WorldWideScience

Sample records for technology ethernet wifi

  1. Usage of Wifi Technology for PLC Programming

    OpenAIRE

    Jaromír ŠKUTA

    2009-01-01

    This contribution describes usage of WIFI technology for programming and parameterization of application in PLC. INSYS WLAN unit from the Microelectronics INSYS Corporation is the base of application. Software access point with using USB WIFI component WL167 is running in industrial PC. Particular PC clients are connecting into network infrastructure PLC by the help of this access point and INSYS WLAN unit. This connection allows configuring and uploading program into this PLC.

  2. EMERGING BROADBAND WIRELESS TECHNOLOGIES: WIFI AND WIMAX

    Directory of Open Access Journals (Sweden)

    Rama K. Raju

    2012-07-01

    Full Text Available Now-a-days there is high demand for broadband mobile services. Traditional high-speed broadband solutions depend on wired technologies namely digital subscriber line (DSL. Wifi and Wimax are useful in providing any type of connectivity such as the fixed or portable or nomadic connectivity without the requirement of LoS (Line of Sight of the base station. Mobile Broadband Wireless Network (MBWN is a flexible and economical solution for remote areas where wired technology and also terminal mobility cannot be provided. The IEEE Wi-Fi and Wi-Max/802.16 are the most promising technologies for broadband wireless metropolitan area networks (WMANs and these are capable of providing high throughput even on long distances with varied QoS. These technologies ensure a wireless network that enables high speed Internet access to residential, small and medium business customers, as well as Internet access for WiFi hot spots and cellular base stations. These offer support to both point-to-multipoint (P2MP and multipoint-to-multipoint (mesh nodes and offers high speed data (voice, video service to the customers. In this paper, we study the issues related to, benefits and deployment of these technologies.

  3. The research and application of Ethernet over RPR technology

    Science.gov (United States)

    Feng, Xiancheng; Yun, Xiang

    2008-11-01

    With service competitions of carriers aggravating and client's higher service experience requirement, it urges the MAN technology develops forward. When the Core Layer and Distribution Layer technology are mature, all kinds of reliability technologies of MAN access Layer are proposed. EoRPR is one of reliability technologies for MAN access network service protection. This paper elaborates Ethernet over RPR technology's many advantages through analyzing basic principle, address learning and key technologies of Ethernet over RPR. EpRPR has quicker replacing speed, plug and play, stronger QoS ability, convenient service deployment, band fairly sharing, and so on. At the same time the paper proposed solution of Ethernet over RPR in MAN, NGN network and enterprise Private network. So, among many technologies of MAN access network, EoRPR technology has higher reliability and manageable and highly effectiveness and lower costive of Ethernet. It is not only suitable for enterprise interconnection, BTV and NGN access services and so on, but also can meet the requirement of carriers' reducing CAPEX and OPEX's and increase the rate of investment.

  4. A study of the security technology and a new security model for WiFi network

    Science.gov (United States)

    Huang, Jing

    2013-07-01

    The WiFi network is one of the most rapidly developing wireless communication networks, which makes wireless office and wireless life possible and greatly expands the application form and scope of the internet. At the same time, the WiFi network security has received wide attention, and this is also the key factor of WiFi network development. This paper makes a systematic introduction to the WiFi network and WiFi network security problems, and the WiFi network security technology are reviewed and compared. In order to solve the security problems in WiFi network, this paper presents a new WiFi network security model and the key exchange algorithm. Experiments are performed to test the performance of the model, the results show that the new security model can withstand external network attack and ensure stable and safe operation of WiFi network.

  5. Wi-Fi Wireless Networks and Technology

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Most agree that wireless networking represent the future of computer and Internet connectivity worldwide.Wi-Fi continues to be the pre-eminent technology for building general-purpose wireless networks. 1 What is Wireless Networking? Wireless networks utilize radio waves and/or microwaves to maintain communication channels between computers.Wireless net- working is a more modern alternative to wired networking that relies on copper and/or fiber optic cabling between network devices.

  6. Radiofrequency exposure from wireless LANs utilizing Wi-Fi technology.

    Science.gov (United States)

    Foster, Kenneth R

    2007-03-01

    This survey measured radiofrequency (RF) fields from wireless local area networks (WLANs) using Wi-Fi technology against a background of RF fields in the environment over the frequency range 75 MHz-3 GHz. A total of 356 measurements were conducted at 55 sites (including private residences, commercial spaces, health care and educational institutions, and other public spaces) in four countries (U.S., France, Germany, Sweden). Measurements were conducted under conditions that would result in the higher end of exposures from such systems. Where possible, measurements were conducted in public spaces as close as practical to the Wi-Fi access points. Additional measurements were conducted at a distance of approximately 1 m from a laptop while it was uploading and downloading large files to the WLAN. This distance was chosen to allow a useful comparison of fields in the far-field of the antenna in the laptop, and give a representative measure of the exposure that a bystander might receive from the laptop. The exposure to the user, particularly if the antenna of the client card were placed against his or her body, would require different measurement techniques beyond the scope of this study. In all cases, the measured Wi-Fi signal levels were very far below international exposure limits (IEEE C95.1-2005 and ICNIRP) and in nearly all cases far below other RF signals in the same environments. An discusses technical aspects of the IEEE 802.11 standard on which WLANs operate that are relevant to determining the levels of RF energy exposure from WLANs. Important limiting factors are the low operating power of client cards and access points, and the low duty cycle of transmission that normally characterizes their operation.

  7. Distribution of combustible gas alarm based on embedded Ethernet technology

    Institute of Scientific and Technical Information of China (English)

    DING Xi-bo; ZHANG Jun-jie; WANG Yang

    2008-01-01

    One kind of combustible gas alarms based on industrial Ethernet was designed to prevent the gas leakage in industrial production sites. The alarm adopted the high performance microprocessor LPC2214 as the main chip. The embedded operating system μC/OS-Ⅱ and TCP/IP protocol stack ulP running on LPC2214 con-stitute a development platform of application of the combustible gas alarm. The test shows that it can automati-cally and continuously detect combustible gas in industrial production sites in several positions;it can give out sound-light alarm and take protective measures immediately against the gas leakage ; and it can send the detected data to PC through the Etheruet interface to realize the remote detection. The designed project provides a refer-ence to design industrial devices based on industrial Ethernet.

  8. Exploration and Study on WIFI Technology%WIFI技术的深入探讨与研究

    Institute of Scientific and Technical Information of China (English)

    王娟; 郭家奇; 刘微

    2011-01-01

    WIFI is a broadband wireless technology with the advantages of super high speed of accessing and wide coverage scope. The paper analyzed the WIFI technology, the application of WIFI and its development trend.%WIFI是一项宽带无线技术,具有接入速率高、覆盖范围大等优点.本文将对WIFI技术、WIFI的应用和发展趋势进行分析.

  9. The CMS Event Builder Demonstrator and Results with Ethernet and Myrinet Switch Technologies

    Institute of Scientific and Technical Information of China (English)

    G.Antchev; L.Berti; 等

    2001-01-01

    The data acquisition system for the CMS experiment at the Large Hadron Collider (LHC) will require a large and high performance event building network.Several architectures and swithch technologies are currently being evaluated.This paper describes demonstrators which have been set up to study a small-scale event builder based on PCs emulating high performance sources and sinks connected via Ethernet or Myrinet switches.Results from ongoing studies,including measurements on throughput and scaling,are presented.

  10. Research on DSP Ethernet Communication Technology%DSP以太网通信技术研究

    Institute of Scientific and Technical Information of China (English)

    董超; 朱军; 史勃

    2012-01-01

    阐述嵌入式以太网通信技术的一般原理.用TMS320F2812的DSP和RTL8019AS以太网控制芯片为电池化成设备控制系统实现了以太网通信功能.详细介绍硬件接口电路的设计,根据DSP的体系结构编写了简化的协议栈,并用DSP专用的实时操作系统DSP/BIOS与协议栈协同工作,最后用以太网测试程序对所设计的软、硬件进行了测试.%The general principle of embedded Ethernet communication technology was introduced. TI' sTMS320F2812 DSP and Realtek's RTL8019AS Ethernet control chip were employed to implement Ethernetcommunication for battery formation equipment control system. The hardware interface circuit design and theDSP-based simplified protocol stack with simplified architecture were presented to cooperate with DSP's DSP/BIOS real-time operation system,and then Ethernet testing program was applied to the software and hardwaredesigned.

  11. Ethernet access network based on free-space optic deployment technology

    Science.gov (United States)

    Gebhart, Michael; Leitgeb, Erich; Birnbacher, Ulla; Schrotter, Peter

    2004-06-01

    The satisfaction of all communication needs from single households and business companies over a single access infrastructure is probably the most challenging topic in communications technology today. But even though the so-called "Last Mile Access Bottleneck" is well known since more than ten years and many distribution technologies have been tried out, the optimal solution has not yet been found and paying commercial access networks offering all service classes are still rare today. Conventional services like telephone, radio and TV, as well as new and emerging services like email, web browsing, online-gaming, video conferences, business data transfer or external data storage can all be transmitted over the well known and cost effective Ethernet networking protocol standard. Key requirements for the deployment technology driven by the different services are high data rates to the single customer, security, moderate deployment costs and good scalability to number and density of users, quick and flexible deployment without legal impediments and high availability, referring to the properties of optical and wireless communication. We demonstrate all elements of an Ethernet Access Network based on Free Space Optic distribution technology. Main physical parts are Central Office, Distribution Network and Customer Equipment. Transmission of different services, as well as configuration, service upgrades and remote control of the network are handled by networking features over one FSO connection. All parts of the network are proven, the latest commercially available technology. The set up is flexible and can be adapted to any more specific need if required.

  12. A Wireless Physiological Signal Monitoring System with Integrated Bluetooth and WiFi Technologies.

    Science.gov (United States)

    Yu, Sung-Nien; Cheng, Jen-Chieh

    2005-01-01

    This paper proposes a wireless patient monitoring system which integrates Bluetooth and WiFi wireless technologies. A wireless portable multi-parameter device was designated to acquire physiological signals and transmit them to a local server via Bluetooth wireless technology. Four kinds of monitor units were designed to communicate via the WiFi wireless technology, including a local monitor unit, a control center, mobile devices (personal digital assistant; PDA), and a web page. The use of various monitor units is intending to meet different medical requirements for different medical personnel. This system was demonstrated to promote the mobility and flexibility for both the patients and the medical personnel, which further improves the quality of health care.

  13. Ethernet traffic measurement

    OpenAIRE

    Santschi, Yann; Corthay, François

    2012-01-01

    The goal of this project is to create a FPGA Ethernet traffic measurement point and interface it with an existing measurement network, named DPMI, that is developed in Blekinge Institute of Technology.

  14. WiFi技术及其应用与发展%WIFI technology and its application and development

    Institute of Scientific and Technical Information of China (English)

    李晓阳

    2012-01-01

    随着网络和通信技术的发展,家庭用户对无线通信的需求与日俱增,WiFi凭借其独特的优势得到了普遍认可,显示出极大的应用前景.简单地介绍了WiFi的含义和发展历程,详细说明了WiFi的特点及技术优势,并将其与有线网络作了比较.最后对WiFi的应用和未来进行讨论.%As the development of network and communication technology the demand of wireless communication from home users grows with each passing day. WiFi with its unique advantages is universal recognition and shows its great potential applications. This article simple introduced the meaning of WiFi and its histoty, it shows the details of WiFi from its characteristics and technological advantages, compared WiFi with cable network. At last it discussed on the future of WiFi.

  15. DESIGN OF ARM BASED REAL TIME PERSONNEL MONITORING SYSTEM USING WI-FI TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Rekha George

    2013-01-01

    Full Text Available Nowadays we constantly come across the need to transfer remote data to monitor center which will be far away from the place of data acquisition. Traditional data acquisition system using wires cannot satisfy these requirements due to its heavy cost and impracticability. Embedded devices with network communication which makes it more powerful and easier to monitor and control remote data, is one of the major outcomes of the developments in the field of communication and networking technologies. This study presents the design of a real time personnel monitoring system based on wireless technology. ARM embedded processor and Wi-Fi module are used as hardware platform in this project. Data transfer over the wireless network is based on the TCP/IP protocol which is a part of the Wi-Fi module. Using this designed system an officer can monitor the personnel in the organization by opening a web page from a place that is geographically far. This system is based on the conversion of serial to wireless data which could be transferred over the wireless network to the server and also over the internet. At the completion of the design, the result shows that data is transferred between the ARM processor and the host system using the wireless network.

  16. Fast BPM data distribution for global orbit feedback using commercial gigabit ethernet technology

    Energy Technology Data Exchange (ETDEWEB)

    Hulsart, R.; Cerniglia, P.; Michnoff, R.; Minty, M.

    2011-03-28

    In order to correct beam perturbations in RHIC around 10Hz, a new fast data distribution network was required to deliver BPM position data at rates several orders of magnitude above the capability of the existing system. The urgency of the project limited the amount of custom hardware that could be developed, which dictated the use of as much commercially available equipment as possible. The selected architecture uses a custom hardware interface to the existing RHIC BPM electronics together with commercially available Gigabit Ethernet switches to distribute position data to devices located around the collider ring. Using the minimum Ethernet packet size and a field programmable gate array (FPGA) based state machine logic instead of a software based driver, real-time and deterministic data delivery is possible using Ethernet. The method of adapting this protocol for low latency data delivery, bench testing of Ethernet hardware, and the logic to construct Ethernet packets using FPGA hardware will be discussed. A robust communications system using almost all commercial off-the-shelf equipment was developed in under a year which enabled retrofitting of the existing RHIC BPM system to provide 10 KHz data delivery for a global orbit feedback scheme using 72 BPMs. Total latencies from data acquisition at the BPMs to delivery at the controller modules, including very long transmission distances, were kept under 100 {micro}s, which provide very little phase error in correcting the 10 Hz oscillations. Leveraging off of the speed of Gigabit Ethernet and wide availability of Ethernet products enabled this solution to be fully implemented in a much shorter time and at lower cost than if a similar network was developed using a proprietary method.

  17. Study of Performance of the combined MIM0 MMSE VBLAST-OFDM for Wi-Fi (802.11n

    Directory of Open Access Journals (Sweden)

    Souhila Ferouani

    2011-09-01

    Full Text Available Wireless technologies such as WiFi and Bluetooth have transformed the world of networks, and this technical revolution is still in its infancy. Wi-Fi (802.11b and g now offers a limited range. It is also very susceptible to interference originating DECT phones and other wireless units. Finally, the Wi-Fi in its current version is much slower in terms of flows, the good old Ethernet. All this should change over to succeed the 802.11g. The 802.11n standard expected to provide data rates higher than an Ethernet connection and double the range. The use of combination VBLAST-MMSE-OFDM with MIMO (multiple input-multiple outputs can leverage the advantage of both methods: the robustness of the link on frequency selective channels for OFDM and robustness of uncorrelated channels for OFDM and robustness of uncorrelated channels for MIMO space-coded. This article discusses the impact of technology (MIMO wireless transmission of type Wi-Fi (802.11n, in a context-VBLAST MMSE-OFDM. We will carry out a study of performance in terms of BER for a Rayleigh channel that characterizes most communication systems without son.

  18. The Predigest Project of TCP/IP Protocol Communication System Based on DSP Technology and Ethernet

    Science.gov (United States)

    hong-you, Wang; san-ping, Zhao

    The paper introduce a predigest project of TCP/IP based on DSP CMOS chip TMS320F2407 and Ethernet interface. The system design the Network Interface Controller using TMS320F2407and TRL8019AS,it simplify TCP/IP, achieve simple protocol stack in DSP, and achieve Data transmission by software program. The experiment indicated that, the communication system constructed by TMS320F2407andTRL8019AS is low cast, simple and reliable.

  19. Evaluation and Critical Technical Study of Li-Fi Compared with Wi-Fi and WiMax Technology

    Directory of Open Access Journals (Sweden)

    Md. Biplob Hossain

    2015-09-01

    Full Text Available Modern life becomes easier and wireless communications play an important role to do so. In computer networking, wireless technology is a modern alternative to networks that use cables. Li-Fi is a wireless communication system in which light is used as a carrier signal instead of traditional radio frequency as in Wi-Fi. Li-Fi is a technology that uses light emitting diodes to transmit data wirelessly. Li-Fi is a form of Visible Light Communication (VLC. VLC uses rapid pulses of light to transmit information wirelessly that cannot be detected by the human eye. In modern age everyone wants to use wireless data but capacity is drying up. Wireless radio frequencies are getting higher, complexities are increasing and RF interferences continue to grow. In order to overcome this problem in future, light –fidelity (Li-Fi become a better technology. This new wireless technology can save a large amount of electricity by transmitting data through the light bulbs. Li-Fi is a better alternative to Wi-Fi and WiMAX in wireless communication. Li-Fi has thousand times greater speed than Wi-Fi and provides security as the visible light is unable to penetrate through the walls, which propose a new era of wireless communication. Such technology has brought not only greener but safer and cheaper future of communication. Despite of numerous advantages of Li-Fi technology, there exist some drawbacks also. Line of sight propagation problem is one of them. So we proposed a new method that not only reduces this problem buy also increase the performance of this technology.

  20. User localization in complex environments by multimodal combination of GPS, WiFi, RFID, and pedometer technologies.

    Science.gov (United States)

    Dao, Trung-Kien; Nguyen, Hung-Long; Pham, Thanh-Thuy; Castelli, Eric; Nguyen, Viet-Tung; Nguyen, Dinh-Van

    2014-01-01

    Many user localization technologies and methods have been proposed for either indoor or outdoor environments. However, each technology has its own drawbacks. Recently, many researches and designs have been proposed to build a combination of multiple localization technologies system which can provide higher precision results and solve the limitation in each localization technology alone. In this paper, a conceptual design of a general localization platform using combination of multiple localization technologies is introduced. The combination is realized by dividing spaces into grid points. To demonstrate this platform, a system with GPS, RFID, WiFi, and pedometer technologies is established. Experiment results show that the accuracy and availability are improved in comparison with each technology individually.

  1. User Localization in Complex Environments by Multimodal Combination of GPS, WiFi, RFID, and Pedometer Technologies

    Directory of Open Access Journals (Sweden)

    Trung-Kien Dao

    2014-01-01

    Full Text Available Many user localization technologies and methods have been proposed for either indoor or outdoor environments. However, each technology has its own drawbacks. Recently, many researches and designs have been proposed to build a combination of multiple localization technologies system which can provide higher precision results and solve the limitation in each localization technology alone. In this paper, a conceptual design of a general localization platform using combination of multiple localization technologies is introduced. The combination is realized by dividing spaces into grid points. To demonstrate this platform, a system with GPS, RFID, WiFi, and pedometer technologies is established. Experiment results show that the accuracy and availability are improved in comparison with each technology individually.

  2. Providing resilience for carrier ethernet multicast traffic

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang

    2009-01-01

    This paper presents an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we detail how multicast traffic, which is essential for e.g. IPTV can be protected. We present Carrier Ethernet resilience methods for linear and ring networks and show by simulation...... that the availability of a multicast connection can be significantly increased by applying relevant resilience techniques....

  3. Providing resilience for carrier ethernet multicast traffic

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang

    2009-01-01

    This paper presents an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we detail how multicast traffic, which is essential for e.g. IPTV can be protected. We present Carrier Ethernet resilience methods for linear and ring networks and show by simulation...

  4. High capacity carrier ethernet transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Zhang, Jiang; Yu, Hao

    2009-01-01

    Ethernet as a transport technology has, up to now, lacked the features such as network layer architecture, customer separation and manageability that carriers require for wide-scale deployment. However, with the advent of PBB-TE and T-MPLS, it is now possible to use Ethernet as a transport...... technology, making the use of Ethernet as a convergence layer for Next Generation Networks a distinct possibility. Triple Play services, in particular IPTV, are expected to be a main drivers for carrier Ethernet, however, a number of challenges must be addressed including QoS enabled control plane, enhanced...... OAM functions, survivability and the increased bandwidth requirements of carrier class systems. This article provides an overview of PBB-TE and T-MPLS and demonstrates how IPTV services can be realized in the framework of Carrier Ethernet. In addition we provide a case study on performing bit error...

  5. Towards 100 gigabit carrier ethernet transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Zhang, Jiang; Yu, Hao

    2010-01-01

    Ethernet as a transport technology has, up to now, lacked the features such as network layer architecture, customer separation and manageability that carriers require for wide-scale deployment. However, with the advent of PBB-TE and TMPLS, it is now possible to use Ethernet as a transport...... technology, making the use of Ethernet as a convergence layer for Next Generation Networks a distinct possibility. Triple Play services, in particular IPTV, are expected to be a main drivers for carrier Ethernet, however, a number of challenges must be addressed including QoS enabled control plane, enhanced...... OAM functions, survivability and the increased bandwidth requirements of carrier class systems. This article provides an overview of PBB-TE and T-MPLS and demonstrates how IPTV services can be realized in the framework of Carrier Ethernet. In addition we provide a case study on performing bit error...

  6. Towards 100 gigabit carrier ethernet transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Zhang, Jiang; Yu, Hao;

    2010-01-01

    Ethernet as a transport technology has, up to now, lacked the features such as network layer architecture, customer separation and manageability that carriers require for wide-scale deployment. However, with the advent of PBB-TE and TMPLS, it is now possible to use Ethernet as a transport...... technology, making the use of Ethernet as a convergence layer for Next Generation Networks a distinct possibility. Triple Play services, in particular IPTV, are expected to be a main drivers for carrier Ethernet, however, a number of challenges must be addressed including QoS enabled control plane, enhanced...... OAM functions, survivability and the increased bandwidth requirements of carrier class systems. This article provides an overview of PBB-TE and T-MPLS and demonstrates how IPTV services can be realized in the framework of Carrier Ethernet. In addition we provide a case study on performing bit error...

  7. High capacity carrier ethernet transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Zhang, Jiang; Yu, Hao;

    2009-01-01

    Ethernet as a transport technology has, up to now, lacked the features such as network layer architecture, customer separation and manageability that carriers require for wide-scale deployment. However, with the advent of PBB-TE and T-MPLS, it is now possible to use Ethernet as a transport...... technology, making the use of Ethernet as a convergence layer for Next Generation Networks a distinct possibility. Triple Play services, in particular IPTV, are expected to be a main drivers for carrier Ethernet, however, a number of challenges must be addressed including QoS enabled control plane, enhanced...... OAM functions, survivability and the increased bandwidth requirements of carrier class systems. This article provides an overview of PBB-TE and T-MPLS and demonstrates how IPTV services can be realized in the framework of Carrier Ethernet. In addition we provide a case study on performing bit error...

  8. DIY WiFi

    CERN Document Server

    Jungnickel, Katrina

    2013-01-01

    Who makes WiFi?Why do different makers matter?What do barbeques and backyards have to do with the internet?This book explores how WiFi is made from the ground up, or in this case from the backyard out. Forged around barbeques, made of found, adapted and off-the-shelf materials and installed in ordinary domestic spaces, this book documents the collective work of individuals committed to making 'Ournet not the internet'.Drawing on rich ethnographic material, Jungnickel's research on community WiFi networking provides an overdue account of the innovative digital cultures and practices of ordinary people making extra-ordinary things. What make-do methods, mods and tales of resourceful ingenuity permit is another way of seeing how technologies come into being. It brings to life an Australian version of WiFi, enriching global studies of wireless technology by signalling the potential of comparative studies. Critically, the book presents the first sustained study of homebrew high-tech backyard technologists who imbu...

  9. The Patent Analysis Based on DII Data of Wifi Technology of Smartphone%基于 DII 检索数据的智能手机Wifi 技术专利分析

    Institute of Scientific and Technical Information of China (English)

    滕蔓; 王昊; 杨慧波

    2013-01-01

    Based on the data retrieved from Derwent Innovation Index and limited by theme as well as IP class number, this paper presents an all-scale patent analysis of wifi technology of smartphone by retrieving, classifying and analyzing the patents registered with SIPO and other IPOs. Qualitative and quantitative methods are also employed in this paper so as to show an overview of the developing trends, ad-vancing process, key labs, and hotspot technicians and so on in the field of wifi technology of smartphone.%  以 Derwent Innovation Index 为数据源,通过主题和 IP 分类号为限定条件,检索全球范围内关于智能手机wifi 技术的相关专利,并对结果进行归类、整理,结合定性和定量的分析方法,从而得出该技术的发展趋势、技术路线、技术领先者、发展热点等信息。

  10. Design and Performance Evaluation of Optical Ethernet Switching Architecture with Liquid Crystal on Silicon-Based Beam-Steering Technology

    Science.gov (United States)

    Cheng, Yuh-Jiuh; Chou, H.-H.; Shiau, Yhi; Cheng, Shu-Ying

    2016-07-01

    A non-blocking optical Ethernet switching architecture with liquid crystal on a silicon-based beam-steering switch and optical output buffer strategies are proposed. For preserving service packet sequencing and fairness of routing sequence, priority and round-robin algorithms are adopted at the optical output buffer in this research. Four methods were used to implement tunable fiber delay modules for the optical output buffers to handle Ethernet packets with variable bit-rates. The results reported are based on the simulations performed to evaluate the proposed switching architecture with traffic analysis under a traffic model captured from a real-core network.

  11. Putting 'Local' Back into Public Wifi Hotspots

    DEFF Research Database (Denmark)

    Korn, Matthias; Klokmose, Clemens Nylandsted

    2012-01-01

    Public Wifi hotspots in cafes and public places are based on wireless local area network technology (WLAN). In contrast to the common understanding of connecting directly to the internet when connecting to a Wifi hotspot, we are proposing to bring the original notion of connecting to a local netw...

  12. WIRELESS FIDELITY (Wi-Fi) BROADBAND NETWORK ...

    African Journals Online (AJOL)

    ES Obe

    market under the name WaveLAN with speeds of 1 Mbit/s to 2 Mbit/s ... Macintosh and open source UNIX and ... The main strength of Wi-Fi is its simplicity and ... technology, Wi-Fi has its weaknesses. The ..... and Operations”, Communications.

  13. Modeling and testing of ethernet transformers

    Science.gov (United States)

    Bowen, David

    2011-12-01

    Twisted-pair Ethernet is now the standard home and office last-mile network technology. For decades, the IEEE standard that defines Ethernet has required electrical isolation between the twisted pair cable and the Ethernet device. So, for decades, every Ethernet interface has used magnetic core Ethernet transformers to isolate Ethernet devices and keep users safe in the event of a potentially dangerous fault on the network media. The current state-of-the-art Ethernet transformers are miniature (explored which are capable of exceptional miniaturization or on-chip fabrication. This dissertation thoroughly explores the performance of the current commercial Ethernet transformers to both increase understanding of the device's behavior and outline performance parameters for replacement devices. Lumped element and distributed circuit models are derived; testing schemes are developed and used to extract model parameters from commercial Ethernet devices. Transfer relation measurements of the commercial Ethernet transformers are compared against the model's behavior and it is found that the tuned, distributed models produce the best transfer relation match to the measured data. Process descriptions and testing results on fabricated thin-film dielectric-core toroid transformers are presented. The best results were found for a 32-turn transformer loaded with 100Ω, the impedance of twisted pair cable. This transformer gave a flat response from about 10MHz to 40MHz with a height of approximately 0.45. For the fabricated transformer structures, theoretical methods to determine resistance, capacitance and inductance are presented. A special analytical and numerical analysis of the fabricated transformer inductance is presented. Planar cuts of magnetic slope fields around the dielectric-core toroid are shown that describe the effect of core height and winding density on flux uniformity without a magnetic core.

  14. Experimental approach for seeing through walls using Wi-Fi enabled software defined radio technology

    Directory of Open Access Journals (Sweden)

    Isaac Cushman

    2016-11-01

    Full Text Available Modern handheld target detection methods are typically restricted to line of sight (LOS techniques. The design of a new method to detect moving targets through non-transparent surfaces could greatly aid the safety of hazardous military and government operations. In this paper, we develop through-wall virtual imaging using Wi-Fi enabled software defined radio to see moving objects and their relative locations. We use LabVIEW and NI Universal Software Radio Peripheral (NI USRP2921 radios with Ettus Research LP0965 directive antennas devices to detect moving objects behind walls by sending and receiving a signal with respect to the USRP's location. Based on the signal-to-interference ratio of our signal (rather than the traditional signal-to-noise method, we could determine the target object behind the wall. The two major applications for this project are: detecting an active shooter that is standing on the other side of the wall and detecting abnormalities in the human body such as breast cancer with more sensitive antennas. Likewise, firefighters, law enforcement officers, and military men would find more practical purposes for the use of this system in their fields. We evaluate the proposed model using experimental results.

  15. Research and Implementation of Power over Ethernet Technology%以太网供电PoE技术的研究与实现

    Institute of Scientific and Technical Information of China (English)

    王景忠; 王俊芳; 于立佳; 王立莹

    2012-01-01

    Power over Ethernet technology defines a method that allows data and DC power to be delivered simultaneously over Ethernet.It can improve the applications of low-power network devices.The paper gives an analysis about the characteristics of PoE technology conforming to IEEE 802.3af standard.The structure and power supply process of the system adopting PoE technology are introduced in detail,and on that base,the power sourcing equipment based on MAX5945 and powered device based on MAX5941 are designed.The engineering practice shows the practicability of the theory and the methods.%以太网供电(Power over Ethernet,POE)技术是一种在以太网上同时传输数据信号和直流电源的方法,促进了低功耗网络设备的应用。阐述了符合IEEE 802.3af标准的以太网供电技术的特点,详细介绍了采用PoE技术的系统构成及其供电过程。在此基础上完成了基于MAX5945的以太网供电设备和基于MAX5941的以太网受电设备的设计。所给出的理论和方法都通过实践检验,具有一定的实用性。

  16. Evaluating multicast resilience in carrier ethernet

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang;

    2010-01-01

    This paper gives an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we show how multicast traffic, which is essential for IPTV can be protected. We detail the ackground for resilience mechanisms and their control and e present Carrier Ethernet...... resilience methods for linear nd ring networks. By simulation we show that the vailability of a multicast connection can be significantly increased by applying protection methods....

  17. Evaluating multicast resilience in carrier ethernet

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang

    2010-01-01

    This paper gives an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we show how multicast traffic, which is essential for IPTV can be protected. We detail the ackground for resilience mechanisms and their control and e present Carrier Ethernet...... resilience methods for linear nd ring networks. By simulation we show that the vailability of a multicast connection can be significantly increased by applying protection methods....

  18. The study on Clock Synchronization Technology for Ethernet%PTP同步技术性能研究

    Institute of Scientific and Technical Information of China (English)

    王晓冬

    2014-01-01

    For the application of network time protocol PTP on ethernet, this paper has made researches on the fucntion and process of PTP and proposed the implemenation soltuion of PTP on NS2 platform. The synchornization performace of PTP on ethernet has been also investigated in this paper through simulation, which indicated that IEEE 1588 PTP on ethernet has excellent synchronization performance which could reach ns level resolution and has good anti-noise capability. The simulation result has proved the validity and feasibility of the proposed solution.%针对网络时间协议PTP在以太网上的应用,研究了PTP协议的功能和流程,提出了PTP协议在NS2平台下的实现方案,并通过仿真研究了PTP协议在以太网环境中的同步性能。研究结果表明,IEEE 1588标准的PTP协议在以太网上具有极佳的同步性能,其同步精度可以达到ns级别,并且具有良好的抗噪能力。数值仿真结果说明了该仿真方案的有效性和可行性。

  19. Distributed Wi-Fi Interference Coordination for Dense Deployments

    DEFF Research Database (Denmark)

    Abinader, Fuad; Choudhury, Sayantan; Souza Jr., Vicente A.

    2017-01-01

    with proper OBSS interference coordination. We propose a novel distributed interference coordination scheme for Wi-Fi scheduled mode operation, and evaluate it through system level simulations. Results indicate that the proposed scheme provides significant improvements over Enhanced Distributed Channel Access......Unlicensed spectrum is increasingly being used by mobile operators to meet the mobile traffic demand, and Wi-Fi is foreseen as one of the technologies for implementing mobile traffic offloading. However, Wi-Fi efficiency does not scale well as node density increases, and IEEE 802.11ax Task Group...... (TGax) was created in 2014 for developing WiFi technology enhancements in dense deployments. This paper investigates Wi-Fi performance in the presence of Overlapping Basic Subscriber Set (OBSS) Wi-Fi networks in indoor dense deployments. We observe that Wi-Fi could benefit from scheduled operation...

  20. Communication Performance Over A Gigabit Ethernet Network

    Directory of Open Access Journals (Sweden)

    Mr.Nitish Meena

    2014-09-01

    Full Text Available A present computing imposes heavy demands on the optical communication network. Gigabit Ethernet technology can provide the required bandwidth to meet these demands. However, it has also involve the communication Impediment to progress from network media to TCP(Transfer control protocol processing. In this paper, present an overview of Gigabit per second Ethernet technology and study the end-to-end Gigabit Ethernet communication bandwidth and retrieval time. Performance graphs are collected using NetPipe in this clearly show the performance characteristics of TCP/IP over Gigabit Ethernet. These indicate the impact of a number of factors such as processor speeds, network adaptors, versions of the Linux Kernel or opnet softwar and device drivers, and TCP/IP(Internet protocol tuning on the performance of Gigabit Ethernet between two Pentium II/350 PCs. Among the important conclusions are the marked superiority of the 2.1.121 and later development kernels and 2.2.x production kernels of Linux or opnet softwar used and that the ability to increase the MTU(maximum transmission unit Further than the Ethernet standard of 1500 could significantly enhance the throughput reachable.

  1. The Design and Implementation of a Low Cost and High Security Smart Home System Based on Wi-Fi and SSL Technologies

    Science.gov (United States)

    Xu, Chong-Yao; Zheng, Xin; Xiong, Xiao-Ming

    2017-02-01

    With the development of Internet of Things (IoT) and the popularity of intelligent mobile terminals, smart home system has come into people’s vision. However, due to the high cost, complex installation and inconvenience, as well as network security issues, smart home system has not been popularized. In this paper, combined with Wi-Fi technology, Android system, cloud server and SSL security protocol, a new set of smart home system is designed, with low cost, easy operation, high security and stability. The system consists of Wi-Fi smart node (WSN), Android client and cloud server. In order to reduce system cost and complexity of the installation, each Wi-Fi transceiver, appliance control logic and data conversion in the WSN is setup by a single chip. In addition, all the data of the WSN can be uploaded to the server through the home router, without having to transit through the gateway. All the appliance status information and environmental information are preserved in the cloud server. Furthermore, to ensure the security of information, the Secure Sockets Layer (SSL) protocol is used in the WSN communication with the server. What’s more, to improve the comfort and simplify the operation, Android client is designed with room pattern to control home appliances more realistic, and more convenient.

  2. Proposal for tutorial: Resilience in carrier Ethernet transport

    DEFF Research Database (Denmark)

    Berger, Michael Stübert; Wessing, Henrik; Ruepp, Sarah Renée

    2009-01-01

    This tutorial addresses how Carrier Ethernet technologies can be used in the transport network to provide resilience to the packet layer. Carrier Ethernet networks based on PBB-TE and T-MPLS/MPLS-TP are strong candidates for reliable transport of triple-play services. These technologies offer...

  3. Study on the Power over Ethernet (POE) Technology%对以太网供电(PoE)技术的研究

    Institute of Scientific and Technical Information of China (English)

    胡云

    2011-01-01

    以太网供电这项创新的技术,通过CAT5/5e/6类非屏蔽双绞线,对网络终端设备既传输数据又提供直流供电,极大地减少部署终端设备的电源和管理成本。结合IEEE802.3af/at标准内容,介绍了以太网供电系统的组成,分析了以太网供电的基本原理,展望了超越IEEE802.3at标准的应用。%The new Power over Ethernet (POE) technology allows Ethernet appliances to transmit data as well as provide DC power through the cat 5/5e and cat 6 unshielded twistedpair cable, greatly reduced the amount of power supply for terminals and the management cost. Combining with IEEE802.3 af/at standard, the paper introduced and the constitution of PoE, analyzed its basic principle and looks forward the application of standard beyond IEEE802.3at.

  4. Issues in WiFi Networks

    Directory of Open Access Journals (Sweden)

    Nicolae Tomai

    2009-06-01

    Full Text Available The paper has four sections. First section is intro in WiFi technology and terminology. The second section shows the security architectures and algorithms used in WiFi networks. Both important mechnisms: encryption/decryption as well as authentication is analyzed within simple IEEE 802.11 aproach in section three and four. The architectures such as WPA or WPA2 are not subject of this paper.

  5. Application Research of WiFi Technology in the Wireless Home Network%WiFi技术在家庭无线网络中的应用研究

    Institute of Scientific and Technical Information of China (English)

    万亮

    2012-01-01

    通过比较几种无线组网技术,说明了WiFi技术在组建家庭无线网络时所拥有的巨大优势,回顾了WiFi技术的发展阶段,论述了WiFi在家庭无线网络中的实现。%Through the comparison of several kinds of wireless networking technology, it's showed that the WiFi technology has great advantages in the formation of a family wireless network. This paper reviews the devel- opment of WiFi technology, and discusses the implementation of WiFi in home wireless network.

  6. LTE OFFLOADING THROUGH WiFi NETWORKS

    Directory of Open Access Journals (Sweden)

    A. N. Steputin

    2015-11-01

    Full Text Available The subject of the article is Wi-Fi offloading of LTE networks as one of the methods for solving a problem of the lack of availability of network resources in the future. Comparison of mobile networks offloading technologies, such as femtocells, Small Cells and Wi-Fi, is given. Architecture of cooperative LTE+Wi-Fi network including both new network components and new functions for standard LTE network components is presented as well as interaction between components. Special attention is paid to the usage of mobile IP protocols providing connection to the LTE Core both by trusted and untrusted Wi-Fi access. Evaluation of implementation effectiveness and prospective of the technology is given. The relation between amounts of users reconnected to Wi-Fi, data rate of LTE network and amount of access points are submitted as a part of the simulation of user’s equipment transition process from LTE to Wi-Fi network. A conclusion based on the research is made that stepwise phase-in of this technology enables to solve the problem of mobile network resources shortage in metropolises due to permanent traffic growth. It is presented that access points addition and transference of the customers to Wi-Fi network significantly reduce the overload on the base station herewith it increases some data rate with preservation of quality of provided services.

  7. Ethernet Operation Administration and Maintenance ; Opportunities for the NREN community

    NARCIS (Netherlands)

    Prins, M.J.; Malhotra, R.

    2011-01-01

    Ethernet started its life as a Local Area Network technology and initially did not have Operations, Administration and Maintenance (OAM) features like IP Ping, IP Traceroute and SDH Loss of Frame. Monitoring and management was mainly done on the IP level. In the case of delivery of Ethernet connecti

  8. Wi—Fi无线网络技术在校园网中的应用%The Wi-Fi Wireless NetworkTechnology In The Campus Network

    Institute of Scientific and Technical Information of China (English)

    程杰

    2012-01-01

    Wi-Fi wireless network technology matures to replace the traditional Bluetooth, HomeRF technology in aH walks of life. Especially it' s widely used in many campus. Mobility, convenience, high-speed and openness and other characteristics, they have brought me a lot of convenience, but it is these innate characteristics, they have the security risks of concern. This article will focus on analyzing the Wi-Fi wireless technology services for the campus, how to plan and construct the wireless campus a little recommendations and raised a little advice on wireless network security.%随着计Wi—Fi无线网络技术日趋成熟,其取代传统的蓝牙技术、HomeRF技术,在各行各业特别是校园中被广泛的使用。其所具备的移动性、便捷性、高速性及开放性等特征,给我带来了诸多便利,但也正是这些与生俱来的特点,其所具备的安全隐患也备受关注。本文将重点分析Wi—Fi无线技术如何为校园服务、如何规划建设无线校园及对无线网络安全提出些许建议。

  9. Industrial Communication with Ethernet and Fieldbuses

    Institute of Scientific and Technical Information of China (English)

    Martin Müller

    2004-01-01

    @@ With its open protocol structures, its strengths in universal communication and its free choice of topology, Ethernet has long since established itself as the standard in office communication. In the field of industrial communications, on the other hand, various Fieldbuses have emerged to date as the defacto standard. This is largely due to geographical reasons or specific application requirements. In countless machines and systems worldwide, they serve to connect sensors and actuators with control technology. Ethernet is already used in the industry for communicating between various machines and subsystems. It is therefore natural and obvious that the industry should also be interested in using the global communication standard Ethernet for connecting sensors and actuators. However, this is not possible without modifying or adding to the standard Ethernet technology. The reasons for this include the complexity of the protocol, the processing power required in each simple device and the increased project efforts.As a result, various companies and organizations are working on Ethernet extensions, especially those that will enable real-time processing.

