of aggressive nature few centres use high dose chemotherapy with autologus stem cell transplant in newly diagnosed cases but in recurrent setting the literature is very sparse. The present case represents the management of pinealoblastoma in the recurrent setting with reirradiation and adjuvant carmustine chemotherapy wherein the management guidelines are not definitive.

  2. Optimal Provision of Public Goods

    DEFF Research Database (Denmark)

    Kreiner, Claus Thustrup; Verdelin, Nicolaj

    2012-01-01

    The standard approach to the optimal provision of public goods highlights the importance of distortionary taxation and distributional concerns. A new approach neutralizes distributional concerns by adjusting the income tax schedule. We demonstrate that both approaches are derived from the same ba...... of optimal provision are different, and the modified Samuelson rule is likely to lead to underprovision...

  3. Lung Cancer Indicators Recurrence

    Science.gov (United States)

    This study describes prognostic factors for lung cancer spread and recurrence, as well as subsequent risk of death from the disease. The investigators observed that regardless of cancer stage, grade, or type of lung cancer, patients in the study were more

  4. Chronic recurrent multifocal osteomyelitis

    NARCIS (Netherlands)

    Wedman, Jan; van Weissenbruch, Ranny

    2005-01-01

    We report what is, to our best knowledge, the first case of chronic recurrent multifocal osteomyelitis (CRMO) in which the frontal and sphenoid bones were involved. Characterized by a prolonged and fluctuating course of osteomyelitis at different sites, CRMO is self-limited, although sequelae can oc

  5. Recurrent Gliosarcoma in Pregnancy

    OpenAIRE

    2014-01-01

    Gliosarcoma is a rare tumor of the central nervous system and it constitutes about 1 to 8% of all malignant gliomas. In this report we are presenting a recurrent gliosarcoma case during a pregnancy in a 30-year-old woman. This is the first report presenting gliosarcoma in the pregnancy.

  6. Recurrent gallstone ileus.

    Science.gov (United States)

    Hayes, Nicolas; Saha, Sanjoy

    2012-11-01

    Mechanical small bowel obstructions caused by gallstones account for 1% to 3% of cases. In these patients, 80% to 90% of residual gallstones in these patients will pass through a remaining fistula without consequence. Recurrent gallstone ileus has been reported in 5% of patients. We report the case of a woman, aged 72 years, who presented with mechanical small bowel obstruction caused by gallstone ileus. After successful surgical therapy for gallstone ileus, the patient's symptoms recurred, and she was diagnosed with recurrent gallstone ileus requiring a repeat operation. While management of gallstone ileus can be achieved through a single-stage operation including enterolithotomy and cholecystectomy with repair of biliary-enteric fistula or by enterolithotomy alone, the literature supports enterolithotomy alone as the treatment of choice for gallstone ileus due to decreased mortality and morbidity. However, the latter approach does not obviate potential recurrence. We present this case of recurrent gallstone ileus to elucidate and review the pathogenesis, presentation, diagnosis, and consensus recommendations regarding management of this disorder.

  7. Acute Recurrent Pancreatitis

    Directory of Open Access Journals (Sweden)

    Glen A Lehman

    2003-01-01

    Full Text Available History, physical examination, simple laboratory and radiological tests, and endoscopic retrograde cholangiopancreatography (ERCP are able to establish the cause of recurrent acute pancreatitis in 70% to 90% of patients. Dysfunction of the biliary and/or pancreatic sphincter, as identified by sphincter of Oddi manometry, accounts for the majority of the remaining cases. The diagnosis may be missed if the pancreatic sphincter is not evaluated. Pancreas divisum is a prevalent congenital abnormality that is usually innocuous but can lead to recurrent attacks of acute pancreatitis or abdominal pain. In select cases, endoscopic sphincterotomy of the minor papilla can provide relief of symptoms and prevent further attacks. A small proportion of patients with idiopathic pancreatitis have tiny stones in the common bile duct (microlithiasis. Crystals can be visualized during microscopic analysis of bile that is aspirated at the time of ERCP. Neoplasia is a rare cause of pancreatitis, and the diagnosis can usually be established by computerized tomography or ERCP. A wide variety of medications can also cause recurrent pancreatitis. ERCP, sphincter of Oddi manometry, and microscopy of aspirated bile should be undertaken in patients with recurrent pancreatitis in whom the diagnosis is not obvious.

  8. Recurrent Spatial Transformer Networks

    DEFF Research Database (Denmark)

    Sønderby, Søren Kaae; Sønderby, Casper Kaae; Maaløe, Lars;

    2015-01-01

    We integrate the recently proposed spatial transformer network (SPN) [Jaderberg et. al 2015] into a recurrent neural network (RNN) to form an RNN-SPN model. We use the RNN-SPN to classify digits in cluttered MNIST sequences. The proposed model achieves a single digit error of 1.5% compared to 2...

  9. Fuzzy Logic-based Intelligent Scheme for Enhancing QoS of Vertical Handover Decision in Vehicular Ad-hoc Networks

    Science.gov (United States)

    Azzali, F.; Ghazali, O.; Omar, M. H.

    2017-08-01

    The design of next generation networks in various technologies under the “Anywhere, Anytime” paradigm offers seamless connectivity across different coverage. A conventional algorithm such as RSSThreshold algorithm, that only uses the received strength signal (RSS) as a metric, will decrease handover performance regarding handover latency, delay, packet loss, and handover failure probability. Moreover, the RSS-based algorithm is only suitable for horizontal handover decision to examine the quality of service (QoS) compared to the vertical handover decision in advanced technologies. In the next generation network, vertical handover can be started based on the user’s convenience or choice rather than connectivity reasons. This study proposes a vertical handover decision algorithm that uses a Fuzzy Logic (FL) algorithm, to increase QoS performance in heterogeneous vehicular ad-hoc networks (VANET). The study uses network simulator 2.29 (NS 2.29) along with the mobility traffic network and generator to implement simulation scenarios and topologies. This helps the simulation to achieve a realistic VANET mobility scenario. The required analysis on the performance of QoS in the vertical handover can thus be conducted. The proposed Fuzzy Logic algorithm shows improvement over the conventional algorithm (RSSThreshold) in the average percentage of handover QoS whereby it achieves 20%, 21% and 13% improvement on handover latency, delay, and packet loss respectively. This is achieved through triggering a process in layer two and three that enhances the handover performance.

  10. A CONTEXT AWARE BASED PRE-HANDOFF SUPPORT APPROACH TO PROVIDE OPTIMAL QOS FOR STREAMING APPLICATIONS OVER VEHICULAR AD HOC NETWORKS – HOSA

    Directory of Open Access Journals (Sweden)

    K. RAMESH BABU

    2015-06-01

    Full Text Available Large variations in network Quality of Service (QoS such as bandwidth, latency, jitter, and reliability may occur during media transfer over vehicular ad hoc networks (VANET. Usage of VANET over mobile and wireless computing applications experience “bursty” QoS behavior during the execution over distributed network scenarios. Applications such as streaming media services need to adapt their functionalities to any change in network status. Moreover, an enhanced software platform is necessary to provide adaptive network management services to upper software components. HOSA, a handoff service broker based architecture for QoS adaptation over VANET supports in providing awareness. HOSA is structured as a middleware platform both to provide QoS awareness to streaming applications as well to manage dynamic ad hoc network resources with support over handoff in an adaptive fashion. HOSA is well analyzed over routing schemes such as TIBSCRPH, SIP and ABSRP where performance of HOSA was measured using throughput, traffic intensity and end to end delay. HOSA has been analyzed using JXTA development toolkit over C++ implemented classes to demonstrate its performance over varying node mobility established using vehicular mobility based conference application.

  11. An MBS-Assisted Femtocell Transmit Power Control Scheme with Mobile User QoS Guarantee in 2-Tier Heterogeneous Femtocell Networks

    Science.gov (United States)

    Yang, Chih-Cheng; Sheu, Shiann-Tsong

    2013-01-01

    This study investigates how to adjust the transmit power of femto base station (FBS) to mitigate interference problems between the FBSs and mobile users (MUs) in the 2-tier heterogeneous femtocell networks. A common baseline of deploying the FBS to increase the indoor access bandwidth requires that the FBS operation will not affect outdoor MUs operation with their quality-of-service (QoS) requirements. To tackle this technical problem, an FBS transmit power adjustment (FTPA) algorithm is proposed to adjust the FBS transmit power (FTP) to avoid unwanted cochannel interference (CCI) with the neighboring MUs in downlink transmission. FTPA reduces the FTP to serve its femto users (FUs) according to the QoS requirements of the nearest neighboring MUs to the FBS so that the MU QoS requirement is guaranteed. Simulation results demonstrate that FTPA can achieve a low MU outage probability as well as serve FUs without violating the MU QoS requirements. Simulation results also reveal that FTPA has better performance on voice and video services which are the major trend of future multimedia communication in the NGN. PMID:24391461

  12. A novel differentiated-resilience provisioning scheme of service level agreements for the GMPLS/ASON network

    Science.gov (United States)

    Tan, Zhi; Cao, Hongyu

    2008-11-01

    Network service support to ensure quality of service (QoS) is a key requirement for many applications, we present a novel management plane oriented service architecture which provides network resource scheduling service in large-scale GMPLS/ASON network environment based on the service level agreement(SLA) conducted between service customers and service providers. It applies the updated service-oriented and policy translation structure with excellent expansibility and efficiency in the running process. The architecture contains four components: Application Monitor Service, SLA Management, Policy management and Service management. In addition, vertical service mapping and differentiated-resilience provisioning schemes of service level agreement(SLA) applied to the GMPLS/ASON networks are discussed, which is expected to be the near- and long-term network technology thanks, among other things, to the great bandwidth capacity offered by optical devices.