  10. Embedded Ethernet Controller using ARM LPC2138

    Directory of Open Access Journals (Sweden)

    S.P.Magadum

    2013-05-01

    Full Text Available — With the development of network technology and communication technology needs that industrial control can be completed via network has become a trend. Here the proposed system consists of an ARM processor LPC2148 with an external Ethernet interface controller WIZ810MJ and the whole system can function as a web server. In the system the data can be transmitted transparently between host and serial device. The host can communicate with any serial device connected Ethernet without knowing each other’s physical location. Since ARM processor has fast execution capability and Ethernet standard can provide internet access with reasonable speed, this system is suitable for enhancing security in industrial conditions by remotely monitoring various industrial appliances where high safety and care is a necessity. There is no doubt that this system will be useful for a wide variety of industrial applications.

  11. Prototipo de RINA sobre Ethernet

    OpenAIRE

    Bergesio, Leonardo

    2013-01-01

    Este PFM se enmarca dentro del trabajo a realizar por el proyecto IRATI. IRATI es un proyecto STReP (Specific Targeted Research Project) financiado por la Unión Europea dentro del programa FP7 (Seventh Framework Programme for Research and Technological Development). El objetivo general de IRATI es conseguir una mayor compresión y exploración de RINA. El trabajo que se reportará en este PFM es (aproximadamente) la primera fase del diseño y desarrollo de un prototipo de RINA sobre Ethernet en e...

  12. Wi-Fi Coexistence with Duty Cycled LTE-U

    OpenAIRE

    Pang, Yimin; Babaei, Alireza; Andreoli-Fang, Jennifer; Hamzeh, Belal

    2016-01-01

    Coexistence of Wi-Fi and LTE-Unlicensed (LTE-U) technologies has drawn significant concern in industry. In this paper, we investigate the Wi-Fi performance in the presence of duty cycle based LTE-U transmission on the same channel. More specifically, one LTE-U cell and one Wi-Fi basic service set (BSS) coexist by allowing LTE-U devices transmit their signals only in predetermined duty cycles. Wi-Fi stations, on the other hand, simply contend the shared channel using the distributed coordinati...

  13. WIFI and WIMAX Optimization Design of Transmission and Application

    Science.gov (United States)

    Wang, Peng; Wu, Xian Li

    WIFI (Wireless Fidelity) and WIMAX (Worldwide Interoperability for Microwave Access) using OFDM / OFDMA, MIMO technology to achieve speeds in a unified platform for data, voice, high-definition video and other wireless transmission, For many industries of wireless communication may be short, very considerable practical prospect. This paper focuses on WIFI and WIMAX transmission optimization design, including space-time coding (abbreviated as: STC), multiple-access control (MAC) protocol of the mathematical model; traffic channel terminal mobility cross-layer design to achieve multi-layer co-optimization, improve the WIFI and WIMAX, transmission efficiency, making WIFI and WIMAX transmission are more reasonable.

  14. WiFi技术助推外语语音室向智慧语言实验室转型%The Transformation of the Foreign Language Lab to the Smart Language Lab Boosted by WiFi Technology

    Institute of Scientific and Technical Information of China (English)

    郭迎

    2016-01-01

    随着信息技术与网络技术的高速发展,WiFi技术改变了人们访问互联网的方式,使人们摆脱了电线和网线的束缚,具有极大的应用前景。从智慧语言实验室的应用出发,阐述了WiFi技术的特点及优势,介绍了智慧语言实验室的特点及其WiFi网络规划,讨论了WiFi技术在智慧语言实验室发展中所起的重要作用。%Along with the high speed development of information technology and network technology, the WiFi technology, which has changed people’s way to access the Internet,makes people get rid of the bondage of wires and cables, and has a great application prospect. Starting from the application of the smart language lab, this paper expounds the characteristics and advantages of the WiFi technology, introduces the features of the smart language lab and its WiFi network planning, and discusses the important role of the WiFi technology in the development of the smart language lab.

  15. Design and Implement of WiFi Wireless Measurement and Control Network%基于WiFi的无线测控系统设计与实现

    Institute of Scientific and Technical Information of China (English)

    曾磊; 张海峰; 侯维岩

    2011-01-01

    本文研究了WiFi技术应用于工业测控网络,开发出WiFi无线终端和WiFi无线接入点设备.WiFi无线终端实现工业现场设备的数据采集与无线传送.WiFi无线网络传输速率高,具有较强的抗干扰能力,适合在恶劣的工业现场环境中使用.WiFi无线接入点设备实现了与有线网络的无缝连接.由核心处理器、电源电路、WiFi无线模块、以太网功能模块、SPI电路、LED指示灯、复位电路等构成硬件电路设计.介绍了Linux操作系统的移植和WiFi无线模块驱动程序的移植,以及相应的软件流程图.该系统解决了工业现场环境中设备不能布线或很难布线时的数据采集问题.%This dissertation studies WiFi technology for industrial measurement and control network. A WiFi wireless terminal and a WiFi wireless access point device are developed. The WiFi wireless terminal realizes data acquisition of the devices in industrial field and wireless transmission. The WiFi wireless network has high transfer rate which is with a strong and - interference ability and suitable for harsh industrial field environment. The WiFi wireless access point device achieves seamless connectivity with the wired network. The hardware circuit consists of core processor, power supply circuit, WiFi wireless module, Ethernet module, SPI circuit, LED indicator and reset circuit. Transplantation of Linux operating system, WiFi wireless driver program, and the software flow chart are introduced. The system resolves the data acquisition problems when it is difficult or impossible to wire in industrial field environment.

  16. Ethernet ring protection with managed FDB using APS payload

    Science.gov (United States)

    Im, Jinsung; Ryoo, Jeong-dong; Joo, Bheom Soon; Rhee, J.-K. Kevin

    2007-11-01

    Ethernet ring protection (ERP) is a new technology based on OAM (operations, administration, and maintenance) being standardized by the ITU-T G.8032 working group. In this paper, we present the recent development of Ethernet ring protection which is called FDB (filtering database) flush scheme and propose a new Ethernet ring protection technique introducing a managed FDB using APS to deliver information how to fix FDB selectively. We discuss the current development of the ERP technology at ITU-T and performance comparisons between different proposals.

  17. WiFi技术在医院物联网中的应用研究%Research on WiFi Technology for Medical-use Internet-of-Things

    Institute of Scientific and Technical Information of China (English)

    温浩杰; 丁京杰

    2015-01-01

    Aiming at the application of WiFi technology in hospital in IOT, this article outlines the research background and the research status at home and abroad, after that it introduces the relevant knowledge and theory of the Internet of Things and WiFi technology. IOT sensing terminal was designed based on WiFi technology and WiFi technology into a small volume and low-cost embedded systems was introduced in the form of "ARM+WiFi SoC". The driver for WiFi chip on the physical layer and trans-planted embedded TCP/IP protocol stack on the network layer and the transport layer was developed, after that the upper layer application was also developed which could send acquisited data by Socket. The system reaches the primary goal by testing.%针对WiFi技术在医院物联网中的应用,通过ARM+WiFi SoC的方式,设计基于WiFi技术的医院物联网传感终端,在小体积低成本的嵌入式系统上实现WiFi功能。在物理层开发WiFi芯片的驱动程序,在网络层和传输层移植嵌入式TCP/IP协议栈,并开发上层应用实现数据采集和Socket发送;结合医院物联网的具体应用,将所开发的WiFi体温采集终端投入到临床应用中,经验证,WiFi数据采集终端达到了预期的效果。

  18. Wi-Fi Coexistence with Duty Cycled LTE-U

    Directory of Open Access Journals (Sweden)

    Yimin Pang

    2017-01-01

    Full Text Available Coexistence of Wi-Fi and LTE-Unlicensed (LTE-U technologies has drawn significant concern in industry. In this paper, we investigate the Wi-Fi performance in the presence of duty cycle based LTE-U transmission on the same channel. More specifically, one LTE-U cell and one Wi-Fi basic service set (BSS coexist by allowing LTE-U devices to transmit their signals only in predetermined duty cycles. Wi-Fi stations, on the other hand, simply contend the shared channel using the distributed coordination function (DCF protocol without cooperation with the LTE-U system or prior knowledge about the duty cycle period or duty cycle of LTE-U transmission. We define the fairness of the above scheme as the difference between Wi-Fi performance loss ratio (considering a defined reference performance and the LTE-U duty cycle (or function of LTE-U duty cycle. Depending on the interference to noise ratio (INR being above or below −62 dbm, we classify the LTE-U interference as strong or weak and establish mathematical models accordingly. The average throughput and average service time of Wi-Fi are both formulated as functions of Wi-Fi and LTE-U system parameters using probability theory. Lastly, we use the Monte Carlo analysis to demonstrate the fairness of Wi-Fi and LTE-U air time sharing.

  19. Jet Engine Control Using Ethernet with a BRAIN (Postprint)

    Science.gov (United States)

    2008-07-01

    of isolation against environment or system faults, such as ground faults or lightning (e.g. by being able to be transformer coupled). Interlocking...Braided Ring Availability Integrity Network. SAE World Congress. Paper No 2007-01-1492. 2007. [IEC04] IEC . “Real Time Ethernet Control Automation...Technology (EtherCAT)”, Proposal for a Publicly Available Specification for Real-Time Ethernet, document IEC , 65C/355/NP, Date of circulation: 2004

  20. Reliability in automotive ethernet networks

    DEFF Research Database (Denmark)

    Soares, Fabio L.; Campelo, Divanilson R.; Yan, Ying;

    2015-01-01

    This paper provides an overview of in-vehicle communication networks and addresses the challenges of providing reliability in automotive Ethernet in particular.......This paper provides an overview of in-vehicle communication networks and addresses the challenges of providing reliability in automotive Ethernet in particular....

  1. Security of Mobile Devices and Wi-Fi Networks

    OpenAIRE

    Hong, Zimeng

    2015-01-01

    Along with the progress of times and the development of science and technology, mobile devices have become more and more popular. At the same time, an increasing number of Wi-Fi networks are being built for the demand of mobile devices. Therefore, the security between mobile devices and Wi-Fi networks became a main object in the IT area. The purpose of the thesis is to analyze security threats and give relative advises for all the mobile device and Wi-Fi network users. The thesis mainly ta...

  2. Ethernet-Based Services for Next Generation Networks

    Science.gov (United States)

    Hernandez-Valencia, Enrique

    Over the last few years, Ethernet technology and services have emerged as an indispensable component of the broadband networking and telecommunications infrastructure, both for network operators and service providers. As an example, Worldwide Enterprise customer demand for Ethernet services by itself is expected to hit the 30B US mark by year 2012. Use of Ethernet technology in the feeder networks that support residential applications, such as "triple play" voice, data, and video services, is equally on the rise. As the synergies between packet-aware transport and service oriented equipment continue to be exploited in the path toward transport convergence. Ethernet technology is expected to play a critical part in the evolution toward converged Optical/Packet Transport networks. Here we discuss the main business motivations, services, and technologies driving the specifications of so-called carrier Ethernet and highlight challenges associated with delivering the expectations for low implementation complexity, easy of use, provisioning and management of networks and network elements embracing this technology.

  3. Coordinated Dynamic Spectrum Management of LTE-U and Wi-Fi Networks

    OpenAIRE

    2015-01-01

    This paper investigates the co-existence of Wi-Fi and LTE in emerging unlicensed frequency bands which are intended to accommodate multiple radio access technologies. Wi-Fi and LTE are the two most prominent access technologies being deployed today, motivating further study of the inter-system interference arising in such shared spectrum scenarios as well as possible techniques for enabling improved co-existence. An analytical model for evaluating the baseline performance of co-existing Wi-Fi...

  4. Implementation of Embedded Ethernet Based on Hardware Protocol Stack in Substation Automation System

    Institute of Scientific and Technical Information of China (English)

    MA Qiang; ZHAO Jianguo; LIU Bingxu

    2008-01-01

    Embedded Ethernet technology has been utilized increasingly widely as the communication mode in the substation automation system (SAS). This paper introduces the current applying situation about embedded Ethernet in SAS First. After analyzing the protocol levels used in SAS based on embedded Ethernet and the differences between the TCP and UDP, UDP/IP is selected as the communication protocol between the station-level and bay-level devices for its real-time characteristic. Then a new kind of implementation of the embedded Ethernet is presented based on hardware protocol stack. The designed scheme can be implemented easily, reduce cost significantly and shorten developing cycle.

  5. Ethernet for Aerospace Applications - Ethernet Heads for the Skies

    Science.gov (United States)

    Grams, Paul R.

    2015-01-01

    One of the goals of aerospace applications is to reduce the cost and complexity of avionic systems. Ethernet is a highly scalable, flexible, and popular protocol. The aerospace market is large, with a forecasted production of over 50,000 turbine-powered aircraft valued at $1.7 trillion between 2012 and 2022. Boeing estimates demand for commercial aircraft by 2033 to total over 36,000 with a value of over $5 trillion. In 2014 US airlines served over 750 million passengers and this is growing over 2% yearly. Electronic fly-by-wire is now used for all airliners and high performance aircraft. Although Ethernet has been widely used for four decades, its use in aerospace applications is just beginning to become common. Ethernet is the universal solution in commercial networks because of its high bandwidths, lower cost, openness, reliability, maintainability, flexibility, and interoperability. However, when Ethernet was designed applications with time-critical, safety relevant and deterministic requirements were not given much consideration. Many aerospace applications use a variety of communication architectures that add cost and complexity. Some of them are SpaceWire, MIL-STD-1553, Avionics Full Duplex Switched Ethernet (AFDX), and Time-Triggered Ethernet (TTE). Aerospace network designers desire to decrease the number of networks to reduce cost and effort while improving scalability, flexibility, openness, maintainability, and reliability. AFDX and TTE are being considered more for critical aerospace systems because they provide redundancy, failover protection, guaranteed timing, and frame priority and are based on Ethernet IEEE 802.3. This paper explores the use of AFDX and TTE for aerospace applications.

  6. User Localization in Complex Environments by Multimodal Combination of GPS, WiFi, RFID, and Pedometer Technologies

    OpenAIRE

    Trung-Kien Dao; Hung-Long Nguyen; Thanh-Thuy Pham; Eric Castelli; Viet-Tung Nguyen; Dinh-Van Nguyen

    2014-01-01

    Many user localization technologies and methods have been proposed for either indoor or outdoor environments. However, each technology has its own drawbacks. Recently, many researches and designs have been proposed to build a combination of multiple localization technologies system which can provide higher precision results and solve the limitation in each localization technology alone. In this paper, a conceptual design of a general localization platform using combination of multiple localiz...

  7. 基于ARM和WI-FI技术的大麦田间监控系统设计%Barley field monitoring system based on the ARM and WI-FI technology

    Institute of Scientific and Technical Information of China (English)

    毛红玉; 高晓阳; 李红岭; 张明艳; 杨占峰; 孔彦龙; 杨倩

    2014-01-01

    This paper presented a monitoring system which carried out barley images acquisition and wireless transmission based on ARM and WI-FI technology.The system used the wireless monitoring net-work coupled with PC under the control of monitoring software designed,employed WI-FI wireless commu-nication and adopted wireless sensor network and ARM precessor which had realized barely video acquisi-tion and automatic wireless transmission.The build client system displayed 25 frames per second to meet the requirement.%试验介绍了一种基于 ARM和 WI-FI 技术的大麦图像采集与无线传输系统的设计。系统构建了基于Linux的嵌入式系统的无线监控网络,采用 WI-FI 无线通信技术,将大麦田间图像信息经由无线传感器网络和ARM控制器处理,在设计的视频采集软硬件控制下,实现了大麦生长视频信息的自动采集和无线传输,结果表明:搭建系统的客户端能满足25帧/s显示的视频流要求。该研究对发展现代农业生产和实现大麦栽培决策信息化具有重要意义。

  8. Carrier ethernet network control plane based on the Next Generation Network

    DEFF Research Database (Denmark)

    Fu, Rong; Wang, Yanmeng; Berger, Michael Stubert

    2008-01-01

    architecture of the next generation network (NGN). As an essential candidate among the NGN transport technologies, the definition of Carrier Ethernet (CE) is also introduced here. The second part of this paper depicts the contribution on the T-MPLS based Carrier Ethernet network with control plane based on NGN...

  9. 基于WIFI技术的搜救小车的设计%Design of Search and Rescue Vehicle Based on WIFI Technology

    Institute of Scientific and Technical Information of China (English)

    陆旻忆; 宋林桂

    2015-01-01

    为了在灾难现场等复杂环境下进行生命迹象、视频图像数据、环境参数等现场环境的实时监测,文章设计一种基于WIFI技术的搜救小车。Windows监控端通过RT5350路由器与STC12C5A60S2单片机通信,发出控制信号给直流马达控制器,实现小车行动控制。热释电模块、摄像头模块、温度传感器模块、烟雾传感器模块进行生命迹象、视频图像数据、温度数据、有害气体数据等现场环境信息的采集,并实时回传给Windows监控端并显示。%In order to carry out the real-time monitoring of life signs,video image data,environmental parameters and so on in the disaster scene,this paper designs a search and rescue car based on WIFI technology.Windows monitoring terminal sends out the control signal to the DC motor controller for controling the car operation through RT5350 router and STC12C5A60S2 microcontroller communication.Pyroelectric power module,camera module,temperature sensor module and smoke sensor module detect any signs oflife,video,temperature and harmful gases in the field,and return to monitor the Windows terminal and display in real time.

  10. 10BASE5 Ethernet Cable & Vampire Tap

    CERN Multimedia

    1983-01-01

    10BASE5 Thick Ethernet Cable, 10Mbit/sec. In the 1980s and early 1990's, Ethernet became more popular and provided a much faster data transmission rate. This cable is one of the first ethernet cables from 1983, a thick, bulky affair. Computers were attached via "Vampire Taps" which were connectors screwed straight through the shielding of the cable.

  11. Low Cost Network Emulator with Ethernet and E1 Interfaces

    Directory of Open Access Journals (Sweden)

    Zbynek Kocur

    2010-01-01

    Full Text Available Contemporary Next Generation Networks (NGN are mainly built on the Internet Protocol (IP and Ethernet. Major challenge for emerging types of wired and wireless IP-based networks is to provide an adequate Quality of Service (QoS for different services. The quality of evaluation requires a detailed knowledge of the performance requirements for particular services and applications. The paper is primarily oriented to the end-to-end testing for the Ethernet-based terminal equipment. The low cost Ethernet network emulator was developed on the Department of Telecommunication Technology of the Faculty of Electrical Engineering of the Czech Technical University in Prague. The extension for emulation network with the E1 interfaces and TDM over IP transmission can be used with external converters.

  12. FPGA Implementation of Real-Time Ethernet for Motion Control

    Directory of Open Access Journals (Sweden)

    Chen Youdong

    2013-01-01

    Full Text Available This paper provides an applicable implementation of real-time Ethernet named CASNET, which modifies the Ethernet medium access control (MAC to achieve the real-time requirement for motion control. CASNET is the communication protocol used for motion control system. Verilog hardware description language (VHDL has been used in the MAC logic design. The designed MAC serves as one of the intellectual properties (IPs and is applicable to various industrial controllers. The interface of the physical layer is RJ45. The other layers have been implemented by using C programs. The real-time Ethernet has been implemented by using field programmable gate array (FPGA technology and the proposed solution has been tested through the cycle time, synchronization accuracy, and Wireshark testing.

  13. Framed bit error rate testing for 100G ethernet equipment

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Ruepp, Sarah Renée; Berger, Michael Stübert

    2010-01-01

    The Internet users behavioural patterns are migrating towards bandwidth-intensive applications, which require a corresponding capacity extension. The emerging 100 Gigabit Ethernet (GE) technology is a promising candidate for providing a ten-fold increase of todays available Internet transmission...... rate. As the need for 100 Gigabit Ethernet equipment rises, so does the need for equipment, which can properly test these systems during development, deployment and use. This paper presents early results from a work-in-progress academia-industry collaboration project and elaborates on the challenges...... of performing bit error rate testing at 100Gbps. In particular, we show how Bit Error Rate Testing (BERT) can be performed over an aggregated 100G Attachment Unit Interface (CAUI) by encapsulating the test data in Ethernet frames at line speed. Our results show that framed bit error rate testing can...

  14. Android平台上WiFi技术在商场员工定位系统中的应用%Application of WiFi Technology in Staff Positioning System on Android Platform

    Institute of Scientific and Technical Information of China (English)

    裴文莲; 詹林

    2013-01-01

    Benefited from the mature GPS technology, outdoor positioning accuracy has been satisfied, while with the increasing number of large buildings, indoor locating application is becoming more important. Android mobile phone provides free Internet access service, such as WiFi and GPRS, so that users can easily connect to network. By comparing different positioning technologies , on the basis of the comparison, WiFi positioning technology is applied to Android platform on a smart phone. This paper realizes large department store positioning service of staff, and a LBS application system which can communicate betueen the client and the server.%得益于成熟的GPS技术,室外定位精度已经让用户比较满意了,然而随着大型建筑物的增多,室内定位应用越发显得重要.Android手机提供了无线WiFi及GPRS等免费上网功能,用户可以方便地连接到网络.本文在对不同定位技术优劣性比较的基础上,将WiFi定位技术运用到Android平台智能手机上,研究大型商场内员工定位服务,实现客户端和服务器端相互通信的LBS应用系统.

  15. Flow Monitoring Experiences at the Ethernet-Layer

    NARCIS (Netherlands)

    Hofstede, Rick; Drago, Idilio; Sperotto, Anna; Pras, Aiko; Lehnert, Ralf

    2011-01-01

    Flow monitoring is a scalable technology for providing summaries of network activity. Being deployed at the IP-layer, it uses fixed flow definitions, based on fields of the IP-layer and higher layers. Since several backbone network operators are considering the deployment of (Carrier) Ethernet in th

  16. Framed bit error rate testing for 100G ethernet equipment

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Ruepp, Sarah Renée; Berger, Michael Stübert;

    2010-01-01

    The Internet users behavioural patterns are migrating towards bandwidth-intensive applications, which require a corresponding capacity extension. The emerging 100 Gigabit Ethernet (GE) technology is a promising candidate for providing a ten-fold increase of todays available Internet transmission...

  17. WiFi in Schools, Electromagnetic Fields and Cell Phones: Alberta Health Fact Sheet

    Science.gov (United States)

    Alberta Education, 2012

    2012-01-01

    Wireless devices and the networks that support them are becoming more common in Alberta schools. WiFi is a wireless networking technology that allows computers and other devices to communicate over a wireless signal. Typically the signal is carried by radio waves over an area of up to 100 meters. Through the implementation of a WiFi network,…

  18. Passive WiFi monitoring of the rhythm of the campus

    NARCIS (Netherlands)

    Kalogianni, E.; Sileryte, R.; Lam, M.; Zhou, K.; Van der Ham, M.; Van der Spek, S.C.; Verbree, E.

    2015-01-01

    Within this research-driven project, passive WiFi monitoring of WiFi enabled devices was used to detect users (students, employees, visitors) of buildings at the campus of Delft University of Technology to gain insight into the Rhythm of the Campus: the occupation, duration of stay and moving

  19. Passive WiFi monitoring of the rhythm of the campus

    NARCIS (Netherlands)

    Kalogianni, E.; Sileryte, R.; Lam, M.; Zhou, K.; Van der Ham, M.; Van der Spek, S.C.; Verbree, E.

    2015-01-01

    Within this research-driven project, passive WiFi monitoring of WiFi enabled devices was used to detect users (students, employees, visitors) of buildings at the campus of Delft University of Technology to gain insight into the Rhythm of the Campus: the occupation, duration of stay and moving patter

  20. A Design of Smarthome Control System Based on Wi-Fi Technology%一种基于Wi-Fi技术的智慧家居控制系统的研制

    Institute of Scientific and Technical Information of China (English)

    李永新; 邓邹超; 柴健强; 吴登鹏; 朱耀东

    2014-01-01

    本文介绍了一种基于Wi-Fi技术的智慧家居控制系统的研制。该系统以PIC24单片机作为主控制器,外扩Wi-Fi无线通讯模块,通过室内无线路由,可实现常见家居电器的远程控制。手机客户端软件采用基于HTML5的Phone Gap技术,可方便安装于 Android,IOS等操作系统。文中重点介绍了智能LED照明系统的开发,该照明系统具有调光调色、时钟、音乐和温度等功能。%A design of smarthome control system based on Wi-Fi technology is introduced in this paper. This system uses the PIC24 MCU as the main controller and can realize expediently remote control of household appliances through expanding Wi-Fi communication module and indoor wireless router. Mobile client software is programmed by HTML5 based on the phone gap technology, and can install easily to android or IOS. The intelligent LED lighting system is discussed in detail, which can adjust brightness and warm of LED lighting, and has some functions such as clock、MP3 player and room thermometer.

  1. Physical Layer Ethernet Clock Synchronization

    Science.gov (United States)

    2010-11-01

    42 nd Annual Precise Time and Time Interval (PTTI) Meeting 77 PHYSICAL LAYER ETHERNET CLOCK SYNCHRONIZATION Reinhard Exel , Georg...5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...Austrian Academy of Sciences Viktor Kaplan StraÃe 2, A-2700 Wiener Neustadt, Austria 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING

  2. The Design of Real-time Monitoring System forAgricultural Greenhouse Environment Based on WIFI Technology%基于WIFI技术的农业大棚环境实时监测系统的设计

    Institute of Scientific and Technical Information of China (English)

    宋林桂; 陈清

    2014-01-01

    本文提出了基于WIFI技术的农业大棚环境实时监测系统的设计思想,通过STM32F103C8T6微控制器和环境监测传感器实时地监测大棚里的环境温湿度、光照、土壤湿度、CO2浓度、视频等环境信息并通过WIFI技术无线将数据信息传到电脑终端,用户可以在电脑终端远程查看大棚里环境信息和作物的生长情况。%This paper puts forward the design thought of agricultural greenhouse environment real time monitoring system based on WIFI technology.Through the micro controller STM32F103C8T6 and environment monitoring sensor real-time monitoring of environmental temperature and humidity,illumination,soil humidity,CO2 concentration,video and sent the data information to the computer terminal through WIFI.The user can remotely view greenhouse environment information and the growth of crop in computer terminal.

  3. FeltRadio – Experiencing Community-generated WiFi Activities

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Gronvall, Erik

    2016-01-01

    FeltRadio is a portable technology for sensing WiFi through sensorial augmentation and Electric Muscle Stimulation (EMS). The technology enables its wearer to sensorially engage with the radio waves and WiFi activities that have become an integrated part of our everyday lives. The sensorial...... engagement changes people’s experience of WiFi activities, and allows them to participate in wireless communication infrastructures in novel ways. This is both an immediately embodied activity as it is a new form of social awareness. In this paper, we briefly present the FeltRadio technology and show how...

  4. Link layer topology discovery in an uncooperative ethernet environment

    CSIR Research Space (South Africa)

    Delport, JP

    2007-05-01

    Full Text Available , Built Environment and Information Technology at the University of Pretoria May 2007 University of Pretoria etd - Delport, J P (2007) Link Layer Topology Discovery in an Uncooperative Ethernet Environment by Johannes Petrus Delport Abstract Knowledge... Network Design 7 Figure 2.1: The Open Systems Interconnection (OSI) reference model. The physical layer provides an abstraction of bit transmission between two systems connected to a single physical link and hides the details of the link technology used...

  5. Safety management of Ethernet broadband access based on VLAN aggregation

    Science.gov (United States)

    Wang, Li

    2004-04-01

    With broadband access network development, the Ethernet technology is more and more applied access network now. It is different from the private network -LAN. The differences lie in four points: customer management, safety management, service management and count-fee management. This paper mainly discusses the safety management related questions. Safety management means that the access network must secure the customer data safety, isolate the broad message which brings the customer private information, such as ARP, DHCP, and protect key equipment from attack. Virtue LAN (VLAN) technology can restrict network broadcast flow. We can config each customer port with a VLAN, so each customer is isolated with others. The IP address bound with VLAN ID can be routed rightly. But this technology brings another question: IP address shortage. VLAN aggregation technology can solve this problem well. Such a mechanism provides several advantages over traditional IPv4 addressing architectures employed in large switched LANs today. With VLAN aggregation technology, we introduce the notion of sub-VLANs and super-VLANs, a much more optimal approach to IP addressing can be realized. This paper will expatiate the VLAN aggregation model and its implementation in Ethernet access network. It is obvious that the customers in different sub-VLANs can not communication to each other because the ARP packet is isolated. Proxy ARP can enable the communication among them. This paper will also expatiate the proxy ARP model and its implementation in Ethernet access network.

  6. Evaluating Wi-Fi indoor positioning approaches in a real world environment

    OpenAIRE

    Hantoush, Raafat

    2016-01-01

    Global positioning system(GPS) does not provide generally a good positioning performance in an indoor location because of many reasons (Henniges, 2012). On the other hand, other alternatives such as the WI-FI technology has become recently in a popular use to provide indoor localization. And that is due to many reasons, such as the wide spread of WI-FI infrastructure in the indoor environments and the low cost of this technology. This study attempts to evaluate different WI-FI indoor position...

  7. Emerging Communication Technologies (ECT) Phase 2 Report. Volume 3; Ultra Wideband (UWB) Technology

    Science.gov (United States)

    Bastin, Gary L.; Harris, William G.; Chiodini, Robert; Nelson, Richard A.; Huang, PoTien; Kruhm, David A.

    2003-01-01

    The Emerging Communication Technology (ECT) project investigated three First Mile communication technologies in support of NASA s Second Generation Reusable Launch Vehicle (2nd Gen RLV), Orbital Space Plane, Advanced Range Technology Working Group (ARTWG) and the Advanced Spaceport Technology Working Group (ASTWG). These First Mile technologies have the purpose of interconnecting mobile users with existing Range Communication infrastructures. ECT was a continuation of the Range Information System Management (RISM) task started in 2002. RISM identified the three advance communication technologies investigated under ECT. These were Wireless Ethernet (Wi-Fi), Free Space Optics (FSO), and Ultra Wideband (UWB). Due to the report s size, it has been broken into three volumes: 1) Main Report 2) Appendices 3) UWB

  8. High-Performance Message Passing over generic Ethernet Hardware with Open-MX

    OpenAIRE

    Goglin, Brice

    2011-01-01

    International audience; In the last decade, cluster computing has become the most popular high-performance computing architecture. Although numerous technological innovations have been proposed to improve the interconnection of nodes, many clusters still rely on commodity Ethernet hardware to implement message passing within parallel applications. We present Open-MX, an open-source message passing stack over generic Ethernet. It offers the same abilities as the specialized Myrinet Express sta...

  9. Ethernet susceptibility to electric fast transients

    NARCIS (Netherlands)

    van Leersum, B.J.A.M.; Buesink, Frederik Johannes Karel; Bergsma, J.G.; Leferink, Frank Bernardus Johannes

    2013-01-01

    The effect of Electric Fast Transients (EFT) phenomena in an Ethernet interface set-up is investigated in order to get more insight in coupling and interference mechanisms, robustness and susceptibility levels of a typical Ethernet installation on board of a naval vessel. It is shown that already a

  10. Intelligent Parking Guidance System Based on Wi-Fi and Bluetooth Technology%基于Wi-Fi和蓝牙技术的停车场智能引导系统

    Institute of Scientific and Technical Information of China (English)

    岳永霞; 金华

    2016-01-01

    针对目前停车场引导系统存在的诸多弊端,基于Wi-Fi和蓝牙技术的特点以及Android智能手机的功能,提出一种停车场智能引导系统的设计方案。系统采用Android智能手机为客户端,利用Wi-Fi和蓝牙技术完成手机客户端与服务器端的数据交互,实现停车场信息统一管理和汽车身份自动验证的功能;利用Dijkstra最短路径算法,实现室内停车场的路线引导功能。系统无需车载其他设备,且停车全过程无需人工操作。%Aiming at lots of disadvantages existing in parking guidance systems, an intelligent parking guidance system based on the characteristics of Wi-Fi and Bluetooth technology and the functions of Android smart phones is proposed.The system uses An-droid smart phones as the client.By using Wi-Fi and Bluetooth technology, the client and server-side data communication, park-ing information unified management, and automatic car-identity authentication can be realized.The function of indoor parking guidance can be achieved by using the Dijkstra.The intelligent parking guidance system needn’ t on-board equipment and manual operation.

  11. Mobile data offloading: an agent-based modelling study on the effectiveness of Wi-Fi offloading

    OpenAIRE

    Breukers, Yorick; de Reuver, Mark; Oey, Michel; Bouwman, Harry

    2015-01-01

    To reduce the load on cellular networks, offloading to Wi-Fi has long been discussed as a technological solution. Despite advances in scheduling algorithms and incentive schemes, most mobile operators do not actively promote Wi-Fi offloading and most Wi-Fi usage is limited to stationary in-home contexts of use. This study assesses the proportion of users on the street that can be offloaded to Wi-Fi access points, taking into account different city topologies, speed of movement and technical c...

  12. Wifi无线局域网技术的应用与研究%Wifi Wireless LAN Technology Application and Research

    Institute of Scientific and Technical Information of China (English)

    张宁

    2011-01-01

    随着互联网的迅速发展及普及,Wi-Fi无线覆盖网络区域的形成,如何在覆盖广、带宽高、低使用资费的Wi-Fi无线局域网络中,提高信息安全性及IP地址的有效分配,减少无效IP地址占用变成了一个很实际的问题。%With the rapid development and popularization of the Intemet,Wi-Fi wireless network coverage area to form,how to cover a wide bandwidth,high and low use rates of Wi-Fi wireless local area network,to improve information security and the efficient allocation of IP addresses,reduce occupancy invalid IP address into a very practical problem.

  13. 无源光网络技术在配、用电通信网中的组网研究%Research on configuration of distribution and power supply communication network with the ethernet passive optical network technology

    Institute of Scientific and Technical Information of China (English)

    孙圆圆

    2013-01-01

    Aiming at the difficulty problems of pilot application of Ethernet Passive Optical Network (EPON)technology in internal experimental unit of distribution and power supply communication network,through analyzing each structure characteristic of distribution network and power supply net-work,puts forward typical configuration network mode for distribution and power supply communica-tion network and the problems need pay attention to apply. The research result shows that distribution communication network should use chain configuration network based on the distribution line,power supply communication network should use the subsidence mode of optical line terminal(OLT) configu-ration network based on the margin capacity of trunk fiber optic cable and the number of tenement in residential section to calculate comprehensively.%  针对无源光网(Ethernet Passive Optical Network, EPON)技术在全国配、用电通信网中的试点应用的难点问题,通过分析配、用电网各自的结构特点,根据EPON技术在配、用电通信网全国试点的应用经验,提出配、用电通信网目前典型的组网模式及应用中需要注意的问题,为EPON技术在配、用电通信网建设中大规模应用奠定基础。研究结果表明:配电通信网应根据配电线路采用链型组网,用电通信网需要根据主干光纤富裕度和小区户数综合考虑是否采用光线路终端(Optical Line Terminal, OLT)下沉模式进行组网。

  14. Převodník Ethernet na RS-232

    OpenAIRE

    Dreiseitel, Jiří

    2012-01-01

    Práce je věnována problematice konstrukce převodníku Ethernet na RS-232 za pomocí jednočipového mikrokontroléru. Cílem je seznámit čtenáře se síťovou technologií Ethernet a technologií pro sériový přenos založený na protokolu RS-232 a zároveň s technologií vestavěných systémů pro konstrukci zařízení.Součástí práce je kompletní návrh převodníku Ethernet na RS-232 včetně návrhu a implementace firmware v jazyce C za využití LwIP TCP/IP stacku. Převodník je postaven na základě vývojového kitu STM...

  15. Design of Coal Mine Communication System Based on WiFi Technology%基于WiFi技术的煤矿井下通讯系统的设计

    Institute of Scientific and Technical Information of China (English)

    石发强

    2013-01-01

      根据煤矿安全生产的需要,设计了一种基于WiFi技术的煤矿井下无线通讯系统。该系统井下部分包括人员定位、无线通讯、视频采集、语音通话、环境参数监测、分站等设备,地面部分包括主机、交换机、服务器、网关等,以无线WiFi通讯AP为节点,可实现井下定位、VOIP语音、无线移动数字视频、传感器监测等功能的一体化。试验结果表明,该系统结构简单、运行稳定、抗干扰能力强、可靠性高。%A coal mine communication system based on WiFi technology was designed according to the needs of safe production in the mine. The underground facilities of the system include the personnel positioning system,wireless communication, video collection,voice call, environmental parameter monitoring and substation, its ground facilities include the host, switches, servers,gateways, etc. The system took the wireless WiFi AP as the nodes and can realize the integration of underground positioning,VOIP voice,wireless mobile digital video,sensors monitoring and so on. The test results showed that the system has the features of simple structure,stable operation,strong anti-interference ability and high reliability.

  16. Emerging Communication Technologies (ECT) Phase 3 Final Report

    Science.gov (United States)

    Bastin, Gary L.; Harris, William G.; Bates, Lakesha D.; Nelson, Richard A.

    2004-01-01

    The Emerging Communication Technology (ECT) project investigated three First Mile communication technologies in support of NASA s Second Generation Reusable Launch Vehicle (2nd Gen RLV), Orbital Space Plane, Advanced Range Technology Working Group (ARTWG) and the Advanced Spaceport Technology Working Group (ASTWG). These First Mile technologies have the purpose of interconnecting mobile users with existing Range Communication infrastructures. ECT was a continuation of the Range Information System Management (RISM) task started in 2002. RISM identified the three advance communication technologies investigated under ECT. These were Wireless Ethernet (Wi-Fi), Free Space Optics (FSO), and Ultra Wideband (UWB). Due to the report s size, it has been broken into three volumes: 1) Main Report 2) Appendices 3) UWB.

  17. Approaching Incast Congestion with Multi-host Ethernet Controllers

    CERN Document Server

    Jereczek, Grzegorz Edmund; The ATLAS collaboration

    2017-01-01

    The bursty many-to-one communication pattern, typical for data acquisition systems, but also present in datacenter networks, is particularly demanding for commodity TCP/IP and Ethernet technologies. We expand our study of building incast-resistant networks based on software switches running on commercial-off-the-shelf servers. In this paper we provide the estimates for costs and physical area required to build such a network. Our estimates indicate that our proposed design offers significant cost advantage over traditional solutions, but higher space utilisation. Next, we show how the latter can be improved with multi-host Ethernet controllers, as an alternative to typical network interface cards. This can also make software switching easier to adapt in datacenter as a solution for incast congestion. We confirm the capabilities for incast-avoidance by evaluating the performance of a reference platform.

  18. Wireless optical communication for FDDI, fast Ethernet, and ATM connectivity

    Science.gov (United States)

    Medved, David B.; Azancot, Yossi

    1995-09-01

    The bandwidth limitations of spread spectrum RF technology are easily removed by use of optical carriers. A variety of wireless connectivity system applications have been achieved using IR LED (not laser) at data rates up to 125 Mbps and with low frequency corners below 100 Kbps. By use of the UWINTM principle it is possible to achieve wireless communications which are protocol independent. Thus, an urgent installation which must serve today as an Ethernet or Token Ring wireless connection in the future can be used at FDDI, Fast Ethernet, 100 VG Anylan or ATM without any modification to the original installation. In this paper we describe three separate applications of this principle where there are significant trade-offs between range and angular coverage.

  19. 浅析以太网与 web技术在铝电解工业控制系统中的应用%Brief Analysis on Application of Ethernet and Web Technology in Control System of Aluminum Electrolytic Industry

    Institute of Scientific and Technical Information of China (English)

    刘永强; 李凌晶

    2012-01-01

    阐述了在铝电解工业控制系统中通过采用以太网和web技术进行数据整合的方法,通过节点服务器的架设实现公司内四级网络的物理连通,再使用数据库编程和.NET技术开发应用程序,制作统一的用户界面和综合数据报表,并根据管理人员的需求对数据进行深度挖掘和处理,有效缩短了管理人员获取生产相关数据的时间,为铝电解生产管理人员提供一个便捷、高效、实用的数据分析平台.%n the control system of aluminum electrolytic industry, by means of the data integration method adopting Ethernet and Web technology, the uniform user interface and the comprehensive data reporting were made by setting up node servers to achieve physical connection for four-level network in the company, and using database programming and. Net technology to develop the application program. In addition, according to managements' demand, deep-mining data and data processing were earned out so as to effectively reduce the time to obtain related production data, which provides a convenient, efficient and practical data analysis platform for management in aluminum electrolytic production.

  20. An Innovative Algorithm to Implement Flow Control in Full Duplex Ethernet

    Institute of Scientific and Technical Information of China (English)

    WANGTao; GENing; FENGChongxi

    2003-01-01

    Nowadays Ethernet is a widely used LAN technology.It is based on a Media access control (MAC) method called Carrier sense multiple access with Collision detection(CAMS/CD).With CSMA/CD,hosts on Ethernet must operate in half duplex mode;with collision detection and random backoff,Ethernet is a self-contained LAN in the aspect of flow control.After the appearance of switching Ethernet,applications of full duplex Ethernet are booming,and how to manage network bandwidth and switch ports without CSMA/CD is a major issue.In this way,IEEE specifled and explicit flow control scheme,called "PAUSE operation" in Standard 802.3.In order to implement IEEE PAUSE operation and flow control effectively,we propose an innovative algorithm called Queue Length based PAUSE operation-QLPAUSE.It will set the pause time parameter according to the instant input port queue length and local condition checking.With it the hosts can make better use of the full duplex link.With the simulation results,it is proved that QLPAUSE is an active flow control,and it is an easy-to-implement and high efflciency scheme.Finally,the application of this algorithm is provided,with more and more Switching Ethernet,and PAUSE operation is accepted and supported by more and more manufacturers.Within many implementation methods,QLPAUSE is a best candidate.

  1. Framework for Ethernet Network Functionality Testing

    Directory of Open Access Journals (Sweden)

    Mirza Aamir Mehmood

    2011-11-01

    Full Text Available Computer networks and telecommunication systems use a wide range of applications. Therefore, the power and complexity of computer networks are increasing every day which enhances the possibilities of the end user, but also makes harder the work of those who have to design, maintain and make a network efficient, optimized and secure. Ethernet functionality testing as a generic term used for checking connectivity, throughput and capability to transfer packets over the network. Especially in the packet-switch environment, Ethernet testing has become an essential part for deploying a reliable network. A platform and vendor independent framework is required to verify and test the functionality of the Ethernet network and to verify the functionality and performance of the TCP/IP stack. NetBurst is developed for Ethernet functionality testing

  2. UB Ethernet module heats up ATM race

    National Research Council Canada - National Science Library

    MacAskill, Skip

    1993-01-01

      Ungermann-Bass Inc. (UB) has announced the DragonSwitch, a new Ethernet switching module for its intelligent hub line, along with a net management application for its NetDirector net management system that will let net...

  3. 基于Wi-Fi技术的移动SNS近距离传播方式研究%Research of Short Range Propagation Mode of Mobile SNS Based on Wi-Fi Technology

    Institute of Scientific and Technical Information of China (English)

    许彪

    2015-01-01

    Because of the low precision of GPS satellite positioning and weak signal of mobile phone in indoor environment,mobile SNS in indoor and close social network have some scalability deficiencies.This paper presents the close social network expansion algorithm based on Wi-Fi technology.The information of MAC address and user algorithm first saves the SNS mobile phone users in the Wi-Fi server,then Ping communication to find all the peripheral equipment MAC address in the server database after the match with all equipment within the same LAN,the social network peripheral equipment,and the eventual establishment of social network.The experimental results show that mobile SNS using this algorithm is more effective and will rapidly realize expansion from short-range in social networks than the GPS positioning technology.%由于手机中GPS定位精度低和室内环境中卫星信号弱,造成了移动SNS在室内和近距离环境中社交网络扩展性能差。针对这种情况,提出了基于Wi-Fi技术的近距离社交网络扩展算法设计。算法首先在服务器端保存SNS用户手机Wi-Fi的MAC地址与用户的对应信息,然后与同一局域网内的所有设备进行Ping通信找到所有周边设备MAC地址,再在服务器端数据库中对MAC地址进行匹配后,确定其为周边的社交网络设备,并最终建立社交网络。实验结果表明,移动SNS采用该算法比采用GPS等定位技术能更加有效、快速地扩展近距离范围内的社交网络。

  4. Emerging Communication Technologies (ECT) Phase 2 Report. Volume 1; Main Report

    Science.gov (United States)

    Bastin, Gary L.; Harris, William G.; Chiodini, Robert; Nelson, Richard A.; Huang, PoTien; Kruhm, David A.

    2003-01-01

    The Emerging Communication Technology (ECT) project investigated three First Mile communication technologies in support of NASA s Second Generation Reusable Launch Vehicle (2nd Gen RLV), Orbital Space Plane, Advanced Range Technology Working Group (ARTWG) and the Advanced Spaceport Technology Working Group (ASTWG). These First Mile technologies have the purpose of interconnecting mobile users with existing Range Communication infrastructures. ECT was a continuation of the Range Information System Management (RISM) task started in 2002. RISM identified the three advance communication technologies investigated under ECT. These were Wireless Ethernet (Wi-Fi), Free Space Optics (FSO), and Ultra Wideband (UWB). Due to the report s size, it has been broken into three volumes: 1) Main Report 2) Appendices 3) UWB.

  5. Industrial Ethernet in the Production of Tomorrow -Requirements- Challenges-Hazards

    Institute of Scientific and Technical Information of China (English)

    Peter Klüger

    2004-01-01

    @@ 1 Foreword Do we really need Ethernet in the production of tomorrow?I think, the answer is YES. The production technology of today has to meet the challenge to develop new strategies for a highly flexible, highly available and cost-effective automation technology.

  6. WiFi无线通信定位技术在露天矿中应用研究%Application Study on WIFI Wireless Location Technology in Open Pit

    Institute of Scientific and Technical Information of China (English)

    王斌; 王春毅

    2011-01-01

    针对露天矿实际生产管理需求,利用WIFI无线通信定位技术,在露天矿山建立卡车定位、语音生产调度和视频监控一体化的数字化监控调度平台.该系统不仅可以满足露天矿的日常生产调度,而且可以实现对矿山设备人员无线定位和视频监控,有利于矿山的安全生产管理,提高矿山企业的劳动生产效率,降低开采成本.%In view of the request of production management in open pit, the integration of digital surveillance dispatching platform is designed based on WIFI wireless communications technology.The system includes truck positioning, voice production scheduling and video monitoring in open pit.The system can not only conduct production scheduling in mining area, but also achieve mining equipment and personnel wireless location and wireless video monitoring.Thus, the mining enterprises reinforces safety management and improves the productivity efficiency by use of the system.At the same time,the spending of production is reduced.

  7. 基于Wi-Fi物联网技术的电缆隧道安全管理系统%Cable Tunnel Safety Management System Based on Wi-Fi IOT Technology

    Institute of Scientific and Technical Information of China (English)

    吕海晶

    2013-01-01

    In view of the ubiquitous hidden dangers existed in cable tunnel, such as, unknowing personnel-location is not known, communication blind district, poor environment and low oxygen content, the cable tunnel safety management system was developed by advanced Wi-Fi internet of things technology, realizing accurate personnel position, voice scheduling, video surveillance and online environment monitoring. The system has good compatibility, offers a platform shared by multi-modules. The whole scheme is feasible and economic.%针对电缆隧道普遍存在的隧道内人员位置不可知、通信存在盲区、环境恶劣、含氧量低等安全隐患,采用先进的Wi-Fi物联网技术,开发了电缆隧道安全管理系统,实现人员的精准定位、语音调度、视频监控以及隧道内环境在线监测等功能,多个模块共用一套平台,系统具有很好的兼容性,经济运行比高。

  8. 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.

  9. Ethernet Networks for Real-Time Use in the ATLAS Experiment

    CERN Document Server

    Meirosu, C; Martin, B

    2005-01-01

    Ethernet became today's de-facto standard technology for local area networks. Defined by the IEEE 802.3 and 802.1 working groups, the Ethernet standards cover technologies deployed at the first two layers of the OSI protocol stack. The architecture of modern Ethernet networks is based on switches. The switches are devices usually built using a store-and-forward concept. At the highest level, they can be seen as a collection of queues and mathematically modelled by means of queuing theory. However, the traffic profiles on modern Ethernet networks are rather different from those assumed in classical queuing theory. The standard recommendations for evaluating the performance of network devices define the values that should be measured but do not specify a way of reconciling these values with the internal architecture of the switches. The introduction of the 10 Gigabit Ethernet standard provided a direct gateway from the LAN to the WAN by the means of the WAN PHY. Certain aspects related to the actual use of WAN ...

  10. Wi-Fi Crowdsourced Fingerprinting Dataset for Indoor Positioning

    Directory of Open Access Journals (Sweden)

    Elena Simona Lohan

    2017-10-01

    Full Text Available Benchmark open-source Wi-Fi fingerprinting datasets for indoor positioning studies are still hard to find in the current literature and existing public repositories. This is unlike other research fields, such as the image processing field, where benchmark test images such as the Lenna image or Face Recognition Technology (FERET databases exist, or the machine learning field, where huge datasets are available for example at the University of California Irvine (UCI Machine Learning Repository. It is the purpose of this paper to present a new openly available Wi-Fi fingerprint dataset, comprised of 4648 fingerprints collected with 21 devices in a university building in Tampere, Finland, and to present some benchmark indoor positioning results using these data. The datasets and the benchmarking software are distributed under the open-source MIT license and can be found on the EU Zenodo repository.

  11. ANALYSIS OF WIFI AND WIMAX AND WIRELESS NETWORK COEXISTENCE

    Directory of Open Access Journals (Sweden)

    Shuang Song

    2014-12-01

    Full Text Available Wireless networks are very popular nowadays. Wireless Local Area Network (WLAN that uses the IEEE 802.11 standard and WiMAX (Worldwide Interoperability for Microwave Access that uses the IEEE 802.16 standard are networks that we want to explore. WiMAX has been developed over 10 years, but it is still unknown by most people. However, compared with WLAN, it has many advantages in transmission speed and coverage area. This paper will introduce these two technologies and make comparisons between WiMAX and WiFi. In addition, wireless network coexistence of WLAN and WiMAX will be explored through simulation. Lastly we want to discuss the future of WiMAX in relation to WiFi.

  12. MALL NAVIGATION SYSTEM USING WI-FI Router

    Directory of Open Access Journals (Sweden)

    Ankita Paul ,Rohit Das , Abhik Sarkar

    2012-12-01

    Full Text Available There have been various navigation and tracking systems being developed with the help of technologies like GPS, GSM, Bluetooth, IR, Wi-Fi and Radar. A shopping Mall is a vast place, & we often get confused with the direction of the nearest ATMs or even rest rooms. So we have simplified this method with the “Mall Navigation System”. Smart phones have become very popular these days, so we have combined the idea of a smart phone application helping you in an alienated mall. The idea revolves around our smart phones & the “WIFI” provided by the mall. An application that needs real-time, fast, & reliable data processing. The WIFI router will install NAVIGATION software by which it will detect our present location and with a view finder & our maps we detect the desired location.

  13. To localise or to be localised with WiFi in the Hubei museum?

    Science.gov (United States)

    Verbree, E.; Zlatanova, S.; van Winden, K. B. A.; van der Laan, E. B.; Makri, A.; Taizhou, L.; Haojun, A.

    2013-11-01

    Indoor localisation is in demand for a variety of applications within the built environment. An overall solution based on a single technology has not yet been determined. The aim of this paper is to gain insight on Signal Strength monitoring by a special kind of WiFi Monitors in comparison to the commonly known fingerprinting method for the purpose of a 3D indoor navigation system. Ttwo different WiFi based localisation techniques are tested during the MSc Geomatics DaRen Syntheses Project in the Hubei Provincial Museum, China. The first method detects the beacon frames send by smartphones, laptops and other WiFi enabled devices in range using Libelium Meshlium Xtreme monitors. Their MAC addresses and the signal strength is measured by the Meshlium Xtreme and stored on an external database. We call this method WiFi monitoring. The second method a Wifi enabled device, like a smartphone, measures the signal strength of multiple Wifi Access Points in range to localise itself based on a previously created radio map. This method is known as WiFi fingerprinting. Both methods have some advantages and disadvantages. Advantages of the common way of WiFi fingerprinting are that the implementation costs are relatively low, because it is usually possible to use (a part of) the existing WiFi AP infrastructure. WiFi fingerprinting can reach a relatively high accuracy in the order of magnitude of meters. Finally, the location granularity can be adjusted to what is necessary for the purpose of the indoor localisation. This makes it employable for a wide range of purposes. The question remains how suitable these methods are for a 3D indoor navigation system for the Hubei provincial museum. One important aspect is the localisation-granularity necessary for the application. In a museum it is not necessary to know the exact X,Y position of a user (such high accuracy is unnecessary), more important is to know in which room the user is located so the information on exhibitions can be

  14. Architecture of fast IP forwarding engine in gigabit ethernet system

    Science.gov (United States)

    Do, Han C.; Lee, Hyeong H.; Cha, Kyoon Hyun

    1999-11-01

    In recent years, Internet traffic has been increased rapidly as a result of the Internet which accommodates multimedia traffic such as IP telephony and video conference. Gigabit routing technology is one possible approach to handle such internet traffic. This paper presents an efficient IP forwarding architecture adequate for Gigabit Ethernet switching system. The presented IP forwarding architecture is based upon distributed and pipelined process, which can effectively facilitate searching, editing, traffic classification, forwarding, and traffic management in parallel. Additionally, it can also process packets at full wire-speed in the ASIC level.

  15. Ethernet-based Mass Volume Train Security Detection Network

    Directory of Open Access Journals (Sweden)

    D. Q. He

    2013-07-01

    Full Text Available As the existing train communication network transmission rate is low, large capacity status and fault diagnosis data, the event log data, passenger information which are stored in different vehicles equipments, it is difficult to realize fault diagnosis and intelligent maintenance efficiently and timely. Based on the train level and vehicle level Ethernet network, this paper will focus on network construction technology and real-time performance of mass volume onboard security detection network. The research results will improve control and network function of train.

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

    CERN Document Server

    Perez, André

    2013-01-01

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

  17. Capacity planning for Carrier Ethernet LTE backhaul networks

    DEFF Research Database (Denmark)

    Checko, Aleksandra; Ellegaard, Lars; Berger, Michael Stübert

    2012-01-01

    With the introduction of LTE networks operators need to plan a new, IP-based mobile backhaul. In this paper, we provide recommendation on dimensioning LTE backhaul networks links using three methods: delay-, dimensioning formula- and overbooking factor-based. Results are obtained from OPNET simul...... and verified. Simulation in this work proves that Carrier Ethernet, one of the candidate technologies for mobile backhaul, protects the network from users that want to flood the network with their data and manages to keep the delay experienced by other users low....

  18. Monitoring pohybu osob v uzavřeném objektu pomoci WiFi technologie

    OpenAIRE

    Olmr, Martin

    2015-01-01

    This thesis aims to draft technology and its practical verification for online monitoring of people in closed buildings (hospitals, hospices, ...). The technology will be based on WiFi triangulation and evaluated self-designed device. In the practical part will be tested reliability, accuracy and economic comparison with alternative technologies.

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

    Directory of Open Access Journals (Sweden)

    Waleed Kh. Alzubaidi

    2012-12-01

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

  20. The genesis of WiFi and its applications

    CERN Document Server

    CERN. Geneva

    2008-01-01

    In 1985 changes to US regulations caused a paradigm shift by permitting the use of radio spectrum for devices that did not need to have an end-user license. After a few years, products appeared on the market and a group developed a standard for broadband wireless communications among computers. The presentation will explain how the standard developed and was adopted by the Wi-Fi Alliance, as well as the global harmonization and expansion of the available radio spectrum to over half a GHz. The success of Wi-Fi and user innovation and initiatives makes it a vehicle to bring broadband internet to rural areas both in developing as well as in developed countries. Vic Hayes is a Senior Research Fellow at the Delft University of Technology and is writing a book titled "The genesis of Wi-Fi and the road toward global success". He holds a BSEE and joined NCR in the Netherlands in 1974. He co-established and chaired the IEEE 802.11 Standards Working Group for Wireless Local Area Networks and became known as the "Fathe...

  1. Optical frame synchronizer for 10 G Ethernet packets aiming at 1 Tb/s OTDM Ethernet

    DEFF Research Database (Denmark)

    Hu, Hao; Palushani, Evarist; Laguardia Areal, Janaina;

    2010-01-01

    Synchronization of 10 G Ethernet packets to a local clock was demonstrated using a phase modulator and a SMF as retiming elements. Error free performances for the synchronized packets with different lengths were achieved.......Synchronization of 10 G Ethernet packets to a local clock was demonstrated using a phase modulator and a SMF as retiming elements. Error free performances for the synchronized packets with different lengths were achieved....

  2. Protection switching for carrier ethernet multicast

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Berger, Michael Stübert

    2010-01-01

    This paper addresses network survivability for IPTV multicast transport in Carrier Ethernet networks. The impact of link failures is investigated and suggestions for intelligent multicast resilience schemes are proposed. In particular, functions of the multicast tree are integrated with the Carrier...

  3. Coexistence of ZigBee-Based WBAN and WiFi for Health Telemonitoring Systems.

    Science.gov (United States)

    Kim, Yena; Lee, SeungSeob; Lee, SuKyoung

    2016-01-01

    The development of telemonitoring via wireless body area networks (WBANs) is an evolving direction in personalized medicine and home-based mobile health. A WBAN consists of small, intelligent medical sensors which collect physiological parameters such as electrocardiogram, electroencephalography, and blood pressure. The recorded physiological signals are sent to a coordinator via wireless technologies, and are then transmitted to a healthcare monitoring center. One of the most widely used wireless technologies in WBANs is ZigBee because it is targeted at applications that require a low data rate and long battery life. However, ZigBee-based WBANs face severe interference problems in the presence of WiFi networks. This problem is caused by the fact that most ZigBee channels overlap with WiFi channels, severely affecting the ability of healthcare monitoring systems to guarantee reliable delivery of physiological signals. To solve this problem, we have developed an algorithm that controls the load in WiFi networks to guarantee the delay requirement for physiological signals, especially for emergency messages, in environments with coexistence of ZigBee-based WBAN and WiFi. Since WiFi applications generate traffic with different delay requirements, we focus only on WiFi traffic that does not have stringent timing requirements. In this paper, therefore, we propose an adaptive load control algorithm for ZigBee-based WBAN/WiFi coexistence environments, with the aim of guaranteeing that the delay experienced by ZigBee sensors does not exceed a maximally tolerable period of time. Simulation results show that our proposed algorithm guarantees the delay performance of ZigBee-based WBANs by mitigating the effects of WiFi interference in various scenarios.

  4. Indoor Positioning using Wi-Fi

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Krarup, Mads Vering; Stisen, Allan;

    The past decade has witnessed substantial research on methods for indoor Wi-Fi positioning. While much effort has gone into achieving high positioning accuracy and easing fingerprint collection, it is our contention that the general problem is not sufficiently well understood, thus preventing...... deployments and their usage by applications to become more widespread. Based on our own and published experiences on indoor Wi-Fi positioning deployments, we hypothesize the following: Current indoor Wi-Fi positioning systems and their utilization in applications are hampered by the lack of understanding...... of the requirements present in the real-world deployments. In this paper, we report findings from qualitatively studying organisational requirements for indoor Wi-Fi positioning. The studied cases and deployments cover both company and public-sector settings and the deployment and evaluation of several types...

  5. Power optimization and performance improvement for embedded Ethernet SOC

    Institute of Scientific and Technical Information of China (English)

    ZHENG Zhao-xia; ZOU Lian-ying; GAO Jun

    2008-01-01

    Information appliance is the combination of traditional home appliances and the internet technology. In this article, an Ethernet controller system-on-chip (SOC) solution for information appliances is presented. To achieve high performance, the embedded 8 bits 8051 micro control unit (MCU) is optimized by an independent instruction bus and a data bus. Besides, a two-stage pipeline feature is added. Compared with the existing 8051 core, the enhanced one-cycle MCU offers ten times improvement in instruction execution efficiency. Mean- while, the performance of media access control (MAC) circuit is greatly improved by adopting various techniques such as direct memory access (DMA) control, paging strategy, etc. To reduce the power consumption, clock gating, low power supply, and multi-working-clock are adopted. Moreover, to achieve rapid data communication in different clock frequency circuits, a simple ping-pong first in first out (FIFO) circuit is realized. The chip is implemented using TSMC 0.25 μm two-poly four-metal mixed signal complementary metal oxide semiconductor (CMOS) technology. Its die area is mm. The test results show that the maximum throughput of Ethernet packets can reach 7 Mb/s while the power consumption is rather low-the working current is just about 200 mA.

  6. How much can Wi-Fi offload?

    DEFF Research Database (Denmark)

    Hu, Liang; Coletti, Claudio; Nguyen, Huan Cong;

    2012-01-01

    This paper is envisaged to provide a first quantitative study on how much indoor deployed Wi-Fi can offload the operator’s 3G HSPA macro cellular networks in a real largescale dense-urban scenario. Wi-Fi has been perceived as a costeffective mean of adding wireless capacity by leveraging low......-cost access points and unlicensed spectrum. However, the quantitative offloading gain that Wi-Fi can achieve is still unknown. We studied the Wi-Fi offloading gain as a function of access point density, where it is shown that 10 access points/km2 can already boost average user throughput by 300% and the gain...... increases linearly proportional to the access point density. Indoor Wi-Fi deployment also significantly reduces the number of users in outage, especially for indoor area. A user is considered to be in outage if they have a user throughput less than 512 kbps. We also propose three Wi-Fi deployment algorithms...

  7. Next Generation to Connect the Wi-Fi with IEEE Cloud Router

    OpenAIRE

    Kaur, Ramandeep

    2014-01-01

    The Wi-Fi has many features for internet access. There are many Wi-Fi technologies are used with the help of router. He latest router is AC router, it is also known as 802.11AC router with many benefits include speed, band etc. Ac router offers the ultimate performance and excellent bandwidth with antennas compare of N router (802.11N router).It is also upgrade the previous technology network. The wireless communication devices are upgrade time to time. Ac router is beneficial for HD videos...

  8. Improving Wi-Fi Based Indoor Positioning Using Bluetooth Add-Ons

    DEFF Research Database (Denmark)

    Baniukevic, Artur; Sabonis, Dovydas; Jensen, Christian S.

    2011-01-01

    enabling indoor LBSs. Existing indoor positioning services typically use a single technology such as Wi-Fi, RFID or Bluetooth. Wi-Fi based indoor positioning is relatively easy to deploy, but does often not offer good positioning accuracy. In contrast, the use of RFID or Bluetooth for positioning requires...... is achieved than what can be achieved by each technology in isolation. We design a flexible and extensible system architecture with an effective online position estimation algorithm for the hybrid system. The system is evaluated empirically in the building of our department. The results show that the hybrid...

  9. Next Generation to Connect the Wi-Fi with IEEE Cloud Router

    OpenAIRE

    Kaur, Ramandeep

    2014-01-01

    The Wi-Fi has many features for internet access. There are many Wi-Fi technologies are used with the help of router. He latest router is AC router, it is also known as 802.11AC router with many benefits include speed, band etc. Ac router offers the ultimate performance and excellent bandwidth with antennas compare of N router (802.11N router).It is also upgrade the previous technology network. The wireless communication devices are upgrade time to time. Ac router is beneficial for HD videos...

  10. Improving Wi-Fi Based Indoor Positioning Using Bluetooth Add-Ons

    DEFF Research Database (Denmark)

    Baniukevic, Artur; Sabonis, Dovydas; Jensen, Christian S.

    2011-01-01

    enabling indoor LBSs. Existing indoor positioning services typically use a single technology such as Wi-Fi, RFID or Bluetooth. Wi-Fi based indoor positioning is relatively easy to deploy, but does often not offer good positioning accuracy. In contrast, the use of RFID or Bluetooth for positioning requires...... is achieved than what can be achieved by each technology in isolation. We design a flexible and extensible system architecture with an effective online position estimation algorithm for the hybrid system. The system is evaluated empirically in the building of our department. The results show that the hybrid...

  11. "Performance Evaluation of Wi-Fi comparison with WiMAX Networks"

    CERN Document Server

    Murty, M Sreerama; Rao, Srinivas; 10.5121/ijdps.2012.3127

    2012-01-01

    Wireless networking has become an important area of research in academic and industry. The main objectives of this paper is to gain in-depth knowledge about the Wi-Fi- WiMAX technology and how it works and understand the problems about the WiFi- WiMAX technology in maintaining and deployment. The challenges in wireless networks include issues like security, seamless handover, location and emergency services, cooperation, and QoS.The performance of the WiMAX is better than the Wi-Fi and also it provide the good response in the access. It's evaluated the Quality of Service (Qos) in Wi-Fi compare with WiMAX and provides the various kinds of security Mechanisms. Authentication to verify the identity of the authorized communicating client stations. Confidentiality (Privacy) to secure that the wirelessly conveyed information will remain private and protected. Take necessary actions and configurations that are needed in order to deploy Wi-Fi -WiMAX with increased levels of security and privacy

  12. Advanced Integration of WiFi and Inertial Navigation Systems for Indoor Mobile Positioning

    Science.gov (United States)

    Evennou, Frédéric; Marx, François

    2006-12-01

    This paper presents an aided dead-reckoning navigation structure and signal processing algorithms for self localization of an autonomous mobile device by fusing pedestrian dead reckoning and WiFi signal strength measurements. WiFi and inertial navigation systems (INS) are used for positioning and attitude determination in a wide range of applications. Over the last few years, a number of low-cost inertial sensors have become available. Although they exhibit large errors, WiFi measurements can be used to correct the drift weakening the navigation based on this technology. On the other hand, INS sensors can interact with the WiFi positioning system as they provide high-accuracy real-time navigation. A structure based on a Kalman filter and a particle filter is proposed. It fuses the heterogeneous information coming from those two independent technologies. Finally, the benefits of the proposed architecture are evaluated and compared with the pure WiFi and INS positioning systems.

  13. Advanced Integration of WiFi and Inertial Navigation Systems for Indoor Mobile Positioning

    Directory of Open Access Journals (Sweden)

    Evennou Frédéric

    2006-01-01

    Full Text Available This paper presents an aided dead-reckoning navigation structure and signal processing algorithms for self localization of an autonomous mobile device by fusing pedestrian dead reckoning and WiFi signal strength measurements. WiFi and inertial navigation systems (INS are used for positioning and attitude determination in a wide range of applications. Over the last few years, a number of low-cost inertial sensors have become available. Although they exhibit large errors, WiFi measurements can be used to correct the drift weakening the navigation based on this technology. On the other hand, INS sensors can interact with the WiFi positioning system as they provide high-accuracy real-time navigation. A structure based on a Kalman filter and a particle filter is proposed. It fuses the heterogeneous information coming from those two independent technologies. Finally, the benefits of the proposed architecture are evaluated and compared with the pure WiFi and INS positioning systems.

  14. Ethernet/IP工业以太网的研究及应用%Research and application of Ethernet/IP industrial Ethernet

    Institute of Scientific and Technical Information of China (English)

    李武杰; 郑晟; 陈文辉

    2011-01-01

    It describes the improvod development status of industrial Ethernet, then it not only makes the detailed analysis about the Ethernet/IP protocol model, its “producer/consumer” communication mode and the CIP message communication mechanism which is facing the “link”, but also points out the advantage of Ethernet/IP network application in industrial control. Simultaneously, it advances the method of Ethernet/lP network composition and communication settings of the Ethernet/IP network in the expressway tunnel. It successfully achieved a good monitoring in the expressway tunnel by using the Ethernet/IP network.%介绍了工业以太网的发展改进状况,对Ethernet/IP这种新型工业以太网的协议模型及其采用的"生产者/消费者"通讯模式和面向"连接"的,CIP(Common Industrial Protocol,CIP)报文通信机制做了详细分析,同时指出了Ether-net/IP网络应用在工业控制领域的优势.提出了Ethernet/IP工业以太网在高速公路隧道监控中具体的组网方案和通讯设置手段,利用Ethernet/IP网络成功地实现了时该高速公路隧道的良好监控.

  15. Ethernet Networks: Current Trends and Tools

    CERN Document Server

    El-Sayed, Abdulqader M

    2009-01-01

    Ethernet topology discovery has gained increasing interest in the recent years. This trend is motivated mostly by increasing number of carrier Ethernet networks as well as the size of these networks, and consequently the increasing sales of these networks. To manage these networks efficiently, detailed and accurate knowledge of their topology is needed. Knowledge of a network's entities and the physical connections between them can be useful in various prospective. Administrators can use topology information for network planning and fault detecting. Topology information can also be used during protocol and routing algorithm development, for performance prediction and as a basis for accurate network simulations. From a network security perspective, threat detection, network monitoring, network access control and forensic investigations can benefit from accurate network topology information. In this paper, we analyze market trends and investigate current tools available for both research and commercial purposes...

  16. SynUTC - high precision time synchronization over ethernet networks

    CERN Document Server

    Höller, R; Horauer, M; Kerö, N; Schmid, U; Schossmaier, K

    2002-01-01

    This article describes our SynUTC (Synchronized Universal Time Coordinated) technology, which enables high-accuracy distribution of GPS time and time synchronization of network nodes connected via standard Ethernet LANs. By means of exchanging data packets in conjunction with moderate hardware support at nodes and switches, an overall worst-case accuracy in the range of some 100 ns can be achieved, with negligible communication overhead. Our technology thus improves the 1 ms-range accuracy achievable by conventional, software-based approaches like NTP by 4 orders of magnitude. Applications can use the high-accuracy global time provided by SynUTC for event timestamping and event generation both at hardware and software level. SynUTC is based upon inserting highly accurate time information into dedicated data packets at the media-independent interface (MII) between the physical layer transceiver and the network controller upon packet transmission and reception, respectively. As a consequence, every node has acc...

  17. Messaging and Voice Conferencing through Wi-Fi Network

    OpenAIRE

    Miss. Nayana H S,; Dr. M C Padma

    2014-01-01

    The use of Wi-Fi enabled android phones as IP phones, and their communication within a local wireless LAN is discussed in this paper. This proposed model is a form of telecommunication that allows exchange of data and voice via Wi-Fi network. The phones, which are Wi-Fi enabled and have android operating system, can be used to communicate with each other through the Wi-Fi communication channel. Proposed system incorporates messaging (Text and voice), conferencing (group conver...

  18. To localise or to be localised with WiFi in the Hubei museum?

    OpenAIRE

    E. Verbree; S. Zlatanova; Van Winden, K.B.A.; Laan, E. B.; Makri, A; L. Taizhou; Haojun, A.

    2013-01-01

    Indoor localisation is in demand for a variety of applications within the built environment. An overall solution based on a single technology has not yet been determined. The aim of this paper is to gain insight on Signal Strength monitoring by a special kind of WiFi Monitors in comparison to the commonly known fingerprinting method for the purpose of a 3D indoor navigation system. Ttwo different WiFi based localisation techniques are tested during the MSc Geomatics DaRen Syntheses P...

  19. An Optimization Approach to Coexistence of Bluetooth and Wi-Fi Networks Operating in ISM Environment

    Science.gov (United States)

    Klajbor, Tomasz; Rak, Jacek; Wozniak, Jozef

    Unlicensed ISM band is used by various wireless technologies. Therefore, issues related to ensuring the required efficiency and quality of operation of coexisting networks become essential. The paper addresses the problem of mutual interferences between IEEE 802.11b transmitters (commercially named Wi-Fi) and Bluetooth (BT) devices.An optimization approach to modeling the topology of BT scatternets is introduced, resulting in more efficient utilization of ISM environment consisting of BT and Wi-Fi networks. To achieve it, the Integer Linear Programming approach has been proposed. Example results presented in the paper illustrate significant benefits of using the proposed modeling strategy.

  20. An ARIMA model for forecasting Wi-Fi data network traffic values

    Directory of Open Access Journals (Sweden)

    Cesar Augusto Hernández Suarez

    2010-07-01

    Full Text Available This present scientific and technological research was aimed at showing that time series represent an excellent tool for data traffic modelling within Wi-Fi networks. Box-Jenkins methodology (described herein was used for this purpose. Wi-Fi traffic modelling through correlated models, such as time series, allowed a great part of the data’s behaviourl dynamics to be adjusted into a sin- gle equation and future traffic values to be estimated based on this. All this is advantageous when it comes to planning integrated coverage, reserving resources and performing more efficient and timely control at different levels of the Wi-Fi data network func- tional hierarchy. A six order ARIMA traffic model was obtained as a research outcome which predicted traffic with relatively small mean square error values for an 18-day term.

  1. Performance and accuracy test of a WiFi indoor positioning system

    Science.gov (United States)

    Retscher, Guenther; Moser, Eva; Vredeveld, Dennis; Heberling, Dirk; Pamp, Joerg

    2007-09-01

    Location based-services and personal navigation require the location determination of a user not only in outdoor environments but also indoor. For indoor location already established wireless infrastructure such as WiFi (Wireless Fidelity) or WLAN (Wireless Local Area Networks) can be employed. This approach has the advantage that no costly hardware installations are necessary inside a building if WiFi is already available. The IMST GmbH has developed a software framework called "ipos" for indoor positioning technologies. The principle of the developed platform and the performance of the location determination using WiFi in a localization testbed of IMST GmbH are presented in this paper.

  2. Enabling LTE and WiFi Coexisting in 5 GHz for Efficient Spectrum Utilization

    OpenAIRE

    Hongyu Sun; Zhiyi Fang; Qun Liu; Zheng Lu; Ting Zhu

    2017-01-01

    Due to the increasing mobile traffic demands in cellular network, researchers have proposed the coexistence of LTE and WiFi technologies in 5 GHz unlicensed bands. Therefore, how to efficiently utilize the spectrum in 5 GHz becomes extremely important. To avoid the channel access conflicts, current LTE Unlicensed (LTE-U) technology introduces the duty cycle of LTE, while License-Assisted Access (LAA) technology introduces Listen-Before-Talk (LBT) mechanism. While these two technologies improv...

  3. Challenges for Social Sensing using WiFi Signals

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Nurmi, Petteri

    2012-01-01

    for the capture of more complex social phenomena. One of the most promising modalities for this purpose is WiFi, as it works both indoors and outdoors, and as WiFi signal environment tends to contain significant spatial variation. A challenge in using WiFi, however, is that the signals are affected by many noise...

  4. Bluetooth Navigation System using Wi-Fi Access Points

    CERN Document Server

    Agrawal, Rohit

    2012-01-01

    There have been various navigation and tracking systems being developed with the help of technologies like GPS, GSM, Bluetooth, IR, Wi-Fi and Radar. Outdoor positioning systems have been deployed quite successfully using GPS but positioning systems for indoor environments still do not have widespread deployment due to various reasons. Most of these use only a single technology for positioning but using more than one in cooperation with each other is always advantageous for obtaining greater accuracy. Particularly, the ones which use Bluetooth are better since they would enhance the scalability of such a system because of the fact that this technology is in use by the common people so it would always be easy to track them. Moreover it would also reduce the hardware installation cost to some extent. The system that has been introduced here uses Bluetooth primarily for positioning and tracking in combination with Wi-Fi access points. The reason that makes the commercial application of such a system easier and ch...

  5. Wi-Fi real time location systems

    Science.gov (United States)

    Doll, Benjamin A.

    This thesis objective was to determine the viability of utilizing an untrained Wi-Fi. real time location system as a GPS alternative for indoor environments. Background. research showed that GPS is rarely able to penetrate buildings to provide reliable. location data. The benefit of having location information in a facility and how they might. be used for disaster or emergency relief personnel and their resources motivated this. research. A building was selected with a well-deployed Wi-Fi infrastructure and its. untrained location feature was used to determine the distance between the specified. test points and the system identified location. It was found that the average distance. from the test point throughout the facility was 14.3 feet 80% of the time. This fell within. the defined viable range and supported that an untrained Wi-Fi RTLS system could be a. viable solution for GPS's lack of availability indoors.

  6. To localise or to be localised with Wifi in the Hubei museum?

    NARCIS (Netherlands)

    Verbree, E.; Zlatanova, S.; Van Winden, K.; Van der Laan, E.B.; Makri, A.; Taizhou, L.; Haojun, A.

    2013-01-01

    Indoor localisation is in demand for a variety of applications within the built environment. An overall solution based on a single technology has not yet been determined. The aim of this paper is to gain insight on Signal Strength monitoring by a special kind of WiFi Monitors in comparison to the

  7. To localise or to be localised with Wifi in the Hubei museum?

    NARCIS (Netherlands)

    Verbree, E.; Zlatanova, S.; Van Winden, K.; Van der Laan, E.B.; Makri, A.; Taizhou, L.; Haojun, A.

    2013-01-01

    Indoor localisation is in demand for a variety of applications within the built environment. An overall solution based on a single technology has not yet been determined. The aim of this paper is to gain insight on Signal Strength monitoring by a special kind of WiFi Monitors in comparison to the co

  8. Wi-Fi and health: review of current status of research.

    Science.gov (United States)

    Foster, Kenneth R; Moulder, John E

    2013-12-01

    This review summarizes the current state of research on possible health effects of Wi-Fi (a commercial name for IEEE 802.11-compliant wireless networking). In response to public concerns about health effects of Wi-Fi and wireless networks and calls by government agencies for research on possible health and safety issues with the technology, a considerable amount of technology-specific research has been completed. A series of high quality engineering studies have provided a good, but not complete, understanding of the levels of radiofrequency (RF) exposure to individuals from Wi-Fi. The limited number of technology-specific bioeffects studies done to date are very mixed in terms of quality and outcome. Unequivocally, the RF exposures from Wi-Fi and wireless networks are far below U.S. and international exposure limits for RF energy. While several studies report biological effects due to Wi-Fi-type exposures, technical limitations prevent drawing conclusions from them about possible health risks of the technology. The review concludes with suggestions for future research on the topic.

  9. Deterministic Ethernet for Space Applications

    Science.gov (United States)

    Fidi, C.; Wolff, B.

    2015-09-01

    Typical spacecraft systems are distributed to be able to achieve the required reliability and availability targets of the mission. However the requirements on these systems are different for launchers, satellites, human space flight and exploration missions. Launchers require typically high reliability with very short mission times whereas satellites or space exploration missions require very high availability at very long mission times. Comparing a distributed system of launchers with satellites it shows very fast reaction times in launchers versus much slower once in satellite applications. Human space flight missions are maybe most challenging concerning reliability and availability since human lives are involved and the mission times can be very long e.g. ISS. Also the reaction times of these vehicles can get challenging during mission scenarios like landing or re-entry leading to very fast control loops. In these different applications more and more autonomous functions are required to fulfil the needs of current and future missions. This autonomously leads to new requirements with respect to increase performance, determinism, reliability and availability. On the other hand side the pressure on reducing costs of electronic components in space applications is increasing, leading to the use of more and more COTS components especially for launchers and LEO satellites. This requires a technology which is able to provide a cost competitive solution for both the high reliable and available deep-space as well as the low cost “new space” markets. Future spacecraft communication standards therefore have to be much more flexible, scalable and modular to be able to deal with these upcoming challenges. The only way to fulfill these requirements is, if they are based on open standards which are used cross industry leading to a reduction of the lifecycle costs and an increase in performance. The use of a communication network that fulfills these requirements will be

  10. Design and Qualification of the Interconnect for a High-Performance Modular 10Gigabit Ethernet Switch

    CERN Document Server

    Oltean, Alexandra Dana; Martin, B

    2006-01-01

    The 10 Gigabit Ethernet standard, IEEE802.3ae, was adopted in 2002 and represented a ten-fold increase in performance over the previous 1Gigabit standard IEEE 802.3z. The standard itself covers only the details of the individual point-to-point links and does not address any system issues of how Ethernet switches may be built or deployed. Designing a switched system involves choosing an appropriate architecture, selecting the best available silicon technology and determining suitable electronic packaging. The EU funded ESTA project was established to perform the basic research and development that would define the specifications for building an Ethernet switch to meet 10Gbps switching requirements. The part of the project carried out at CERN, within which this thesis work was done, involved the development, construction and validation of the backplane support for this 10Gbps Ethernet switch. In addition the program required that there be developed an understanding of where the limits of performance lay in term...

  11. Fault Tolerant Ethernet Based Network for Time Sensitive Applications in Electrical Power Distribution Systems

    Directory of Open Access Journals (Sweden)

    Leos Bohac

    2013-01-01

    Full Text Available The paper analyses and experimentally verifies deployment of Ethernet based network technology to enable fault tolerant and timely exchange of data among a number of high voltage protective relays that use proprietary serial communication line to exchange data in real time on a state of its high voltage circuitry facilitating a fast protection switching in case of critical failures. The digital serial signal is first fetched into PCM multiplexer where it is mapped to the corresponding E1 (2 Mbit/s time division multiplexed signal. Subsequently, the resulting E1 frames are then packetized and sent through Ethernet control LAN to the opposite PCM demultiplexer where the same but reverse processing is done finally sending a signal into the opposite protective relay. The challenge of this setup is to assure very timely delivery of the control information between protective relays even in the cases of potential failures of Ethernet network itself. The tolerance of Ethernet network to faults is assured using widespread per VLAN Rapid Spanning Tree Protocol potentially extended by 1+1 PCM protection as a valuable option.