  13. Coping with Fear of Recurrence

    Science.gov (United States)

    ... What Comes Next After Finishing Treatment Coping With Fear of Recurrence Having a Baby After Cancer: Pregnancy ... treatment and preparing for the future. Coping With Fear of Recurrence Learn ways to manage the fear ...

  14. LTE Dynamic Resource Allocation Algorithm based on QoS Optimization%基于QoS优化的LTE动态资源分配算法

    Institute of Scientific and Technical Information of China (English)

    郑智华

    2014-01-01

    文中对下一代移动通信系统LTE的动态资源分配算法进行研究,通过分析不同业务类型的QoS需求,设定用户使用业务类型的QoS参数,确定优先级大小,通过QOS 来表示不同业务的时间延迟;同时对小区切换用户的优先等级分析,设置了切换因子,提出了基于QoS优化的改进算法,并进行系统仿真计算分析,结果表明和传统算法相比,系统性能得到有效改进,进一步提高了系统公平性并增加小区吞吐量。%LTE dynamic resource allocation algorithm for the next generation mobile communication systems is discussed. Through the analysis on different types of traffic QoS requirements, the QoS parameters of us-er service types are determined and priority levels also established, and QoS is used to display different service time-delays. Meanwhile, the handoff factor is also set up through priority analysis of the cell hand-off users. Thus the modified dynamic resource allocation algorithm based on QoS optimization is further proposed and simulated. Simulation results show that the system performance is effectively improved, mo-reover,the system fairness and cell throughput also increased as compared with traditional algorithms.

  15. Chaotic diagonal recurrent neural network

    Institute of Scientific and Technical Information of China (English)

    Wang Xing-Yuan; Zhang Yi

    2012-01-01

    We propose a novel neural network based on a diagonal recurrent neural network and chaos,and its structure andlearning algorithm are designed.The multilayer feedforward neural network,diagonal recurrent neural network,and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map.The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks.

  16. Immunomodulators to treat recurrent miscarriage

    NARCIS (Netherlands)

    Prins, Jelmer R.; Kieffer, Tom E.C.; Scherjon, Sicco A.

    2014-01-01

    Recurrent miscarriage is a reproductive disorder affecting many couples. Although several factors are associated with recurrent miscarriage, in more than 50% of the cases the cause is unknown. Maladaptation of the maternal immune system is associated with recurrent miscarriage and could explain part

  17. Imaging of recurrent prostate cancer

    NARCIS (Netherlands)

    Futterer, J.J.

    2012-01-01

    Approximately 30\\% of patients who underwent radical prostatectomy or radiation therapy will develop biochemical recurrent disease. Biochemical recurrent disease is defined as an increase in the serum value of prostate-specific antigen (PSA) after reaching the nadir. Prostate recurrence can present

  18. Immunomodulators to treat recurrent miscarriage

    NARCIS (Netherlands)

    Prins, Jelmer R.; Kieffer, Tom E. C.; Scherjon, Sicco A.

    2014-01-01

    Recurrent miscarriage is a reproductive disorder affecting many couples. Although several factors are associated with recurrent miscarriage, in more than 50% of the cases the cause is unknown. Maladaptation of the maternal immune system is associated with recurrent miscarriage and could explain part

  19. Training Recurrent Networks

    DEFF Research Database (Denmark)

    Pedersen, Morten With

    1997-01-01

    Training recurrent networks is generally believed to be a difficult task. Excessive training times and lack of convergence to an acceptable solution are frequently reported. In this paper we seek to explain the reason for this from a numerical point of view and show how to avoid problems when tra...... training. In particular we investigate ill-conditioning, the need for and effect of regularization and illustrate the superiority of second-order methods for training......Training recurrent networks is generally believed to be a difficult task. Excessive training times and lack of convergence to an acceptable solution are frequently reported. In this paper we seek to explain the reason for this from a numerical point of view and show how to avoid problems when...

  20. Spatial recurrence plots.

    Science.gov (United States)

    Vasconcelos, D B; Lopes, S R; Viana, R L; Kurths, J

    2006-05-01

    We propose an extension of the recurrence plot concept to perform quantitative analyzes of roughness and disorder of spatial patterns at a fixed time. We introduce spatial recurrence plots (SRPs) as a graphical representation of the pointwise correlation matrix, in terms of a two-dimensional spatial return plot. This technique is applied to the study of complex patterns generated by coupled map lattices, which are characterized by measures of complexity based on SRPs. We show that the complexity measures we propose for SRPs provide a systematic way of investigating the distribution of spatially coherent structures, such as synchronization domains, in lattice profiles. This approach has potential for many more applications, e.g., in surface roughness analyzes.

  1. Modularity promotes epidemic recurrence

    CERN Document Server

    Jesan, T; Sinha, Sitabhra

    2016-01-01

    The long-term evolution of epidemic processes depends crucially on the structure of contact networks. As empirical evidence indicates that human populations exhibit strong community organization, we investigate here how such mesoscopic configurations affect the likelihood of epidemic recurrence. Through numerical simulations on real social networks and theoretical arguments using spectral methods, we demonstrate that highly contagious diseases that would have otherwise died out rapidly can persist indefinitely for an optimal range of modularity in contact networks.

  2. Recurrent Gallstone Ileus

    OpenAIRE

    Hayes, Nicolas; Saha, Sanjoy

    2012-01-01

    Mechanical small bowel obstructions caused by gallstones account for 1% to 3% of cases. In these patients, 80% to 90% of residual gallstones in these patients will pass through a remaining fistula without consequence. Recurrent gallstone ileus has been reported in 5% of patients. We report the case of a woman, aged 72 years, who presented with mechanical small bowel obstruction caused by gallstone ileus. After successful surgical therapy for gallstone ileus, the patient's symptoms recurred, a...

  3. An Analytical Framework for Performance of Different Fault Restoration Policies with QoS Constraints in MPLS Networks

    Institute of Scientific and Technical Information of China (English)

    Xian-Si Tan; Zong-Kai Yang; Liang Ou; Jing-Wen Chen; Ya-Jie Ma

    2004-01-01

    An analytical framework for the performance of different protection switching restoration mechanisms with different protection policies in Multi-Protocol Label Switching (MPLS) networks is developed, where the protection policy may be 1 + 1, 1:1, n:l or n:m. As a general rule, it aims at the MPLS networks with the protection paths created in advance of fault occurrence without resources reserved, and it reroutes the protected traffic in the event of link or router failures while trying to maintain quality of service (QoS) requirements. Based on the proposed protocol for processing faults, an analytical model and an evaluating model are created, and the benefits and penalties of different mechanisms with different protection policies are evaluated. In particular, an improvement on the proposed protocol is presented to overcome the drawbacks of n:m protection policy in which m > 1 and n> 1.

  4. Supporting QoS in MANET by a Fuzzy Priority Scheduler and Performance Analysis with Multicast Routing Protocols

    Directory of Open Access Journals (Sweden)

    Shanmugavel S

    2005-01-01

    Full Text Available Mobile ad hoc network is an autonomous system of mobile nodes characterized by wireless links. The major challenge in ad hoc networks lies in adapting multicast communication to environments, where mobility is unlimited and failures are frequent. Such problems increase the delays and decrease the throughput. To meet these challenges, to provide QoS, and hence to improve the performance, a scheduler can be used. In this paper we design a fuzzy-based priority scheduler to determine the priority of the packets. The performance of the scheduler is studied with the multicast routing protocols. The scheduler is evaluated in terms of the quantitative metrics such as packet delivery ratio and average end-to-end delay and the results are found to be encouraging.

  5. Supporting QoS in MANET by a Fuzzy Priority Scheduler and Performance Analysis with Multicast Routing Protocols

    Directory of Open Access Journals (Sweden)

    Gomathy C.

    2005-01-01

    Full Text Available Mobile ad hoc network is an autonomous system of mobile nodes characterized by wireless links. The major challenge in ad hoc networks lies in adapting multicast communication to environments, where mobility is unlimited and failures are frequent. Such problems increase the delays and decrease the throughput. To meet these challenges, to provide QoS, and hence to improve the performance, a scheduler can be used. In this paper we design a fuzzy-based priority scheduler to determine the priority of the packets. The performance of the scheduler is studied with the multicast routing protocols. The scheduler is evaluated in terms of the quantitative metrics such as packet delivery ratio and average end-to-end delay and the results are found to be encouraging.

  6. 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.

  7. Security Enhancement With Optimal QOS Using EAP-AKA In Hybrid Coupled 3G-WLAN Convergence Network

    CERN Document Server

    Shankar, R; Dananjayan, P; 10.5121/iju.2010.1303

    2010-01-01

    The third generation partnership project (3GPP) has addressed the feasibility of interworking and specified the interworking architecture and security architecture for third generation (3G)-wireless local area network (WLAN), it is developing, system architecture evolution (SAE)/ long term evolution (LTE) architecture, for the next generation mobile communication system. To provide a secure 3G-WLAN interworking in the SAE/LTE architecture, Extensible authentication protocol-authentication and key agreement (EAP-AKA) is used. However, EAP-AKA have several vulnerabilities. Therefore, this paper not only analyses the threats and attacks in 3G-WLAN interworking but also proposes a new authentication and key agreement protocol based on EAP-AKA. The proposed protocol combines elliptic curve Diffie-Hellman (ECDH) with symmetric key cryptosystem to overcome the vulnerabilities. The proposed protocol is used in hybrid coupled 3G-WLAN convergence network to analyse its efficiency in terms of QoS metrics, the results ob...