  12. 融合GPRS与嵌入式以太网技术的指纹考勤系统设计%DESIGNING FINGERPRINT TIME AND ATTENDANCE SYSTEM BASED ON INTEGRATION OF GPRS AND EMBEDDED ETHERNET TECHNOLOGY

    Institute of Scientific and Technical Information of China (English)

    钟海林; 王宜怀; 舒胜强

    2011-01-01

    In this paper, by integrating the techniques of GPRS, embedded Ethernet, flash memory and intelligent power management, we designed a fingerprint Time and Attendance System, which is based on embedded Ethernet module integrated microcontroller MCF52223 (produced by Freescale Corporation) and GTM900-B of HuaWei Company. This design has some excellent advantages, such as optional communication mode, offline attendance checking supported and intelligent power management, can meet the needs of diverse attendance management. As the fingerprint is unique and can not be replicated, it eliminates the problem of surrogated attendance checking in IC attendance system. This research can be the reference to similar applications.%结合GPRS、嵌入式以太网、Flash存储、智能电源管理等技术,并以Freescale公司集成嵌入式以太网模块的MCF52233微控制器和华为GTM900-B为基础,设计了融合GPRS与嵌入式以太网技术的指纹考勤系统.该设计具有通信方式可选、支持脱机考勤、智能电源管理等特点,满足了考勤管理的多样性需求.同时由于指纹的唯一性和不可复制性,杜绝了IC考勤中的替考问题,可为同类应用借鉴.

  13. Challenges for Social Sensing using WiFi Signals

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Nurmi, Petteri

    2012-01-01

    for the capture of more complex social phenomena. One of the most promising modalities for this purpose is WiFi, as it works both indoors and outdoors, and as WiFi signal environment tends to contain significant spatial variation. A challenge in using WiFi, however, is that the signals are affected by many noise...... sources, such as fast fading, body attenuation, hardware differences and varying access points densities. In this paper we review existing work on using WiFi for social sensing and outline challenges that have to be addressed to utilize WiFi at large for social sensing....

  14. Gateway Deployment optimization in Cellular Wi-Fi Mesh Networks

    Directory of Open Access Journals (Sweden)

    Rajesh Prasad

    2006-07-01

    Full Text Available With the standardization of IEEE 802.11, there has been an explosive growth of wireless local area networks (WLAN. Recently, this cost effective technology is being developed aggressively for establishing metro-scale “cellular Wi-Fi” network to support seamless Internet access in the urban area. We envision a large scale WLAN system in the future where Access Points (APs will be scattered over an entire city enabling people to use their mobile devices ubiquitously. The problem addressed in this paper involves finding the minimum number of gateways and their optimal placement so as to minimize the network installation costs while maintaining reliability, flexibility and an acceptable grade of service. The problem is modeled taking a network graph, where the nodes represents either the Access Points of IEEE 802.11 or wired backbone gateways. In this paper, we present two methods (1 an innovative approach using integer linear programming (ILP for gateway selection in the cellular Wi-Fi network, and (2 a completely new heuristic (OPEN/CLOSE to solve the gateway selection problem. In the ILP model, we developed a set of linear inequalities based on various constraints. The ILP model is solved by using lp-solve, a simplex-based software for linear and integer programming problems. The second approach is an OPEN/CLOSE heuristic, tailored for cellular Wi-Fi, which arrives at a sub-optimal solution. Java programming language is used for simulation in OPEN/CLOSE heuristic. Extensive simulations are carried out for performance evaluation. Simulation results show that the proposed approaches can effectively identify a set of gateways at optimal locations in a cellular Wi-Fi network, resulting in an overall cost reduction of up to 50%. The technique presented in this paper is generalized and can be used for gateway selection for other networks as well.

  15. Private synchronization technique for heterogeneous wireless network (WiFi and WiMAX)

    Science.gov (United States)

    Al-Sherbaz, Ali; Adams, Chris; Jassim, Sabah

    2008-04-01

    Horizontal developments in communication systems have led to the emergence of new wireless technologies like WiMAX, 3G and 4G. These expansions can provide new opportunities for further advances and exciting applications in particular if we can integrate different technology standards into heterogeneous wireless networks. WiMAX and WiFi wireless networks are two examples of different standard technologies that cannot communicate with each other using existing protocols. These two standards differ in frequency, protocol and management mechanisms, and hence to construct a heterogeneous network using WiFi and WiMAX devices these differences need to be harmonised and resolved. Synchronization is the first step towards in such a process. In this paper we propose a private synchronization technique that enables WiFi and WiMAX devices to communicate with each other. Precise time synchronization in the micro second resolution range is required. The CPU clock is used as a reference for this private synchronization. Our private synchronization solution is based on interposing an extra thin layer between MAC and PHY layers in both WiFi and WiMAX. This extra thin layer will assign alternate synchronization and other duties to the two systems.

  16. Gigabit Ethernet Asynchronous Clock Compensation FIFO

    Science.gov (United States)

    Duhachek, Jeff

    2012-01-01

    Clock compensation for Gigabit Ethernet is necessary because the clock recovered from the 1.25 Gb/s serial data stream has the potential to be 200 ppm slower or faster than the system clock. The serial data is converted to 10-bit parallel data at a 125 MHz rate on a clock recovered from the serial data stream. This recovered data needs to be processed by a system clock that is also running at a nominal rate of 125 MHz, but not synchronous to the recovered clock. To cross clock domains, an asynchronous FIFO (first-in-first-out) is used, with the write pointer (wprt) in the recovered clock domain and the read pointer (rptr) in the system clock domain. Because the clocks are generated from separate sources, there is potential for FIFO overflow or underflow. Clock compensation in Gigabit Ethernet is possible by taking advantage of the protocol data stream features. There are two distinct data streams that occur in Gigabit Ethernet where identical data is transmitted for a period of time. The first is configuration, which happens during auto-negotiation. The second is idle, which occurs at the end of auto-negotiation and between every packet. The identical data in the FIFO can be repeated by decrementing the read pointer, thus compensating for a FIFO that is draining too fast. The identical data in the FIFO can also be skipped by incrementing the read pointer, which compensates for a FIFO draining too slowly. The unique and novel features of this FIFO are that it works in both the idle stream and the configuration streams. The increment or decrement of the read pointer is different in the idle and compensation streams to preserve disparity. Another unique feature is that the read pointer to write pointer difference range changes between compensation and idle to minimize FIFO latency during packet transmission.

  17. Study Application of RADIUS Protocol on Ethernet

    Institute of Scientific and Technical Information of China (English)

    GUO Fang; YANG Huan-yu; LI Hong

    2004-01-01

    This paper presents how to apply the RADIUS (Remote Authentication Dial In User Service)protocol ,which is generally applied to dial-up network, to the authentication & charge of Broad Band accessing control system on Ethernet. It is provided that the Broad Band accessing control system included a self-designed communication protocol is used in communicating between an terminal user and Network Access Server .The interface module on the servers side and the Radius system is also given in this article.

  18. Stationarity Testing of Accumulated Ethernet Traffic

    Directory of Open Access Journals (Sweden)

    Zhiping Lu

    2013-01-01

    Full Text Available We investigate the stationarity property of the accumulated Ethernet traffic series. We applied several widely used stationarity and unit root tests, such as Dickey-Fuller test and its augmented version, Phillips-Perron test, as well as the Kwiatkowski-Phillips-Schmidt-Shin test and some of its generalizations, to the assessment of the stationarity of the traffic traces at the different time scales. The quantitative results in this research provide evidence that when the time scale increases, the accumulated traffic series are more stationary.

  19. WiFi Is on the Way

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    WiFi mobile phones soon may get a nod of approval from China’s telecom industry regulator At present, China’s telecom regulator prohibits phone calls made via the Internet or the browsing of Web pages via a mobile phone in wire-

  20. Enterasys Networks delivers standards-based 10-Gigabit ethernet modules for its Enterasys X-Pedition Routers and Enterasys Matrix Switches

    CERN Multimedia

    2002-01-01

    Enterasys Networks Inc. has announced new 10-Gigabit Ethernet modules for the Enterasys X-Pedition ER16 routers and Enterasys Matrix E1 OAS (Optical Access Switch). The addition of 10-Gigabit Ethernet technology enables the Enterasys X-Pedition ER16 enables real-time delivery of high-bandwidth, advanced applications across local area network (LAN), wide area network (WAN) and metropolitan area network (MAN) environments (1/2 page).

  1. OPTIMASI POSISI PILOT MENGGUNAKAN ALGORITMA GENETIKA UNTUK MENINGKATKAN KINERJA Wi-Fi 802.11n

    Directory of Open Access Journals (Sweden)

    Wahyul Amien Syafei

    2013-12-01

    Full Text Available Wi-Fi is wireless communication technology that  used widely not only for accessing the internet but also communicating data, image, voice and video. The newest wi-fi technology is 802.11n as an extention of 802.11a/b/g. By  combining OFDM and MIMO techniques it can provide throughput up to 600Mbps. One of important factors to achieve such high throughput is the pilot position in training sequence. Wi-fi802.11n allocates it’s pilots orthogonally. This research optimizes the pilot location using Genetic Algorithm Differential Evolution. Optimum pilot position improves the accuracy of synchronization which leads to enhance the performance. The invented optimum pilot position set then be implemented into wi-fi 802.11n simulator to be analyzed the performance enhancement which represented in grafic BER vs SNR curve.Run test under channel model B and D proof that the invented optimum pilot position gives performance enhancement of 0,5 dB and maintain it’s stability compared towi-fi 802.11n system with  set ortogonal pilot position.

  2. Temperature and Humidity Detection Device Based on WiFi Technology%基于WiFi无线通信的温湿度检测节点设计

    Institute of Scientific and Technical Information of China (English)

    贾浩强; 李耀

    2014-01-01

    基于 AM2303温湿度传感器、STC15F104W 单片机和 WiFi 模块设计了一种无线温湿度检测节点。介绍了AM2303及其通信协议、WiFi模块及其组网特性等,并且给出了读取 AM2303数据的软件流程。经测试,该节点通信距离远,组网灵活,可很好地应用于粮库粮情检测等实际工作环境。%A kind of wireless temperature and humidity detection node are designed based on AM2303 temperature and humidity sensor, STC15F104W microcontroller and WiFi module.This paper introduces AM2303 and its communication protocols,WiFi module and the characteristics of network.The flowcharts of reading data are given.The hardware test shows that the node has long distance of com-munication,flexible networking,and it can be well applied in actual work environments such as granary testing.

  3. Esearch and Application of Wi-Fi Technology in 3G Mobile Phone Design%Wi-Fi技术在3G手机设计方案中的应用与研究

    Institute of Scientific and Technical Information of China (English)

    陈驰

    2012-01-01

    针对3G手机行业内嵌Wi-Fi芯片设计方案的广泛市场需求和实施过程中可能存在的问题,通过对IEEE 802.11协议、双芯片架构、以及Wi-Fi和蓝牙的频带冲突、数据总线并发在3G手机设计方案中的应用等问题的分析,提出了3G手机行业集成Wi-Fi功能的解决方案,详细论述了解决方案的设计、实现过程.%This paper aims at the wide market demand and the problems that may exist in the implementation of the Wi-Fi chip embedded in the 3G mobile phone design,presented an integrated Wi-Fi function solution of 3G mobile phone and discussed in details the design and implementation process through the analysis of application problems,such as IEEE802.11 protocol,two-chip architecture,Wi-Fi and Bluetooth bands conflict,concurrent data bus.

  4. Possibilities of implementation of synchronous Ethernet in popular Ethernet version using timing and interference constraints

    Directory of Open Access Journals (Sweden)

    Seetaiah KILARU

    2015-12-01

    Full Text Available Popular network architectures are following packet based architectures instead of conventional Time division multiplexing. The existed Ethernet is basically asynchronous in nature and was not designed based on timing transfer constraints. To achieve the challenge of next generation network with respect to efficient bandwidth and faster data rates, we have to deploy the network which has less latency. This can be achieved by Synchronous Ethernet (SyncE. In Sync-E, Phase Locked Loop (PLL was used to recover the incoming jitter from clock recovery circuit. Then feed the PLL block to transmission device. We have to design the network in an unaffected way that the functions of Ethernet should run in normal way even we introduced timing path at physical layer. This paper will give detailed outlook on how Sync-E is achieved from Asynchronous format. Reference model of 100 Base-TX/FX was analyzed with respect to timing and interference constraints. Finally, it was analyzed with the data rate improvement with the proposed method.

  5. Fronthaul evolution: From CPRI to Ethernet

    Science.gov (United States)

    Gomes, Nathan J.; Chanclou, Philippe; Turnbull, Peter; Magee, Anthony; Jungnickel, Volker

    2015-12-01

    It is proposed that using Ethernet in the fronthaul, between base station baseband unit (BBU) pools and remote radio heads (RRHs), can bring a number of advantages, from use of lower-cost equipment, shared use of infrastructure with fixed access networks, to obtaining statistical multiplexing and optimised performance through probe-based monitoring and software-defined networking. However, a number of challenges exist: ultra-high-bit-rate requirements from the transport of increased bandwidth radio streams for multiple antennas in future mobile networks, and low latency and jitter to meet delay requirements and the demands of joint processing. A new fronthaul functional division is proposed which can alleviate the most demanding bit-rate requirements by transport of baseband signals instead of sampled radio waveforms, and enable statistical multiplexing gains. Delay and synchronisation issues remain to be solved.

  6. ETHERNET PACKET PROCESSOR FOR SOC APPLICATION

    Directory of Open Access Journals (Sweden)

    Raja Jitendra Nayaka

    2012-07-01

    Full Text Available As the demand for Internet expands significantly in numbers of users, servers, IP addresses, switches and routers, the IP based network architecture must evolve and change. The design of domain specific processors that require high performance, low power and high degree of programmability is the bottleneck in many processor based applications. This paper describes the design of ethernet packet processor for system-on-chip (SoC which performs all core packet processing functions, including segmentation and reassembly, packetization classification, route and queue management which will speedup switching/routing performance. Our design has been configured for use with multiple projects ttargeted to a commercial configurable logic device the system is designed to support 10/100/1000 links with a speed advantage. VHDL has been used to implement and simulated the required functions in FPGA.

  7. GiGabit Ethernet mezzanines for DAQ and Trigger links of LHCb

    CERN Document Server

    Müller, H; Guirao, A

    2003-01-01

    The LHCb experiment uses IEEE 802.ab (GiGabit ethernet) technology for the data transport and readout network layer between the L1 data buffers and the CPU farm. The common way to interface the L1 buffers in LHCb to the physical layers of GiGabitEthernet (GBE) is specified in this document. The SPI-3 industry standard is used as a narrow, FiFo-like interface which can be easily implemented in the FPGAs of the L1 boards. The SPI-3 protocol on the mezzanine cards is handled by commercial chips. Up to 4 bidirectional GBE channels can be implemented on a 149*74 mm mezzanine of stackheight 11 mm. These are interfaced through one 150 pin, high-speed connector which is defined here as LHCb standard.

  8. Ethernet-Enabled Power and Communication Module for Embedded Processors

    Science.gov (United States)

    Perotti, Jose; Oostdyk, Rebecca

    2010-01-01

    The power and communications module is a printed circuit board (PCB) that has the capability of providing power to an embedded processor and converting Ethernet packets into serial data to transfer to the processor. The purpose of the new design is to address the shortcomings of previous designs, including limited bandwidth and program memory, lack of control over packet processing, and lack of support for timing synchronization. The new design of the module creates a robust serial-to-Ethernet conversion that is powered using the existing Ethernet cable. This innovation has a small form factor that allows it to power processors and transducers with minimal space requirements.

  9. Radiation Hardened 10BASE-T Ethernet Physical Layer (PHY)

    Science.gov (United States)

    Lin, Michael R. (Inventor); Petrick, David J. (Inventor); Ballou, Kevin M. (Inventor); Espinosa, Daniel C. (Inventor); James, Edward F. (Inventor); Kliesner, Matthew A. (Inventor)

    2017-01-01

    Embodiments may provide a radiation hardened 10BASE-T Ethernet interface circuit suitable for space flight and in compliance with the IEEE 802.3 standard for Ethernet. The various embodiments may provide a 10BASE-T Ethernet interface circuit, comprising a field programmable gate array (FPGA), a transmitter circuit connected to the FPGA, a receiver circuit connected to the FPGA, and a transformer connected to the transmitter circuit and the receiver circuit. In the various embodiments, the FPGA, transmitter circuit, receiver circuit, and transformer may be radiation hardened.

  10. Interfacing the Controllogics PLC over Ethernet/IP.

    Energy Technology Data Exchange (ETDEWEB)

    Kasemir, K. U. (Kay-Uwe); Dalesio, L. R. (Leo R.)

    2001-01-01

    The Allen-Bradley ControlLogix [1] line of programmable logic controllers (PLCs) offers several interfaces: Ethernet, ControlNet, DeviceNet, RS-232 and others. The ControlLogix Ethernet interface module 1756-ENET uses EtherNet/IP, the ControlNet protocol [2], encapsulated in Ethernet packages, with specific service codes [3]. A driver for the Experimental Physics and Industrial Control System (EPICS) has been developed that utilizes this EtherNet/IP protocol for controllers running the vxWorks RTOS as well as a Win32 and Unix/Linux test program. Features, performance and limitations of this interface are presented.

  11. Where did my wifi go? Measuring soil moisture using wifi signal strength

    Science.gov (United States)

    Hut, Rolf; de Jeu, Richard

    2015-04-01

    Soil moisture is tricky to measure. Currently soil moisture is measured at small footprints using probes and other field devices, or at large footprints using satellites. Promising developments in measuring soil moisture are using fiber optic cables for measurements along a line, or using cosmos rays for field scale measurements. In this demonstration we present a low cost alternative to measure soil moisture at footprints of a few square meters. We use a wifi hotspot and a wifi dongle, both mounted in a cantenna for beam forming. We aim the hotspot on a piece of soil and put the dongle in the path of the reflection. By logging the signal strength of the wifi netwerk, we have a proxy for soil moisture. A first proof of concept is presented.

  12. Research on Ethernet remote update technology for TMS320C6416 program%TMS320C6416程序以太网远程更新技术研究

    Institute of Scientific and Technical Information of China (English)

    陈绍炜; 魏刚; 王子

    2014-01-01

    In view of remote software maintenance and update of DSP without debugger,a scheme of remote update for DSP program which is based on trivial file transfer protocol(TFTP)and can be applied to a platform without operation system is pro-posed according to bootloading principle of TI C6000 series DSP. A hierarchical structure of system software design laying em-phasis on the procedure of program loading and updating is presented. High efficiency and stability embedding of the network protocol is realized in DSP platform by transplanting the lightweight TCP/IP stack (LwIP). Project practice indicates that the scheme optimizes the expense of system resource from network protocol,improves the flexibility of Ethernet development on DSP,and is beneficial to promote the system performance.%针对脱离调试器下,DSP远程软件维护和升级问题,从TI C6000系列DSP程序自加载原理出发,提出了一种基于简单文件传输协议(TFTP)和可用于无操作系统平台的程序远程更新方案,给出了系统软件设计结构,重点设计了程序加载更新的过程,并通过移植轻型TCP/IP协议栈(LwIP),实现了网络协议在DSP平台下的高效稳定嵌入。工程实践表明,该方案优化了网络协议对系统资源的开销,提高了DSP下以太网功能开发的灵活性,有益于系统性能的提升和改进。

  13. Messaging and Voice Conferencing through Wi-Fi Network

    Directory of Open Access Journals (Sweden)

    Miss. Nayana H S,

    2014-06-01

    Full Text Available The use of Wi-Fi enabled android phones as IP phones, and their communication within a local wireless LAN is discussed in this paper. This proposed model is a form of telecommunication that allows exchange of data and voice via Wi-Fi network. The phones, which are Wi-Fi enabled and have android operating system, can be used to communicate with each other through the Wi-Fi communication channel. Proposed system incorporates messaging (Text and voice, conferencing (group conversation and file sharing services through the Wi-Fi network. When users enters the Wi-Fi network, proposed system displays the list of other users they are having this system on their mobile in that network. Using the system services, user can communicate with other user by exchanging packets to IP address of destination user, with the condition that both communicating person should be in same Wi-Fi network. The proposed system allows communication through Wi-Fi which requires neither any internet connectivity nor any service from the service providers. In this paper, the proposed system shall eliminate the usage of service providers for short-distance calls and decreases the cost that gets accrued in the consumer’s monthly bill. This system allows free conferencing, file sharing and messaging services within the Wi-Fi network that will greatly reduce the communication cost in large organizations.

  14. Enabling LTE and WiFi Coexisting in 5 GHz for Efficient Spectrum Utilization

    Directory of Open Access Journals (Sweden)

    Hongyu Sun

    2017-01-01

    Full Text Available Due to the increasing mobile traffic demands in cellular network, researchers have proposed the coexistence of LTE and WiFi technologies in 5 GHz unlicensed bands. Therefore, how to efficiently utilize the spectrum in 5 GHz becomes extremely important. To avoid the channel access conflicts, current LTE Unlicensed (LTE-U technology introduces the duty cycle of LTE, while License-Assisted Access (LAA technology introduces Listen-Before-Talk (LBT mechanism. While these two technologies improve the spectrum utilization by using time division access schema, we believe that more efficient spectrum utilization can be achieved by enabling simultaneous transmissions from LTE and WiFi. In this paper, we propose a novel method (i.e., Low Amplitude Stream Injection (LASI method to enable the simultaneous transmissions of WiFi and LTE frames in the same channel and recover the data from the conflicts. To further utilize the LASI method, we introduce the Conflict-Tolerant Channel Allocation (CTCA algorithm to optimize the channel allocation and achieve more efficient spectrum utilization in 5 GHz. Extensive simulation results show that our approach achieves lower latency and higher throughput. Compared with the state-of-the-art LTE-U and LAA technologies, our approach can improve the spectrum efficiency 2.9 times.

  15. Queuing Time Prediction Using WiFi Positioning Data in an Indoor Scenario.

    Science.gov (United States)

    Shu, Hua; Song, Ci; Pei, Tao; Xu, Lianming; Ou, Yang; Zhang, Libin; Li, Tao

    2016-11-22

    Queuing is common in urban public places. Automatically monitoring and predicting queuing time can not only help individuals to reduce their wait time and alleviate anxiety but also help managers to allocate resources more efficiently and enhance their ability to address emergencies. This paper proposes a novel method to estimate and predict queuing time in indoor environments based on WiFi positioning data. First, we use a series of parameters to identify the trajectories that can be used as representatives of queuing time. Next, we divide the day into equal time slices and estimate individuals' average queuing time during specific time slices. Finally, we build a nonstandard autoregressive (NAR) model trained using the previous day's WiFi estimation results and actual queuing time to predict the queuing time in the upcoming time slice. A case study comparing two other time series analysis models shows that the NAR model has better precision. Random topological errors caused by the drift phenomenon of WiFi positioning technology (locations determined by a WiFi positioning system may drift accidently) and systematic topological errors caused by the positioning system are the main factors that affect the estimation precision. Therefore, we optimize the deployment strategy during the positioning system deployment phase and propose a drift ratio parameter pertaining to the trajectory screening phase to alleviate the impact of topological errors and improve estimates. The WiFi positioning data from an eight-day case study conducted at the T3-C entrance of Beijing Capital International Airport show that the mean absolute estimation error is 147 s, which is approximately 26.92% of the actual queuing time. For predictions using the NAR model, the proportion is approximately 27.49%. The theoretical predictions and the empirical case study indicate that the NAR model is an effective method to estimate and predict queuing time in indoor public areas.

  16. FUSION OF LOCATION FINGERPRINTING AND TRILATERATION BASED ON THE EXAMPLE OF DIFFERENTIAL WI-FI POSITIONING

    Directory of Open Access Journals (Sweden)

    G. Retscher

    2017-09-01

    Full Text Available Positioning of mobile users in indoor environments with Wireless Fidelity (Wi-Fi has become very popular whereby location fingerprinting and trilateration are the most commonly employed methods. In both the received signal strength (RSS of the surrounding access points (APs are scanned and used to estimate the user’s position. Within the scope of this study the advantageous qualities of both methods are identified and selected to benefit their combination. By a fusion of these technologies a higher performance for Wi-Fi positioning is achievable. For that purpose, a novel approach based on the well-known Differential GPS (DGPS principle of operation is developed and applied. This approach for user localization and tracking is termed Differential Wi-Fi (DWi-Fi by analogy with DGPS. From reference stations deployed in the area of interest differential measurement corrections are derived and applied at the mobile user side. Hence, range or coordinate corrections can be estimated from a network of reference station observations as it is done in common CORS GNSS networks. A low-cost realization with Raspberry Pi units is employed for these reference stations. These units serve at the same time as APs broadcasting Wi-Fi signals as well as reference stations scanning the receivable Wi-Fi signals of the surrounding APs. As the RSS measurements are carried out continuously at the reference stations dynamically changing maps of RSS distributions, so-called radio maps, are derived. Similar as in location fingerprinting this radio maps represent the RSS fingerprints at certain locations. From the areal modelling of the correction parameters in combination with the dynamically updated radio maps the location of the user can be estimated in real-time. The novel approach is presented and its performance demonstrated in this paper.

  17. Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations.

    Science.gov (United States)

    Paknahad, Maryam; Mortazavi, S M J; Shahidi, Shoaleh; Mortazavi, Ghazal; Haghani, Masoud

    2016-01-01

    Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations. Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups. The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009). Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

  18. Application of WiFi Technology in the Remote Monitoring System for Temperature and Humidity%WiFi技术在温湿度远程监测系统中的应用

    Institute of Scientific and Technical Information of China (English)

    刘军良

    2014-01-01

    针对当前温湿度远程监测布线复杂、采集速度慢等缺点,提出了一种新颖的分布式无线监测系统。系统由DHT11数字式温湿度传感器、单片机STM32F103和WiFi模块等组成。各采集节点利用STM32F103单片机采集温湿度,然后通过WiFi模块和无线路由器把各采集节点的温湿度参数发送到远程服务器上。试验表明,该系统布线简单、采集速度快、应用灵活,可实现范围分布广泛的温湿度集中可视化监控,具有一定的推广使用价值。%Aiming at the disadvantages of current remote monitoring system, e. g. , complex wiring and slow acquisition speed, etc. , a new distributed wireless monitoring system is proposed. The system is composed of DHT11 digital temperature humidity sensor, single chip machine STM32F103 and WiFi module. The temperature and humidity are collected by using STM32F103 single chip machine in each collection node, then, these parameters are transmitted to remote server through WiFi module and wireless router. The experiments show that the system is simple wiring, fast collecting and flexible applying; it can be used in centralized visual monitoring for widely distributed temperature and humidity parameters, and possesses certain values of promotion and application.

  19. Radiation Hardened Ethernet PHY and Switch Fabric Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Innoflight will develop a new family of radiation hardened (up to 3 Mrad(Si)), fault-tolerant, high data-rate (up to 8 Gbps), low power Gigabit Ethernet PHY and...

  20. Architecture of WiFi Based Broadcast Network for Rural Community

    Directory of Open Access Journals (Sweden)

    Jumshed Akhtar

    2016-04-01

    Full Text Available Digital divide is a reality in developing nations. Most of the technological advancements are available only in urban areas and rural community is still deprived of communication technology even in 21 st century. To ensure the availability of Internet, TV (Television and other high data-rate services to the rural community; use of high power ISM (Industrial, Scientific and Medical band broadcast should be of interest. The aim of this research work is to design a WiFi based broadcast network that provides broadband access to remote areas and to study the propagation characteristics of this network in a typical rural community in the plains of Pakistan. This paper uses extensive measurements in indoor and outdoor environments of village ?Lower Kot Ratta? to develop a WiFi broadband broadcast propagation model for rural areas of Pakistan. The proposed model is simple, flexible and more suitable for rural areas as compared to existing models

  1. A Control System for Tobacco Shred Production Line Based on Industrial Ethernet

    Science.gov (United States)

    Zhang, Li; Zheng, Guang; Zhang, Xinfeng; Liu, Lei; Xi, Lei

    The Industrial Ethernet based on IP realizes interconnection of industrial network and information network, and it is the most potential technology in the new industrial net products. In this paper, the defects of the original control system for tobacco shred production line are analyzed, and the new design plan of control system based on EtherNet/IP is presented. The control net adopts redundant 1000M fiber optic ring network that consists of six managed Industrial Ethernet Switches, and they are distributed to the central control room, leaf processing line, shred processing line, mixed stem shred processing line, online mositure regain processing line and cut tobacco dryer control cabinet. The switch in the central control room works in the pattern of redundancy management, which can switch the link in the event of the failure in link of ring net, the recovery time of link line is less than 500ms, and each main PLC of control section has dual Network Adapters. The plan has been applied for reform of 5000kg/h Tobacco Primary Processing Line in Nanyang Cigarette Factory of China Tobacco Henan Industrial Corporation, and the configurable software and Industry Ethernet network which has been used promots the capability of automatic control system fundamentally, showing much better transmission efficiency and reliability, realizing the goal of high cost performance and making equipment's ability of handling grow fast.

  2. Wi-Fi 第四张无线网络的魅力%The Charm of the Fourth Generation Wireless NetworksWi-Fi

    Institute of Scientific and Technical Information of China (English)

    曹江海

    2013-01-01

      Wi-Fi 是一种可以将个人电脑、手持设备(如 PDA、手机)等终端以无线方式相互连接的技术.Wi-Fi 是一个无线网络通信技术的品牌,由 Wi-Fi 联盟(WiFi Alliance)所持有.目的是改善基 IEEE802.11标准的无线网络产品之间的互通性.使 Wi-Fi 设备无需接入传统家庭、办公室或热点网络,即可实现相互连接.%Wi -Fi is a terminal, which consists of personal computers, handheld devices like PDA, mobilephone, wirelessly interconnected technology .Wi-Fi is a brand of wireless network communication technology, held by the Wi-Fi Alliance (WiFi Alliance). The aim is to improve the interoperability between wireless networking products based on the IEEE802.11 standard. Wi-Fi devices can get interconnected without access to traditional home, office or hotspot network.

  3. Synchronization, retiming and OTDM of an asynchronous 10 Gigabit Ethernet NRZ packet using a time lens for Terabit Ethernet

    DEFF Research Database (Denmark)

    Hu, Hao; Laguardia Areal, Janaina; Mulvad, Hans Christian Hansen;

    2011-01-01

    An asynchronous 10G Ethernet packet is synchronized and retimed to a master clock using a time lens. The NRZ packet is converted into an RZ packet and multiplexed with a serial 1.28 Tb/s signal.......An asynchronous 10G Ethernet packet is synchronized and retimed to a master clock using a time lens. The NRZ packet is converted into an RZ packet and multiplexed with a serial 1.28 Tb/s signal....

  4. Tracking Human Mobility Using WiFi Signals

    DEFF Research Database (Denmark)

    Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu

    2015-01-01

    to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population...

  5. Going Wi-Fi in Canada: municipal and community initiatives

    OpenAIRE

    Powell, Alison; Shade, Leslie Regan

    2006-01-01

    Urban community Wi-Fi in Canada is at a nascent stage; active non-profit groups through dedicated volunteers, support the development or deployment of Wi-Fi services in community spaces throughout their regions. This article discusses recent initiatives.

  6. Desing of Roof Separation Indicator System Based on ZigBee and Industrial Ethernet Technology%基于ZigBee和以太网技术的巷道顶板离层数据在线监测系统设计

    Institute of Scientific and Technical Information of China (English)

    王立飞; 王晓荣

    2016-01-01

    针对目前矿用顶板离层仪主要采用有线的传输方式,这种方式存在安装不方便、成本高、灵活性和扩展性差的缺点。因此,笔者根据顶板离层的测量原理,结合巷道现场实际情况,在STM32处理器上将ZigBee与以太网结合,运用RT-thread操作系统,设计了一种采用ZigBee和以太网技术2层通讯的顶板离层数据在线监测系统。矿下实验证明,该系统测量范围在0~300 mm,测量精度达到2%,ZigBee 部分数据传输稳定,实时上传数据,方便了顶板离层检测的自动化。%Aimed at the present mine roof separation indicator that mainly adopts the transmission mode of cable, this method has the disadvantage of inconvenience for installation,high cost and poor flexibility and scalability. Therefore,according to the measurement principle of roof abscission layer and the practical situation of the roadway scene,the author combined ZiggBee and Ethernet on the STM32 processor,applied RT-thread operating system,de⁃signed an on-line roof separation monitoring system based on ZigBee and Ethernet technology. Mine experiment proves that the measuring range of this system is 0-300 mm,the precision is 2%,and the transmission of partial data of ZigBee is stable and real time,which makes the automatic roof separation and detection convenient.

  7. A novel method for constructing a WIFI positioning system with efficient manpower.

    Science.gov (United States)

    Du, Yuanfeng; Yang, Dongkai; Xiu, Chundi

    2015-04-10

    With the rapid development of WIFI technology, WIFI-based indoor positioning technology has been widely studied for location-based services. To solve the problems related to the signal strength database adopted in the widely used fingerprint positioning technology, we first introduce a new system framework in this paper, which includes a modified AP firmware and some cheap self-made WIFI sensor anchors. The periodically scanned reports regarding the neighboring APs and sensor anchors are sent to the positioning server and serve as the calibration points. Besides the calculation of correlations between the target points and the neighboring calibration points, we take full advantage of the important but easily overlooked feature that the signal attenuation model varies in different regions in the regression algorithm to get more accurate results. Thus, a novel method called RSSI Geography Weighted Regression (RGWR) is proposed to solve the fingerprint database construction problem. The average error of all the calibration points' self-localization results will help to make the final decision of whether the database is the latest or has to be updated automatically. The effects of anchors on system performance are further researched to conclude that the anchors should be deployed at the locations that stand for the features of RSSI distributions. The proposed system is convenient for the establishment of practical positioning system and extensive experiments have been performed to validate that the proposed method is robust and manpower efficient.

  8. A Novel Method for Constructing a WIFI Positioning System with Efficient Manpower

    Directory of Open Access Journals (Sweden)

    Yuanfeng Du

    2015-04-01

    Full Text Available With the rapid development of WIFI technology, WIFI-based indoor positioning technology has been widely studied for location-based services. To solve the problems related to the signal strength database adopted in the widely used fingerprint positioning technology, we first introduce a new system framework in this paper, which includes a modified AP firmware and some cheap self-made WIFI sensor anchors. The periodically scanned reports regarding the neighboring APs and sensor anchors are sent to the positioning server and serve as the calibration points. Besides the calculation of correlations between the target points and the neighboring calibration points, we take full advantage of the important but easily overlooked feature that the signal attenuation model varies in different regions in the regression algorithm to get more accurate results. Thus, a novel method called RSSI Geography Weighted Regression (RGWR is proposed to solve the fingerprint database construction problem. The average error of all the calibration points’ self-localization results will help to make the final decision of whether the database is the latest or has to be updated automatically. The effects of anchors on system performance are further researched to conclude that the anchors should be deployed at the locations that stand for the features of RSSI distributions. The proposed system is convenient for the establishment of practical positioning system and extensive experiments have been performed to validate that the proposed method is robust and manpower efficient.

  9. Secure Level Transmission in Wi-Fi Using Cryptography

    Directory of Open Access Journals (Sweden)

    K. Prasuna

    2013-11-01

    Full Text Available Wi-Fi, is a mechanism that allows electronic devices to exchange data wirelessly over a computer network Wi-Fi suggests Wireless Fidelity, resembling the long-established audio-equipment classification term Hi-Fi or High Fidelity.This paper first gives some background information about WiFi system and security issues in ad hoc networks, then it concentrates on the specific security measures like hybrid encryption techniques using both AES and RSA algorithms and also the different standards. To provide the security for the data transmitted through WiFi ,it uses WEP algorithm,WEP64 and WEP128 and then it moves to WPA (Wi-Fi Protected Access as the key is short in WEP.WPA use the TKIP and depends on RC4,which consist of 128 bit and 48 bit. The security comparisons show that WPA and TPIK is more advantageous than WEP and hence it is more preferable.

  10. Tracking Human Mobility Using WiFi Signals

    DEFF Research Database (Denmark)

    Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu;

    2015-01-01

    We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location...... to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population....... These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking....

  11. Tracking Human Mobility Using WiFi Signals.

    Directory of Open Access Journals (Sweden)

    Piotr Sapiezynski

    Full Text Available We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population. These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking.

  12. Tracking Human Mobility Using WiFi Signals.

    Science.gov (United States)

    Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu; Lehmann, Sune

    2015-01-01

    We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population. These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking.

  13. Wi-Fi Walkman: A wireless handhold that shares and recommends music on peer-to-peer networks

    NARCIS (Netherlands)

    Wang, J.; Reinders, M.J.T.; Pouwelse, J.; Lagendijk, R.L.

    2005-01-01

    The Wi-Fi walkman is a mobile multimedia application that we developed to investigate the technological and usability aspects of human-computer interaction with personalized, intelligent and context-aware wearable devices in peer-to-peer wireless environments such as the future home, office, or

  14. Wireless Data Acquisition System Based on LabVIEW and Wi-Fi Technology%基于LabVIEW和Wi-Fi技术的无线数据采集系统

    Institute of Scientific and Technical Information of China (English)

    张志军; 徐小力; 吴国新

    2013-01-01

    针对传统有线数据采集系统存在布线、改线工程量大,维护与拓展困难且费时费力等缺陷,设计了一套基于Wi-Fi技术的无线数据采集系统.系统以LabVIEW为软件开发平台,进行虚拟仪器前面板设计与后台程序的缩写;利用Wi-Fi无线数据收发模决及其余硬件设备实现监测数据的无线采集与传输,并对整个系统进行了实验验证.%Considering the wiring shortcomings of traditional wired data acquisition systems, a Wi-Fi-based wireless data acquisition system was designed, which takes LabVIEW as the platform to design virtual instrument front panel and to write background program; making use of Wi-Fi modules and other hard equipment, the monitoring data were wirelessly collected and transported and the whole system were verified through experiments.

  15. WiFi networks and malware epidemiology

    Science.gov (United States)

    Hu, Hao; Myers, Steven; Colizza, Vittoria; Vespignani, Alessandro

    2009-01-01

    In densely populated urban areas WiFi routers form a tightly interconnected proximity network that can be exploited as a substrate for the spreading of malware able to launch massive fraudulent attacks. In this article, we consider several scenarios for the deployment of malware that spreads over the wireless channel of major urban areas in the US. We develop an epidemiological model that takes into consideration prevalent security flaws on these routers. The spread of such a contagion is simulated on real-world data for georeferenced wireless routers. We uncover a major weakness of WiFi networks in that most of the simulated scenarios show tens of thousands of routers infected in as little as 2 weeks, with the majority of the infections occurring in the first 24–48 h. We indicate possible containment and prevention measures and provide computational estimates for the rate of encrypted routers that would stop the spreading of the epidemics by placing the system below the percolation threshold. PMID:19171909

  16. WiFi networks and malware epidemiology.

    Science.gov (United States)

    Hu, Hao; Myers, Steven; Colizza, Vittoria; Vespignani, Alessandro

    2009-02-03

    In densely populated urban areas WiFi routers form a tightly interconnected proximity network that can be exploited as a substrate for the spreading of malware able to launch massive fraudulent attacks. In this article, we consider several scenarios for the deployment of malware that spreads over the wireless channel of major urban areas in the US. We develop an epidemiological model that takes into consideration prevalent security flaws on these routers. The spread of such a contagion is simulated on real-world data for georeferenced wireless routers. We uncover a major weakness of WiFi networks in that most of the simulated scenarios show tens of thousands of routers infected in as little as 2 weeks, with the majority of the infections occurring in the first 24-48 h. We indicate possible containment and prevention measures and provide computational estimates for the rate of encrypted routers that would stop the spreading of the epidemics by placing the system below the percolation threshold.

  17. Cooperation Techniques between LTE in Unlicensed Spectrum and Wi-Fi towards Fair Spectral Efficiency.

    Science.gov (United States)

    Maglogiannis, Vasilis; Naudts, Dries; Shahid, Adnan; Giannoulis, Spilios; Laermans, Eric; Moerman, Ingrid

    2017-08-31

    On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets) is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT) has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP) announced standards that permit the operation of Long Term Evolution (LTE) in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner.

  18. Wireless Image Acquisition System of WIFI Lens Camera%WIFI镜头机无线图像采集系统

    Institute of Scientific and Technical Information of China (English)

    龚正; 沈建新

    2016-01-01

    Wired camera has many defects such as poor mobility and less flexible, so the paper presents a combination of the camera module, WIFI module and stm32 chips to form a WIFI wireless lens Camera. Through researching on theory and entity of camera module as well as WIFI module, this method implements wireless image data transmission to the display device processor by WIFI wireless data transmission technology, LWIP protocol and Socket network programming. When the display device with WIFI wireless network card could connect to the camera's internal WIFI hotspot, it could conveniently complete wireless image transmission, display and storage through a series of operations like connecting to the server, turning on the camera, preserving the image and so on.%针对有线摄像头移动性差、不够灵活等缺陷,提出将摄像头模块、WIFI模组和stm32芯片组合到一起形成一个WIFI无线镜头机.对摄像头模块和WIFI模组的原理和实物进行了研究,通过WIFI无线数据传输技术、LWIP协议及Socket网络编程将图像数据信息无线发送到显示设备处理器中.最终实现将带有网卡的显示设备连接到WIFI无线镜头机内部的WIFI热点,通过连接服务器、开启相机、保存图片等一系列的操作,方便快捷的完成无线图像传输、显示和存储的工作.

  19. Research on performance of ethernet interface in network centric warfare

    Institute of Scientific and Technical Information of China (English)

    梁永生; 张乃通

    2004-01-01

    The concept of network centric warfare (NCW) and its character, high requirement of real-time synchronization are introduced. The distributed equal-node network architecture in NCW is presented. Based on theoretical analysis on ethernet interface performance, this paper presents that forwarding latency between ethernet interface devices is a key influence factor of real-time synchronization in NCW. Ethernet fundamental is briefly introduced. The model between a switch under test (SUT) and a smartbits card is presented and used for two interconnecting switches in NCW. On condition that ignoring the latency of connecting fiber or twisted pairs and processing latency of the smartbits test system, this paper presents that clock frequency tolerance (CFT) between a SUT and a smartbits card is a leading influence factor of forwarding latency of an ethernet switch. The formulae to calculate internal forwarding latency and forwarding latency caused by its CFT are deduced. Theoretical calculation on forwarding latency of an ethernet switch based on the given CFT and test time is implemented. Experimental study on primary forwarding latency and secondary forwarding latency is implemented and forwarding latency between the SUT and the smartbits card is measured, thus testifying the accuracy of the above theoretical analysis that the CFT is a key influence factor of forwarding latency. The measures to satisfy the needs of forwarding latency in NCW are presented.

  20. Technologie WiFi Direct a její praktické využití

    OpenAIRE

    Starý, Tomáš

    2014-01-01

    The aim of this bachelor thesis is to determine the possibilities of practical usage of Wi-Fi Direct technology based on experimental verification which will be carried out using two mobile devices. Basic analysis of network properties will be performed on these two devices and the measured results will be compared with the theoretical values of Ad-hoc and BlueTooth technologies. We will determine where this new technology could be used in practice based on this comparison.

  1. Sobivanje naprav različnih Wi-Fi generacij

    OpenAIRE

    PLATIŠE, NEJC

    2016-01-01

    V diplomskem delu raziščemo medsebojne vplive sobivanja naprav različnih Wi-Fi generacij. Najprej se seznanimo s teoretičnimi lastnostmi različnih Wi-Fi standardov in načinom, kako ti sobivajo med seboj. Nato povzamemo bistvene lastnosti standarda Bluetooth in medsebojnega vpliva med Bluetooth in Wi-Fi prenosi. V nadaljevanju zasnujemo dve postavitvi brezžičnega omrežja, in sicer na krajši razdalji, kjer se vse naprave nahajajo v istem prostoru, ter na daljši razdalji, kjer so nap...

  2. Tracking Human Mobility Using WiFi Signals

    DEFF Research Database (Denmark)

    Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu

    2015-01-01

    We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign locatio....... These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking....

  3. Tracking Human Mobility using WiFi signals

    OpenAIRE

    Piotr Sapiezynski; Arkadiusz Stopczynski; Radu Gatej; Sune Lehmann

    2015-01-01

    We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the lo...

  4. Comparison of High Performance Network Options: EDR InfiniBand vs.100Gb RDMA Capable Ethernet

    Energy Technology Data Exchange (ETDEWEB)

    Kachelmeier, Luke Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States); Van Wig, Faith Virginia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Missouri Univ. of Science and Technology, Rolla, MO (United States); Erickson, Kari Natania [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2016-08-08

    These are the slides for a presentation at the HPC Mini Showcase. This is a comparison of two different high performance network options: EDR InfiniBand and 100Gb RDMA capable ethernet. The conclusion of this comparison is the following: there is good potential, as shown with the direct results; 100Gb technology is too new and not standardized, thus deployment effort is complex for both options; different companies are not necessarily compatible; if you want 100Gb/s, you must get it all from one place.

  5. A Reconfigurable Hybrid Architecture for HomePNA3.1/ Ethernet MAC

    Directory of Open Access Journals (Sweden)

    Mohammad Khalily Dermany

    2011-12-01

    Full Text Available With the growing demands of home networking, the existing networking technologies are not able to satisfy user expectations any more. HomePNA (Home Phoneline Networking Alliance is a solution for having high bandwidth without new cabling.In this paper, we propose a new reconfigurable hybrid architecture for HomePNA3.0. We implement the architecture in behavioural level using VHDL language. Our implementation was able to have HomePNA3.1 and Ethernet MACs together. The system synthesis show that our implementation decrease number of logical element by 32%.

  6. Real-time Performance Evaluation of Line Topology Switched Ethernet

    Institute of Scientific and Technical Information of China (English)

    Fan Cen; Tao Xing; Ke-Tong Wu

    2008-01-01

    Recently, switched Ethernet has become an active area of research because of its wide uses in industry. However, its uses have various real-time constraints on data communications. This paper analyzes the performance of the line topology switched Ethernet as a data acquisition network. Network calculus theory, which has been successfully applied to assess the real-time performance of packet-switched networks, is used to analyze the networks. To properly describe the activity of switches, a novel approach of modeling data flows into or out of switches is addressed. Based on our model, a concisely analytical expression of the maximal end-to-end delay in line topology switched Ethernet is derived. Finally, the relative simulation results are demonstrated. These results agree well with the analytical results, and thus they validate the data flow modeling techniques.

  7. Next generation network based carrier ethernet test bed for IPTV traffic

    DEFF Research Database (Denmark)

    Fu, Rong; Berger, Michael Stübert; Zheng, Yu;

    2009-01-01

    This paper presents a Carrier Ethernet (CE) test bed based on the Next Generation Network (NGN) framework. After the concept of CE carried out by Metro Ethernet Forum (MEF), the carrier-grade Ethernet are obtaining more and more interests and being investigated as the low cost and high performance...... services of transport network to carry the IPTV traffic. This test bed is approaching to support the research on providing a high performance carrier-grade Ethernet transport network for IPTV traffic....

  8. A computer tool to support in design of industrial Ethernet.

    Science.gov (United States)

    Lugli, Alexandre Baratella; Santos, Max Mauro Dias; Franco, Lucia Regina Horta Rodrigues

    2009-04-01

    This paper presents a computer tool to support in the project and development of an industrial Ethernet network, verifying the physical layer (cables-resistance and capacitance, scan time, network power supply-POE's concept "Power Over Ethernet" and wireless), and occupation rate (amount of information transmitted to the network versus the controller network scan time). These functions are accomplished without a single physical element installed in the network, using only simulation. The computer tool has a software that presents a detailed vision of the network to the user, besides showing some possible problems in the network, and having an extremely friendly environment.

  9. An Android/LAMP Mobile In/Out Board Based on Wi-Fi Fingerprinting

    Directory of Open Access Journals (Sweden)

    Keith Kelley

    2011-10-01

    Full Text Available Library technology and other professionals with diverse skills must be able to locate each other during the workday, in order to most responsively serve their clients. While staff often carry cellular phones, contact can be especially challenging given the constant, highly mobile nature of library work, especially on larger campuses with variable cellular phone service. Western Michigan University (WMU Libraries has developed an Android/LAMP application that library staff may use on their increasingly prevalent Wi-Fi enabled mobile devices to “check in” at various locations where they do work, so that their colleagues may locate them as needed. The application takes advantage of WMU’s widespread Wi-Fi network, a set of free platform and software development tools and open standards, and methods from the computer science literature, and overcomes GPS and telephony limitations. This article describes the application, which is based on Wi-Fi fingerprinting, and suggests how other developers could use it and new methods from the computer science literature as starting points to create their own applications.

  10. INDOOR LOCALIZATION USING WI-FI BASED FINGERPRINTING AND TRILATERATION TECHIQUES FOR LBS APPLICATIONS

    Directory of Open Access Journals (Sweden)

    S. Chan

    2012-06-01

    Full Text Available The past few years have seen wide spread adoption of outdoor positioning services, mainly GPS, being incorporated into everyday devices such as smartphones and tablets. While outdoor positioning has been well received by the public, its indoor counterpart has been mostly limited to private use due to its higher costs and complexity for setting up the proper environment. The objective of this research is to provide an affordable mean for indoor localization using wireless local area network (WLAN Wi-Fi technology. We combined two different Wi-Fi approaches to locate a user. The first method involves the use of matching the pre-recorded received signal strength (RSS from nearby access points (AP, to the data transmitted from the user on the fly. This is commonly known as "fingerprint matching". The second approach is a distance-based trilateration approach using three known AP coordinates detected on the user's device to derive the position. The combination of the two steps enhances the accuracy of the user position in an indoor environment allowing location-based services (LBS such as mobile augmented reality (MAR to be deployed more effectively in the indoor environment. The mapping of the RSS map can also prove useful to IT planning personnel for covering locations with no Wi-Fi coverage (ie. dead spots. The experiments presented in this research helps provide a foundation for the integration of indoor with outdoor positioning to create a seamless transition experience for users.

  11. The Making of a Sustainable Wireless City? Mapping Public Wi-Fi Access in Shanghai

    Directory of Open Access Journals (Sweden)

    Mingfeng Wang

    2016-01-01

    Full Text Available In the context of the global information economy, ready access to the Internet is critical to a city’s competitiveness, which has prompted a number of cities to launch plans to establish wireless networks. Most literature on the development of wireless cities focuses on cities in Western countries, and few have discussed how Chinese cities have adopted wireless technologies in their urban infrastructure development efforts. This paper examines recent development and spatial distribution of public Wi-Fi access in Shanghai, a leading business hub in China. We mapped Wi-Fi hotspots through the government sponsored “i-Shanghai” project and China Mobile Communications Corporation (CMCC. We find that while telecommunication providers have been proactively deploying WLAN (wireless local area network,a proxy of public Wi-Fi or wireless access hotspots in Shanghai, neither government sponsored WLAN hotspots nor facilities established by CMCC could cover the old traditional neighborhoods in the central city and sub-districts in remote rural areas. We also address the development of a more sustainable wireless city in Shanghai with a particular focus on digital divide and social equity issues.

  12. Dynamic WIFI-Based Indoor Positioning in 3D Virtual World

    Science.gov (United States)

    Chan, S.; Sohn, G.; Wang, L.; Lee, W.

    2013-11-01

    A web-based system based on the 3DTown project was proposed using Google Earth plug-in that brings information from indoor positioning devices and real-time sensors into an integrated 3D indoor and outdoor virtual world to visualize the dynamics of urban life within the 3D context of a city. We addressed limitation of the 3DTown project with particular emphasis on video surveillance camera used for indoor tracking purposes. The proposed solution was to utilize wireless local area network (WLAN) WiFi as a replacement technology for localizing objects of interest due to the wide spread availability and large coverage area of WiFi in indoor building spaces. Indoor positioning was performed using WiFi without modifying existing building infrastructure or introducing additional access points (AP)s. A hybrid probabilistic approach was used for indoor positioning based on previously recorded WiFi fingerprint database in the Petrie Science and Engineering building at York University. In addition, we have developed a 3D building modeling module that allows for efficient reconstruction of outdoor building models to be integrated with indoor building models; a sensor module for receiving, distributing, and visualizing real-time sensor data; and a web-based visualization module for users to explore the dynamic urban life in a virtual world. In order to solve the problems in the implementation of the proposed system, we introduce approaches for integration of indoor building models with indoor positioning data, as well as real-time sensor information and visualization on the web-based system. In this paper we report the preliminary results of our prototype system, demonstrating the system's capability for implementing a dynamic 3D indoor and outdoor virtual world that is composed of discrete modules connected through pre-determined communication protocols.

  13. WiFi Hot Spot Service Business for the Automotive and Oil Industries: A Competitive Analysis

    Directory of Open Access Journals (Sweden)

    Louis-Francois PAU

    2010-01-01

    Full Text Available While you refuel for gas, why not refuel for information or upload vehicle data, using a cheap wireless technology as WiFi? This paper analyzes in extensive detail the user segmentation by vehicle usage, service offering, and full business models from WiFi hot spot services delivered to and from vehicles (private, professional, public around gas stations. Are also analyzed the parties which play a role in such services: authorization, provisioning and delivery, with all the dependencies modelled by attributed digraphs. Account is made of WiFi base station technical capabilities and costs. Five year financial models (CAPEX, OPEX, and data pertain to two possible service suppliers: multi-service oil companies, and mobile service operators (or MVNOs. Model optimization on the return-on-investment (R.O.I. is carried out for different deployment scenarios, geographical coverage assumptions, as well as tariff structures. Comparison is also being made with public GPRS and 3G data services, as precursors to HSPA/LTE, and the effect of WiFi roaming is analyzed. Regulatory implications, including those dealing with public safety, are addressed. Analysis shows that due to manpower costs and marketing costs, suitable R.O.I. will not be achieved unless externalities are accounted for and innovative tariff structures are introduced. Open issues and further research are outlined. Further work is currently carried out with automotive electronics sector, wireless systems providers, wireless terminals platform suppliers, and vehicle manufacturers. Future relevance of this work is also discussed for the emerging electrical reloading grids for electrical vehicles.

  14. PERANCANGAN TELEROBOTIKA SEDERHANA DENGAN KAMERA WIFI

    Directory of Open Access Journals (Sweden)

    Fina Supegina

    2016-06-01

    Full Text Available Di zaman yang sudah modern seperti ini perkembangan teknologi yang sangat begitu cepat. Suatu mekanisme dan sistem dapat dengan mudah diselesaikan dalam suatu pekerjaan secara otomatis. Untuk itu diperlukan robot yang memiliki kecerdasan dan keunggulan tertentu dalam suatu pekerjaanya di bidang masing–masing. Robot dibuat untuk mampu memenuhi kebutuhan jasmani seseorang. Salah satu aplikasinya adalah membantu manusia untuk mengawasi rumah atau ruangan secara otomatis. Misalnya, sistem CCTV yang diletakan di suatu  tempat atau sudut yang memang tidak terlihat oleh orang lain untuk melihat situasi rumah dan pergerakan-pergerakan manusia yang ada di sekitar rumah agar tidak terjadi hal-hal yang tidak diinginkan. Penelitian ini menghasilkan sebuah mobil kontrol yang dapat difungsikan untuk memonitoring ruangan dengan wifi kamera sebagai CCTV-nya dan dikendalikan melalui smart phone android. Mobil kontrol yang dibuat mampu dimonitor dengan beberapa gadget sekaligus dan dapat dikontrol dengan jarak yang cukup jauh oleh semua pengguna android.

  15. Holography of Wi-fi Radiation

    Science.gov (United States)

    Holl, Philipp M.; Reinhard, Friedemann

    2017-05-01

    Wireless data transmission systems such as wi-fi or Bluetooth emit coherent light—electromagnetic waves with a precisely known amplitude and phase. Propagating in space, this radiation forms a hologram—a two-dimensional wave front encoding a three-dimensional view of all objects traversed by the light beam. Here we demonstrate a scheme to record this hologram in a phase-coherent fashion across a meter-sized imaging region. We recover three-dimensional views of objects and emitters by feeding the resulting data into digital reconstruction algorithms. Employing a digital implementation of dark-field propagation to suppress multipath reflection, we significantly enhance the quality of the resulting images. We numerically simulate the hologram of a 10-m-sized building, finding that both localization of emitters and 3D tomography of absorptive objects could be feasible by this technique.

  16. 铁通江苏分公司WIFI运营平台的设计与实现%WIFI Operating Platform of Jiangsu Branch of China Railway Design and Implementation

    Institute of Scientific and Technical Information of China (English)

    支伟

    2015-01-01

    With the development of Internet,WIFI technology get more and more application.The paper mainly aimed at tietong jiangsu branch points,WIFI service development present situation by studying of cloud management platform , construction of tietong jiangsu branch WIFI operating platform.%随着网络的发展,WIFI技术得到越来越多地应用,文章主要针对目前铁通江苏分公司WIFI业务发展现状,通过对云管理运营平台的研究,构建铁通江苏分公司WIFI运营平台.

  17. Wi-Fi Networks Security and Accessing Control

    Directory of Open Access Journals (Sweden)

    Tarek S. Sobh

    2013-06-01

    Full Text Available As wireless networks access gains popularity in corporate, private and personal networks, the nature of wireless networks opens up new possibilities for network attacks. This paper negotiating Wi-Fi security against scanning of rogue Wi-Fi networks and other related activities and considers the monitoring of Wi-Fi traffic effects. The unauthorized access point (AP problem has raised more attention and resulted in obtaining wireless access without subscriber permission.This work assumes Wi-Fi AP under attack specially rogue AP and/or ad-hoc client. It provides a solution for detecting and preventing this attack. In addition, it provides the required user permissions to allow/block access of the files on the user of ad-hoc client. The experiments include the rogue AP attack are maintained and the effectiveness of the proposed solution are tested.

  18. Dimensionnement-D-un-reseau-Sans-Fil-Wifi

    OpenAIRE

    BELABDELLI, Abdelheq; OUKAZ, Mokhtar

    2014-01-01

    Au cours de ce projet de fin d’études, nous avons étudié la technologie WIFI en présentant ses différentes architectures et nous avons développé un outil de dimensionnement d’un réseau de transmission de données haut débit d’accès WIFI. Lors de ce projet, nous avons présenté la technologie WIFI en montrant ces différentes fonctionnalités et en étudiant ses techniques d’accès au support. Ensuite, nous avons étudié les différentes architectures d’un réseau WI-FI : l’architecture en couche...

  19. An empirical performance study of Intra-vehicular Wireless Sensor Networks under WiFi and Bluetooth interference

    OpenAIRE

    Lin, Jiun-Ren; Talty, Timothy; Tonguz, Ozan K.

    2015-01-01

    Intra-Vehicular Wireless Sensor Network (IVWSN) is a new automotive architecture that applies wireless technologies to the communications between Electrical Control Units (ECUs) and sensors. It can potentially help achieve better fuel economy, reduce wiring complexity, and support additional new applications. In the existing works, most of the popular wireless technologies applied on IVWSNs occupy the same 2.4 GHz ISM frequency bands as WiFi and Bluetooth do. It is therefore essential to eval...

  20. Paper on Proposed System for Placing Free Call over Wi-Fi Network Using Voip and SIP

    Directory of Open Access Journals (Sweden)

    Bhushan R. Jichkar

    2014-01-01

    Full Text Available The Wi-Fi, also known as 802.11b, has become the preferred technology for wireless local area networking in both business and home environments. Even though it was designed primarily for private applications, Wi-Fi is also being deployed in public places to create so-called hotspots, where Wi-Fi-capable users can obtain internet access. This new domain of application could be the major future market opportunity for Wi-Fi, but in order to take advantage of it, several key challenges, both technical and business-related, must be overcome. Today the most cost effective use of Wi-Fi is calling over network. We have various facilities today such as Skype, T-Mobile, T-pad, Jaxtr for communicating over network but some restriction are placed on such system like Skype support only pc to pc calling for cellular and landline call this free service become paid. T mobile also follows the same problem. Hence to overcome such issue we are developing a system which allows free calling over Wi-Fi network using VoIP service. Our system allows peer to peer calling and an additional feature of group calling. For supporting group calling feature we are using SIP (Session Initiation Protocol. This technology will help us to find a way for free calling and thus ultimately helps to private organization for reducing bills over communication. In this paper, the system will be implemented as well as the performance will be tested by doing actual implementation of this system.

  1. 10Gig Ethernet goes halfway round the world

    CERN Multimedia

    Betts, Bryan

    2004-01-01

    In a project that could enable bigger SANs and computing grids, nuclear physicists have built a native 10 Gigabit Ethernet network linking Switzerland and Japan. The 18,500 kilometer LAN crosses 17 ime zones, as it follows fibers through Amsterdam, Chicago and Seattle

  2. An Audio Stream Redirector for the Ethernet Speaker

    Science.gov (United States)

    Mandrekar, Ishan; Prevelakis, Vassilis; Turner, David Michael

    2004-01-01

    The authors have developed the "Ethernet Speaker" (ES), a network-enabled single board computer embedded into a conventional audio speaker. Audio streams are transmitted in the local area network using multicast packets, and the ES can select any one of them and play it back. A key requirement for the ES is that it must be capable of playing any…

  3. Performance Analysis of Two Ethernet over E1 Schemes

    Institute of Scientific and Technical Information of China (English)

    CHEN Wentao; JIN Depeng; ZENG Lieguang

    2007-01-01

    The Ethernet over E1 approach,which takes advantage of widely deployed telecom networks,is an efficient and economical way to interconnect two Ethernets in different regions.Two Ethernet over E1 schemes, namely a byte granularity scheme and a frame granularity scheme are discussed. The byte granularity scheme partitions Ethernet frames into several pieces for transmission and has a strict requirement on the maximum delay difference of multiple E1 links. To solve this problem, the newly proposed frame granularity scheme transmits separately each frame through E1 links without any partitioning. The architecture designs of both schemes are presented. This paper evaluates the throughput and delay performances of both schemes, both analytically from results calculated from delay models and using test results from field programmable gate array (FPGA) implementation. Although the frame granularity scheme has a slightly worse delay performance, it has a higher throughput, and is the only choice able to overcome large delay differences of the E1 links.

  4. Analytical Performance Evaluation of IPv6 and IPv4 Over 10 Gigabit Ethernet and InfiniBand using IPoIB

    Directory of Open Access Journals (Sweden)

    Eric Gamess

    2016-08-01

    Full Text Available IPv6 is the response to the shortage of IPv4 addresses. It was defined almost twenty years ago by the IETF as a replacement of IPv4, and little by little, it is becoming more preponderant as the Internet protocol. The growth of Internet has led to the development of high performance networks. On one hand, Ethernet has evolved significantly and today it is common to find 10 Gigabit Ethernet networks in LANs. On the other hand, another approach for high performance networking is based on RDMA (Remote Direct Memory Access which offers innovative features such as kernel bypass, zero copy, offload of splitting and assembly of messages in packets to the CAs (Channel Adapters, etc. InfiniBand is currently the most popular technology that implements RDMA. It uses verbs instead of sockets and a big effort of the community is required to port TCP/IP software to InfiniBand, to take advantage of its benefits. Meanwhile, IPoIB (IP over InfiniBand is a protocol that has been proposed and permits the execution of socket-based applications on top of InfiniBand, without any change, at the expense of performance. In this paper, we make a performance evaluation of IPv6 and IPv4 over 10 Gigabit Ethernet and IPoIB. Our results show that 10 Gigabit Ethernet has a better throughput than IPoIB, especially for small and medium payload sizes. However, as the payload size increases, the advantage of 10 Gigabit Ethernet is reduced in comparison to IPoIB/FDR. With respect to latency, IPoIB did much better than 10 Gigabit Ethernet. Finally, our research also indicates that in a controlled environment, IPv4 has a better performance than IPv6.

  5. Dynamic Power-Saving Method for Wi-Fi Direct Based IoT Networks Considering Variable-Bit-Rate Video Traffic

    Directory of Open Access Journals (Sweden)

    Meihua Jin

    2016-10-01

    Full Text Available With the arrival of the era of Internet of Things (IoT, Wi-Fi Direct is becoming an emerging wireless technology that allows one to communicate through a direct connection between the mobile devices anytime, anywhere. In Wi-Fi Direct-based IoT networks, all devices are categorized by group of owner (GO and client. Since portability is emphasized in Wi-Fi Direct devices, it is essential to control the energy consumption of a device very efficiently. In order to avoid unnecessary power consumed by GO, Wi-Fi Direct standard defines two power-saving methods: Opportunistic and Notice of Absence (NoA power-saving methods. In this paper, we suggest an algorithm to enhance the energy efficiency of Wi-Fi Direct power-saving, considering the characteristics of multimedia video traffic. Proposed algorithm utilizes the statistical distribution for the size of video frames and adjusts the lengths of awake intervals in a beacon interval dynamically. In addition, considering the inter-dependency among video frames, the proposed algorithm ensures that a video frame having high priority is transmitted with higher probability than other frames having low priority. Simulation results show that the proposed method outperforms the traditional NoA method in terms of average delay and energy efficiency.

  6. Dynamic Power-Saving Method for Wi-Fi Direct Based IoT Networks Considering Variable-Bit-Rate Video Traffic.

    Science.gov (United States)

    Jin, Meihua; Jung, Ji-Young; Lee, Jung-Ryun

    2016-10-12

    With the arrival of the era of Internet of Things (IoT), Wi-Fi Direct is becoming an emerging wireless technology that allows one to communicate through a direct connection between the mobile devices anytime, anywhere. In Wi-Fi Direct-based IoT networks, all devices are categorized by group of owner (GO) and client. Since portability is emphasized in Wi-Fi Direct devices, it is essential to control the energy consumption of a device very efficiently. In order to avoid unnecessary power consumed by GO, Wi-Fi Direct standard defines two power-saving methods: Opportunistic and Notice of Absence (NoA) power-saving methods. In this paper, we suggest an algorithm to enhance the energy efficiency of Wi-Fi Direct power-saving, considering the characteristics of multimedia video traffic. Proposed algorithm utilizes the statistical distribution for the size of video frames and adjusts the lengths of awake intervals in a beacon interval dynamically. In addition, considering the inter-dependency among video frames, the proposed algorithm ensures that a video frame having high priority is transmitted with higher probability than other frames having low priority. Simulation results show that the proposed method outperforms the traditional NoA method in terms of average delay and energy efficiency.

  7. Embedding LTE-U within Wi-Fi Bands for Spectrum Efficiency Improvement

    OpenAIRE

    2016-01-01

    Driven by growing spectrum shortage, Long-term Evolution in unlicensed spectrum (LTE-U) has recently been proposed as a new paradigm to deliver better performance and experience for mobile users by extending the LTE protocol to unlicensed spectrum. In the paper, we first present a comprehensive overview of the LTE-U technology, and discuss the practical challenges it faces. We summarize the existing LTE-U operation modes and analyze several means for LTE-U coexistence with Wi-Fi medium access...

  8. Research on Frequency Planning of 5.8GHz in Wi-Fi Network of Wireless City%5.8GHz频段在无线城市Wi-Fi网络中的规划探讨

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    At present, wireless city is rapidly deployed in China. Wi-Fi technology is one of the major realization schemes. According to the current Wi-Fi frequency situation, this paper introduces the band of 5.8GHz into the application of Wi-Fi network and discusses the solution to frequency allocation under the coexistence multiple Wi-Fi networks.%  目前我国正在迅速开展无线城市的建设,Wi-Fi技术是主要的实现手段之一。针对Wi-Fi频率现状,通过介绍5.8GHz频段在Wi-Fi网络中的应用,探讨了在多Wi-Fi网络共存情况下的频率分配思路和方法。

  9. A campus-wide Wi-Fi service for CERN

    CERN Multimedia

    2016-01-01

    Improvements are coming to CERN’s Wi-Fi service as connectivity is improved in offices, restaurants and meeting rooms.   All Wi-Fi traffic will be routed via central controllers in CERN’s Computer Centre to provide a better managed service. (Image: Veronika McQuade/CERN) The IT department’s Communication Systems group has provided Wi-Fi connectivity at CERN for many years now but with a focus on meeting rooms, auditoriums and informal meeting places such as the restaurants. Although some buildings have Wi-Fi coverage in offices, most do not and CERN’s Wi-Fi service is lagging behind the demand driven by the growing number of tablets, lightweight laptops and other wireless-only devices. Furthermore, the current network infrastructure can’t cope with the many devices in the Main Auditorium during events such as the recent LIGO announcement and it often has difficulty handling the demand at Restaurant 1 during lunchtimes. The wireless access points d...

  10. ARQ Security in Wi-Fi and RFID Networks

    CERN Document Server

    Elsabagh, Mohamed; Youssef, Moustafa; Gamal, Hesham El

    2010-01-01

    In this paper, we present two practical ARQ-Based security schemes for Wi-Fi and RFID networks. Our proposed schemes enhance the confidentiality and authenticity functions of these networks, respectively. Both schemes build on the same idea; by exploiting the statistical independence between the multipath fading experienced by the legitimate nodes and potential adversaries, secret keys are established and then are continuously updated. The continuous key update property of both schemes makes them capable of defending against all of the passive eavesdropping attacks and most of the currently-known active attacks against either Wi-Fi or RFID networks. However, each scheme is tailored to best suit the requirements of its respective paradigm. In Wi-Fi networks, we overlay, rather than completely replace, the current Wi-Fi security protocols. Thus, our Wi-Fi scheme can be readily implemented via only minor modifications over the IEEE 802.11 standards. On the other hand, the proposed RFID scheme introduces the firs...

  11. Investigation on QoS of Campus-wide WiFi Networks

    OpenAIRE

    Sulaiman, Norrozila; Yaakub, Che Yahaya

    2010-01-01

    WiFi is widely implemented in campus wide including administrative, teaching and student's accommodation. Wireless communications are associated with interconnect devices which includes cellular networks, infrared, bluetooth and WiFi enabled devices. It involves mobility and freedom of assessing information anytime and anywhere. A study on WiFi networks in a campus environment is presented in this paper. The aim of the research was to investigate the connectivity problems to WiFi networks. Th...

  12. Private Hospital La Clinique de La Qiataigneraie Deployed Wi-Fi Network to Optimize the Management of its Operating Rooms

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Symbol Technologies, Inc. (NYSE:SBL), The Enterprise Mobility Company, and Ekahau, one of the leading suppliers of Wi-Fi positioning solutions, today announced that the La Chataigneraie private clinic implemented the Ekahau Real Time Location System (RTLS) solution. The wireless solution incorporates two Symbol WS5100 wireless switches and 30 AP300 access ports, and is used to improve communications in and between its 16 operating rooms.

  13. Free WiFi as Strategic Competitive Advantage for Fast-Food Outlet in the Knowledge Era

    OpenAIRE

    N. I. Yusop; L. K. Tiong; Z. M. Aji; M. K. Kasiran

    2011-01-01

    Problem statement: The growth of food outlets in Malaysia brings about the stiff competition among the players in food industry. To remain competitive, each outlet needs to adopt its own strategy in order to secure their return on investment and profitability. In knowledge era, technology has become an added value in achieving competitive advantage. The aim of this research is to assess whether providing free WiFi can be a strategy to remain competitive. Porter's 5forces&#...

  14. High Performance Ethernet Packet Processor Core for Next Generation Networks

    Directory of Open Access Journals (Sweden)

    Raja Jitendra Nayaka

    2012-10-01

    Full Text Available As the demand for high speed Internet significantly increasing to meet the requirement of large datatransfers, real-time communication and High Definition ( HD multimedia transfer over IP, the IP basednetwork products architecture must evolve and change. Application specific processors require highperformance, low power and high degree of programmability is the limitation in many general processorbased applications. This paper describes the design of Ethernet packet processor for system-on-chip (SoCwhich performs all core packet processing functions, including segmentation and reassembly, packetizationclassification, route and queue management which will speedup switching/routing performance making itmore suitable for Next Generation Networks (NGN. Ethernet packet processor design can be configuredfor use with multiple projects targeted to a FPGA device the system is designed to support 1/10/20/40/100Gigabit links with a speed and performance advantage. VHDL has been used to implement and simulatedthe required functions in FPGA.

  15. Using CSMA/CD for Ethernet Passive Optical Network (EPON)

    Institute of Scientific and Technical Information of China (English)

    季晓飞; 范戈

    2004-01-01

    Using CSMA/CD for EPON can eliminate the augmentations, such as multi-point control protocol and point-to-point emulation, added to the existing 802.3 architecture due to the incompatibility of PON to Ethernet.Both full-duplex EPON system and half-duplex EPON system using CSMA/CD were proposed. In the full-duplex EPON, CSMA/CD is used as the upstream MAC protocol. In the half-duplex EPON system, both upstream and downstream traffic contend for the optical channel through CSMA/CD protocol. The upstream lightwave redirection and collision detection techniques were given. By the analysis and simulation, the throughput performance of the half-duplex EPON system is proven to be as well as that of the existing high speed half-duplex Ethernet LAN.

  16. Using a Control System Ethernet Network as a Field Bus

    CERN Document Server

    De Van, William R; Lawson, Gregory S; Wagner, William H; Wantland, David M; Williams, Ernest

    2005-01-01

    A major component of a typical accelerator distributed control system (DCS) is a dedicated, large-scale local area communications network (LAN). The SNS EPICS-based control system uses a LAN based on the popular IEEE-802.3 set of standards (Ethernet). Since the control system network infrastructure is available throughout the facility, and since Ethernet-based controllers are readily available, it is tempting to use the control system LAN for "fieldbus" communications to low-level control devices (e.g. vacuum controllers; remote I/O). These devices may or may not be compatible with the high-level DCS protocols. This paper presents some of the benefits and risks of combining high-level DCS communications with low-level "field bus" communications on the same network, and describes measures taken at SNS to promote compatibility between devices connected to the control system network.

  17. Indoor infrared wireless communication system based on Ethernet network

    Science.gov (United States)

    Yang, Xin; Gong, Mali; Zhang, Kai; Zhang, Haitao; Yan, Ping; Jin, Wei; Jiang, Feng; Meng, Yu; Zou, Shanshan

    2002-12-01

    In this paper, we present an infrared wireless indoor communication system that bases on Ethernet network. The bit rate of Ethernet is 10Mbps, but after Manchester coding, in the physical layer the actual bit rate is 20Mbps. In our designs, the transmitter uses laser diodes (LDs). The transmitter consists of differential input circuit, LD driver circuit. The receiver consists of a coated truncated spherical concentrator whose field of view (FOV) is 40 degree, a large area Si PIN photo-detector followed by transimpedance amplifier, second-stage amplifier, low-pass filter (LPF), high-pass filter (HPF), limiting amplifier and differential output circuit. The network is constructed as a base-terminals configuration and two transit wavelengths are used for base and terminals respectively to avoid collision. Experimental testing was conducted in a room with size 5m × 5m × 3m and the network could work well.

  18. Cooperation Techniques between LTE in Unlicensed Spectrum and Wi-Fi towards Fair Spectral Efficiency

    Directory of Open Access Journals (Sweden)

    Vasilis Maglogiannis

    2017-08-01

    Full Text Available On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP announced standards that permit the operation of Long Term Evolution (LTE in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner.

  19. Data acquisition and meter unit based in wifi communication protocol

    Directory of Open Access Journals (Sweden)

    Gerardo Cázarez Ayala

    2012-05-01

    Full Text Available Without doubt, the competitive fast rhythm of the industries is one of the main causes helped bring to the accelerated growth of the electronic technology and the communication. The need to develop new products with a best quality, cheaper and faster as assure and increase the quality of the products in the international markets, requires of new technologies to the metering, monitoring and control of their production processes, of which finality is to improve the processes to guaranteed their products in the market in the less time possible, the best quality and low cost for the final consumer. This work is based in the design and implementation of a Wireless Data Acquisition Unit based in WiFi protocol, which is oriented to meter, monitoring and the control of processes in the industry, commercial and the home automation applications, using one of the wirelessprotocols with the biggest acceptance in the market, with the main objective of to take advantage of the installed physical infrastructure in the place of the application, like industry, company or house. The Unit is based in the RN-131G, a Roving Network company module, which is able to work in stand-alone mode with ultralow power consummation and supporting the IEEE 802.11b/g protocols, in which is possible to achieve transfer rates of up to 11 Mbps and 54 Mbps in /b & /g specifications respectively. Whit this unit is possible to meter up to 5 analogs signals with 14 bits precision and has include a temperature and relative humidity sensors. This unit can meter two digital signals and act mean two digitals outputs, and gas include an USB port for communication and programming tasks.

  20. Synchronous ethernet and IEEE 1588 in telecoms next generation synchronization networks

    CERN Document Server

    2013-01-01

    This book addresses the multiple technical aspects of the distribution of synchronization in new generation telecommunication networks, focusing in particular on synchronous Ethernet and IEEE1588 technologies. Many packet network engineers struggle with understanding the challenges that precise synchronization distribution can impose on networks. The usual “why”, “when” and particularly “how” can cause problems for many engineers. In parallel to this, some other markets have identical synchronization requirements, but with their own design requirements, generating further questions. This book attempts to respond to the different questions by providing background technical information. Invaluable information on state of-the-art packet network synchronization and timing architectures is provided, as well as an unbiased view on the synchronization technologies that have been internationally standardized over recent years, with the aim of providing the average reader (who is not skilled in the art) wi...

  1. New attacks on Wi-Fi Protected Setup

    Directory of Open Access Journals (Sweden)

    Hamed Mohtadi

    2015-09-01

    Full Text Available Wi-Fi Protected Setup (WPS is a network security standard that is used to secure networks in home and office, introduced in 2006 by the Wi-Fi Alliance. It provides easier configuration setup and is used in almost all recent Wi-Fi devices. In this paper we propose two attacks on this standard. The first attack is an offline brute force attack that uses imbalance on registration protocol. This attack needs user action, but it is more efficient than previous attacks. The second attack uses weaknesses in the implementation of WPS and provides an improved evil twin attack. This attack shows that even by completely disabling the WPS on the routers, all vulnerabilities are not covered.

  2. Real-Time Control of Wi-Fi Surveillance Robot

    Directory of Open Access Journals (Sweden)

    Poh Eng Fong

    2011-01-01

    Full Text Available This paper presents the design of a low cost Wi-Fi surveillance robot. The purpose of this surveillance robot is to navigate and deal with multiple-angled monitoring towards the environment with inexpensive hardware and free software cost. The desirable wireless standards used in this design is IEEE 802.11b/g (Wi-Fi due to its  range up to 152 meters with 54Mbps. Robot will be constructed in four wheels. Two driven wheels are needed to navigate the direction along with two caster wheels.

  3. All-IP-Ethernet architecture for real-time sensor-fusion processing

    Science.gov (United States)

    Hiraki, Kei; Inaba, Mary; Tezuka, Hiroshi; Tomari, Hisanobu; Koizumi, Kenichi; Kondo, Shuya

    2016-03-01

    Serendipter is a device that distinguishes and selects very rare particles and cells from huge amount of population. We are currently designing and constructing information processing system for a Serendipter. The information processing system for Serendipter is a kind of sensor-fusion system but with much more difficulties: To fulfill these requirements, we adopt All IP based architecture: All IP-Ethernet based data processing system consists of (1) sensor/detector directly output data as IP-Ethernet packet stream, (2) single Ethernet/TCP/IP streams by a L2 100Gbps Ethernet switch, (3) An FPGA board with 100Gbps Ethernet I/F connected to the switch and a Xeon based server. Circuits in the FPGA include 100Gbps Ethernet MAC, buffers and preprocessing, and real-time Deep learning circuits using multi-layer neural networks. Proposed All-IP architecture solves existing problem to construct large-scale sensor-fusion systems.

  4. Ethernet Based Remote Monitoring And Control Of Temperature By Using Rabbit Processor

    Directory of Open Access Journals (Sweden)

    B.V.S.GOUD

    2012-09-01

    Full Text Available Networking is a major component of the processes and control instrumentation systems as the network’s architecture solves many of the Industrial automation problems. There is a great deal of benefits in the process of industrial parameters to adopt the Ethernet control system. Hence an attempt has been made to develop an Ethernet based remote monitoring and control of temperature. In the present work the experimental result shows that remote monitoring and control system (RMACS over the Ethernet.

  5. Investigation on QoS of Campus-wide WiFi Networks

    CERN Document Server

    Sulaiman, Norrozila

    2010-01-01

    WiFi is widely implemented in campus wide including administrative, teaching and student's accommodation. Wireless communications are associated with interconnect devices which includes cellular networks, infrared, bluetooth and WiFi enabled devices. It involves mobility and freedom of assessing information anytime and anywhere. A study on WiFi networks in a campus environment is presented in this paper. The aim of the research was to investigate the connectivity problems to WiFi networks. The study includes WiFi performance analysis as well as network auditing. Channel overlapping and saturation condition were some of the problems encountered. Different types of software were used for analyzing the results.

  6. Wi-Fi Tags for the Remote and Virtual Laboratory

    Directory of Open Access Journals (Sweden)

    D. Ursutiu

    2008-04-01

    Full Text Available With the advancement of computer technologiesto faster processors and more memory, the WorldWideWeb,wireless communication, and miniaturization of sensortechnology, it is now possible to simulate and executeengineering and science laboratory projects on a remotecomputer. With Internet connection, students have access to"virtual laboratories" via the www, experiment-orientedproblems can be now offered without the overhead incurredwhen maintaining a full laboratory. This paper investigatesthe opportunity that a new wireless sensor technologybrings to remote laboratories.G2 Microsystems of Campbell, California, USA, released in2007 the first ever ultra-low power Wi-Fi System on a Chip(SoC named G2C501. This SoC includes a 32-bit CPU,crypto accelerator, real-time clock and a versatile sensorinterface that can serve as a standalone host subsystem. TheG2C501 goes beyond today’s basic radio frequencyidentification (RFID technology to offer intelligent trackingand sensor capabilities that leverage IEEE 802.11 (Wi-Finetworks. Due to its support for multiple locationtechnologies, small form factor and ultra-low powerconsumption, the G2C502 SoC can be integrated into Wi-Fisensor tags that lower cost of ownership and meet the needsof a variety of industries including consumer electronics,pharmaceuticals, chemical manufacturing, cold chain andmore.A battery powered, small size ultra low-power Wi-Fiwireless measurement node name IP Sensor has been builtusing the G2C501 SoC. Sensors for measurement oftemperature, humidity, light, and vibration or motion arecurrently mounted on the IP Sensor board. The node is ableto read a sensor and send data to the network by using anIP-based application protocol such as UDP.This paper describes the new IP Sensor

  7. Rancang Bangun Antena Mikrostrip Biquad Ganda untuk Aplikasi Wi-Fi

    Directory of Open Access Journals (Sweden)

    Herudin.