  8. Capacity allocation mechanism based on differentiated QoS in 60 GHz radio-over-fiber local access network

    Science.gov (United States)

    Kou, Yanbin; Liu, Siming; Zhang, Weiheng; Shen, Guansheng; Tian, Huiping

    2017-03-01

    We present a dynamic capacity allocation mechanism based on the Quality of Service (QoS) for different mobile users (MU) in 60 GHz radio-over-fiber (RoF) local access networks. The proposed mechanism is capable for collecting the request information of MUs to build a full list of MU capacity demands and service types at the Central Office (CO). A hybrid algorithm is introduced to implement the capacity allocation which can satisfy the requirements of different MUs at different network traffic loads. Compared with the weight dynamic frames assignment (WDFA) scheme, the Hybrid scheme can keep high priority MUs in low delay and maintain the packet loss rate less than 1% simultaneously. At the same time, low priority MUs have a relatively better performance.

  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. Statistical Quality of Service to Increase Qos/Qoe of IP-Based Gateway for Integrating Heterogeneous Wireless Devices

    Directory of Open Access Journals (Sweden)

    Pon. Arivanantham

    2016-01-01

    Full Text Available In broadcast service area above communications supported cellular wireless networks, data is communicated to several addressees from a right of entry point/base station. Multicast significantly progresses the network effectiveness to dispense data to multiple addressees as associated to multiple unicast gatherings of the similar data to each receiver independently, by taking improvement of the communal nature of the wireless intermediate. These algorithms need to be intended to be responsible for the essential Quality of Service (QoS towards an extensive assortment of applications while permitting seamless roaming between multitudes of access network technologies. This paper proposed a cellular-aided mobile ad hoc network (CAMA structural design, in which a CAMA representative in the cellular network accomplishes the control data, while the data is transported over the mobile terminals (MTs. The routing and security info is substituted among MTs and the negotiator over cellular radio channels. A location centered routing protocol, the multi-selection greedy positioning routing (MSGPR protocol, is projected. This novel feature makes it more appropriate in the actual world. In accumulation, dynamic new call blocking possibility is initially familiarized to make handoff decision for wireless networks. This paper proposes a novel technique to afford QoS sustenance by means of an assistant network to recuperate the failure of multicast data in the major network. A wireless device might misplace some of the multicast records send above the major network. The experiment results have exposed that the proposed algorithm outclasses traditional algorithms in bandwidth deployment, handoff dropping rate and handoff rate.

  11. QoS and energy management in cognitive radio network case study approach

    CERN Document Server

    Mishra, Vishram; Lau, Chiew-Tong

    2017-01-01

    This book covers the important aspects involved in making cognitive radio devices portable, mobile and green, while also extending their service life. At the same time, it presents a variety of established theories and practices concerning cognitive radio from academia and industry. Cognitive radio can be utilized as a backbone communication medium for wireless devices. To effectively achieve its commercial application, various aspects of quality of service and energy management need to be addressed. The topics covered in the book include energy management and quality of service provisioning at Layer 2 of the protocol stack from the perspectives of medium access control, spectrum selection, and self-coexistence for cognitive radio networks.

  12. Multiscale recurrence quantification analysis of order recurrence plots

    Science.gov (United States)

    Xu, Mengjia; Shang, Pengjian; Lin, Aijing

    2017-03-01

    In this paper, we propose a new method of multiscale recurrence quantification analysis (MSRQA) to analyze the structure of order recurrence plots. The MSRQA is based on order patterns over a range of time scales. Compared with conventional recurrence quantification analysis (RQA), the MSRQA can show richer and more recognizable information on the local characteristics of diverse systems which successfully describes their recurrence properties. Both synthetic series and stock market indexes exhibit their properties of recurrence at large time scales that quite differ from those at a single time scale. Some systems present more accurate recurrence patterns under large time scales. It demonstrates that the new approach is effective for distinguishing three similar stock market systems and showing some inherent differences.

  13. Recurrent Pregnancy Loss

    Directory of Open Access Journals (Sweden)

    Véronique Piroux

    1997-01-01

    Full Text Available Antiphospholipid antibodies (APA are associated with thrombosis, thrombocytopenia and fetal loss but they occur in a variety of diseases. Despite many efforts, a correlation between the specificity of particular subgroups of APA and particular clinical situations remains to be established. The antigens at the origin of APA remain to be identified. We discuss here the possible links between cell apoptosis or necrosis, leading to plasma membrane alterations, and the occurrence of APA in response to sustained stimulation. The pathogenic potential of APA is also considered with respect to recurrent pregnancy loss.

  14. Recurrent Miller Fisher syndrome.

    Science.gov (United States)

    Madhavan, S; Geetha; Bhargavan, P V

    2004-07-01

    Miller Fisher syndrome (MFS) is a variant of Guillan Barre syndrome characterized by the triad of ophthalmoplegia, ataxia and areflexia. Recurrences are exceptional with Miller Fisher syndrome. We are reporting a case with two episodes of MFS within two years. Initially he presented with partial ophthalmoplegia, ataxia. Second episode was characterized by full-blown presentation characterized by ataxia, areflexia and ophthalmoplegia. CSF analysis was typical during both episodes. Nerve conduction velocity study was fairly within normal limits. MRI of brain was within normal limits. He responded to symptomatic measures initially, then to steroids in the second episode. We are reporting the case due to its rarity.

  15. Recurrence Relations and Determinants

    CERN Document Server

    Janjic, Milan

    2011-01-01

    We examine relationships between two minors of order n of some matrices of n rows and n+r columns. This is done through a class of determinants, here called $n$-determinants, the investigation of which is our objective. We prove that 1-determinants are the upper Hessenberg determinants. In particular, we state several 1-determinants each of which equals a Fibonacci number. We also derive relationships among terms of sequences defined by the same recurrence equation independently of the initial conditions. A result generalizing the formula for the product of two determinants is obtained. Finally, we prove that the Schur functions may be expressed as $n$-determinants.

  16. Recurrent correlation associative memories.

    Science.gov (United States)

    Chiueh, T D; Goodman, R M

    1991-01-01

    A model for a class of high-capacity associative memories is presented. Since they are based on two-layer recurrent neural networks and their operations depend on the correlation measure, these associative memories are called recurrent correlation associative memories (RCAMs). The RCAMs are shown to be asymptotically stable in both synchronous and asynchronous (sequential) update modes as long as their weighting functions are continuous and monotone nondecreasing. In particular, a high-capacity RCAM named the exponential correlation associative memory (ECAM) is proposed. The asymptotic storage capacity of the ECAM scales exponentially with the length of memory patterns, and it meets the ultimate upper bound for the capacity of associative memories. The asymptotic storage capacity of the ECAM with limited dynamic range in its exponentiation nodes is found to be proportional to that dynamic range. Design and fabrication of a 3-mm CMOS ECAM chip is reported. The prototype chip can store 32 24-bit memory patterns, and its speed is higher than one associative recall operation every 3 mus. An application of the ECAM chip to vector quantization is also described.

  17. 14 CFR 91.1065 - Initial and recurrent pilot testing requirements.

    Science.gov (United States)

    2010-01-01

    ... Ownership Operations Program Management § 91.1065 Initial and recurrent pilot testing requirements. (a) No... following areas— (1) The appropriate provisions of parts 61 and 91 of this chapter and the management... beginning of the 12th month before that service, that pilot has passed a competency check given by...

  18. Study on the performance of the A*Prune QoS routing algorithm for intelligent optical networks and its improvements

    Institute of Scientific and Technical Information of China (English)

    SUN Quan; WANG Gong-pu

    2006-01-01

    The A*Prune quality of service (QoS) routing algorithm was proposed to compute K-shortest paths satisfying multiple QoS constraints. The A*Prune is considered to be one of the practical routing algorithms for intelligent optical networks because of its flexibility in handling many practical constraints. This article gives detailed performance studies of the algorithm through extensive simulation experiments. We found that both the running time and the memory space requirements of the algorithm are large, especially when the network size increases. In this article, we also propose an approach to improving the performance of the A*Prune algorithm. The improvements should make the A*Prune algorithm more attractive for practical use in intelligent optical networks.

  19. Improvement on Routing Protocol QoS AODV for Mobile Ad Hoc Network%自组网路由协议QoS AODV的改进

    Institute of Scientific and Technical Information of China (English)

    崔鹤鸣; 向勇

    2008-01-01

    QoS AODV协议是目前自组网QoS路由协议的研究热点.由于只能由目的节点返回路由确认RREP,它的协议开销较大.提出了一种基于QoS AODV的改进协议AQ-AODV (Advanced Q-AODV).通过建立QoS分级路由表并改进QOS-LOST分组的转发机制,可由中间节点返回RREP.仿真实验表明,AQ-AODV的协议开销比AODV和QoS AODV有较大幅度降低,同时分组递交率和分组平均传输延迟也略有改善.

  20. [Treatment of recurrent posterior epistaxis].

    Science.gov (United States)

    Bro, Søren Pauli; Bille, Jesper; Petersen, Kristian Bruun

    2017-08-21

    30% of the patients presenting with epistaxis at emergency wards and otorhinolaryngeal specialist departments have posterior bleeding. Traditional treatment with packing often leads to initial treatment failure, and many patients experience recurrent bleeding within the following month. Recurrent posterior epistaxis should be treated with local electrocautery or endoscopic ligation of the sphenopalatine artery to reduce patient discomfort, hospital stay, risk of treatment failure and recurrence.

  1. Social Housing Provision in Copenhagen

    DEFF Research Database (Denmark)

    Tsenkova, Sasha; Vestergaard, Hedvig

    The paper provides an overview of trends and processes of change affecting new social housing provision in Denmark with a focus on Copenhagen. The local responses are reviewed within the context of changes to the unitary national housing system that functions with a robust range of private and non......-profit housing providers, and a wide range of fiscal and regulatory instruments enhancing the competitive performance of the social housing sector. The research analyses recent housing policy measures and their impact on new social housing provision in Copenhagen. The emphasis is on the mix of housing policy...... instruments implemented in three major policy domains-fiscal, financial and regulatory-to promote the production of new social housing. The system of new social housing provision is examined as a dynamic process of interaction between public and private institutions defining housing policy outcomes...

  2. Models of Public Service Provision

    DEFF Research Database (Denmark)

    Andersen, Lotte Bøgh; Kristensen, Nicolai; Pedersen, Lene Holm

    2013-01-01

    This article extends the framework of Le Grand (2003, 2010) to encompass responsiveness, and the main argument is that the combination of employee motivation, user capacity, and models of public service provision potentially has serious implications for responsiveness across service areas. Although...... research on employee motivation thrives, especially in the public service motivation (PSM) literature, few studies have investigated user capacity empirically, and we know little about the combination of PSM, user capacity and models of service provision. Analyzing four central service areas (day care......, schools, hospitals, and universities), we find variations in both user capacity and PSM. Taking this variation as a point of departure we discuss what implications different combinations of employee motivation, user capacity, and models of public service provision may have for responsiveness....

  3. Psychosocial adjustment to recurrent cancer.

    Science.gov (United States)

    Mahon, S M; Cella, D F; Donovan, M I

    1990-01-01

    This descriptive study of the perceptions and needs of people with recurrent malignancies asks three questions: How do patients describe the meaning of a recurrence of cancer? Do individuals perceive the diagnosis of recurrence and the initial diagnosis of cancer differently? What are the key psychosocial problems associated with recurrent cancer? The theoretical framework was based on Lazarus and Folkman's theory of stress, appraisal, and coping. Subjects completed the Impact of Event Scale (IES), the Psychosocial Adjustment to Illness Scale--Self-Report (PAIS), and a semistructured qualitative interview. The interview elicited perceptions of the event of recurrence and differences between the diagnosis of recurrence and the initial diagnosis. The convenience sample included 40 patients diagnosed with recurrent cancer within the last 30 days. Many subjects (78%) reported that the recurrence was more upsetting than the initial diagnosis. Scores on both the IES and the PAIS were high when compared to normative samples of patients with cancer suggesting that this sample of patients experienced a lot of psychological distress as well as problems at home, work, and in their social lives. These concerns often were unknown to caregivers. Although more research is needed, the authors propose that, with more accurate assessment, more effective intervention could be implemented and the quality of life improved for patients with recurrent cancer.

  4. Epidemiology of recurrent venous thrombosis

    Directory of Open Access Journals (Sweden)

    D.D. Ribeiro

    2012-01-01

    Full Text Available Venous thrombosis, including deep vein thrombosis and pulmonary embolism, is a common disease that frequently recurs. Recurrence can be prevented by anticoagulants, but this comes at the risk of bleeding. Therefore, assessment of the risk of recurrence is important to balance the risks and benefits of anticoagulant treatment. This review briefly outlines what is currently known about the epidemiology of recurrent venous thrombosis, and focuses in more detail on potential new risk factors for venous recurrence. The general implications of these findings in patient management are discussed.

  5. Dynamic provisioning for community services

    CERN Document Server

    Qi, Li

    2013-01-01

    Dynamic Provisioning for Community Services outlines a dynamic provisioning and maintenance mechanism in a running distributed system, e.g. the grid, which can be used to maximize the utilization of computing resources and user demands. The book includes a complete and reliable maintenance system solution for the large-scale distributed system and an interoperation mechanism for the grid middleware deployed in the United States, Europe, and China. The experiments and evaluations have all been practically implemented for ChinaGrid, and the best practices established can help readers to construc

  6. 75 FR 15777 - Common Crop Insurance Regulations, Basic Provisions; and Various Crop Insurance Provisions

    Science.gov (United States)

    2010-03-30

    ... Provisions, Small Grains Crop Insurance Provisions, Cotton Crop Insurance Provisions, Sunflower Seed Crop... previous rules implementing the Food, Conservation, and Energy Act of 2008 (2008 Farm Bill). DATES..., Cotton Crop Insurance Provisions, Sunflower Seed Crop Insurance Provisions, Coarse Grains Crop Insurance...

  7. 基于Web服务社区的可信QOS评价模型%Reliable QoS Evaluation Model Based on Web Service Community

    Institute of Scientific and Technical Information of China (English)

    陈彦; 吴毅坚; 赵文耘

    2009-01-01

    Aiming at the problem that QoS evaluation is impossible or unreliable when involved criterions are beyond service domain, this paper presents a reliable QoS evaluation model based on Web service community. This model defines the assistant domain Ontology besides the domain Ontology, and mares it possible to correctly evaluate the QoS in different domain by using criterion trees and criterion forest weighted by Analytic Hierarchy Process(AHP). It imports Web service community to manage services on overall control that improves reliability of the evaluation.%针对涉及本领域之外QoS评价的不可计算和不可信问题,提出基于Web服务社区的可信QoS评价模型.该模型在本领域外定义辅助领域本体,并在两者中使用层次分析法构造评价树和评价森林,使本领域外的QoS可以被正确评价.引入Web服务社区概念,通过主Web服务进行宏观总体控制,提高评价结果的可信度.

  8. Research on Web Service Selection Based on QoS and Reputation%支持QoS和信任度的Web服务选择研究

    Institute of Scientific and Technical Information of China (English)

    贾峰; 文志诚; 李长云; 曾茂林

    2009-01-01

    Aiming at the incredibility factors of QoS attribute values from service providers and rating from users, this paper proposes a reputation-enhanced Web service selection with QoS. Firstly, the providers' QoS attribute values are revised periodically by Monitoring and statistics of past mntime data; and then reputation values based on probability statistics theory and time forgetting factor are comput-ed; at last, users and rating become credible through user evaluation algorithm. Simulation experiment shows that this approach is avail-able.%针对目前服务提供者发布的QoS属性值、用户提供的评分存在不可信因素,提出一种支持QoS增强信任度的Web服务选择方法.对以往运行数据进行监控统计,阶段性修正提供者发布QoS属性值,以概率统计理论为基础,结合时间衰减因子计算信任度,通过用户可信评测算法,实现用户及评分的可信.根据模拟实验说明了该方法的有效性.

  9. Design and Performance Evaluation of Contention Resolution Schemes with QoS Support for Multimedia Traffic in High Bit-Rate Wireless Communications

    Science.gov (United States)

    Srichavengsup, Warakorn; Charoenpanichkit, Akkarapat; Wuttisittikulkij, Lunchakorn

    This paper considers the problem of contention resolution algorithm for multi-class with quality of service (QoS) constrained for wireless communication. Five different channel reservation schemes are proposed, namely, UNI+MLA, UNI+DS, UNI+DS+MLA, Partial UNI and Partial UNI+MLA schemes for multimedia traffic, all are extensions of our recently proposed UNI scheme for single-class traffic. The goal is to achieve the highest system performance and enable each traffic type to meet its QoS requirements. We evaluate the performance of each scheme by mathematical analysis. The numerical results show that our proposed schemes are effective in enabling each traffic type to achieve the best successful rate possible in this kind of environment. Finally when comparing between our proposed schemes and conventional technique in terms of both throughput performance and QoS requirements it is found that the UNI+MLA, UNI+DS+MLA and Partial UNI+MLA schemes are relatively efficient and suitable for practical applications.

  10. Qos Real-Time Control Technology on Internet of Things%基于物联网的QoS实时控制技术研究

    Institute of Scientific and Technical Information of China (English)

    郑志凌; 杜飞明; 杨幸

    2015-01-01

    With the increasing development of Internet of Things(IOT) technology and related business needs, the terminations of IOT not only required anytime and anywhere to access the network, but also need to safeguard the necessary normal operation of relevant QoS on daily business, this article analyzes the case studies of the QoS application of IOT in control technology and packet scheduling algorithm, and propose based on QoS service model of IOT and real-time control technology.%随着物联网技术的发展和相关业务需求的增加,物联网终端不仅要求能随时、随地接入网络,而且需要保障相关业务正常运行所必须的QoS,该文在分析了物联网的应用情况,研究了QoS的控制技术和分组调度算法,提出了基于物联网的QoS服务模型以及实时控制技术。

  11. 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.

  12. Recurrent pregnancy loss

    DEFF Research Database (Denmark)

    Egerup, P; Kolte, A M; Larsen, E C

    2016-01-01

    STUDY QUESTION: Is there a different prognostic impact for consecutive and non-consecutive early pregnancy losses in women with secondary recurrent pregnancy loss (RPL)? SUMMARY ANSWER: Only consecutive early pregnancy losses after the last birth have a statistically significant negative prognostic...... impact in women with secondary RPL. WHAT IS KNOWN ALREADY: The risk of a new pregnancy loss increases with the number of previous pregnancy losses in patients with RPL. Second trimester losses seem to exhibit a stronger negative impact than early losses. It is unknown whether the sequence of pregnancy...... losses plays a role for the prognosis in patients with a prior birth. STUDY DESIGN, SIZE, DURATION: This retrospective cohort study of pregnancy outcome in patients with unexplained secondary RPL included in three previously published, Danish double-blinded placebo-controlled trials of intravenous...

  13. Recurrent vulvovaginal candidiasis.

    Science.gov (United States)

    Sobel, Jack D

    2016-01-01

    Recurrent vulvovaginal candidiasis (RVVC) is a common cause of significant morbidity in women in all strata of society affecting millions of women worldwide. Previously, RVVC occurrence was limited by onset of menopause but the widespread use of hormone replacement therapy has extended the at-risk period. Candida albicans remains the dominant species responsible for RVVC, however optimal management of RVVC requires species determination and effective treatment measures are best if species-specific. Considerable progress has been made in understanding risk factors that determine susceptibility to RVVC, particularly genetic factors, as well as new insights into normal vaginal defense immune mechanisms and their aberrations in RVVC. While effective control of RVVC is achievable with the use of fluconazole maintenance suppressive therapy, cure of RVVC remains elusive especially in this era of fluconazole drug resistance. Vaccine development remains a critical challenge and need.