    2014-03-01

    Full Text Available Wi-Fi is a technology that is a very major today . WiFi stands for Wireless Fidelity , is a set of standards used for Wireless Local Network ( Wireless Local Area Networks . In Indonesia this standard is based on IEEE 802.11 specification . Its function is to connect to a local area network wirelessly . One of the supporting devices is antenna . Selection of the proper antenna , good design and proper installation will ensure the performance of the telecommunications system . Microstrip antenna has the advantages of a low- profile shape , which is easy and cheap to mass produced but has a small gain and bandwidth . In this study designed a double biquad microstrip antenna using FR4 material ( epoxy . The double biquad microstrip antenna works at a frequency of 2.4 GHz ˗ 2.5 GHz which can be used for 802.11b Wireless Fidelity technology . Microstrip antenna measurement results that have made a double biquad has a 555 MHz bandwidth with a value of 1.135 VSWR and return loss is -25.23 dB. The resulting vertical radiation pattern has a HPBW ( Half Power Beamwidth about 41̊ and horizontal radiation pattern has a HPBW about 35̊ , the results of these measurements indicate microstrip antenna made double biquad realizable and can be used in applications 802.11b WirelessFidelity.

  8. Autonomous WiFi Sensor for Heating Systems in the Internet of Things

    Directory of Open Access Journals (Sweden)

    C. A. Trasviña-Moreno

    2016-01-01

    Full Text Available In smart cities and home applications, the use of Wireless Sensor Networks to extract environmental data becomes more common with the passing of time. These sensors are used for a wide array of applications, but mainly to manage energy consumption in domestic buildings. One of the key energy consumers in households is heating systems. To monitor them, sensors are used with wireless communication protocols, like ZigBee, to transmit data to a central processing unit (CPU. WiFi communications, on the contrary, are rarely seen in these implementations due to its high energy consumption, although almost in every home one can find such networks. Yet, with the Internet of Things (IoT, new revisions of the standard have arisen which enable this technology for wireless sensing. To validate this theory and fill a technological necessity, this proposal is presented. In this work, the design and implementation of an autonomous WiFi sensor, paired with thermoelectric energy harvesting, are presented as an IoT solution for monitoring heating devices. For this, a thorough analysis of the proposed architecture is presented. Tests regarding energy consumption and generation, efficiency, and real world scenario trials are done. Finalizing, a comparison between the obtained results and current implementations is shown.

  9. Domotics – A Cost Effective Smart Home Automation System Using Wifi as Network Infrastructure

    Directory of Open Access Journals (Sweden)

    Abhinav Talgeri

    2014-08-01

    Full Text Available This paper describes an investigation into the potential for remote controlled operation of home automation (also called as Domotics systems. It considers problems with their implementation, discusses possible solutions through various network technologies and indicates how to optimize the use of such systems. This paper emphasizes on the design and prototype implementation of new home automation system that uses WiFi technology as a network infrastructure connecting its parts. The proposed can be viewed on two fold; the first part is the software (web server, which presents system core that manages, controls, and monitors users’ home. Users and system administrator can locally (LAN or remotely (internet manage the system code. Second part is hardware interface module, which provides appropriate interface to sensors and actuator of home automation system. Unlike most of available home automation system in the market the proposed system is scalable that one server can manage many hardware interface modules as long as it exists on WiFi network coverage.

  10. Wifi, WiMax and LTE multi-hop mesh networks basic communication protocols and application areas

    CERN Document Server

    Wei, Hung-Yu; Dixit, Sudhir

    2013-01-01

    Wifi, WiMAX, and Cellular Multihop Networks presents an overview of WiFi-based and WiMAX-based multihop relay networks. As the first text to cover IEEE 802.16j multihop hop relay technology, this revolutionary resource explores the latest advances in multi-hop and ad-hoc networking. Not only does this reference provide the technological aspects, but also the applications for the emerging technology and architectural issues. Ranging from introductory material to advanced topics, this guidebook, plus PowerPoint slides, is essential for engineers, researchers, and students interested in

  11. IPbus: a flexible Ethernet-based control system for xTCA hardware

    Science.gov (United States)

    Ghabrous Larrea, C.; Harder, K.; Newbold, D.; Sankey, D.; Rose, A.; Thea, A.; Williams, T.

    2015-02-01

    The ATCA and μTCA standards include industry-standard data pathway technologies such as Gigabit Ethernet which can be used for control communication, but no specific hardware control protocol is defined. The IPbus suite of software and firmware implements a reliable high-performance control link for particle physics electronics, and has successfully replaced VME control in several large projects. In this paper, we outline the IPbus control system architecture, and describe recent developments in the reliability, scalability and performance of IPbus systems, carried out in preparation for deployment of μTCA-based CMS upgrades before the LHC 2015 run. We also discuss plans for future development of the IPbus suite.

  12. Transport Network Technologies – Study and Testing

    DEFF Research Database (Denmark)

    Bozorgebrahimi, K.; Channegowda, M.; Colmenero, A.

    Following on from the theoretical research into Carrier Class Transport Network Technologies (CCTNTs) documented in DJ1.1.1, this report describes the extensive testing performed by JRA1 Task 1. The tests covered EoMPLS, Ethernet OAM, Synchronous Ethernet, PBB-TE, MPLS-TP, OTN and GMPLS...

  13. The development of WIFIS: a wide integral field infrared spectrograph

    Science.gov (United States)

    Sivanandam, Suresh; Chou, Richard C. Y.; Moon, Dae-Sik; Ma, Ke; Millar-Blanchaer, Maxwell; Eikenberry, Stephen S.; Chun, Moo-Young; Kim, Sang Chul; Raines, Steven N.; Eisner, Joshua

    2012-09-01

    We present the current results from the development of a wide integral field infrared spectrograph (WIFIS). WIFIS offers an unprecedented combination of etendue and spectral resolving power for seeing-limited, integral field observations in the 0.9 - 1.8 μm range and is most sensitive in the 0.9 - 1.35 μ,m range. Its optical design consists of front-end re-imaging optics, an all-reflective image slicer-type, integral field unit (IFU) called FISICA, and a long-slit grating spectrograph back-end that is coupled with a HAWAII 2RG focal plane array. The full wavelength range is achieved by selecting between two different gratings. By virtue of its re-imaging optics, the spectrograph is quite versatile and can be used at multiple telescopes. The size of its field-of-view is unrivalled by other similar spectrographs, offering a 4.511x 1211 integral field at a 10-meter class telescope (or 2011 x 5011 at a 2.3-meter telescope). The use of WIFIS will be crucial in astronomical problems which require wide-field, two-dimensional spectroscopy such as the study of merging galaxies at moderate redshift and nearby star/planet-forming regions and supernova remnants. We discuss the final optical design of WIFIS, and its predicted on-sky performance on two reference telescope platforms: the 2.3-m Steward Bok telescope and the 10.4-m Gran Telescopio Canarias. We also present the results from our laboratory characterization of FISICA. IFU properties such as magnification, field-mapping, and slit width along the entire slit length were measured by our tests. The construction and testing of WIFIS is expected to be completed by early 2013. We plan to commission the instrument at the 2.3-m Steward Bok telescope at Kitt Peak, USA in Spring 2013.

  14. 基于 WiFi 的专用无线局域网应用研究%Research on Special Lan Based on Wifi

    Institute of Scientific and Technical Information of China (English)

    罗袁君; 伍诗雨; 刘俊; 周继华

    2015-01-01

    The most popular wireless network protocols include Zigbee,WiFi,Bluetooth,etc. Various communication modes ensure that the user access to the network successfully in a complex scene. WAPI,based on WiFi communications technology,is approbated by users for its ultra -secure transmis-sion performance and has good application prospects in enterprise networking,secure communication and security monitoring network.This paper designs WAPI dedicated wireless LAN and discusses equipment frame,networking and engineering based on WAPI wireless communication technology.%当前国际主流的无线组网通信方式主要有 Zigbee、WiFi、蓝牙等。各种通信模式保证了在复杂场景下的用户顺利接入网络。WAPI 是基于 WiFi 的通信技术。WAPI 无线通信协议因其超高保密传输性能,得到了用户认可,在企业内部组网、保密通信、安防监控网络等领域具有非常广泛的应用前景。本课题研究用 WAPI 无线通信协议构建专用无线局域网,详细探讨了基于 WAPI无线通信技术的设备构架、组网、工程实现等设计技术。

  15. Ethernet-Based DAQ System for QUIET-II Detectors

    Science.gov (United States)

    Nagai, M.; Ishidoshiro, K.; Higuchi, T.; Ikeno, M.; Hasegawa, M.; Hazumi, M.; Tajima, O.; Tanaka, M.; Uchida, T.

    2012-06-01

    The B-modes in cosmic microwave background polarization are a smoking gun for the inflationary universe. For the detection of the B-modes, having a large detector array is a generic approach since the B-modes is so faint pattern ( T b≲0.1 μK). The Q/U Imaging ExperimenT Phase-II (QUIET-II) is proposed to search the B-modes, using an array with 500 HEMT-based polarimeters. Each polarimeter element has 4-outputs, therefore we have to manage 2000 channels in total. We developed a scalable DAQ system based on TCP/Ethernet for QUIET-II. The DAQ system is composed of the polarimeters, ADC boards, a Master Clock and a control computer (PC). The analog signals from the polarimeters are digitized on the ADC boards. On-board demodulation, which synchronizes the phase flip modulations on the polarimeter, extracts the polarized components in the digitized signal. The Master Clock distributes all necessary clocks to the ADC boards as well as the polarimeters. This scheme guarantees the synchronization of the modulations and demodulations. We employed Ethernet-based communication scheme between the data collection program (Collector) on the PC and the ADC boards as well as the Master Clock. Such an Ethernet-based communication scheme allows us to construct a simple structure of the upper level software, which results in the high scalability to increase the number of channels. All basic functions and requirements are confirmed by the laboratory tests; demonstration with test signals as well as the signals from the polarimeters, measurements of the data transfer rate, and the synchronous operation with two ADC boards. Therefore, the DAQ system is confirmed to be suitable for QUIET-II.

  16. Towards Terabit Carrier Ethernet and Energy Efficient Optical Transport Networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders

    error correction and energy efficiency. Scheduling and address lookup are key functions and potential bottle necks in high speed network nodes, as the minimum packet/frame sizes in both the popular Ethernet protocol, as well as the Internet Protocol (IP) still remains constant (84B and 40B, respectively...... requirements. Forward Error Correction (FEC) is already a standard component of the Optical Transport Network (OTN) protocol as a means of increasing the bitrate-length product of optical links. However, the requirements for higher bitrates also drive a requirement for higher spectral efficiency in order...

  17. Research on Encryption Mechanism of Ethernet Passive Optical Network

    Institute of Scientific and Technical Information of China (English)

    XU Wei-liang; FAN hong

    2006-01-01

    An ethernet-passive-optical-network consists of one optical-line-terminator and multiple optical-network-units oith passive optical components. The network is susceptible to variable security threats. In this paper we propose a security model and an encryption layer placed at reconciliation sublayer. We also propose advanced encryption standard as an ideal cipher algorithm to encrypt downstream data . We then discuss three different methods to solve the problem of the last plaintext group, and the methods are realized on digital signal processing. Finally, we study efficiency and delay issues of the three methods.

  18. CBRS Spectrum Sharing between LTE-U and WiFi: A Multiarmed Bandit Approach

    Directory of Open Access Journals (Sweden)

    Imtiaz Parvez

    2016-01-01

    Full Text Available The surge of mobile devices such as smartphone and tablets requires additional capacity. To achieve ubiquitous and high data rate Internet connectivity, effective spectrum sharing and utilization of the wireless spectrum carry critical importance. In this paper, we consider the use of unlicensed LTE (LTE-U technology in the 3.5 GHz Citizens Broadband Radio Service (CBRS band and develop a multiarmed bandit (MAB based spectrum sharing technique for a smooth coexistence with WiFi. In particular, we consider LTE-U to operate as a General Authorized Access (GAA user; hereby MAB is used to adaptively optimize the transmission duty cycle of LTE-U transmissions. Additionally, we incorporate downlink power control which yields a high energy efficiency and interference suppression. Simulation results demonstrate a significant improvement in the aggregate capacity (approximately 33% and cell-edge throughput of coexisting LTE-U and WiFi networks for different base station densities and user densities.

  19. A Crowd-Sourcing Indoor Localization Algorithm via Optical Camera on a Smartphone Assisted by Wi-Fi Fingerprint RSSI

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2016-03-01

    Full Text Available Indoor positioning based on existing Wi-Fi fingerprints is becoming more and more common. Unfortunately, the Wi-Fi fingerprint is susceptible to multiple path interferences, signal attenuation, and environmental changes, which leads to low accuracy. Meanwhile, with the recent advances in charge-coupled device (CCD technologies and the processing speed of smartphones, indoor positioning using the optical camera on a smartphone has become an attractive research topic; however, the major challenge is its high computational complexity; as a result, real-time positioning cannot be achieved. In this paper we introduce a crowd-sourcing indoor localization algorithm via an optical camera and orientation sensor on a smartphone to address these issues. First, we use Wi-Fi fingerprint based on the K Weighted Nearest Neighbor (KWNN algorithm to make a coarse estimation. Second, we adopt a mean-weighted exponent algorithm to fuse optical image features and orientation sensor data as well as KWNN in the smartphone to refine the result. Furthermore, a crowd-sourcing approach is utilized to update and supplement the positioning database. We perform several experiments comparing our approach with other positioning algorithms on a common smartphone to evaluate the performance of the proposed sensor-calibrated algorithm, and the results demonstrate that the proposed algorithm could significantly improve accuracy, stability, and applicability of positioning.

  20. A Crowd-Sourcing Indoor Localization Algorithm via Optical Camera on a Smartphone Assisted by Wi-Fi Fingerprint RSSI.

    Science.gov (United States)

    Chen, Wei; Wang, Weiping; Li, Qun; Chang, Qiang; Hou, Hongtao

    2016-03-19

    Indoor positioning based on existing Wi-Fi fingerprints is becoming more and more common. Unfortunately, the Wi-Fi fingerprint is susceptible to multiple path interferences, signal attenuation, and environmental changes, which leads to low accuracy. Meanwhile, with the recent advances in charge-coupled device (CCD) technologies and the processing speed of smartphones, indoor positioning using the optical camera on a smartphone has become an attractive research topic; however, the major challenge is its high computational complexity; as a result, real-time positioning cannot be achieved. In this paper we introduce a crowd-sourcing indoor localization algorithm via an optical camera and orientation sensor on a smartphone to address these issues. First, we use Wi-Fi fingerprint based on the K Weighted Nearest Neighbor (KWNN) algorithm to make a coarse estimation. Second, we adopt a mean-weighted exponent algorithm to fuse optical image features and orientation sensor data as well as KWNN in the smartphone to refine the result. Furthermore, a crowd-sourcing approach is utilized to update and supplement the positioning database. We perform several experiments comparing our approach with other positioning algorithms on a common smartphone to evaluate the performance of the proposed sensor-calibrated algorithm, and the results demonstrate that the proposed algorithm could significantly improve accuracy, stability, and applicability of positioning.

  1. Upstream Channel Utilization of CSMA/CD-Based Ethernet over Passive Optical Networks

    Institute of Scientific and Technical Information of China (English)

    Elaine; Wong; Chang-Joon; Chae

    2003-01-01

    We demonstrate that an asynchronous CSMA/CD protocol with an optical loop-back star coupler can achieve high upstream channel utilizatbn in an Ethernet PON, readily supporting a large installed base of Ethernet 10BaseT and 100BaseT interfaces.

  2. Upstream Channel Utilization of CSMA/CD-Based Ethernet over Passive Optical Networks

    Institute of Scientific and Technical Information of China (English)

    Elaine Wong; Chang-Joon Chae

    2003-01-01

    We demonstrate that an asynchronous CSMA/CD protocol with an optical loop-back star coupler can achieve high upstream channel utilization in an Ethernet PON, readily supporting a large installed base of Ethernet 10BaseT and 100BaseT interfaces.

  3. Access for Internet of Things using Smartphone as a Gateway utilizing LTE and WiFi

    DEFF Research Database (Denmark)

    Mathur, Prateek; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

    2016-01-01

    the data to the Internet. In this paper we present a system model wherein the smartphone functions as a gateway for the IoT devices operating on NFC, ZigBee and Bluetooth. The smartphone functioning as a gateway for transferring IoT data. The system modelled in the form of a Markov Chain based......Communicating the Internet of Things (IoT) data relying on Long-Term Evolution (LTE) and WiFi has been been presented in the relevant literature. However, this necessitates devices to have LTE/WiFi capability of their own, that has limitations in the form of power consumption, and radio access...... congestion. Alternatively, Bluetooth, ZigBee, and Near Field Communication (NFC) are promising technologies for low power personal area network communication, and used for IoT devices. These technologies have not been truly examined for their capacity for IoT as they require a custom gateway to communicate...

  4. Upgrading Gigabit Ethernet with Multi-window CWDM Technique

    Institute of Scientific and Technical Information of China (English)

    井文才; 张以谟; 周革

    2002-01-01

    In this paper, a new scheme has been proposed to achieve high-performance local area network adopting 5~15 nm separated coarse wavelength division multiplexing (CWDM) technique. Using this scheme, the current single-wavelength gigabit Ethernet can be seamlessly upgraded to multi-wavelength network. Not only can the network bandwidth be broadened, but also wavelength routing can be achieved among different sub-networks. The data packet communication latency can be reduced one-to-two magnitudes in comparison with that of the current gigabit Ethernet. To expand the network scale, multi-wavelength-window CWDM technique can be adopted. Two kinds of network interface cards have been designed using opto-electronics devices at the 850 nm and 1300 nm wavelength windows, respectively. Experiments indicate that the two kinds of CWDM signals can be selectively received at the corresponding optical detectors. By introducing two optical dropping devices in the network, multi-wavelength-window (850 nm, 1300 nm and 1550 nm) CWDM system can be achieved.

  5. Feasibility Study of 8-Bit Microcontroller Applications for Ethernet

    Directory of Open Access Journals (Sweden)

    Lech Gulbinovič

    2011-08-01

    Full Text Available Feasibility study of 8-bit microcontroller applications for Ethernet is presented. Designed device is based on ATmega32 microcontroller and 10 Mbps Ethernet controller ENC28J60. Device is simulated as mass queuing theoretical model with ticket booking counter. Practical explorations are accomplished and characteristics are determined. Practical results are compared to theoretical ones. Program code and device packet processing speed optimization are discussed. Microcontroller packet processing speed and packet latency depend on packet size. For ICMP protocol packet processing speed varies 1.4–2.1 Mbps, latency – 0.8–8.4 ms. UDP protocol packet processing speed varies 1.3–1.8 Mbps, latency – 1.1–9.6 ms. Packet processing speed depends on compilation settings and program code compression level. Best results are reached on optimization le­vel ‑O3, then speed increased ~3% but program code size increased 68% comparing to –Os optimization level.Article in Lithuanian

  6. Prototipo de interfaz de enlace de datos Ethernet/WIP

    Directory of Open Access Journals (Sweden)

    Juan Carlos Merlano Duncan

    2004-01-01

    Full Text Available El grupo de Investigación en Telecomunicaciones y Señales de la Facultad de Ingeniería Electrónica de la Universidad del Norte comenzó la elaboración de un proyecto, conocido como Wireless IP, por medio del cual un computador portátil pudiera tener acceso a la red cableada de la Universidad utilizando una comunicación inalámbrica, teniendo como base el estándar IEEE 802.11b. La parte de hardware del proyecto Wireless IP se dividió en tres módulos, desarrollados por tres grupos de manera independiente: Interfaz de Enlace de Datos Ethernet / WIP, Modem Banda Base y RF y Potencia. En este artículo se describe el diseño, construcción y funcionamiento de la Interfaz de Enlace de Datos Ethernet / WIP y su interconexión con los demás módulos, así como los resultados obtenidos al conectar un computador a una red cableada usando la Interfaz. Todas las pruebas se realizaron utilizando cables, emulando las funciones de los demás grupos

  7. [Suppression of WIFI transcript and protein in non-small cell lung carcinomas].

    Science.gov (United States)

    Korobko, E V; Kalinichenko, S V; Shepelev, M V; Zborovskaia, I B; Allakhverdiev, A K; Zinov'eva, M V; Vinogradova, T V; Sverdlov, E D; Korobko, I V

    2007-01-01

    Changes in WIFI expression, an extracellular inhibitor of Wnt pathway, in non-small cell lung carcinomas were analyzed. Frequent (67% cases) suppression of WIFI transcript in non-small cell lung carcinomas were found. Our results, together with previously published data, suggest that inhibition of WIFI expression often occurs in squamous cell carcinomas and is less typical of adenocarcinomas. It was also found that a decrease in the WIFI transcript in tumors is parallel to concomitant suppression of the WIFI protein level. Our results provide further evidence that the WIFI suppression is a frequent event in the lung carcinogenesis, which might lead to disregulation of Wnt signaling pathway and contribute to tumor progression.

  8. 一种基于以太网帧的声纳模拟器数据传输方案及实现%A Scheme and Implement of Sonar Simulator Data Transmission System Based on Ethernet Frame

    Institute of Scientific and Technical Information of China (English)

    王长清; 蒋景红

    2011-01-01

    在声纳模拟器数据传输实现传统方案中,存在以太网数据传输效率低、扩展性差问题,提出一种基于以太网帧的嵌入式数据传输方案,详细说明了以太网数据传输板的实现,介绍基于LibPCAP库的网络数据采集,并讨论了方案的性能优化.%Aiming at the problem of low Ethernet data transmission rate and poor expansibility of the data dispensation on conventional sonar simulator, a data transmission system based on Ethernet frame was proposed. The implementation of Ethernet data transmission adapter was described in detail. The technology of data capture based on LibPCAP was introduced, and the optimization of system was analyzed.

  9. WIFI AIDED INTEGRITY IMPROVEMENT IN MEMS INS/GNSS INTEGRATION

    Institute of Scientific and Technical Information of China (English)

    刘华; 刘彤

    2013-01-01

    The reliability of global navigation satellite system (GNSS) positioning degrades when satellite signals are interfered .Such degradation is hard to be deteced by a micro-electro mechanical system (MEMS) based inertial system(INS)/GNSS ,integrating navigation system with a conventional Kalman filtering ,which results in poten-tial integrity problem of the system .Hence ,an algorithm combining wireless fidelity (WiFi) signal with a federa-ted Kalman filter (FKF) is proposed to identify the system integrity in dense urban navigation .The criterion of the system integrity detection is created followed by the derivation of the integrity coefficient .The field test shows that integrity changes can be captured by applying WiFi ,and the maximum positioning error is reduced by 67% without compensation of inertial sensors in integrity deterioration .

  10. Travaux pratiques sur les réseaux locaux de type WIFI utilisant des simulations numériques des phénomènes de propagation des ondes électromagnétiques

    CERN Document Server

    Demontoux, François

    2007-01-01

    The wireless network technology WiFi finds more and more applications in the industrial field as for the exchange of information between the people or the equipment. It has the advantage of allowing a great flexibility of the network but requires precautions of installation to be effective (flow, reliability...). The fitter of such a network must have knowledge to install and configure the materials (access points, wifi interface) but also of knowledge in propagation of electromagnetic waves which is the support of the transmission of data. The teaching of this technology requires practical works which must make it possible for the student to implement this knowledge. This article presents the various means of calculations which we implemented within the framework of practical works to allow the student to visualize and thus to better control the phenomena of propagation existing in a WiFI network.

  11. Security Improvement of WPA 2 (Wi-Fi Protected Access 2)

    OpenAIRE

    A.K.M. Nazmus Sakib; Fariha Tasmin Jaigirdar,; Muntasim Munim,; Armin Akter

    2011-01-01

    WPA and WPA2 (Wi-Fi Protected Access) is a certification program developed by the Wi-Fi Alliance to indicate compliance with the security protocol created by the WiFi Alliance to secure wireless networks. The Alliance defined the protocol in response to several weaknesses researchers had found in the previous system: Wired Equivalent Privacy (WEP). Many sophisticated authentication and encryption techniques have been embedded into WPA2 but it still facing a lot of challenging situations. In t...

  12. A WiFi public address system for disaster management.

    Science.gov (United States)

    Andrade, Nicholas; Palmer, Douglas A; Lenert, Leslie A

    2006-01-01

    The WiFi Bullhorn is designed to assist emergency workers in the event of a disaster situation by offering a rapidly configurable wireless of public address system for disaster sites. The current configuration plays either pre recorded or custom recorded messages and utilizes 802.11b networks for communication. Units can be position anywhere wireless coverage exists to help manage crowds or to recall first responders from dangerous areas.

  13. {WiFi GPS} based Combined positioning Algorithm

    OpenAIRE

    Zirari, Soumaya; Canalda, Philippe; Spies, François

    2010-01-01

    International audience; If nowadays, positioning becomes more and more accurate, and covers better and better a territory (indoor and outdoor), it remains territories where traditional (and basic) positioning system (GPS, gsm or WiFi) and hybrid ones (GPS-gsm, GPS-WiFi, GPS-WiFi-gsm,...) are insufficient and requires research investment treating combined positioning. In this paper we propose a GPS-WiFi combined positioning algorithm, based on trilateration technique. Real experiments and othe...

  14. Online Malicious Attack Rectification in Wi-fi Network

    Directory of Open Access Journals (Sweden)

    C.Mistika

    2013-04-01

    Full Text Available Detecting intruder in Wi-Fi network is found to be the fundamental focus of this paper. The proposed work manually selects file from the location database from which it obtains the Received Signal Strength Indicator (RSSI value. Distance is estimated by using the obtained RSSI value. By setting RSSI threshold and by using fingerprinting technique (unique MAC address malicious intruder is detected in the wireless network.

  15. ORION: Orientation Estimation Using Commodity Wi-Fi

    OpenAIRE

    Mahfoudi, Mohamed Naoufal; Turletti, Thierry; Parmentelat, Thierry; FERRERO, Fabien; Lizzi, Leonardo; Staraj, Robert; Dabbous, Walid

    2017-01-01

    International audience; With MIMO, Wi-Fi led the way to the adoption of antenna array signal processing techniques for fine-grained localization using commodity hardware. These techniques, previously exclusive to specific domains of applications, will spur interest to reach beyond localization, and now allow to consider estimating the device’s orientation in space, that once required other sources of information. Wi-Fi’s popularity and the availability of metrics related to channel propagatio...

  16. Super resolution WiFi indoor localization and tracking

    OpenAIRE

    Salman, N.; Alsindi, N; Mihaylova, L.; Kemp, AH

    2014-01-01

    In this paper, we present a complete framework for accurate indoor positioning and tracking using the 802.11a WiFi network. Channel frequency response is first estimated via the least squares (LS) method using an orthogonal frequency division multiplexing (OFDM) pilot symbol. For accurate time of arrival (ToA) distance estimates in multipath environments, super resolution technique i.e. Multiple Signal Classification (MUSIC) is used which capitalizes on the autocorrelation matrix of the estim...

  17. The Development of WIFIS: a Wide Integral Field Infrared Spectrograph

    CERN Document Server

    Sivanandam, Suresh; Moon, Dae-Sik; Ma, Ke; Millar-Blanchaer, Maxwell; Eikenberry, Stephen S; Chun, Moo-Young; Kim, Sang Chul; Raines, Steven N; Eisner, Joshua

    2012-01-01

    We present the current results from the development of a wide integral field infrared spectrograph (WIFIS). WIFIS offers an unprecedented combination of etendue and spectral resolving power for seeing-limited, integral field observations in the 0.9-1.8 um range and is most sensitive in the 0.9-1.35 um range. Its optical design consists of front-end re-imaging optics, an all-reflective image slicer-type, integral field unit (IFU) called FISICA, and a long-slit grating spectrograph back-end that is coupled with a HAWAII 2RG focal plane array. The full wavelength range is achieved by selecting between two different gratings. By virtue of its re-imaging optics, the spectrograph is quite versatile and can be used at multiple telescopes. The size of its field-of-view is unrivalled by other similar spectrographs, offering a 4.5" x 12" integral field at a 10-meter class telescope (or 20" x 50" at a 2.3-meter telescope). The use of WIFIS will be crucial in astronomical problems which require wide-field, two-dimensiona...

  18. Prediction Model for Offloading in Vehicular Wi-Fi Network

    Directory of Open Access Journals (Sweden)

    Mahmoud Abdulwahab Alawi

    2016-12-01

    Full Text Available It cannot be denied that, the inescapable diffusion of smartphones, tablets and other vehicular network applications with diverse networking and multimedia capabilities, and the associated blooming of all kinds of data-hungry multimedia services that passengers normally used while traveling exert a big challenge to cellular infrastructure operators. Wireless fidelity (Wi-Fi as well as fourth generation long term evolution advanced (4G LTE-A network are widely available today, Wi-Fi could be used by the vehicle users to relieve 4G LTE-A networks. Though, using IEE802.11 Wi-Fi AP to offload 4G LTE-A network for moving vehicle is a challenging task since it only covers short distance and not well deployed to cover all the roads. Several studies have proposed the offloading techniques based on predicted available APs for making offload decision. However, most of the proposed prediction mechanisms are only based on historical connection pattern. This work proposed a prediction model which utilized historical connection pattern, vehicular movement and driver profile to predict the next available AP.  The proposed model is compared with the existing models to evaluate its practicability.

  19. Very Tight Coupling between LTE and WiFi: a Practical Analysis

    OpenAIRE

    KHADRAOUI, Younes; Lagrange, Xavier; Gravey, Annie

    2016-01-01

    International audience; The use of the large number of deployed WiFi access points is an interesting solution to offload LTE networks. In the perspective of convergence between fixed and mobile access, it is possible to connect WiFi access points to eNodeBs. With very tight coupling, WiFi and LTE flows are merged just below the IP layer. The objective is to accelerate the process of attachment to a WiFi Access Point and to allow dual WiFi/LTE transmission while providing a seamless experience...

  20. LTE in Unlicensed Bands is neither Friend nor Foe to Wi-Fi

    OpenAIRE

    2016-01-01

    Proponents of deploying LTE in the 5 GHz band for providing additional cellular network capacity have claimed that LTE would be a better neighbour to Wi-Fi in the unlicensed band, than Wi-Fi is to itself. On the other side of the debate, the Wi-Fi community has objected that LTE would be highly detrimental to Wi-Fi network performance. However, there is a lack of transparent and systematic engineering evidence supporting the contradicting claims of the two camps, which is essential for ascert...

  1. SSIDs in the Wild: Extracting Semantic Information from WiFi SSIDs

    OpenAIRE

    Seneviratne, Suranga; Jiang, Fangzhou; Cunche, Mathieu; Seneviratne, Aruna

    2015-01-01

    International audience; WiFi networks are becoming increasingly ubiquitous. In addition to providing network connectivity, WiFi finds applications in areas such as indoor and outdoor localisation, home automation, and physical analytics. In this paper, we explore the semantics of one key attribute of a WiFi network, SSID name. Using a dataset of approximately 120,000 WiFi access points and their corresponding geo-locations, we use a set of similarity metrics to relate SSID names to known busi...

  2. CAN BUS and Ethernet Interconnect System%CAN总线与以太网互连系统

    Institute of Scientific and Technical Information of China (English)

    邬思奇; 戴瑜兴; 肖彬; 王卫国

    2011-01-01

    In order to realize Ethernet and CAN bus's data conversion, Constructed a interconnect system based on embedded technology between CAN bus and Ethernet. Hardware platform of the system let LPC2119 ARM7 as the core,including Ethernet interface module based on ENC28J60, CAN interface module and HMI interface module; Software platform used real-time operating system uC/OS-Ⅱ and embedded LwIP protocol stack. The PC user interface was designed by VC++. Experimental debugging results showed, stable and reliable operation of system on voltage circuit breaker, will have certain practicability and commercial worth.%为了实现以太网与CAN总线的数据交换,构建了一个基于嵌入式的CAN总线与以太网互连系统.系统硬件平台以LPC2119 ARM7为核心,包括由ENC28J60构成的以太网接口模块、CAN接口模块、HMI接口模块;系统软件平台使用了实时操作系统μ C/OS-Ⅱ和嵌入了LwIP协议栈,并用VC++设计了上位机人机界面.实验调试结果表明,该系统在智能断路器上运行稳定可靠,具有一定的实用性和推广价值.

  3. Low-Power Design of Ethernet Data Transmission

    Institute of Scientific and Technical Information of China (English)

    Wen-Ming Pan; Qin Zhang; Jia-Feng Chen; Hao-Yuan Wang; Jia-Chong Kan

    2014-01-01

    For the reliability and power consumption issues of Ethernet data transmission based on the field programmable gate array (FPGA), a low-power consumption design method is proposed, which is suitable for FPGA implementation. To reduce the dynamic power consumption of integrated circuit (IC) design, the proposed method adopts the dynamic control of the clock frequency. For most of the time, when the port is in the idle state or lower-rate state, users can reduce or even turn off the reading clock frequency and reduce the clock flip frequency in order to reduce the dynamic power consumption. When the receiving rate is high, the reading clock frequency will be improved timely to ensure that no data will lost. Simulated and verified by Modelsim, the proposed method can dynamically control the clock frequency, including the dynamic switching of high-speed and low-speed clock flip rates, or stop of the clock flip.

  4. Performance Evaluation of 100 Gigabit Ethernet Switches under Bursty Traffic

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Rytlig, A.; Manolova, Anna Vasileva

    2011-01-01

    Switch fabrics for 100 Gigabit Ethernet systems pose high demands in terms of delay and scalability. In this paper we analyze the performance of a Clos-based switch fabric under uniform and bursty traffic, and compare its performance to a crossbar-based switch design for benchmarking. In particular......, we focus on a Clos-design using a Space-Memory-Memory (SMM) configuration, which has recently gained increased interest due to its reduced hardware complexity. The traffic between the input and the central modules is distributed in either a static, random or Desynchronized Static Round Robin (DSRR......) fashion. Simulation results show that for uniform Bernoulli traffic, the DSRR scheme outperforms the others. Under bursty traffic, the DSRR scheme and the random scheme achieve similar performance. The static scheme performs the worst for both cases. Comparing the SMM design to an Output Queued crossbar...

  5. Auto correct method of AD converters precision based on ethernet

    Directory of Open Access Journals (Sweden)

    NI Jifeng

    2013-10-01

    Full Text Available Ideal AD conversion should be a straight zero-crossing line in the Cartesian coordinate axis system. While in practical engineering, the signal processing circuit, chip performance and other factors have an impact on the accuracy of conversion. Therefore a linear fitting method is adopted to improve the conversion accuracy. An automatic modification of AD conversion based on Ethernet is presented by using software and hardware. Just by tapping the mouse, all the AD converter channel linearity correction can be automatically completed, and the error, SNR and ENOB (effective number of bits are calculated. Then the coefficients of linear modification are loaded into the onboard AD converter card's EEPROM. Compared with traditional methods, this method is more convenient, accurate and efficient,and has a broad application prospects.

  6. An Improved Algorithm to Generate a Wi-Fi Fingerprint Database for Indoor Positioning

    Directory of Open Access Journals (Sweden)

    Zhengqi Zheng

    2013-08-01

    Full Text Available The major problem of Wi-Fi fingerprint-based positioning technology is the signal strength fingerprint database creation and maintenance. The significant temporal variation of received signal strength (RSS is the main factor responsible for the positioning error. A probabilistic approach can be used, but the RSS distribution is required. The Gaussian distribution or an empirically-derived distribution (histogram is typically used. However, these distributions are either not always correct or require a large amount of data for each reference point. Double peaks of the RSS distribution have been observed in experiments at some reference points. In this paper a new algorithm based on an improved double-peak Gaussian distribution is proposed. Kurtosis testing is used to decide if this new distribution, or the normal Gaussian distribution, should be applied. Test results show that the proposed algorithm can significantly improve the positioning accuracy, as well as reduce the workload of the off-line data training phase.

  7. Interference-Aware Opportunistic Dynamic Energy Saving Mechanism for Wi-Fi Enabled IoTs

    Directory of Open Access Journals (Sweden)

    Il-Gu Lee

    2017-07-01

    Full Text Available The wireless local area network (WLAN is one of the most popular wireless technologies offering connectivity today, and one of the candidates for the internet of things (IoTs. However, WLAN’s inefficiency in terms of complexity and relatively large power consumption compared with other wireless standards has been reported as a major barrier for IoTs applications. This paper proposes an interference-aware opportunistic dynamic energy saving mechanism to improve energy efficiency for Wi-Fi enabled IoTs. The proposed scheme optimizes operating clock frequencies adaptively for signal processing when the mobile station transmits packets in partial sub-channels. Evaluation results demonstrate that the proposed scheme improves energy efficiency by approximately 34%.

  8. RADIUS-based Wi-Fi Roaming Service in China%基于 RADIUS协议的无线网络漫游服务

    Institute of Scientific and Technical Information of China (English)

    董科军; 谢建军; 崔悦明; 胡笑然

    2015-01-01

    无线网络漫游服务是实现无处不在的科研活动的基础,如何使各机构单位的科学研究人员,安全、方便地使用全国甚至全球范围内的无线网络漫游服务,是无线网络应用所要解决的关键问题。本论文以 RADIUS协议和 eduroam无线漫游应用为实例,探讨了一种基于 RADIUS认证协议的无线网络漫游服务技术,并对中国科技网无线漫游服务(CSTNET Roam)的架构和部署应用情况进行详细阐述,最后展望了中国科技网无线漫游服务在中国科学院及科研机构的应用前景。%According to the development of the world-wide research activity, Wi-Fi roaming service is getting much important to researchers. How to make it possible for the scientists to use the Wi-Fi infrastructure around the world is the essence of the Wi-Fi application innovation. The paper elaborates a RADIUS-based Wi-Fi roaming technology, discusses the eduroam Wi-Fi roaming service which is initiated by European, presents a CSTNET Roam architecture based on CSTNET ID service in Chinese Academy of Sciences. Finally the paper discusses the user case of CSTNET Roam in the practice around Chinese Academy of Sciences, and describes the future plan of CSTNET roaming map.

  9. A new real-time ethernet MAC protocol for time-critical applications

    Institute of Scientific and Technical Information of China (English)

    沈钢; 许晓鸣; 蔡云泽; 何星; 张卫东

    2002-01-01

    The authors propose a new persistent transmission-based real-time Ethernet MAC protocol that provides a predictable upper bound for the delivery delay of real-time frames. Moreover, it is compatible with the protocol used by the existing Ethernet controllers for conventional datagram traffic and thus standard Ethernet stations can be used in the system without any modification. The paper describes the protocol in detail and analyses the maximum delivery delay for real-time traffic and the efficiency of the channel.

  10. A microcontroller library for Arduino Wi-Fi Direct GainSpan module 1500M and the Wi-Fi Direct Android application

    OpenAIRE

    Majhen, Ivan

    2015-01-01

    Objective of the thesis is to develop microcontroller library for Arduino UNO microcontroller platform that will carry communication via serial UART interface with a wireless module GainSpan 1500M. The module supports a fairly new way of wireless communication, Wi-Fi Direct. Inclusion of library in the user microcontroller program will allow the user to set the parameters of Wi-Fi Direct connection. The library will be using user parameters to control and establish Wi-Fi Direct connection by ...

  11. Design of Pulse Oximeter with WiFi Connectivity and Interoperability with Standard HL7 and IEEE 11073-10404:2008

    Directory of Open Access Journals (Sweden)

    Víctor Ochoa

    2014-12-01

    Full Text Available Given that health is so relevant for global productivity and competitiveness, and that the Information and Communications Technology (ICTs play an important role in all of the productivity factors, this work makes use of the ICTs in health matters proposing the to use a WiFi oximeter. This article describes the operating principles of a Pulse Oximeter (PO which is an opto-electronic non-invasive medical instrument capable of measuring changes in heart rate (HR and SpO2 at the fingertip and its upgrade to the standards; HL7 and IEEE 11073-10404:2008, its design, and its validation against the three existing devices. Variables (SpO2%, Ppm and Temperature were compared, and its performance and impact were discussed the addition of the WiFi technology allows a better communication between devices, causing a greater impact in global competiveness.

  12. Migration of optical core network to next generation networks - Carrier Grade Ethernet Optical Transport Network

    Science.gov (United States)

    Glamočanin, D.