  14. A Practical Optimisation Method to Improve QOS and GOS-Based Key Performance Indicators in GSM Network Cell Cluster Environment [

    Directory of Open Access Journals (Sweden)

    Joseph Isabona

    2014-11-01

    Full Text Available The delivering of both good quality of service (QoS and Grade of Service (GoS in any competitive mob ile communication environment is a major factor to redu cing subscribers’ churn rate. Therefore, it is important for wireless mobile network operators to ensure stability and efficiency by delivering a consistent, reliable and high-quality end user (sub scriber satisfaction. This can only be achieve by conducting a regular network performance monitoring and optimisation as it directly impacts the qualit y of the offered services and hence user satisfaction. I n this paper, we present the results of network performance evaluation and optimisation of a GSM ne twork on cell cluster-basis, in Asaba region, South East Nigeria. We employ a combination of essential key performance indicators such as dropped call rat e, call setup success rate and outage call rate to exa mine overall QoS and GoS performance of the GSM network. Our results after network optimisation sho wed significant performance improvement in terms of call drop rate, call set up success rate, and call block rate across. Specifically, the end user satis faction rate has increased from 94.45%, 87.74%, and 92.85% to 99.05%, 95.38% and 99.03% respectively across the three GSM cell clusters. The GoS is reduced fro m 3.33%, 6.60% and 2.38% to 0.00%, 3.70% and 0.00% respectively. Furthermore, ESA, which corresp ond end points service availability, has improved from 94.44%, 93.40% and 97.62% to 100%, 96.30% and 100% respectively. In addition, the average throughput has improved from 73.74kbits/s, 85.06kbi ts/s and 87.54kbits/s to 77.07kbits/s, 92.38kbits/s and 102kbits/s respectively across the three GSM cell c lusters.

  15. Bereavement Care Provision in Europe

    DEFF Research Database (Denmark)

    Guldin, Mai-Britt; Murphy, Irene; Keegan, Orla

    2015-01-01

    The Bereavement Care Taskforce of the EAPC has conducted a survey on bereavement care service provision in Europe. Mai-Britt Guldin, Irene Murphy, Orla Keegan, Barbara Monroe, Maria Antonia Lacasta Reverte and Inger Benkel report on the results. One of the key findings is that not all palliative...

  16. Nocturnal lagophthalmos and recurrent erosion.

    Science.gov (United States)

    Sturrock, G. D.

    1976-01-01

    The symptoms and corneal changes caused by sleeping with one or both eyes open are described in 102 patients. The clinical picture is identical to that of the microform recurrent erosion. The close relationship between the micro- and macro-forms of recurrent corneal erosion suggests that the latter condition is also precipitated by nocturnal lagophthalmos. Images PMID:1268178

  17. Recurrent dermatitis from jellyfish envenomation.

    OpenAIRE

    Menahem, S; Shvartzman, P.

    1994-01-01

    Jellyfish envenomation can cause an immediate local skin reaction, which is usually a painful linear vesiculourticarial eruption. Persistent, delayed, or recurrent dermatitis is less common. Because jellyfish sting reactions and their management are unfamiliar to family physicians, we describe a case of recurrent local dermatitis after jellyfish envenomation and suggest appropriate treatment.

  18. Equitable provision of social facilities for a range of settlements: guidelines and tools for integrated provision

    CSIR Research Space (South Africa)

    Green, Cheri A

    2013-09-01

    Full Text Available looks at equitable provision of social facilities for a range of settlements and offers guidelines and tools for integrated provision that incorporates the 1) development of fully provisioned quality living environments, 2) improvement of access...

  19. 无线Mesh网络中的多约束QoS路由算法%A Multi-Constrained QoS Routing Protocol in Wireless Mesh Networks

    Institute of Scientific and Technical Information of China (English)

    丁璐; 刘峰; 林琼洁

    2011-01-01

    无线Mesh网络中多媒体数据的实时传输应用日益广泛,这些应用对网络的带宽、时延和抖动有着较高要求,需要无线Mesh网络提供一定的QoS保障机制.QoS路由是实现QoS保障的关键环节.在路由协议AODV的基础上,提出了一种具有多个QoS参数约束的路由算法(MQ-AODV),通过改进路由选择函数及扩展路由维护机制,为多媒体传输应用业务提供QoS保障.在路由发现的过程中,MQ-AODV引入了一个归一化的路由选择函数,简化了多约束路由算法中的NP-complete问题.在路由维护方面,提出了一种路由预先修复机制,在数据流传输过程中保障路径质量.仿真结果表明,MQ-AODV算法比AODV更好地减少了数据流传输的延迟和丢包,有效提高了网络的吞吐量.%Wireless Mesh Networks(WMN) are increasingly used for real time transport of multimedia data. Real-time applications have high requirements on bandwidth, delay, jitter etc, which requires WMN to support QoS. QoS routing is crucial in providing QoS guarantee. A multi-constrained QoS Routing Protocol(MQ-AODV) is proposed in this paper, which providing QoS for different applications in WMN. The new protocol expands both the routing discovery and routing repair mechanism of the AODV protocol. In the process of route discovery, MQ-AODV introduces a unified routing select function, simplifying the NP-complete problem in multi-constrained routing algorithm. In the aspect of route maintenance, presents a pre- repair scheme to protect the quality of the path in the process of data flow transmission. The simulation results show that,compared to the traditional AODV protocol, the MQ-AODV protocol can better fulfill the delay and PER requirements of data flow, at the same time increases network throughput.

  20. Research on Multi-granularity QoS Guarantee Mechanism in SUPANET%SUPANET中多粒度服务质量保障机制研究

    Institute of Scientific and Technical Information of China (English)

    高雨; 曾华燊; 窦军

    2011-01-01

    The Next Generation Internet (NGI) must provide not only fine granularity Quality of Service (QoS) guarantee to a single flow, but also coarse granularity QoS guarantee to a class of flow. To meet the need of NGI in multi-granularity QoS guarantee, this paper describes the original QoS guarantee mechanism of SUPA (Single physical layer User-data transfer &. Switching Platform Architecture ) and proposes an Internet traffic oriented multi-granularity QoS guarantee framework in SUPA. In this framework, a mapping method between Internet traffic and the multi-granularity Virtual Tunnel (VT) is proposed, and an adaptive quota algorithm of thick VT is designed. At last, the effectiveness of the algorithm is proved by simulation. Simulation results show that the adaptive quota algorithm can improve the quota utilization rate of single thick VT and the resources utilization rate of the whole network in comparision with the fixed quota algorithm.%下一代互联网NGI (Next Generation Internet)既需要为单个业务连接提供细粒度的服务质量QoS(Quality of Service),又需要为一类业务流提供粗粒度的QoS.针对这种多粒度的QoS保障需求,在分析单物理层用户数据传输与交换平台体系结构SUPA(Single physical layer User-data transfer&switching Platform Ar-chitecture)原有QoS保障机制的基础上,提出在SUPA网络中为Internet业务流提供多粒度QoS保障的基本框架,设计了Internet业务流与多粒度虚通道的映射方式以及粗虚通道的配额自适应算法,最后通过仿真实验对配额自适应算法进行了验证.仿真实验结果说明:配额自适应比固定配额算法更能提高单个粗虚通道的配额利用率以及全网资源的利用率.

  1. Comparison of QoS guarantee techniques for VoIP over IEEE802.11 wireless LAN

    Science.gov (United States)

    Guo, Fanglu; Chiueh, Tzi-cker

    2008-01-01

    An emerging killer application for enterprise wireless LANs (WLANs) is voice over IP (VoIP) telephony, which promises to greatly improve the reachability and mobility of enterprise telephony service at low cost. None of the commercial IEEE 802.11 WLAN-based VoIP products can support more than ten G.729-quality voice conversations over a single IEEE 802.11b channel on real-world WLANs, even though the physical transmission rate is more than two orders of magnitude higher than an individual VoIP connection's bandwidth requirement. There are two main reasons why these VoIP systems' effective throughput is significantly lower than expected: VoIP's stringent latency requirement and substantial per-WLAN-packet overhead. Time-Division Multiple Access (TDMA) is a well-known technique that provides per-connection QoS guarantee as well as improves the radio channel utilization efficiency. This paper compares the effective throughput of IEEE 802.11, IEEE 802.11e and a software-based TDMA (STDMA) protocol that is specifically designed to support WLAN-based VoIP applications, on the same commodity IEEE 802.11 WLAN hardware. Empirical measurements from a VOIP over WLAN testbed show that the numbers of G.729-quality voice conversations that IEEE 802.11, IEEE 802.11e and STDMA can support over a single IEEE 802.11b channel are 18, 22 and 50, respectively.

  2. Contiguous Frequency-Time Resource Allocation and Scheduling for Wireless OFDMA Systems with QoS Support

    Directory of Open Access Journals (Sweden)

    Bader F

    2009-01-01

    Full Text Available The orthogonal frequency division multiple access (OFDMA scheme has been selected as a potential candidate for many emerging broadband wireless access standards. In this paper, a new joint scheduling and resource allocation scheme is proposed for the OFDMA systems using contiguous subcarrier permutation. The proposed resource allocation algorithm provides contiguous sets of frequency-time resource units following a rectangular shape yielding a reduction on the required burst signalling. The joint scheduling and resource allocation process is divided into two phases: the QoS requirements fulfilment and the input buffers emptying status. For each phase, a specific prioritization function is defined in order to obtain a trade-off between the fairness and the spectral efficiency maximization. The new prioritization scheme provides a reduction of 50% of the 99th percentile from the delivered packets delay in case of non real-time services, and 30% of the packet loss rate in case of real-time services compared to the proportional fair scheduling function. On the other hand, it is also demonstrated that using the rectangular data packing algorithm, the number of required bursts per frame can be reduced up to a few tenths without compromising the performance.