    2017-05-01

    In order to maintain the continuity of the telecom operators’ network construction, while monitoring development needs, increasing customers’ demands and application of technological improvements, it is necessary to migrate optical transport core network to the next generation networks - Carrier Grade Ethernet Optical Transport Network (OTN CE). The primary objective of OTN CE is to realize an environment that is based solely on the switching in the optical domain, i.e. the realization of transparent optical networks and optical switching to the second layer of ISO / OSI model. The realization of such a network provides opportunities for further development of existing, but also technologically more demanding, new services. It is also a prerequisite to provide higher scalability, reliability, security and quality of QoS service, as well as prerequisites for the establishment of SLA (Service Level Agreement) for existing services, especially traffic in real time. This study aims to clarify the proposed model, which has the potential to be eventually adjusted in accordance with new scientific knowledge in this field as well as market requirements.

  13. PERFORMANCE ANALYSIS OF MESSAGE PASSING INTERFACE COLLECTIVE COMMUNICATION ON INTEL XEON QUAD-CORE GIGABIT ETHERNET AND INFINIBAND CLUSTERS

    Directory of Open Access Journals (Sweden)

    Roswan Ismail

    2013-01-01

    Full Text Available The performance of MPI implementation operations still presents critical issues for high performance computing systems, particularly for more advanced processor technology. Consequently, this study concentrates on benchmarking MPI implementation on multi-core architecture by measuring the performance of Open MPI collective communication on Intel Xeon dual quad-core Gigabit Ethernet and InfiniBand clusters using SKaMPI. It focuses on well known collective communication routines such as MPI-Bcast, MPI-AlltoAll, MPI-Scatter and MPI-Gather. From the collection of results, MPI collective communication on InfiniBand clusters had distinctly better performance in terms of latency and throughput. The analysis indicates that the algorithm used for collective communication performed very well for all message sizes except for MPI-Bcast and MPI-Alltoall operation of inter-node communication. However, InfiniBand provides the lowest latency for all operations since it provides applications with an easy to use messaging service, compared to Gigabit Ethernet, which still requests the operating system for access to one of the server communication resources with the complex dance between an application and a network.

  14. A Flexible, Ethernet Fronthaul for 5^th Generation Mobile and Beyond

    OpenAIRE

    Gomes, Nathan J.; Jungnickel, Volker; Chanclou, Philippe; Elbers, Joerg-Peter; Turnbull, Peter

    2016-01-01

    Using Ethernet in the fronthaul can deliver the statistical multiplexing gains offered by\\ud the new functional splits proposed for the radio access network, but latency and delay variations\\ud are challenges that must be overcome.

  15. Tag4M, a Wi-Fi RFID Active Tag Optimized for Sensor Measurements

    OpenAIRE

    Folea, Silviu; Ghercioiu, Marius

    2010-01-01

    This presentation introduces a Wi-Fi tag named Tag4M. The novelty of the design is Wi-Fi with ultra-low power, in a very small package that is running on a battery for years and offers a platform for sensor measurements using the existing (Internet) network

  16. Mārketinga koncepcijas izveide Wi-Fi pakalpojumam Latvijā

    OpenAIRE

    Zauers, Mārtiņš 

    2008-01-01

    Maģistra darbā Wi-Fi mārketinga koncepcijas izveide Latvijā autors apkopo teoriju par mārketingu un tā koncepcijas izveidi, analizē tehnisko literatūru par Wi-Fi, Wi-Fi vēsturi, izveidošanos Latvijā un apkopo datus par Wi-Fi tirgus attīstību Latvijā, kā arī Lattelecom Wi-Fi pakalpojumu. Pētījuma mērķis ir analizēt un vērtēt Lattelecom Wi-Fi pakalpojuma pieejamību Latvijā un izstrādāt tā mārketinga koncepciju. Analizējot Wi-Fi pakalpojuma tirgu Latvijā, pētījuma daļā autors izveido Wi-Fi p...

  17. Experiences, challenges and lessons from rolling out a rural WiFi mesh network

    CSIR Research Space (South Africa)

    Rey-Moreno, C

    2013-01-01

    Full Text Available rural communities worldwide. This paper argues that the latest wave of WiFi mesh networks offers benefits that traditional top-down WiFi and mobile networks do not. In addition, we propose ethnographic and participatory methods to aid the effective...

  18. 3G Femto or 802.11g WiFi

    DEFF Research Database (Denmark)

    Jørgensen, Niels T.K.; Rodriguez Larrad, Ignacio; Elling, Jan;

    2014-01-01

    In this paper HSPA Release 6 femto and IEEE 802.11g WiFi indoor data solutions are investigated from an end user perspective. Femto and WiFi access points are deployed at typical locations in an urban environment and end user performance is measured. Three key performance indicators (KPI) were...... defined - downlink and uplink user data rates, latency and mobile power consumption. These three KPIs are of high importance when choosing an indoor data solution. Our measurements show that the downlink and uplink data rates of the WiFi solution are significantly higher than femto data rates. Similarly......, latency results show that WiFi outperforms the femto solution. Especially, the radio resource control (RRC) connection set-up time increases the latency for the femto. In terms of idle power consumption the best results are obtained when the mobile camps on the femto. Whereas, WiFi performs best in all...

  19. BACnet Ethernet与BACnet IP网关的设计与实现%Design and Implementation of a BACnet Ethernet and BACnet IP Gateway

    Institute of Scientific and Technical Information of China (English)

    李春旺; 田沛哲; 吴义民; 王浩宇

    2012-01-01

    针对BACnet Ethernet驱动技术的应用局限性,设计了一种BACnet IP和BACnet Ethernet网关.通过基于微处理电路LM3S6911+的核心控制单元完成BACnet IP报文和BACnet Ethernet报文的双向解析与重新封装运算,实现了BACnet和IP通信协议之间的互通信和互操作,为楼宇自动化系统的高效便捷管理和先进优化算法嵌入楼宇自动化系统提供了新的途径.%Aimed at application limitations of BACnet ( building automation and control networks) Ethernet driving technology, a gateway is designed for BACnel Ethernet and BACnet IP. The bi-directional parsing and re-encapsulation operations between BACnet IP message and BACnet Ethernet message have been realized through a central control unit of the micro-processing circuit LM3S6911 +, fulfilling interoperability of BACnet and IP communication protocols. Thus, the study provides a new way for building automation system with efficient management and advanced optimization algorithm embedded in building automation system.

  20. Fire Extinguisher Robot Using Ultrasonic Camera and Wi-Fi Network Controlled with Android Smartphone

    Science.gov (United States)

    Siregar, B.; Purba, H. A.; Efendi, S.; Fahmi, F.

    2017-03-01

    Fire disasters can occur anytime and result in high losses. It is often that fire fighters cannot access the source of fire due to the damage of building and very high temperature, or even due to the presence of explosive materials. With such constraints and high risk in the handling of the fire, a technological breakthrough that can help fighting the fire is necessary. Our paper proposed the use of robots to extinguish the fire that can be controlled from a specified distance in order to reduce the risk. A fire extinguisher robot was assembled with the intention to extinguish the fire by using a water pump as actuators. The robot movement was controlled using Android smartphones via Wi-fi networks utilizing Wi-fi module contained in the robot. User commands were sent to the microcontroller on the robot and then translated into robotic movement. We used ATMega8 as main microcontroller in the robot. The robot was equipped with cameras and ultrasonic sensors. The camera played role in giving feedback to user and in finding the source of fire. Ultrasonic sensors were used to avoid collisions during movement. Feedback provided by camera on the robot displayed on a screen of smartphone. In lab, testing environment the robot can move following the user command such as turn right, turn left, forward and backward. The ultrasonic sensors worked well that the robot can be stopped at a distance of less than 15 cm. In the fire test, the robot can perform the task properly to extinguish the fire.

  1. Control4 Portable WiFi Touch Screen

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Control4提供了智能家居中的一站式控制方案,包括家庭自动化、背景音乐以及家庭影院等娱乐系统的控制,这款Portable WiFi Touch Screen控制器采用无线网络的连接方式,控制面板可以随时随地带在身边,同时它还提供了多个操作页面.

  2. Design of Mine-used Multi-function WiFi Signal Converter%矿用多功能WiFi信号转换器的设计

    Institute of Scientific and Technical Information of China (English)

    孙钢; 刘炜; 景振兴

    2011-01-01

    The paper introduced composition and signal transform mode of mine-used multi-function WiFi signal converter. The converter uses wireless antenna to receive and transmit wireless signals,and realizes mutual change of wireless signal and wire signals of RS485,Ethernet port,sensor and voice port,so as to expediently realize interconnection among various interfaces of mine monitoring device,and effectively slove compatibility problem among various kinds of monitoring systems and communication systems.%介绍了矿用多功能WiFi信号转换器的组成及信号的转换方式.该转换器可通过天线收发无线信号,可实现无线信号与RS485口、以太网口、传感器接口和语音接口等有线信号的相互转换,方便地完成了煤矿井下各种监控设备接口之间的互联,有效解决了各种监控系统和通信系统之间的兼容性问题.

  3. Discovering Human Presence Activities with Smartphones Using Nonintrusive Wi-Fi Sniffer Sensors: The Big Data Prospective

    OpenAIRE

    Weijun Qin; Jiadi Zhang; Bo Li; Limin Sun

    2013-01-01

    With the explosive growth and wide-spread use of smartphones with Wi-Fi enabled, people are used to accessing the internet through Wi-Fi network interfaces of smartphones. Smartphones periodically transmit Wi-Fi messages, even when not connected to a network. In this paper, we describe the Mo-Fi system which monitors and aggregates large numbers of continuous Wi-Fi message transmissions from nearby smartphones in the area of interest using nonintrusive Wi-Fi sniffer sensors. In this paper, we...

  4. Discovering Human Presence Activities with Smartphones Using Nonintrusive Wi-Fi Sniffer Sensors: The Big Data Prospective

    OpenAIRE

    Weijun Qin; Jiadi Zhang; Bo Li; Limin Sun

    2013-01-01

    With the explosive growth and wide-spread use of smartphones with Wi-Fi enabled, people are used to accessing the internet through Wi-Fi network interfaces of smartphones. Smartphones periodically transmit Wi-Fi messages, even when not connected to a network. In this paper, we describe the Mo-Fi system which monitors and aggregates large numbers of continuous Wi-Fi message transmissions from nearby smartphones in the area of interest using nonintrusive Wi-Fi sniffer sensors. In this paper, we...

  5. Elektroměr s rozhraním Ethernet

    OpenAIRE

    Binek, Tomáš

    2011-01-01

    Tato práce je věnována problematice měření elektrické energie s pomocí vestavěných systémů s následnou možností odesílání dat do počítačové sítě. Jsou rozebrány základní principy fungování analogových a digitálních elektroměrů. Součástí práce je návrh elektroměru s rozhraním Ethernet, založeného na integrovaném obvdu MCP3909 a mikrokontroleru PIC18F97J60. V implementační části je navržen postup pro prezentaci dat měřiče pomocí HTML stránky a její zpracování na připojeném počítači. This the...

  6. High Performance Gigabit Ethernet Switches for DAQ Systems

    CERN Document Server

    Barczyk, Artur

    2005-01-01

    Commercially available high performance Gigabit Ethernet (GbE) switches are optimized mostly for Internet and standard LAN application traffic. DAQ systems on the other hand usually make use of very specific traffic patterns, with e.g. deterministic arrival times. Industry's accepted loss-less limit of 99.999% may be still unacceptably high for DAQ purposes, as e.g. in the case of the LHCb readout system. In addition, even switches passing this criteria under random traffic can show significantly higher loss rates if subject to our traffic pattern, mainly due to buffer memory limitations. We have evaluated the performance of several switches, ranging from "pizza-box" devices with 24 or 48 ports up to chassis based core switches in a test-bed capable to emulate realistic traffic patterns as expected in the readout system of our experiment. The results obtained in our tests have been used to refine and parametrize our packet level simulation of the complete LHCb readout network. In this paper we report on the...

  7. Study on an Indoor Positioning System for Harsh Environments Based on Wi-Fi and Bluetooth Low Energy.

    Science.gov (United States)

    de Blasio, Gabriel; Quesada-Arencibia, Alexis; García, Carmelo R; Molina-Gil, Jezabel Miriam; Caballero-Gil, Cándido

    2017-06-06

    This paper presents a study of positioning system that provides advanced information services based on Wi-Fi and Bluetooth Low Energy (BLE) technologies. It uses Wi-Fi for rough positioning and BLE for fine positioning. It is designed for use in public transportation system stations and terminals where the conditions are "hostile" or unfavourable due to signal noise produced by the continuous movement of passengers and buses, data collection conducted in the constant presence thereof, multipath fading, non-line of sight (NLOS) conditions, the fact that part of the wireless communication infrastructure has already been deployed and positioned in a way that may not be optimal for positioning purposes, variable humidity conditions, etc. The ultimate goal is to provide a service that may be used to assist people with special needs. We present experimental results based on scene analysis; the main distance metric used was the Euclidean distance but the Mahalanobis distance was also used in one case. The algorithm employed to compare fingerprints was the weighted k-nearest neighbor one. For Wi-Fi, with only three visible access points, accuracy ranged from 3.94 to 4.82 m, and precision from 5.21 to 7.0 m 90% of the time. With respect to BLE, with a low beacon density (1 beacon per 45.7 m²), accuracy ranged from 1.47 to 2.15 m, and precision from 1.81 to 3.58 m 90% of the time. Taking into account the fact that this system is designed to work in real situations in a scenario with high environmental fluctuations, and comparing the results with others obtained in laboratory scenarios, our results are promising and demonstrate that the system would be able to position users with these reasonable values of accuracy and precision.

  8. Study on an Indoor Positioning System for Harsh Environments Based on Wi-Fi and Bluetooth Low Energy

    Science.gov (United States)

    de Blasio, Gabriel; Quesada-Arencibia, Alexis; García, Carmelo R.; Molina-Gil, Jezabel Miriam; Caballero-Gil, Cándido

    2017-01-01

    This paper presents a study of positioning system that provides advanced information services based on Wi-Fi and Bluetooth Low Energy (BLE) technologies. It uses Wi-Fi for rough positioning and BLE for fine positioning. It is designed for use in public transportation system stations and terminals where the conditions are “hostile” or unfavourable due to signal noise produced by the continuous movement of passengers and buses, data collection conducted in the constant presence thereof, multipath fading, non-line of sight (NLOS) conditions, the fact that part of the wireless communication infrastructure has already been deployed and positioned in a way that may not be optimal for positioning purposes, variable humidity conditions, etc. The ultimate goal is to provide a service that may be used to assist people with special needs. We present experimental results based on scene analysis; the main distance metric used was the Euclidean distance but the Mahalanobis distance was also used in one case. The algorithm employed to compare fingerprints was the weighted k-nearest neighbor one. For Wi-Fi, with only three visible access points, accuracy ranged from 3.94 to 4.82 m, and precision from 5.21 to 7.0 m 90% of the time. With respect to BLE, with a low beacon density (1 beacon per 45.7 m2), accuracy ranged from 1.47 to 2.15 m, and precision from 1.81 to 3.58 m 90% of the time. Taking into account the fact that this system is designed to work in real situations in a scenario with high environmental fluctuations, and comparing the results with others obtained in laboratory scenarios, our results are promising and demonstrate that the system would be able to position users with these reasonable values of accuracy and precision. PMID:28587285

  9. MicroTCA implementation of synchronous Ethernet-Based DAQ systems for large scale experiments

    CERN Document Server

    Girerd, C; Carlus, B; Gardien, S; Marteau, J; Tromeur, W

    2009-01-01

    Large LAr TPCs are among the most powerful detectors to address open problems in particle and astro-particle physics, such as CP violation in leptonic sector, neutrino properties and their astrophysical implications, proton decay search etc. The scale of such detector implies severe constraints on their readout and DAQ system. In this article we describe a data acquisition scheme for this new generation of large detectors. The main challenge is to propose a scalable and easy to use solution able to manage a large number of channels at the lowest cost. It is interesting to note that these constraints are very similar to those existing in Network Telecommunication Industry. We propose to study how emerging technologies like ATCA and $\\mu$TCA could be used in neutrino experiments. We describe the design of an Advanced Mezzanine Board (AMC) including 32 ADC channels. This board receives 32 analogical channels at the front panel and sends the formatted data through the $\\mu$TCA backplane using a Gigabit Ethernet l...

  10. IPbus A flexible Ethernet-based control system for xTCA hardware

    CERN Document Server

    Williams, Thomas Stephen

    2014-01-01

    The ATCA and uTCA standards include industry-standard data pathway technologies such as Gigabit Ethernet which can be used for control communication, but no specific hardware control protocol is defined. The IPbus suite of software and firmware implements a reliable high-performance control link for particle physics electronics, and has successfully replaced VME control in several large projects. In this paper, we outline the IPbus system architecture, and describe recent developments in the reliability, scalability and performance of IPbus systems, carried out in preparation for deployment of uTCA-based CMS upgrades before the LHC 2015 run. We also discuss plans for future development of the IPbus suite.SUMMARY IPbus will be used for controlling the uTCA electronics in the CMS HCAL, TCDS, Pixel and Level-1 trigger upgrades. IPbus control has already been extensively used in the work of these upgrade projects so far, and final uTCA systems will be deployed in the experiment starting from Autumn 2014. IPbus is...

  11. The new LHCb trigger and DAQ strategy a system architecture based on gigabit-ethernet

    CERN Document Server

    Barczyk, A; Gaspar, C; Gavillet, P; Jacobsson, R; Jost, B; Neufeld, N; Vannerem, P

    2004-01-01

    The LHCb software trigger has two levels: a high-speed trigger running at 1 MHz with strictly limited latency and a second level running below 40 kHz without latency limitations. The trigger strategy requires full flexibility in the distribution of the installed CPU power to the two software trigger levels because of the unknown background levels and event topology distribution at the time the LHC accelerator will start its operation. This requirement suggests using a common CPU farm for both trigger levels fed by a common data acquisition (DAQ) infrastructure. The limited latency budget of the first level of software trigger has an impact on the organization of the CPU farm performing the trigger function for optimal usage of the installed CPU power. We will present the architecture and the design of the hardware infrastructure for the entire LHCb software triggering system based on Ethernet as link technology that fulfills these requirements. The performance of the event-building of the combined traffic of ...

  12. Automatic Construction of Wi-Fi Radio Map Using Smartphones

    Science.gov (United States)

    Liu, Tao; Li, Qingquan; Zhang, Xing

    2016-06-01

    Indoor positioning could provide interesting services and applications. As one of the most popular indoor positioning methods, location fingerprinting determines the location of mobile users by matching the received signal strength (RSS) which is location dependent. However, fingerprinting-based indoor positioning requires calibration and updating of the fingerprints which is labor-intensive and time-consuming. In this paper, we propose a visual-based approach for the construction of radio map for anonymous indoor environments without any prior knowledge. This approach collects multi-sensors data, e.g. video, accelerometer, gyroscope, Wi-Fi signals, etc., when people (with smartphones) walks freely in indoor environments. Then, it uses the multi-sensor data to restore the trajectories of people based on an integrated structure from motion (SFM) and image matching method, and finally estimates location of sampling points on the trajectories and construct Wi-Fi radio map. Experiment results show that the average location error of the fingerprints is about 0.53 m.

  13. Inferring Stop-Locations from WiFi.

    Directory of Open Access Journals (Sweden)

    David Kofoed Wind

    Full Text Available Human mobility patterns are inherently complex. In terms of understanding these patterns, the process of converting raw data into series of stop-locations and transitions is an important first step which greatly reduces the volume of data, thus simplifying the subsequent analyses. Previous research into the mobility of individuals has focused on inferring 'stop locations' (places of stationarity from GPS or CDR data, or on detection of state (static/active. In this paper we bridge the gap between the two approaches: we introduce methods for detecting both mobility state and stop-locations. In addition, our methods are based exclusively on WiFi data. We study two months of WiFi data collected every two minutes by a smartphone, and infer stop-locations in the form of labelled time-intervals. For this purpose, we investigate two algorithms, both of which scale to large datasets: a greedy approach to select the most important routers and one which uses a density-based clustering algorithm to detect router fingerprints. We validate our results using participants' GPS data as well as ground truth data collected during a two month period.

  14. Inferring Stop-Locations from WiFi.

    Science.gov (United States)

    Wind, David Kofoed; Sapiezynski, Piotr; Furman, Magdalena Anna; Lehmann, Sune

    2016-01-01

    Human mobility patterns are inherently complex. In terms of understanding these patterns, the process of converting raw data into series of stop-locations and transitions is an important first step which greatly reduces the volume of data, thus simplifying the subsequent analyses. Previous research into the mobility of individuals has focused on inferring 'stop locations' (places of stationarity) from GPS or CDR data, or on detection of state (static/active). In this paper we bridge the gap between the two approaches: we introduce methods for detecting both mobility state and stop-locations. In addition, our methods are based exclusively on WiFi data. We study two months of WiFi data collected every two minutes by a smartphone, and infer stop-locations in the form of labelled time-intervals. For this purpose, we investigate two algorithms, both of which scale to large datasets: a greedy approach to select the most important routers and one which uses a density-based clustering algorithm to detect router fingerprints. We validate our results using participants' GPS data as well as ground truth data collected during a two month period.

  15. WiFi and WiMAX Secure Deployments

    Directory of Open Access Journals (Sweden)

    Panagiotis Trimintzios

    2010-01-01

    Full Text Available Wireless Broadband offers incredibly fast, “always on” Internet similar to ADSL and sets the user free from the fixed access areas. In order to achieve these features standardisation was achieved for Wireless LAN (WLANs and Wireless Metropolitan Area Networks (WMANs with the advent of IEEE802.11 and IEEE802.16 family of standards, respectively. One serious concern in the rapidly developing wireless networking market has been the security of the deployments since the information is delivered freely in the air and therefore privacy and integrity of the transmitted information, along with the user-authentication procedures, become a very important issue. In this article, we present the security characteristics for the WiFi and the WiMAX networks. We thoroughly present the security mechanisms along with a threat analysis for both IEEE 802.11 and the 802.16 as well as their amendments. We summarise in a comparative manner the security characteristics and the possible residual threats for both standards. Finally focus on the necessary actions and configurations that are needed in order to deploy WiFi and WiMAX with increased levels of security and privacy.

  16. AUTOMATIC CONSTRUCTION OF WI-FI RADIO MAP USING SMARTPHONES

    Directory of Open Access Journals (Sweden)

    T. Liu

    2016-06-01

    Full Text Available Indoor positioning could provide interesting services and applications. As one of the most popular indoor positioning methods, location fingerprinting determines the location of mobile users by matching the received signal strength (RSS which is location dependent. However, fingerprinting-based indoor positioning requires calibration and updating of the fingerprints which is labor-intensive and time-consuming. In this paper, we propose a visual-based approach for the construction of radio map for anonymous indoor environments without any prior knowledge. This approach collects multi-sensors data, e.g. video, accelerometer, gyroscope, Wi-Fi signals, etc., when people (with smartphones walks freely in indoor environments. Then, it uses the multi-sensor data to restore the trajectories of people based on an integrated structure from motion (SFM and image matching method, and finally estimates location of sampling points on the trajectories and construct Wi-Fi radio map. Experiment results show that the average location error of the fingerprints is about 0.53 m.

  17. Effects of Implementing Adaptable Channelization in Wi-Fi Networks

    Directory of Open Access Journals (Sweden)

    Abid Hussain

    2016-01-01

    Full Text Available The unprecedented increase of wireless devices is now facing a serious threat of spectrum scarcity. The situation becomes even worse due to inefficient frequency distribution protocols, deployed in trivial Wi-Fi networks. The primary source of this inefficiency is static channelization used in wireless networks. In this work, we investigate the use of dynamic and flexible channelization, for optimal spectrum utilization in Wi-Fi networks. We propose optimal spectrum sharing algorithm (OSSA and analyze its effect on exhaustive list of essential network performance measuring parameters. The elementary concept of the proposed algorithm lies in the fact that frequency spectrum should be assigned to any access point (AP based on its current requirement. The OSSA algorithm assigns channels with high granularity, thus maximizing spectrum utilization by more than 20% as compared to static width channel allocation. This optimum spectrum utilization, in turn, increases throughput by almost 30% in many deployment scenarios. The achieved results depict considerable decrease in interference, while simultaneously increasing range. Similarly signal strength values at relatively longer distances improve significantly at narrower channel widths while simultaneously decreasing bit error rates. We found that almost 25% reduction in interference is possible in certain scenarios through proposed algorithm.

  18. The current state of evidence regarding the health effects of wifi communication systems Sistemas de comunicación wifi y efectos sobre la salud. El estado de las evidencias actuales Sistemas de comunicação wifi e efeitos na saúde: O estado atual da evidência

    Directory of Open Access Journals (Sweden)

    Francisco Vargas Marcos

    2012-08-01

    Full Text Available Some communication media have reported alleged health risks, especially in schools, related to exposure to Radio Frequencies (RF emitted by wifi telecommunication systems. These reports have generated demands for information, which the relevant environmental health authorities have to deal with in a transparent, clear and effective way, based on current scientific evidence. This study describes the main technical features of wifi systems, the rules that govern their operation, the authorized levels of emission, and the levels observed in some specific studies.Until now, very few specific studies have been undertaken about the health effects associated to exposure to RF emitted by these systems. This article describes the main risk assessments and the more relevant studies published by prestigious specialized international agencies.The study details the current state of knowledge about the health effects of RF and the international recommendations proposed, regarding the safety of these technologies. It concludes that, to date, there is no consistent evidence that exposure to the RF signals emitted by wifi systems, below internationally accepted guidelines, has adverse health effects on the general population. There are no scientific reasons to justify that wifi systems should be removed from schools or should not be used by the rest of the population.En algunos medios de comunicación se ha informado sobre supuestos riesgos para la salud, especialmente en el ámbito escolar, derivados de la exposición a las radiofrecuencias (RF emitidas por los sistemas de telecomunicación inalámbricos (wifi, en su abreviatura en inglés. Estas noticias han generado demandas de información que las autoridades sanitarias competentes en salud ambiental deben responder de forma transparente, clara, eficaz y basada en el conocimiento científico actual. En este trabajo se describen las principales características técnicas de estos sistemas, las normas que

  19. Electromagnetic immunity of implantable pacemakers exposed to wi-fi devices.

    Science.gov (United States)

    Mattei, Eugenio; Censi, Federica; Triventi, Michele; Calcagnini, Giovanni

    2014-10-01

    The purpose of this study is to evaluate the potential for electromagnetic interference (EMI) and to assess the immunity level of implantable pacemakers (PM) when exposed to the radiofrequency (RF) field generated by Wi-Fi devices. Ten PM from five manufacturers, representative of what today is implanted in patients, have been tested in vitro and exposed to the signal generated by a Wi-Fi transmitter. An exposure setup that reproduces the actual IEEE 802.11b/g protocol has been designed and used during the tests. The system is able to amplify the Wi-Fi signal and transmits at power levels higher than those allowed by current international regulation. Such approach allows one to obtain, in case of no EMI, a safety margin for PM exposed to Wi-Fi signals, which otherwise cannot be derived if using commercial Wi-Fi equipment. The results of this study mitigate concerns about using Wi-Fi devices close to PM: none of the PM tested exhibit any degradation of their performance, even when exposed to RF field levels five times higher than those allowed by current international regulation (20 W EIRP). In conclusion, Wi-Fi devices do not pose risks of EMI to implantable PM. The immunity level of modern PM is much higher than the transmitting power of RF devices operating at 2.4 GHz.

  20. Dominant Channel Occupancy for Wi-Fi Backscatter Uplink in Industrial Internet of Things

    Directory of Open Access Journals (Sweden)

    Jung-Hyok Kwon

    2016-12-01

    Full Text Available This paper presents a dominant channel occupancy (DCO mechanism for the Wi-Fi backscatter uplink in the industrial Internet of things (IIoT. The DCO provides high-priority channel access and reliable burst transmission to the Wi-Fi backscatter devices, thereby enabling the Wi-Fi backscatter tag to deliver its tag information to the Wi-Fi reader without interference from neighboring legacy Wi-Fi devices to guarantee the timeliness and reliability of the IIoT system. For the former, we consider three types of medium access control (MAC configurations: “carrier sense multiple access with collision avoidance (CSMA/CA starting with short inter-frame space (SIFS”, “freezing of the backoff period”, and “reduced CWmin.” In addition, the DCO uses the SIFS between burst packets to guarantee reliable burst transmission. To verify the effectiveness of DCO and determine a proper value for MAC parameters, we conduct experimental simulations under IEEE 802.11n PHY/MAC environments. The simulation results show that the reduced CWmin has the most significant effect on the channel occupancy. The Wi-Fi backscatter devices achieve much higher throughput than the separate cases when two or more configurations are used simultaneously. Moreover, the results exhibit that the use of SIFS between consecutive packets supports reliable burst transmission regardless of the transmission of the legacy Wi-Fi devices in the vicinity.

  1. Predicting the effect of home Wi-Fi quality on Web QoE

    OpenAIRE

    Da Hora, Diego; Neves da Hora, Diego; Teixeira, Renata; Van Doorselaer, Karel; Van Oost, Koen

    2016-01-01

    International audience; Wi-Fi is the preferred way of accessing the Internet for many devices at home, but it is vulnerable to performance problems. The analysis of Wi-Fi quality metrics such as RSSI or PHY rate may indicate a number of problems, but users may not notice many of these problems if they don't degrade the performance of the applications they are using. In this work, we study the effects of the home Wi-Fi quality on Web browsing experience. We instrument a commodity access point ...

  2. Integrating free-space optical communication links with existing WiFi (WiFO) network

    Science.gov (United States)

    Liverman, S.; Wang, Q.; Chu, Y.; Duong, T.; Nguyen-Huu, D.; Wang, S.; Nguyen, T.; Wang, A. X.

    2016-02-01

    Recently, free-space optical (FSO) systems have generated great interest due to their large bandwidth potential and a line-of-sight physical layer of protection. In this paper, we propose WiFO, a novel hybrid system, FSO downlink and WiFi uplink, which will integrate currently available WiFi infrastructure with inexpensive infrared light emitting diodes. This system takes full advantage of the mobility inherent in WiFi networks while increasing the downlink bandwidth available to each end user. We report the results of our preliminary investigation that show the capabilities of our prototype design in terms of bandwidth, bit error rates, delays and transmission distances.

  3. A comparative analysis of Indoor WiFi Positioning at a large building complex

    DEFF Research Database (Denmark)

    Mathisen, Andreas; Krogh, Søren; Stisen, Allan;

    2016-01-01

    Indoor Positioning based on WiFi has received extensive focus from research communities, owing its promises of ubiquitous positioning indoors for a variety of applications. The majority of the existing research on WiFi positioning centers around the improvement of positioning accuracy. However...... are in daily use. The positioning methods covered utilizes received signal strength from existing WiFi infrastructure to ease deployment and maintenance. We identify meaningful key metrics which describe different aspects of the methods’ performance. Using these metrics, we furthermore report on experiences...

  4. PILA: Sub-Meter Localization Using CSI from Commodity Wi-Fi Devices

    OpenAIRE

    Zengshan Tian; Ze Li; Mu Zhou; Yue Jin; Zipeng Wu

    2016-01-01

    The aim of this paper is to present a new indoor localization approach by employing the Angle-of-arrival (AOA) and Received Signal Strength (RSS) measurements in Wi-Fi network. To achieve this goal, we first collect the Channel State Information (CSI) by using the commodity Wi-Fi devices with our designed three antennas to estimate the AOA of Wi-Fi signal. Second, we propose a direct path identification algorithm to obtain the direct signal path for the sake of reducing the interference of mu...

  5. An economic analysis on optical Ethernet in the access network

    Science.gov (United States)

    Kim, Sung Hwi; Nam, Dohyun; Yoo, Gunil; Kim, WoonHa

    2004-04-01

    Nowadays, Broadband service subscribers have increased exponentially and have almost saturated in Korea. Several types of solutions for broadband service applied to the field. Among several types of broadband services, most of subscribers provided xDSL service like ADSL or VDSL. Usually, they who live in an apartment provided Internet service by Ntopia network as FTTC structure that is a dormant network in economical view at KT. Under competitive telecom environment for new services like video, we faced with needing to expand or rebuild portions of our access networks, are looking for ways to provide any service that competitors might offer presently or in the near future. In order to look for new business model like FTTH service, we consider deploying optical access network. In spite of numerous benefits of PON until now, we cannot believe that PON is the best solution in Korea. Because we already deployed optical access network of ring type feeder cable and have densely population of subscribers that mainly distributed inside 6km from central office. So we try to utilize an existing Ntopia network for FTTH service under optical access environment. Despite of such situations, we try to deploy PON solution in the field as FTTC or FTTH architecture. Therefore we analyze PON structure in comparison with AON structure in order to look for optimized structure in Korea. At first, we describe the existing optical access networks and network architecture briefly. Secondly we investigate the cost of building optical access networks by modeling cost functions on AON and PON structure which based on Ethernet protocol, and analyze two different network architectures according to different deployment scenarios: Urban, small town, rural. Finally we suggest the economic and best solution with PON structure to optimize to optical access environment of KT.

  6. Real Time FPGA-Based Ethernet Control Communication for Robotic Arm

    Directory of Open Access Journals (Sweden)

    Ishak Mohamad Khairi

    2017-01-01

    Full Text Available In this paper, an approach for real time control communication using Ethernet is proposed. The strategy to support this at the network level and include Field Programmable Gate Array (FPGA implementation on the Ethernet platform for robotic arm. An embedded Ethernet controller is designed to send data packet via Ethernet Local Area Network (LAN. The transferring data also employs Arduino Mega as the medium of communication between FPGA board and the robotic arm. It is used as the receiver to receive data packet from FPGA board with the interface of Arduino Ethernet shield. The control operation on the robotic arm is performed once the desired data packet length is reached to the Arduino Mega. SolidWorks and MATLAB software are used to design the robotic arm and simulate the robotic arm working flexibility in real world respectively. The result of the average data packet delay between FPGA boards is lower in comparison to Arduiono board. The data packet can send successfully in through the network to test the robotic arm.

  7. 基于WIFI/GPRS/3G/IP的远程测控系统设计

    Institute of Scientific and Technical Information of China (English)

    赵双萍; 邢敬宏; 何辉

    2013-01-01

    In view of function needs for embedded network measurement&control system,this paper presents a resolution scheme of wireless sensor network technology solutions based on WIFI/GPRS/3G/IP.The scheme implements a combination of four data transmission method.According to the corresponding communication protocol, the scheme applied to a variety of dif-ferent occasions, to meet the real-time data communication, stability and practicality.%  就嵌入式网络测控系统的功能要求,提出了一套基于WIFI/GPRS/3G/ IP无线传感网络技术的解决方案;实现了 IP、GPRS、WIFI、3G四种数据传输有机结合的信息传输方案,依据相应的通信协议,规约,应用于多种不同场合,满足数据通信的实时性、稳定性、实用性。

  8. 基于WIFI的无线视频分配器研究%The Research of Wireless Video Distributor Based on WIFI

    Institute of Scientific and Technical Information of China (English)

    吴迪; 宋晓梅

    2013-01-01

    Nowadays,more and more people is trending to use WIFI to send their documents.But it is still a technological challenge to transmit the high-quality video signals in real time.For this reason,we should research a kind of transmission mechanism with high-security and in real-time.Based on the fundamental transmission protocol of WIFI,it can achieve the transmission of video signals in real time.The problems,such as how to send and receive video signals in real time by means of one-to-many,is worthy of study and discussion.Firstly,we should understand the theory of sending and receiving data by WIFI.Then,we farther study the feasibility of sending and receiving video signals by WIFI in real time.%WIFI已成为现代都市生活的一种潮流,高质量实时的视频传输依然是WIFI发展的技术难点.因此,迫切需要研究出一种高安全性、实时性的多点WIFI传输机制.这种机制可在WIFI的基本传输协议基础上,实现视频信号的实时性传输.如何实时地一对多发送和接收视频信号等是值得深入研究和讨论的.首先了解WIFI发送接收数据的机制,然后在此基础上研究通过WIFI实时发送和接收视频信号的可行性.

  9. Wi-Fi Protocol Vulnerability Discovery Based on Fuzzy Testing

    Directory of Open Access Journals (Sweden)

    Kunhua Zhu

    2013-08-01

    Full Text Available To detect the wireless network equipment whether there is protocol vulnerability, using the method of modular design and implementation of a new suitable for Wi-Fi protocol vulnerability discovery fuzzy test framework. It can be independent of its transmission medium, produce deformity packet and implementation of the attack on the target system. The author firstly describes the wireless network protocol vulnerability discovery and fuzzy test in this paper,then focused on the test frame technical scheme, detailed technical realization and so on, and its application are analyzed. In the experimental stage the fuzzy test is applied to a wireless networks gateway, the test results show that the fuzzy test framework can be well applied to the wireless network equipment agreement loophole mining work.  

  10. Automated Irrigation System using WSN and Wi-Fi Module

    Directory of Open Access Journals (Sweden)

    Sharad Shinde

    2017-05-01

    Full Text Available The objective of the developed system is to encourage the efficient water management practices that optimize the usage of water by keeping the crop health and yield intact through the implementation of automated irrigation system. The microcontroller-based solution consists of distributed wireless network (WSN, base or control station and user interface. Each sensor node will have soil-moisture, temperature and humidity sensors placed in the farmland. These WSNs are powered by battery. Base station will collect the sensor information through the use of RF transceiver. An algorithm is developed to monitor soil-moisture and temperature to control the water volume depending upon the set threshold. Base station also sends the sensor information to remote database for logging through Wi-Fi interface. Web application is developed that enables the user for remote monitoring of data and control certain parameters like soil moisture threshold, manual override of water flow, etc.

  11. Modern mine communication technology and system%现代化矿井通信技术与系统

    Institute of Scientific and Technical Information of China (English)

    孙继平

    2013-01-01

    提出了由矿用有线调度通信系统、矿井移动通信系统、矿井广播通信系统和矿井救灾通信系统等组成的煤矿井下通信技术体系.提出矿用调度通信系统应采用矿用有线调度通信系统.提出全矿井移动通信系统宜采用WiFi、3G、4G等通信技术.提出矿井广播通信系统既可采用矿用有线调度通信系统远程供电广播技术,也可采用基于以太环网和无源光网络的IP通信技术.提出矿井救灾通信系统应采用无线多媒体通信技术,宜采用WiFi和MESH等通信技术.提出矿井移动通信系统应满足手机脱网通信、基站脱网通信、无线自组织网络、接入煤矿井下有线宽带传输平台等要求.指出在手机脱网通信、接入煤矿井下有线宽带传输平台、无线自组织网络、矿用无线摄像机、基站脱网通信、多功能矿井移动通信系统、矿井无线宽带传输等方面,WiFi优于WCDMA、CDMA2000和TD-SCDMA.提出多功能矿井移动通信系统和矿井无线宽带传输宜采用WiFi.%The paper proposed coal mine communication technology system which was consisted of mine wired dispatching communication system, mine mobile communication system, mine broadcast communication system and mine rescue communication system. It proposed that mine dispatching communication system should use mine wired dispatching communication system. It proposed that all mine mobile communication system should use communication technologies such as WiFi, 3G and 4G. It proposed that mine broadcast communication system can use either remote powered broadcast technology of mine wired dispatching communication system, or IP communication technology based on Ethernet and passive optical network. It proposed that mine rescue communication system should use wireless multimedia communication technology, and should use communication technologies such as WiFi and MESH. It proposed that mine mobile communication system should meet the

  12. A Gigabit Ethernet link for an FPGA based Beam Loss Measurement System

    CERN Document Server

    Kwiatkowski, M; Dehning, B; Vigano, W; Zamantzas, C

    2013-01-01

    A new Beam Loss Monitoring (BLM) system is under development at the European Organisation for Nuclear Research (CERN) within the LHC Injector Upgrade (LIU) project. The multi-channel system will have the ability to measure beam losses from various types of detectors with high precision and wide dynamic range. Several modes of data acquisition are supported. The data rate in the singlechannel mode is 16 Mbps and in the multi-channel mode 128 Mbps. The Gigabit Ethernet link is implemented in an FPGA, which allows both a high throughput and a quick validation of the digital data processing algorithms using standard PCs in the initial stages of the development. Both TCP and UDP protocols were explored. The implementation of the Ethernet link is flexible and proved to be highly reliable, leading to its planned use in other measurement systems developed at CERN. The implementation details of the Ethernet link and the results achieved will be described in this paper.

  13. CAGE100: Real-Time Multi-Port Packet Capture System for 100 Gigabit Ethernet Traffic

    Energy Technology Data Exchange (ETDEWEB)

    Namazi, Ali; Azimi-Sadjadi, Babak; Lin, Chujen

    2012-06-14

    Future large scale sciences are anticipated to use massive amount of data in their experiments. DOE's ESnet (Energy Science Network) is developing a 100 Gbps backbone based on this state-of-the-art 100 Gigabit Ethernet standard. ESnet will serve thousands of DOE and non-DOE scientists with its high bandwidth backbone, and connect several national laboratories. Current Ethernet test and debug solutions, such as network traffic capturer/analyzer tools, support up to 10 Gbps speed, and the very few capable of handling 100 Gbps are extremely costly. Such tools are essential in the development of high speed devices and routers, and ultimately the success of 100 Gigabit Ethernet.