  3. Exploring a QoS Driven Scheduling Approach for Peer-to-Peer Live Streaming Systems with Network Coding

    Science.gov (United States)

    Cui, Laizhong; Lu, Nan; Chen, Fu

    2014-01-01

    Most large-scale peer-to-peer (P2P) live streaming systems use mesh to organize peers and leverage pull scheduling to transmit packets for providing robustness in dynamic environment. The pull scheduling brings large packet delay. Network coding makes the push scheduling feasible in mesh P2P live streaming and improves the efficiency. However, it may also introduce some extra delays and coding computational overhead. To improve the packet delay, streaming quality, and coding overhead, in this paper are as follows. we propose a QoS driven push scheduling approach. The main contributions of this paper are: (i) We introduce a new network coding method to increase the content diversity and reduce the complexity of scheduling; (ii) we formulate the push scheduling as an optimization problem and transform it to a min-cost flow problem for solving it in polynomial time; (iii) we propose a push scheduling algorithm to reduce the coding overhead and do extensive experiments to validate the effectiveness of our approach. Compared with previous approaches, the simulation results demonstrate that packet delay, continuity index, and coding ratio of our system can be significantly improved, especially in dynamic environments. PMID:25114968

  4. A Game-Theoretic Approach to Energy-Efficient Modulation in CDMA Networks with Delay QoS Constraints

    CERN Document Server

    Meshkati, Farhad; Poor, H Vincent; Schwartz, Stuart C

    2007-01-01

    A game-theoretic framework is used to study the effect of constellation size on the energy efficiency of wireless networks for M-QAM modulation. A non-cooperative game is proposed in which each user seeks to choose its transmit power (and possibly transmit symbol rate) as well as the constellation size in order to maximize its own utility while satisfying its delay quality-of-service (QoS) constraint. The utility function used here measures the number of reliable bits transmitted per joule of energy consumed, and is particularly suitable for energy-constrained networks. The best-response strategies and Nash equilibrium solution for the proposed game are derived. It is shown that in order to maximize its utility (in bits per joule), a user must choose the lowest constellation size that can accommodate the user's delay constraint. This strategy is different from one that would maximize spectral efficiency. Using this framework, the tradeoffs among energy efficiency, delay, throughput and constellation size are ...

  5. Exploring a QoS Driven Scheduling Approach for Peer-to-Peer Live Streaming Systems with Network Coding

    Directory of Open Access Journals (Sweden)

    Laizhong Cui

    2014-01-01

    Full Text Available Most large-scale peer-to-peer (P2P live streaming systems use mesh to organize peers and leverage pull scheduling to transmit packets for providing robustness in dynamic environment. The pull scheduling brings large packet delay. Network coding makes the push scheduling feasible in mesh P2P live streaming and improves the efficiency. However, it may also introduce some extra delays and coding computational overhead. To improve the packet delay, streaming quality, and coding overhead, in this paper are as follows. we propose a QoS driven push scheduling approach. The main contributions of this paper are: (i We introduce a new network coding method to increase the content diversity and reduce the complexity of scheduling; (ii we formulate the push scheduling as an optimization problem and transform it to a min-cost flow problem for solving it in polynomial time; (iii we propose a push scheduling algorithm to reduce the coding overhead and do extensive experiments to validate the effectiveness of our approach. Compared with previous approaches, the simulation results demonstrate that packet delay, continuity index, and coding ratio of our system can be significantly improved, especially in dynamic environments.

  6. Multi-Objective Resource Allocation Scheme for D2D Multicast with QoS Guarantees in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Fangmin Li

    2016-09-01

    Full Text Available Device-to-device (D2D multicast communication can greatly improve the spectrum utilization in a content delivery scenario. However, the co-channel interference and power consumption brought by D2D bring new challenges. All the D2D multicast groups expect to achieve a higher system capacity with less extra energy cost. In this paper, we investigate the uplink resource allocation issue when D2D multicast groups share the resources with other cellular uses (CUs, while guaranteeing a certain level of quality of service (QoS to CUs and D2D users. Firstly we address a flexible tradeoff framework in which the system power consumption and the system capacity (i.e., the number of admitted D2D links are assigned with different weight factors so that these two objectives are jointly considered. Then we propose an efficient resource optimization scheme, which comprises sub-channel allocation and signal-to-interference- plus-noise ratio (SINR assignment. Numerical results validate the effectiveness of the proposed framework, and demonstrate the advantages in dealing with the proposed multi-objective optimization problem.

  7. CROSS-LAYER RESOURCE SCHEDULING WITH QOS GUARANTEES USING ADAPTIVE TOKEN BANK FAIR QUEUING ALGORITHM IN WIRELESS NETWORKS

    Directory of Open Access Journals (Sweden)

    G. INDUMATHI

    2011-06-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM systems are the major cellular platforms for supporting ubiquitous high-speed mobile applications. However, a number of research challenges remain to be tackled. One of the most important challenges is the design of a judicious packet scheduler that will make efficient use of the spectrum bandwidth. Due to the multicarrier nature of the OFDM systems, the applicability and performance of traditional wireless packet scheduling algorithms, which are designed usually for single-carrier systems, are largely unknown. In this paper we present a new scheduler which includes packet scheduling and resource mapping which takes. The proposed algorithm is based on a cross-layer design in that the scheduler is aware of both the channel at the physical layer and the queue state at the data link layer information to achieve proportional fairness while maximizing each user’s packet level QoS performance. The performance of the proposed work is compared to that of the round-robin and weighted fair queuing schedulers. It is observed that from the simulation that the proposed scheduling with adaptive parameter selection provides enhanced performance in terms of queuing delay and spectral efficiency. Also we analyze the achieved fairness of the schemes in terms of different fairness indices available in literature.

  8. Recurrence plots and recurrence quantification analysis of human motion data

    Science.gov (United States)

    Josiński, Henryk; Michalczuk, Agnieszka; Świtoński, Adam; Szczesna, Agnieszka; Wojciechowski, Konrad

    2016-06-01

    The authors present exemplary application of recurrence plots, cross recurrence plots and recurrence quantification analysis for the purpose of exploration of experimental time series describing selected aspects of human motion. Time series were extracted from treadmill gait sequences which were recorded in the Human Motion Laboratory (HML) of the Polish-Japanese Academy of Information Technology in Bytom, Poland by means of the Vicon system. Analysis was focused on the time series representing movements of hip, knee, ankle and wrist joints in the sagittal plane.

  9. [Chronic recurrent multifocal osteomyelitis].

    Science.gov (United States)

    Schilling, F; Eckardt, A; Kessler, S

    2000-01-01

    The aim of this paper is to give a detailed description of the so-called "chronic recurrent multifocal osteomyelitis" (CRMO). The clinical, radiological and histopathological results of an analysis of 29 cases (15 children/adolescents and 14 adults) are presented and correlated to current data from the literature. We could delinate the following points: 1. CRMO is a systemic aseptic inflammation of the bone marrow (Osteitis), it can occur polytopically and association with pustulous dermatologic symptoms is possible. 2. It is not a rare disease 3. Osteomyelitis is probably "reactive" and a plasma-cell sclerotic process with ist own characteristic histologic three-phase course. 4. We could observe 5 specific types of localization which can be documented by X-ray or bone scan. 5. Accompanying arthritis os often present, especially "sympathetic coxitis". 6. The use of drugs in treatment of CRMO (i.e. azithromycin, calcitonin, and bisphosphonates) is discussed. In conclusion we want to point out, that 1. 99mTC bone scan should always be performed when there is suspicion for CRMO to reveal the pattern of affection, 2. the rheumatologist and dermatologist should be contacted, 3. operation is normally not necessary for treatment of the mostly self-limitin disease, and 4. the term "SAPHO syndrome" should be avoided, further differentiation of the diagnosis is necessary.

  10. Chronic recurrent multifocal osteomyelitis.

    Science.gov (United States)

    Roderick, Marion R; Ramanan, Athimalaipet V

    2013-01-01

    Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease occurring primarily in children and adolescents. Episodes of systemic inflammation occur due to immune dysregulation without autoantibodies, pathogens or antigen-specific T cells. CRMO is characterised by the insidious onset of pain with swelling and tenderness over the affected bones. Clavicular involvement was the classical description; however, the metaphyses and epiphyses of long bones are frequently affected. Lesions may occur in any bone, including vertebrae. Characteristic imaging includes bone oedema, lytic areas, periosteal reaction and soft tissue reaction. Biopsies from affected areas display polymorphonuclear leucocytes with osteoclasts and necrosis in the early stages. Subsequently, lymphocytes and plasma cells predominate followed by fibrosis and signs of reactive new bone forming around the inflammation. Diagnosis is facilitated by the use of STIR MRI scanning, potentially obviating the need for biopsy and unnecessary long-term antibiotics due to incorrect diagnosis. Treatment options include non-steroidal anti-inflammatory drugs and bisphosphonates. Biologics have been tried in resistant cases with promising initial results. Gene identification has not proved easy although research in this area continues. Early descriptions of the disease suggested a benign course; however, longer-term follow up shows that it can cause significant morbidity and longer-term disability. Although it has always been thought of as very rare, the prevalence is likely to be vastly underestimated due to poor recognition of the disease.

  11. Recurrent neural collective classification.

    Science.gov (United States)

    Monner, Derek D; Reggia, James A

    2013-12-01

    With the recent surge in availability of data sets containing not only individual attributes but also relationships, classification techniques that take advantage of predictive relationship information have gained in popularity. The most popular existing collective classification techniques have a number of limitations-some of them generate arbitrary and potentially lossy summaries of the relationship data, whereas others ignore directionality and strength of relationships. Popular existing techniques make use of only direct neighbor relationships when classifying a given entity, ignoring potentially useful information contained in expanded neighborhoods of radius greater than one. We present a new technique that we call recurrent neural collective classification (RNCC), which avoids arbitrary summarization, uses information about relationship directionality and strength, and through recursive encoding, learns to leverage larger relational neighborhoods around each entity. Experiments with synthetic data sets show that RNCC can make effective use of relationship data for both direct and expanded neighborhoods. Further experiments demonstrate that our technique outperforms previously published results of several collective classification methods on a number of real-world data sets.

  12. Recurrent Novae in M31

    CERN Document Server

    Shafter, A W; Rector, T A; Schweizer, F; Hornoch, K; Orio, M; Pietsch, W; Darnley, M J; Williams, S C; Bode, M F; Bryan, J

    2014-01-01

    The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova candidates. To pass the initial screen and qualify as a recurrent nova candidate two or more eruptions were required to be coincident within 0.1', although this criterion was relaxed to 0.15' for novae discovered on early photographic patrols. A total of 118 eruptions from 51 potential recurrent nova systems satisfied the screening criterion. To determine what fraction of these novae are indeed recurrent the original plates and published images of the relevant eruptions have been carefully compared. This procedure has resulted in the elimination of 27 of the 51 progenitor candidates (61 eruptions) from further consideration as recurrent novae, with another 8 systems (17 eruptions) deemed unlikely to be recurrent. Of the remaining 16 systems, 12 candidates (32 eruptions) were judged to be recurrent novae, with an additional 4 systems (8 eruptions) b...

  13. Vulvovaginitis candidiasis recurrence during pregnancy.

    Science.gov (United States)

    Fardiazar, Z; Ronaci, F; Torab, R; Goldust, M

    2012-04-15

    Vulvovaginitis is the most common gynecologic condition seen by practitioners rendering primary care to women. Vulvovaginitis Candidiasis (VVC) is the most common type of vaginitis and this study aimed at specifying VVC recurrence during pregnancy. In this prospective study, 150 pregnant women suffering from vaginal excretion, morsus and itching were studied. Initially, the patients were treated using clotrimazole local cream (5 g) for 7 successive days. After initial treatment, the patients were freely visited once a month until delivery considering vaginitis symptoms and VVC recurrence was examined during pregnancy. Mean age of the understudy mothers was 27.26 +/- 3.76. Mean of recurrence number was 0.17 +/- 0.48 during the first trimester. Mean of recurrence number was 0.92 +/- 0.76 during the second trimester. Mean of recurrence number was 2.16 +/- 0.63 during the third trimester. Statistically significant difference was between recurrences during three trimesters of pregnancy (p < 0.001). There is statistically significant difference between mean number of recurrences during three trimesters of pregnancy.

  14. Economic Loan Loss Provision and Expected Loss

    National Research Council Canada - National Science Library

    Hlawatsch, Stefan; Ostrowski, Sebastian

    2010-01-01

    ... adjusted. This however assumes that the loan loss provision and the expected loss are based on a similar economic rationale, which is only valid conditionally in current loan loss provisioning methods according to IFRS...

  15. Optimal Provision of Public Goods

    DEFF Research Database (Denmark)

    Kreiner, Claus Thustrup; Verdelin, Nicolaj

    2009-01-01

    There currently exist two competing approaches in the literature on the optimal provision of public goods. The standard approach highlights the importance of distortionary taxation and distributional concerns. The new approach neutralizes distributional concerns by adjusting the non-linear income...... for the optimal level of a public good without imposing strong assumptions on preferences. This formula shows that distortionary taxation may have a role to play as in the standard approach. However, the main determinants of optimal provision are completely different and the traditional formula with its emphasis...... tax, and finds that this reinvigorates the simple Samuelson rule when preferences are separable in goods and leisure. We provide a synthesis by demonstrating that both approaches derive from the same basic formula. We further develop the new approach by deriving a general, intuitive formula...

  16. Optimal Provision of Public Goods

    DEFF Research Database (Denmark)

    Kreiner, Claus Thustrup; Verdelin, Nicolaj

    There currently exist two competing approaches in the literature on the optimal provision of public goods. The standard approach highlights the importance of distortionary taxation and distributional concerns. The new approach neutralizes distributional concerns by adjusting the non-linear income...... for the optimal level of a public good without imposing any separability assumptions on preferences. This formula shows that distortionary taxation may have a role to play as in the standard approach. However, the main determinants of optimal provision are completely different and the traditional formula with its...... tax, and finds that this reinvigorates the simple Samuelson rule when preferences are separable in goods and leisure. We provide a synthesis by demonstrating that both approaches derive from the same basic formula. We further develop the new approach by deriving a general, intuitive formula...

  17. Imaging for Prostate Cancer Recurrence.

    Science.gov (United States)

    Maurer, Tobias; Eiber, Matthias; Fanti, Stefano; Budäus, Lars; Panebianco, Valeria

    2016-06-01

    Correct identification of metastatic sites in recurrent prostate cancer (PCa) is of crucial importance because it leads to further treatment decisions. To provide an overview on current imaging procedures and their performance in recurrent PCa. Medline search via PubMed was performed with the keywords imaging, recurrent, and prostate cancer as well as more detailed searches including the keywords bone scan, bone scintigraphy, computed tomography, magnetic resonance imaging, positron emission tomography, PET, choline, FDG, prostate-specific membrane antigen, and PSMA, with emphasis on recent literature from 2010 to the present. Non-English published literature was excluded. Abstracts and full-text articles were reviewed and assessed for relevant content. In diagnostic imaging and particularly with newer technologies like positron emission tomography (PET), a profound lack of prospectively designed studies in recurrent PCa has to be noted. In most studies histologic validation has only been performed in a subset of patient cohorts. Heterogeneity of included patient cohorts, lack of standardized assessment, as well as diverging end points, hamper systematic comparison of different image modalities. Thus evidence for currently used imaging in recurrent PCa is only presented descriptively. Computed tomography and magnetic resonance imaging (MRI) as well as bone scintigraphy still represent the standard imaging for recurrent PCa; however, particularly for detection of local recurrence, multiparametric MRI is a valuable imaging modality. PET using choline and particularly tracers against prostate-specific membrane antigen might improve visualization of metastatic lesions. These findings need to be validated in prospective trials. Imaging of recurrent prostate cancer (PCa) is important to guide further treatment. Computed tomography, magnetic resonance imaging, and bone scintigraphy represent the current standard. Positron emission tomography, especially with cancer

  18. Evolutionary Dynamics Of Service Provisioning

    Directory of Open Access Journals (Sweden)

    Harry Katzan, Jr.

    2012-03-01

    Full Text Available Business evolves according to market conditions, based on availability and choice.  The purpose of this paper is to develop a model that describes how service provisioning evolves through a metaphor of selection, survival of the fittest, replication, and mutation.  Clients are free to choose a service provider within a provider category, and the model describes and delineates that behavior.  Equations and examples are given.

  19. Dynamic Prediction Method for Web Service QoS Based on Case-based Reasoning%基于事例推理的Web服务QoS动态预测研究

    Institute of Scientific and Technical Information of China (English)

    刘志中; 王志坚; 周晓峰; 娄渊胜; 尚领

    2011-01-01

    随着面向服务计算技术的发展,网络上出现了大量功能相同而服务质量(QoS)有很大差别的Web服务,QoS逐渐成为评价和选择Web服务的重要依据.目前常用Web服务历史QoS的算术平均值来近似服务的QoS,这种度量方法没有考虑Web服务QoS的动态性,不能准确地度量Web服务的QoS,从而造成被选择的Web服务以较大概率不能满足用户的QoS需求.针对这一问题,提出了一种基于事例推理(CBR)的QoS动态预测方法,该方法将Web服务的QoS与服务的外界环境、所处理的任务类型、任务大小关联起来,利用事例推理技术预测Web服务处理新任务时的QoS.实验结果表明,该预测方法能有效地提高Web服务QoS的准确度.%With the rapid growth of functionally similar Web services over the Web,Quality of Services(QoS) is becoming a decisive factor for Web service selection.However, current QoS measurement method generally takes the mean value of Web service history QoS values as the service's QoS, and hasn't taken the dynamic nature of service performance into consideration, and cannot measure QoS of Web services accurately, as a result, many selected services cannot satisfy consumer's QoS constraints.In our framework, a dynamic QoS prediction method based on Case-Based Reasoning(CBR) was provided, this method associates Web service QoS with the environment of service, task type and task size together,when a new service request comes,CBR is applied to predict QoS of the Web service in completing the new request.Experimental results show that, this method can improve accuracies of QoS of Web service effectively.

  20. STDP in recurrent neuronal networks

    Directory of Open Access Journals (Sweden)

    Matthieu Gilson

    2010-09-01

    Full Text Available Recent results about spike-timing-dependent plasticity (STDP in recurrently connected neurons are reviewed, with a focus on the relationship between the weight dynamics and the emergence of network structure. In particular, the evolution of synaptic weights in the two cases of incoming connections for a single neuron and recurrent connections are compared and contrasted. A theoretical framework is used that is based upon Poisson neurons with a temporally inhomogeneous firing rate and the asymptotic distribution of weights generated by the learning dynamics. Different network configurations examined in recent studies are discussed and an overview of the current understanding of STDP in recurrently connected neuronal networks is presented.

  1. Network Provisioning Using Multimedia Aggregates

    Directory of Open Access Journals (Sweden)

    Joan Vila-Carbó

    2008-01-01

    Full Text Available Multimedia traffic makes network provisioning a key issue. Optimal provisioning of network resources is crucial for reducing the service cost of multimedia transmission. Multimedia traffic requires not only provisioning bandwidth and buffer resources in the network but also guaranteeing a given maximum end-to-end delay. In this paper we present methods and tools for the optimal dimensioning of networks based on multimedia aggregates. The proposed method minimises the network resources reservations of traffic aggregates providing a bounded delay. The paper also introduces several methods to generate multimedia traffic aggregation using real video traces. The method is evaluated using a network topology based on the European GÉANT network. The results of these simulations allow us to discover the relationship between a required delay and the necessary bandwidth reservation (or the achievable utilisation limit. An interesting conclusion of these scenarios is that, following several recommendations, the network utilisation can reach values of around 80% or higher.

  2. Research on Uncertain Information for QoS Routing: Formalization Description and Analysis%QoS路由的不确定信息研究:形式化描述与分析

    Institute of Scientific and Technical Information of China (English)

    桂志波; 胡仲海

    2003-01-01

    In order to guarantee network quality of service(QoS), QoS routing algorithms try to find an optimal path that can provide sufficient resources to accommodate the performance requirements such as delay, jitter, bandwidth, loss rate and so on required by applications. According to unique or multiple metrics, most of the existing routing algorithms take bandwidth and propagation delay as routing metrics and find out the smallest propagation delay path among all widest paths and so on. Realistic networks are a kind of time-varying, dynamic and complex systems, so the network state information required by QoS routing is uncertain inherently. In this paper, formalization description of uncertain information for QoS routing is carried, and its emerging causes are analyzed. Then, the relevant analytical models and optimization algorithms and solutions for QoS routing with uncertain information are discussed based on bandwidth and delay. Moreover, further research on uncertain information for QoS routing is discussed.

  3. The Provision of Paralegal Education in Scotland

    OpenAIRE

    Mcilwhan, Rosemarie; Miller, Alison

    2013-01-01

    This research follows on from research on the Provision of Legal Education in Scotland conducted for the Open University in 2010 and on research mapping the PDA curriculum with the Skills for Justice functional map in 2012. The focus of this research is to map the provision of paralegal education in Scotland and identify gaps in that provision.

  4. 24 CFR 5.321 - Lease provisions.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Lease provisions. 5.321 Section 5... General Requirements § 5.321 Lease provisions. (a) Lease provisions. (1) PHAs which have established pet rules and project owners shall ensure that the leases for all tenants of projects for the elderly...

  5. 7 CFR 250.53 - Contract provisions.

    Science.gov (United States)

    2010-01-01

    ... GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION DONATION OF FOODS FOR USE IN THE UNITED STATES, ITS... Management Companies § 250.53 Contract provisions. (a) Required contract provisions in fixed-price contracts... recipient agency's fixed-price contract with a food service management company. Such provisions must also...

  6. 42 CFR 403.756 - Sunset provision.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Sunset provision. 403.756 Section 403.756 Public... PROVISIONS SPECIAL PROGRAMS AND PROJECTS Religious Nonmedical Health Care Institutions-Benefits, Conditions of Participation, and Payment § 403.756 Sunset provision. (a) Effective date. Beginning with FFY...

  7. 43 CFR 12.948 - Contract provisions.

    Science.gov (United States)

    2010-10-01

    ... administrative, contractual, or legal remedies in instances in which a contractor violates or breaches the... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Contract provisions. 12.948 Section 12.948... Requirements § 12.948 Contract provisions. The recipient shall include, in addition to provisions to define...

  8. 7 CFR 550.50 - Contract provisions.

    Science.gov (United States)

    2010-01-01

    ... legal remedies in instances in which a contractor violates or breaches the contract terms, and provide... 7 Agriculture 6 2010-01-01 2010-01-01 false Contract provisions. 550.50 Section 550.50 Agriculture... Procurement Standards § 550.50 Contract provisions. The recipient shall include, in addition to provisions...

  9. 2 CFR 215.48 - Contract provisions.

    Science.gov (United States)

    2010-01-01

    ... violates or breaches the contract terms, and provide for such remedial actions as may be appropriate. (b... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Contract provisions. 215.48 Section 215.48... Contract provisions. The recipient shall include, in addition to provisions to define a sound and...

  10. 36 CFR 1210.48 - Contract provisions.

    Science.gov (United States)

    2010-07-01

    ... instances in which a contractor violates or breaches the contract terms, and provide for such remedial... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Contract provisions. 1210.48... § 1210.48 Contract provisions. The recipient shall include, in addition to provisions to define a...

  11. 7 CFR 3019.48 - Contract provisions.

    Science.gov (United States)

    2010-01-01

    ... instances in which a contractor violates or breaches the contract terms, and provide for such remedial... 7 Agriculture 15 2010-01-01 2010-01-01 false Contract provisions. 3019.48 Section 3019.48... Standards § 3019.48 Contract provisions. The recipient shall include, in addition to provisions to define...

  12. 24 CFR 84.48 - Contract provisions.

    Science.gov (United States)

    2010-04-01

    ... a contractor violates or breaches the contract terms, and provide for such remedial actions as may... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Contract provisions. 84.48 Section....48 Contract provisions. The recipient shall include, in addition to provisions to define a sound...

  13. 34 CFR 74.48 - Contract provisions.

    Science.gov (United States)

    2010-07-01

    ... remedies in instances in which a contractor violates or breaches the contract terms, and provide for... 34 Education 1 2010-07-01 2010-07-01 false Contract provisions. 74.48 Section 74.48 Education... Procurement Standards § 74.48 Contract provisions. The recipient shall include, in addition to provisions...

  14. Recurrent Wheezing in Infants

    Science.gov (United States)

    Belhassen, Manon; De Blic, Jacques; Laforest, Laurent; Laigle, Valérie; Chanut-Vogel, Céline; Lamezec, Liliane; Brouard, Jacques; Fauroux, Brigitte; de Pouvourville, Gérard; Ginoux, Marine; Van Ganse, Eric

    2016-01-01

    Abstract Recurrent wheezing (RW) has a significant impact on infants, caregivers, and society, but morbidity and related medical resource utilization (MRU) have not been thoroughly explored. The burden of RW needs to be documented with population-based data. The objective was to assess the characteristics, medical management, and MRU of RW infants identified from national claims data. Infants aged from 6 to 24 months, receiving ≥2 dispensations of respiratory drugs within 3 months, and presenting a marker of poor control (index date), were selected. During the 6 months after index date, MRU was described in the cohort and among 3 subgroups with more severe RW, defined as ≥4 dispensations of respiratory drugs, ≥3 dispensations of oral corticosteroids (OCS), or ≥1 hospitalization for respiratory symptoms. A total of 115,489 infants had RW, corresponding to 8.2% of subjects in this age group. During follow-up, 68.7% of infants received inhaled corticosteroids, but only 1.8 U (unit) were dispensed over 6 months, suggesting discontinuous use. Control was mostly inadequate: 61.7% of subjects received OCS, 80.2% antibiotics, and 71.2% short-acting beta-agonists, and medical/paramedical visits were numerous, particularly for physiotherapy. Severe RW concerned 39.0% of the cohort; 32.8% and 11.7% of infants had repeated use of respiratory drugs and OCS, respectively, and 5.5% were hospitalized for respiratory symptoms. In this real-life nation-wide study, RW was common and infants had poor control and high MRU. Interventions are needed to support adequate use of controller therapy, and to improve medical care. PMID:27082618

  15. Opioids and breast cancer recurrence

    DEFF Research Database (Denmark)

    Cronin-Fenton, Deirdre P; Heide-Jørgensen, Uffe; Ahern, Thomas P

    2015-01-01

    BACKGROUND: Opioids may alter immune function, thereby potentially affecting cancer recurrence. The authors investigated the association between postdiagnosis opioid use and breast cancer recurrence. METHODS: Patients with incident, early stage breast cancer who were diagnosed during 1996 through...... 2008 in Denmark were identified from the Danish Breast Cancer Cooperative Group Registry. Opioid prescriptions were ascertained from the Danish National Prescription Registry. Follow-up began on the date of primary surgery for breast cancer and continued until breast cancer recurrence, death......, emigration, 10 years, or July 31, 2013, whichever occurred first. Cox regression models were used to compute hazard ratios and 95% confidence intervals associating breast cancer recurrence with opioid prescription use overall and by opioid type and strength, immunosuppressive effect, chronic use (≥6 months...

  16. Tumoral calcinosis mimicking recurrent osteosarcoma

    National Research Council Canada - National Science Library

    Petscavage, Jonelle M; Richardson, Michael L

    2009-01-01

    We report a case of a tumoral calcinosis mimicking the appearance of recurrent osteosarcoma of the left femur and tibia in a 29-year-old woman with a history of osteosarcoma and chronic renal failure...

  17. Recurrent networks for wave forecasting

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Prabaharan, N.

    , merchant vessel routing, nearshore construction, etc. more efficiently and safely. This paper presents an application of the Artificial Neural Network, namely Backpropagation Recurrent Neural Network (BRNN) with rprop update algorithm for wave forecasting...

  18. Recurrence for random dynamical systems

    CERN Document Server

    Marie, Philippe

    2009-01-01

    This paper is a first step in the study of the recurrence behavior in random dynamical systems and randomly perturbed dynamical systems. In particular we define a concept of quenched and annealed return times for systems generated by the composition of random maps. We moreover prove that for super-polynomially mixing systems, the random recurrence rate is equal to the local dimension of the stationary measure.

  19. Recurrence risks in mental retardation.

    OpenAIRE

    Crow, Y J; Tolmie, J L

    1998-01-01

    Despite improvements in diagnostic techniques and progress made in mapping genes associated with syndromal mental handicap, the estimation of recurrence risks in non-syndromal mental retardation is still dependent on empirical data. Unfortunately, few studies are available to guide the clinician and their results differ significantly. For example, recurrence risks to all sibs of a male index patient with severe mental retardation vary between 3.5% and 14% in commonly quoted series. The presen...

  20. Quality of Service and Service Provisioning on a Competative Market

    NARCIS (Netherlands)

    Nieuwenhuis, Lambertus Johannes Maria; Linnhoff-Popien, C.; Widya, I.A.; Hegering, H.G.

    2000-01-01

    The objective of this paper is to provide an economic and commercial context for QoS research in open distributed environments. The analyses are based on a telecommunications value chain model. The model is used to define possible roles for telecommunications companies, migrating from traditional