  14. The Wide Integral Field Infrared Spectrograph (WIFIS): optomechanical design and development

    Science.gov (United States)

    Meyer, R. Elliot; Moon, Dae-Sik; Sivanandam, Suresh; Ma, Ke; Henderson, Chuck; Blank, Basil; Chou, Chueh-Yi; Jarvis, Miranda; Eikenberry, Stephen S.

    2016-08-01

    We present the optomechanical design and development of the Wide Integral Field Infrared Spectrograph (WIFIS). WIFIS will provide an unrivalled integral field size of 20"×50" for a near-infrared (0.9-1.7 μm) integral-field spectrograph at the 2.3-meter Steward Bok telescope. Its main optomechanical system consists of two assemblies: a room-temperature bench housing the majority of the optical components and a cryostat for a field-flattening lens, thermal blocking filter, and detector. Two additional optical subsystems will provide calibration functionality, telescope guiding, and off-axis optical imaging. WIFIS will be a highly competitive instrument for seeing-limited astronomical investigations of the dynamics and chemistry of extended objects in the near-infrared wavebands. WIFIS is expected to be commissioned during the end of 2016 with scientific operations beginning in 2017.

  15. Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment

    National Research Council Canada - National Science Library

    Zhou, Mu; Tian, Zengshan; Xu, Kunjie; Yu, Xiang; Wu, Haibo

    2014-01-01

    ...) in logarithmic received signal strength (RSS) varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs...

  16. Collaborative WiFi Fingerprinting Using Sensor-Based Navigation on Smartphones

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2015-07-01

    Full Text Available This paper presents a method that trains the WiFi fingerprint database using sensor-based navigation solutions. Since micro-electromechanical systems (MEMS sensors provide only a short-term accuracy but suffer from the accuracy degradation with time, we restrict the time length of available indoor navigation trajectories, and conduct post-processing to improve the sensor-based navigation solution. Different middle-term navigation trajectories that move in and out of an indoor area are combined to make up the database. Furthermore, we evaluate the effect of WiFi database shifts on WiFi fingerprinting using the database generated by the proposed method. Results show that the fingerprinting errors will not increase linearly according to database (DB errors in smartphone-based WiFi fingerprinting applications.

  17. Low Power WiFi: a study on power consumption for Internet of Things

    OpenAIRE

    Amozarrain Perez, Ugaitz

    2015-01-01

    An analysis of a Low-Power WiFi devices and the feasibility of using such a device for Internet of Things applications, for wireless sensor networks more specifically. The device is analyzed in power consumption and performance.

  18. Collaborative WiFi Fingerprinting Using Sensor-Based Navigation on Smartphones.

    Science.gov (United States)

    Zhang, Peng; Zhao, Qile; Li, You; Niu, Xiaoji; Zhuang, Yuan; Liu, Jingnan

    2015-07-20

    This paper presents a method that trains the WiFi fingerprint database using sensor-based navigation solutions. Since micro-electromechanical systems (MEMS) sensors provide only a short-term accuracy but suffer from the accuracy degradation with time, we restrict the time length of available indoor navigation trajectories, and conduct post-processing to improve the sensor-based navigation solution. Different middle-term navigation trajectories that move in and out of an indoor area are combined to make up the database. Furthermore, we evaluate the effect of WiFi database shifts on WiFi fingerprinting using the database generated by the proposed method. Results show that the fingerprinting errors will not increase linearly according to database (DB) errors in smartphone-based WiFi fingerprinting applications.

  19. Gestión Ciudadana de la Tecnología: Una aproximación desde los Science and Technology Studies a las redes wifi y la governance urbana a través de guifi.net Citizen Management of Technology: A Science and Technology Studies approach to wireless networks and urban governance trough guifi.net

    Directory of Open Access Journals (Sweden)

    Yann Bona Beauvois

    2011-03-01

    Full Text Available

    Tesis doctoral a cargo de Yann Bona presentada en el Departamento de Psicología Social de la Univesriddad Autónoma de Barcelona (UAB en diciembre del 2010. Dirigida por el Dr. Joan Pujol Tarrés.

    La tesis trata de ahondar en las formas en las que iniciativas ciudadanas que tienen por objeto la gestión de la tecnología en el espacio urbano se relacionan con las administraciones públicas. Lo hace a partir de nociones y conceptos de los STS tales como cosmopolítica, composición híbrida o democracia técnica. En síntesis, podemos decir que la tesis responde a la pregunta formulada por Bruno Latour de ¿qué significa hacer pasar la política del lado lo de la técnica?. Nosotros ofrecemos una propuesta centrada en lo que denominamos una sociotécnica de las políticas públicas.

    La tesis se basa en un estudio de caso centrado una red sin hilos libre y abierta (ubicada principalmente en Cataluña y llamada guifi.net surgida del deseo e iniciativa de la sociedad civil y que, hasta la fecha, es la más grande del mundo.

    Thesis presented at the Departament de Psicologia Social de la UAB by Yann Bona on December, 2010. Directed by Dr. Joan Pujol Tarrés.

    This dissertation explores the many ways in which citizens aiming to manage technologies in urban scape relate to public administrations. To accomplish it's task, it brings forward certain STS notions such as cosmopolitics, hybrid composition or technical democracy. On a general level, this thesis seeks an answer to Bruno Latour concern with what does it mean to conceive the technical as political?. We offer a set of conclusions based on what we choose to name a Sociotechnique of Public Policy .

    Our work relies on a case study focused on a free and open wireless network (located in Catalunya for the most part and called guifi.net that emerged from the desire and will of Civil Society wich, up to date, turns out to be the world's biggest free

  20. 广电EoC接入技术发展现状及演进趋势%EoC Technology Current Situation and Development Tendency in CATV Network Reconstruction

    Institute of Scientific and Technical Information of China (English)

    武树斌; 吉萌

    2012-01-01

    This paper Analyses the CATV access networks requirement of three-network convergence. EoC ( Ethernet over Coax) is the most important technology suitable for CATV carrier. Then Compares main preva- lent technologies such as WiFi(802.11 n), C-DOCSIS and HomePlug AV. Network topology, physics proper- ties, MAC function and system performance has been analyzed. Combining with the requirement of the state administration of film and television, the paper forecasts that the EPOC and HiNOC are promising technolo- gies.%分析了三网融合条件下广电接入网的需求,提出EoC是适合广电运营商双向网改的重要技术。对比WiFi降频、C—DOCSIS和HomePlugAV等主流技术,从网络拓扑、物理层指标、数据链路层指标、系统指标等多方面进行分析。结合国家广电总局的要求和未来组网运营需求,对EoC技术的发展趋势进行了分析,认为EPOC和HiNOC技术将有非常良好的应用前景。

  1. Modeling and Analyzing the Coexistence of Wi-Fi and LTE in Unlicensed Spectrum

    OpenAIRE

    2015-01-01

    We leverage stochastic geometry to characterize key performance metrics for neighboring Wi-Fi and LTE networks in unlicensed spectrum. Our analysis focuses on a single unlicensed frequency band, where the locations for the Wi-Fi access points (APs) and LTE eNodeBs (eNBs) are modeled as two independent homogeneous Poisson point processes. Three LTE coexistence mechanisms are investigated: (1) LTE with continuous transmission and no protocol modifications; (2) LTE with discontinuous transmissio...

  2. Fusion of WiFi, Smartphone Sensors and Landmarks Using the Kalman Filter for Indoor Localization

    OpenAIRE

    Zhenghua Chen; Han Zou; Hao Jiang; Qingchang Zhu; Yeng Chai Soh; Lihua Xie

    2015-01-01

    Location-based services (LBS) have attracted a great deal of attention recently. Outdoor localization can be solved by the GPS technique, but how to accurately and efficiently localize pedestrians in indoor environments is still a challenging problem. Recent techniques based on WiFi or pedestrian dead reckoning (PDR) have several limiting problems, such as the variation of WiFi signals and the drift of PDR. An auxiliary tool for indoor localization is landmarks, which can be easily identified...

  3. Design of a visible-light-communication enhanced WiFi system

    OpenAIRE

    Shao, Sihua; Khreishah, Abdallah; Ayyash, Moussa; Rahaim, Michael B.; Elgala, Hany; Jungnickel, Volker; Schulz, Dominic; Little, Thomas D. C.

    2015-01-01

    Visible light communication (VLC) has wide unlicensed bandwidth, enables communication in radio frequency (RF) sensitive environments, realizes energy-efficient data transmission, and has the potential to boost the capacity of wireless access networks through spatial reuse. On the other hand, WiFi provides more coverage than VLC and does not suffer from the likelihood of blockage due to the light of sight (LOS) requirement of VLC. In order to take the advantages of both WiFi and VLC, we propo...

  4. Broadband Packaging of Photodetectors for 100 Gb/s Ethernet Applications

    DEFF Research Database (Denmark)

    Jiang, Chenhui; Krozer, Viktor; Bach, Heinz-Gunter;

    2013-01-01

    The packing structure of functional modules is a major limitaion in achieving a desired performance for 100 Gb/s ethernet applications. This paper presents a methodology of developing advanced packaging of photodetectors (PDs) for high-speed data transmission applications by using 3-D electromagn......The packing structure of functional modules is a major limitaion in achieving a desired performance for 100 Gb/s ethernet applications. This paper presents a methodology of developing advanced packaging of photodetectors (PDs) for high-speed data transmission applications by using 3-D...

  5. Implementation of an Ethernet-Based Communication Channel for the Patmos Processor

    DEFF Research Database (Denmark)

    Pezzarossa, Luca; Kenn Toft, Jakob; Lønbæk, Jesper

    The Patmos processor, which is used as the intellectual property of the T-CREST platform, is only equipped with a RS-232 serial port for communication with the outside world. The serial port is a minimal input/output device with a limited speed and without native networking features. An Ethernet ...... on an Altera Cyclone IV FPGA in the aforementioned board, and it was tested with a software application, running on Patmos, that uses the Ethernet communication channel while the system is connected to a small local area network....

  6. Enterasys Networks delivers 10-Gigabit ethernet for the enterprise with new matrix E1 switching family

    CERN Multimedia

    2001-01-01

    Enterasys Networks Inc., today announced its new Matrix E1 family of 10-Gigabit and Gigabit Ethernet switches. The Matrix E1 Optical Access Switch (OAS) enables organizations to deliver applications at 10-Gb speeds across a single fibre optic pair. Jacques Altaber, deputy leader of IT at CERN said "High-bandwith solutions are essential to leveraging more computing power, so 10-Gb Ethernet is the next logical step for us...The Matrix E1 allows us to provide the networking support that our scientists need and gives us a certain future for bandwidth and computing expansion".

  7. A Realization of Theoretical Maximum Performance in IPSec on Gigabit Ethernet

    Science.gov (United States)

    Onuki, Atsushi; Takeuchi, Kiyofumi; Inada, Toru; Tokiniwa, Yasuhisa; Ushirozawa, Shinobu

    This paper describes “IPSec(IP Security) VPN system" and how it attains a theoretical maximum performance on Gigabit Ethernet. The Conventional System is implemented by software. However, the system has several bottlenecks which must be overcome to realize a theoretical maximum performance on Gigabit Ethernet. Thus, we newly propose IPSec VPN System with the FPGA(Field Programmable Gate Array) based hardware architecture, which transmits a packet by the pipe-lined flow processing and has 6 parallel structure of encryption and authentication engines. We show that our system attains the theoretical maximum performance in the short packet which is difficult to realize until now.

  8. Supervising M.Sc. Students working in the 100 Gigabit Ethernet field using OPNET Modeler

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Berger, Michael Stübert; Wessing, Henrik

    2010-01-01

    This paper deals with supervision methods for M.Sc. students who are using OPNET Modeler for their thesis work within the field of 100 Gigabit Ethernet. We detail how we use OPNET Modeler in our M.Sc. projects at the Technical University of Denmark. In particular, we discuss on how we teach...... students to learn OPNET independently and in a short timeframe, and we outline what students find challenging and rewarding by using OPNET Modeler. Furthermore, we show some cases on how OPNET was applied in specific projects within the field of 100 Gigabit Ethernet....

  9. Hybrid scheduling model and analysis of performance for switched industrial Ethernet

    Institute of Scientific and Technical Information of China (English)

    HU Chun-hua; WU Min; LIU Guo-ping; WANG Si-chun

    2007-01-01

    The fact that outburst traffic in industrial Ethernet was focused on that would bring self-similar phenomenon leading to the delay increase of the cyclical data, and a hybrid priority queue schedule model was proposed in which the outburst data was given the highest priority. Some properties of the self-similar outburst data were proved by network calculus, and its service curve scheduled by the switch was gained. And then the performance of the scheduling algorithm was obtained. The simulation results are close to those calculated by using network calculus model. Some results are of actual significance to the construction of switched industrial Ethernet.

  10. Bidirectional and simultaneous FTTX/Ethernet services using RSOA based remodulation and polarization multiplexing technique

    Science.gov (United States)

    Das, Anindya S.; Patra, Ardhendu S.

    2015-08-01

    A bidirectional and simultaneous transmission of Ethernet, FTTX services through single optical carrier wavelength employing polarization multiplexing technique in the transmitter end and the user end. 10 Gbps and 2.5 Gbps datarates are transmitted over 50 km single mode fiber employing POLMUX technique at OLT and ONU to provide Ethernet and FTTX services concurrently to the user. Reflective semiconductor optical amplifier is used to reuse and remodulate the downlink signal to uplink transmission. The upstream and the downstream transmission performances are observed by the bit error rate values and the eye diagrams obtained by the BER analyzer.

  11. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks

    Science.gov (United States)

    Deng, Zhi-An; Wang, Guofeng; Qin, Danyang; Na, Zhenyu; Cui, Yang; Chen, Juan

    2016-01-01

    To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR), and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF). For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning. PMID:27608019

  12. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks.

    Science.gov (United States)

    Deng, Zhi-An; Wang, Guofeng; Qin, Danyang; Na, Zhenyu; Cui, Yang; Chen, Juan

    2016-09-05

    To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR), and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF). For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning.

  13. An Improved Neural Network Training Algorithm for Wi-Fi Fingerprinting Positioning

    Directory of Open Access Journals (Sweden)

    Esmond Mok

    2013-09-01

    Full Text Available Ubiquitous positioning provides continuous positional information in both indoor and outdoor environments for a wide spectrum of location based service (LBS applications. With the rapid development of the low-cost and high speed data communication, Wi-Fi networks in many metropolitan cities, strength of signals propagated from the Wi-Fi access points (APs namely received signal strength (RSS have been cleverly adopted for indoor positioning. In this paper, a Wi-Fi positioning algorithm based on neural network modeling of Wi-Fi signal patterns is proposed. This algorithm is based on the correlation between the initial parameter setting for neural network training and output of the mean square error to obtain better modeling of the nonlinear highly complex Wi-Fi signal power propagation surface. The test results show that this neural network based data processing algorithm can significantly improve the neural network training surface to achieve the highest possible accuracy of the Wi-Fi fingerprinting positioning method.

  14. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks

    Directory of Open Access Journals (Sweden)

    Zhi-An Deng

    2016-09-01

    Full Text Available To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR, and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF. For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning.

  15. Cross-layer Framework for Fine-grained Channel Access in Next Generation High-density WiFi Networks

    OpenAIRE

    ZHAO, HAITAO; Zhang, Shaojie; Garcia-Palacios, Francisco

    2016-01-01

    Densely deployed WiFi networks will play a crucial role in providing the capacity for next generation mobile internet. However, due to increasing interference, overlapped channels in WiFi networks and throughput efficiency degradation, densely deployed WiFi networks is not a guarantee to obtain higher throughput. An emergent challenge is how to efficiently utilize scarce spectrum resources, by matching physical layer resources to traffic demand. In this aspect, access control allocation strat...

  16. Smartphone-Centric Wi-Fi Device-to-Device Sensor Communication for User Mobility in AAL Services

    OpenAIRE

    Wåhslén, Jonas; Lindh, Thomas

    2016-01-01

    This paper evaluates a use-case for smartphone-centric Wi-Fi device-to-device sensor communication that enables user mobility in ambient assisted living (AAL) services. A real-time performance measurement method has been developed and implemented to evaluate the smartphone’s ability to act as a hub and gateway for Wi-Fi connected sensor nodes. The results show that Wi-Fi Direct and Wi-Fi Hotspot are feasible solutions for smartphone-centric device-to-device communication that enables user mob...

  17. Performance Analysis of Cognitive Radio for Wi-Fi Signals Using Cyclostationary Spectrum Sensing

    Directory of Open Access Journals (Sweden)

    Mandeep Singh

    2014-08-01

    Full Text Available The need for radio spectrum usage is increasing day by day with recent advancements in wireless system. But there is limited amount of spectrum available. So that for solving this problem Cognitive Radio (CR is used for purpose of the spectrum utilization properly. Basically the Licensed users use the licensed bands but the unlicensed users should always check spectrum with the help of CR technology. The main aim of cognitive radio is to sense the spectrum continuously. In this paper, we have provided the proposal that how the capacity of the system can be increased by reuse the unused licensed band by simulating a Cognitive radio system. The secondary users can occupy free space (spectrum holes and also licensed bands by continuously monitoring the spectrum. The requirements of cognitive radio systems will be investigated by considering spectrum sensing techniques. To achieve this, a Cyclostationary Spectrum Sensing technique is studied and applied to detect OFDM signals in a noisy environment. The results are obtained for the applications employed in high frequency, such as, Wi-Fi.

  18. Ethernet-Based Passive Optical Local-Area Networks for Fiber-to-the-Desk Application

    NARCIS (Netherlands)

    Radovanovic, Igor; Etten, van Wim; Freriks, Hennie

    2003-01-01

    We introduce optical local-area network (LAN) architectures based on multimode optical fiber and components, short wavelength lasers and detectors, and the widely used fast Ethernet protocol. These architectures are designed to lower the costs associated with passive optical LAN implementation. Furt

  19. Additional Sensitivity Penalty of Burst Mode Receivers in Ethernet PON due to Extinction Ratio

    Institute of Scientific and Technical Information of China (English)

    Sub Han; Ja-Won Seo; Tae-Whan Yoo; Man-Seop Lee

    2003-01-01

    An additional sensitivity penalty of burst mode receivers due to the extinction ratio is analyzed considering the specific transmitter control in Ethernet PON. For an extinction ratio of 6dB, a penalty of 8dB occurs additionally.

  20. Ethernet Based Passive Optical Local Area Networks for Fiber-to-the-Desk Application

    NARCIS (Netherlands)

    Radovanovic, Igor; van Etten, Wim; Freriks, Hennie

    2003-01-01

    We introduce optical local-area network (LAN) architectures based on multimode optical fiber and components, short wavelength lasers and detectors, and the widely used fast Ethernet protocol. These architectures are designed to lower the costs associated with passive optical LAN implementation.

  1. A Small One-Fiber WDM Optical Ethernet PC Card for FTTD

    Institute of Scientific and Technical Information of China (English)

    Naoto Sugimoto; Seiji Fukushima; Yasuhiro Suzuki; Yoshihisa Sakai; Hiromasa Tanobe; Takeshi Kurosaki; Kazuto Noguchi; Kimio Oguchi; Hiromu Toba

    2003-01-01

    A new generation of network interface card for fiber-to-the-desktop has been fabricated. The fabricated card is PC-card size and suitable for notebook PCs. It could become the key element in the coming optical Ethernet age.

  2. New Ethernet Based Optically Transparent Network for Fiber-to-the-Desk Application

    NARCIS (Netherlands)

    Radovanovic, Igor; Etten, van Wim

    2003-01-01

    We present a new optical local area network architecture based on multimode optical fibers and components, short wavelength lasers and detectors and the widely used fast Ethernet protocol. The presented optically transparent network represent a novel approach in fiber-to-the-desk applications. It is

  3. ETHERNET Powerlink的多供应商(Multi—Vender)系统

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    (2005年11月28日,瑞士温特图尔市(Winterthur)在德国纽伦堡市举行的SPS/IPC/DRIVES博览会上,ETHERNET Powerlink标准化协会(EPSG)展示了最新的工业以太网的成果。

  4. Testing and Modeling Ethernet Switches and Networks for Use in ATLAS High-level Triggers

    CERN Document Server

    Dobinson, Robert W; Korcyl, K; Le Vine, M J; Lokier, J; Martin, B; Meirosu, C; Saka, F; Vella, K

    2001-01-01

    The ATLAS second level trigger will use a multi-layered LAN network to transfer 5 Gbyte/s detector data from ~1500 buffers to a few hundred processors. A model of the network has been constructed to evaluate its performance. A key component of the network model is a model of an individual switch, reproducing the behavior measured in real devices. A small number of measurable parameters are used to model a variety of commercial Ethernet switches. Using parameters measured on real devices, the impact on the overall network performance is modeled. In the Atlas context, both 100 Mbit and Gigabit Ethernet links are required. A system is described which is capable of characterizing the behavior of commercial switches with the required number of nodes under traffic conditions resembling those to be encountered in the Atlas experiment. Fast Ethernet traffic is provided by a high density, custom built tester based on FPGAs, programmed in Handel-C and VHDL, while the Gigabit Ethernet traffic is generated using Alteon N...

  5. Efficient Data Transfer Rate and Speed of Secured Ethernet Interface System.

    Science.gov (United States)

    Ghanti, Shaila; Naik, G M

    2016-01-01

    Embedded systems are extensively used in home automation systems, small office systems, vehicle communication systems, and health service systems. The services provided by these systems are available on the Internet and these services need to be protected. Security features like IP filtering, UDP protection, or TCP protection need to be implemented depending on the specific application used by the device. Every device on the Internet must have network interface. This paper proposes the design of the embedded Secured Ethernet Interface System to protect the service available on the Internet against the SYN flood attack. In this experimental study, Secured Ethernet Interface System is customized to protect the web service against the SYN flood attack. Secured Ethernet Interface System is implemented on ALTERA Stratix IV FPGA as a system on chip and uses the modified SYN flood attack protection method. The experimental results using Secured Ethernet Interface System indicate increase in number of genuine clients getting service from the server, considerable improvement in the data transfer rate, and better response time during the SYN flood attack.

  6. Efficient Bandwidth Management for Ethernet Passive Optical Networks

    KAUST Repository

    Elrasad, Amr Elsayed M.

    2016-05-15

    The increasing bandwidth demands in access networks motivates network operators, networking devices manufacturers, and standardization institutions to search for new approaches for access networks. These approaches should support higher bandwidth, longer distance between end user and network operator, and less energy consumption. Ethernet Passive Optical Network (EPON) is a favorable choice for broadband access networks. EPONs support transmission rates up to 10 Gbps. EPONs also support distance between end users and central office up to 20 Km. Moreover, optical networks have the least energy consumption among all types of networks. In this dissertation, we focus on reducing delay and saving energy in EPONs. Reducing delay is essential for delay-sensitive traffic, while minimizing energy consumption is an environmental necessity and also reduces the network operating costs. We identify five challenges, namely excess bandwidth allocation, frame delineation, congestion resolution, large round trip time delay in long-reach EPONs (LR-EPONs), and energy saving. We provide a Dynamic Bandwidth Allocation (DBA) approach for each challenge. We also propose a novel scheme that combines the features of the proposed approaches in one highly performing scheme. Our approach is to design novel DBA protocols that can further reduce the delay and be simultaneously simple and fair. We also present a dynamic bandwidth allocation scheme for Green EPONs taking into consideration maximizing energy saving under target delay constraints. Regarding excess bandwidth allocation, we develop an effective DBA scheme called Delayed Excess Scheduling (DES). DES achieves significant delay and jitter reduction and is more suitable for industrial deployment due to its simplicity. Utilizing DES in hybrid TDM/WDM EPONs (TWDM-EPONs) is also investigated. We also study eliminating the wasted bandwidth due to frame delineation. We develop an interactive DBA scheme, Efficient Grant Sizing Interleaved

  7. Towards Optimal Buffer Size in Wi-Fi Networks

    KAUST Repository

    Showail, Ahmad J.

    2016-01-19

    Buffer sizing is an important network configuration parameter that impacts the quality of data traffic. Falling memory cost and the fallacy that ‘more is better’ lead to over provisioning network devices with large buffers. Over-buffering or the so called ‘bufferbloat’ phenomenon creates excessive end-to-end delay in today’s networks. On the other hand, under-buffering results in frequent packet loss and subsequent under-utilization of network resources. The buffer sizing problem has been studied extensively for wired networks. However, there is little work addressing the unique challenges of wireless environment. In this dissertation, we discuss buffer sizing challenges in wireless networks, classify the state-of-the-art solutions, and propose two novel buffer sizing schemes. The first scheme targets buffer sizing in wireless multi-hop networks where the radio spectral resource is shared among a set of con- tending nodes. Hence, it sizes the buffer collectively and distributes it over a set of interfering devices. The second buffer sizing scheme is designed to cope up with recent Wi-Fi enhancements. It adapts the buffer size based on measured link characteristics and network load. Also, it enforces limits on the buffer size to maximize frame aggregation benefits. Both mechanisms are evaluated using simulation as well as testbed implementation over half-duplex and full-duplex wireless networks. Experimental evaluation shows that our proposal reduces latency by an order of magnitude.

  8. Penentuan Arah Teleskop Digital Melalui Komunikasi Wi-Fi

    Directory of Open Access Journals (Sweden)

    Prima Kurniawan

    2013-09-01

    Full Text Available Teleskop bintang adalah sebuah perangkat instrument yang digunakan untuk melihat benda-benda langit yang jaraknya sangat jauh menjadi terasa dekat. Teleskop yang tersedia pada umumnya belum dilengkapi dengan sistem digital untuk pencitraannya dan otomatisasi untuk penentuan arahnya. Pada tugas akhir ini dibuat suatu sistem digital dan otomatisasi pada teleskop konvensional. Sistem digital digunakan untuk perekaman hasil yang didapatkan oleh teleskop dan ditampilakan pada komputer. Sistem otomatisasi dibuat untuk menentukan pergerakan sudut teleskop dengan sebuah GUI. Mekanik pergerakan teleskop diberikan 2 motor dc sebagai penggerak. Masing-masing motor dc berfungsi untuk menggerakkan tiap sumbu X dan sumbu Y. Digunakan sebuah sistem mikrokontroler menggunakan ATmega 32 sebagai pengolahan data. Fitur ADC mikrokontroler digunakan untuk mengubah data analog perubahan tegangan yang terjadi pada potensiometer menjadi perubahan data digital yang akan dikonversi menjadi nilai pergerakan perubahan sudut. Sistem ini ditambahkan sebuah router yang berfungsi sebagai akses poin untuk jalur pengiriman dan penerimaan data antara komputer dengan mikrokontroler. Ditambahkan sebuah wiznet yang mampu mengkonversi data dari komunikasi serial ke data protokol TCP/IP dan sebaliknya. Pengujian pergerakan sudut sumbu X dilakukan pada sudut 0, 45, 90, 135, 180, 255, 270, 315, dan 360 sedangkan pergerakan sumbu Y dilakukan pada sudut 0, 10, 20, 30, 40, 50, 60, 70, 80, dan 90. Hasil pengujian pada sumbu X dan Y didapatkan beberapa error pada titik-titik tertentu dengan tingkat kesalahan mencapai 3.8% untuk sumbu x dan 2.5% untuk sumbu y. Penentuan pergerakan sudut dilakukan melalui komputer dengan menggunakan komunikasi wi-fi.

  9. Crowd Mobility Analysis using WiFi Sniffers

    Directory of Open Access Journals (Sweden)

    Anas Basalamah

    2016-12-01

    Full Text Available Wi-fi enabled devices such as today’s smart-phones are regularly in-search for connectivity. They continuously send management frames called Probe Requests searching for previ-ously accessed networks. These frames contain the sender’s MAC addresses in clear text, which can be used as an identifier for that sender. Being able to sniff that MAC address at several locations allows us to understand the mobility behavior of that device. In this paper, we present a solar-powered, beagle-bone based standalone system that continuously sniffs the air for probes and extract their MAC addresses. We deployed the system in the world’s largest gathering (The Hajj and tested it at scale. Our objective was to build an infrastructure for non-invasive mass crowd analysis. Our deployment had a total of 8 sniffers covering a population of 185,000 people. We detected 37.5% of the population, analysed their arrival and departure behaviours, identified their smartphone manufacturers and extracted their transition patterns from one sub-location to another. By pre-senting valuable insights on the mobility of our target crowd, we validated the potential of our platform for crowd mobility analysis.

  10. An Improved WiFi Indoor Positioning Algorithm by Weighted Fusion.

    Science.gov (United States)

    Ma, Rui; Guo, Qiang; Hu, Changzhen; Xue, Jingfeng

    2015-08-31

    The rapid development of mobile Internet has offered the opportunity for WiFi indoor positioning to come under the spotlight due to its low cost. However, nowadays the accuracy of WiFi indoor positioning cannot meet the demands of practical applications. To solve this problem, this paper proposes an improved WiFi indoor positioning algorithm by weighted fusion. The proposed algorithm is based on traditional location fingerprinting algorithms and consists of two stages: the offline acquisition and the online positioning. The offline acquisition process selects optimal parameters to complete the signal acquisition, and it forms a database of fingerprints by error classification and handling. To further improve the accuracy of positioning, the online positioning process first uses a pre-match method to select the candidate fingerprints to shorten the positioning time. After that, it uses the improved Euclidean distance and the improved joint probability to calculate two intermediate results, and further calculates the final result from these two intermediate results by weighted fusion. The improved Euclidean distance introduces the standard deviation of WiFi signal strength to smooth the WiFi signal fluctuation and the improved joint probability introduces the logarithmic calculation to reduce the difference between probability values. Comparing the proposed algorithm, the Euclidean distance based WKNN algorithm and the joint probability algorithm, the experimental results indicate that the proposed algorithm has higher positioning accuracy.

  11. Influence of smartphone Wi-Fi signals on adipose-derived stem cells.

    Science.gov (United States)

    Lee, Sang-Soon; Kim, Hyung-Rok; Kim, Min-Sook; Park, Sanghoon; Yoon, Eul-Sik; Park, Seung-Ha; Kim, Deok-Woo

    2014-09-01

    The use of smartphones is expanding rapidly around the world, thus raising the concern of possible harmful effects of radiofrequency generated by smartphones. We hypothesized that Wi-Fi signals from smartphones may have harmful influence on adipose-derived stem cells (ASCs). An in vitro study was performed to assess the influence of Wi-Fi signals from smartphones. The ASCs were incubated under a smartphone connected to a Wi-Fi network, which was uploading files at a speed of 4.8 Mbps for 10 hours a day, for a total of 5 days. We constructed 2 kinds of control cells, one grown in 37°C and the other grown in 39°C. After 5 days of Wi-Fi exposure from the smartphone, the cells underwent cell proliferation assay, apoptosis assay, and flow cytometry analysis. Three growth factors, vascular endothelial growth factor, hepatocyte growth factor, and transforming growth factor-β, were measured from ASC-conditioned media. Cell proliferation rate was higher in Wi-Fi-exposed cells and 39°C control cells compared with 37°C control cells. Apoptosis assay, flow cytometry analysis, and growth factor concentrations showed no remarkable differences among the 3 groups. We could not find any harmful effects of Wi-Fi electromagnetic signals from smartphones. The increased proliferation of ASCs under the smartphone, however, might be attributable to the thermal effect.

  12. 用 RT5370模块实现的低成本嵌入式 WiFi 系统%Low-cost Embedded WiFi System Based on RT5370 Module

    Institute of Scientific and Technical Information of China (English)

    李洋洋

    2014-01-01

    介绍了在嵌入式系统上支持 USB 接口的 WiFi 模块 RT5370的软硬件方案及其具体的移植实现。基于该方案,实现了智能手机通过 WiFi 遥控小车的控制系统。试验表明,低成本嵌入式 WiFi 是可行的,从而为当前热门的嵌入式系统采用 WiFi 探索了低成本的解决方案。%This article introduces the software and hardware solutions of WiFi module RT5370 supporting USB interface in embedded sys-tem,and its implementation of specific transplantation.Based on the solution,the smart car can be controlled by smart phone via WiFi. Experimental result shows that low-cost embedded WiFi is feasible.Therefore,the solution explores a low-cost solution based on WiFi for the current popular embedded system.

  13. Does prolonged radiofrequency radiation emitted from Wi-Fi devices induce DNA damage in various tissues of rats?

    Science.gov (United States)

    Akdag, Mehmet Zulkuf; Dasdag, Suleyman; Canturk, Fazile; Karabulut, Derya; Caner, Yusuf; Adalier, Nur

    2016-09-01

    Wireless internet (Wi-Fi) providers have become essential in our daily lives, as wireless technology is evolving at a dizzying pace. Although there are different frequency generators, one of the most commonly used Wi-Fi devices are 2.4GHz frequency generators. These devices are heavily used in all areas of life but the effect of radiofrequency (RF) radiation emission on users is generally ignored. Yet, an increasing share of the public expresses concern on this issue. Therefore, this study intends to respond to the growing public concern. The purpose of this study is to reveal whether long term exposure of 2.4GHz frequency RF radiation will cause DNA damage of different tissues such as brain, kidney, liver, and skin tissue and testicular tissues of rats. The study was conducted on 16 adult male Wistar-Albino rats. The rats in the experimental group (n=8) were exposed to 2.4GHz frequency radiation for over a year. The rats in the sham control group (n=8) were subjected to the same experimental conditions except the Wi-Fi generator was turned off. After the exposure period was complete the possible DNA damage on the rat's brain, liver, kidney, skin, and testicular tissues was detected through the single cell gel electrophoresis assay (comet) method. The amount of DNA damage was measured as percentage tail DNA value. Based on the DNA damage results determined by the single cell gel electrophoresis (Comet) method, it was found that the% tail DNA values of the brain, kidney, liver, and skin tissues of the rats in the experimental group increased more than those in the control group. The increase of the DNA damage in all tissues was not significant (p>0.05). However the increase of the DNA damage in rat testes tissue was significant (pWi-Fi) does not cause DNA damage of the organs investigated in this study except testes. The results of this study indicated that testes are more sensitive organ to RF radiation.

  14. REQUIREMENTS DEFINITION AND IMPLEMENTATION OF THE APPARATUS FOR DATA COLLECTION FROM OPEN PACKETS OF WI-FI NETWORKS

    OpenAIRE

    Ivanov, D. A.; IVANOV A.L.; SUROVTSOVA T.G.

    2015-01-01

    Mobile devices actively use Wi-Fi for Internet connectivity. Low cost access points are required to allow data collection from open packets of the Wi-Fi networks. These access points are part of hardware and software based solution that monitors radio of the various mobile devices.

  15. Safe at Any Speed: Securing Your Wi-Fi Network Is Easier and More Important than You Might Think

    Science.gov (United States)

    Branzburg, Jeffrey

    2007-01-01

    In this article, the author relates how he discovered that not all Wi-Fi networks are secure. As such, he developed several strategies on how he can be secured whenever he connects to the Internet through a Wi-Fi connection. He discusses how one can change passwords, explains the process of encryption, and provides suggestions on other security…

  16. An Indoor Continuous Positioning Algorithm on the Move by Fusing Sensors and Wi-Fi on Smartphones.

    Science.gov (United States)

    Li, Huaiyu; Chen, Xiuwan; Jing, Guifei; Wang, Yuan; Cao, Yanfeng; Li, Fei; Zhang, Xinlong; Xiao, Han

    2015-12-11

    Wi-Fi indoor positioning algorithms experience large positioning error and low stability when continuously positioning terminals that are on the move. This paper proposes a novel indoor continuous positioning algorithm that is on the move, fusing sensors and Wi-Fi on smartphones. The main innovative points include an improved Wi-Fi positioning algorithm and a novel positioning fusion algorithm named the Trust Chain Positioning Fusion (TCPF) algorithm. The improved Wi-Fi positioning algorithm was designed based on the properties of Wi-Fi signals on the move, which are found in a novel "quasi-dynamic" Wi-Fi signal experiment. The TCPF algorithm is proposed to realize the "process-level" fusion of Wi-Fi and Pedestrians Dead Reckoning (PDR) positioning, including three parts: trusted point determination, trust state and positioning fusion algorithm. An experiment is carried out for verification in a typical indoor environment, and the average positioning error on the move is 1.36 m, a decrease of 28.8% compared to an existing algorithm. The results show that the proposed algorithm can effectively reduce the influence caused by the unstable Wi-Fi signals, and improve the accuracy and stability of indoor continuous positioning on the move.

  17. An Indoor Continuous Positioning Algorithm on the Move by Fusing Sensors and Wi-Fi on Smartphones

    Directory of Open Access Journals (Sweden)

    Huaiyu Li

    2015-12-01

    Full Text Available Wi-Fi indoor positioning algorithms experience large positioning error and low stability when continuously positioning terminals that are on the move. This paper proposes a novel indoor continuous positioning algorithm that is on the move, fusing sensors and Wi-Fi on smartphones. The main innovative points include an improved Wi-Fi positioning algorithm and a novel positioning fusion algorithm named the Trust Chain Positioning Fusion (TCPF algorithm. The improved Wi-Fi positioning algorithm was designed based on the properties of Wi-Fi signals on the move, which are found in a novel “quasi-dynamic” Wi-Fi signal experiment. The TCPF algorithm is proposed to realize the “process-level” fusion of Wi-Fi and Pedestrians Dead Reckoning (PDR positioning, including three parts: trusted point determination, trust state and positioning fusion algorithm. An experiment is carried out for verification in a typical indoor environment, and the average positioning error on the move is 1.36 m, a decrease of 28.8% compared to an existing algorithm. The results show that the proposed algorithm can effectively reduce the influence caused by the unstable Wi-Fi signals, and improve the accuracy and stability of indoor continuous positioning on the move.

  18. Wireless communication technology NFC

    OpenAIRE

    MÁROVÁ, Kateřina

    2014-01-01

    Aim of this bachelor thesis is to handle the issue of new wireless communication technology NFC (Near Field Communication) including a comparison of advantages and disadvantages of NFC with other wireless technologies (Bluetooth, Wi-Fi, etc.). NFC is a technology for wireless communications between different electronic devices, one of which is typically a mobile phone. Near Field Communication allows wireless communication at very short distance by approaching or enclosing two devices and can...

  19. Coexistence of WiFi and WiMAX systems based on PS-request protocols.

    Science.gov (United States)

    Kim, Jongwoo; Park, Suwon; Rhee, Seung Hyong; Choi, Yong-Hoon; Chung, Young-uk; Hwang, Ho Young

    2011-01-01

    We introduce both the coexistence zone within the WiMAX frame structure and a PS-Request protocol for the coexistence of WiFi and WiMAX systems sharing a frequency band. Because we know that the PS-Request protocol has drawbacks, we propose a revised PS-Request protocol to improve the performance. Two PS-Request protocols are based on the time division operation (TDO) of WiFi system and WiMAX system to avoid the mutual interference, and use the vestigial power management (PwrMgt) bit within the Frame Control field of the frames transmitted by a WiFi AP. The performance of the revised PS-Request protocol is evaluated by computer simulation, and compared to those of the cases without a coexistence protocol and to the original PS-Request protocol.

  20. Creating wi-fi bluetooth mesh network for crisis management applications

    Science.gov (United States)

    Al-Tekreeti, Safa; Adams, Christopher; Al-Jawad, Naseer

    2010-04-01

    This paper proposes a wireless mesh network implementation consisting of both Wi-Fi Ad-Hoc networks as well as Bluetooth Piconet/Scatternet networks, organised in an energy and throughput efficient structure. This type of networks can be easily constructed for Crises management applications, for example in an Earthquake disaster. The motivation of this research is to form mesh network from the mass availability of WiFi and Bluetooth enabled electronic devices such as mobile phones and PC's that are normally present in most regions were major crises occurs. The target of this study is to achieve an effective solution that will enable Wi-Fi and/or Bluetooth nodes to seamlessly configure themselves to act as a bridge between their own network and that of the other network to achieve continuous routing for our proposed mesh networks.

  1. Using of GSM and Wi-Fi Signals for Indoor Positioning Based on Fingerprinting Algorithms

    Directory of Open Access Journals (Sweden)

    Juraj Machaj

    2015-01-01

    Full Text Available In the paper framework for indoor positioning utilizing Wi-Fi and GSM signals is introduced. Nowadays, indoor positioning is a very attractive topic for researchers, since accurate and reliable positioning system can unlock new market to service providers. In this paper we will analyse the use of Wi-Fi and GSM signals and their combination for the fingerprinting based positioning in the indoor environment. Performance of positioning system in terms of accuracy was analysed using simulations. In the simulations the position of the mobile device was estimated in three ways, when only GSM signals were used, when only Wi-Fi signals were utilized and when a combination of both signals was used. Three positioning algorithms from the Nearest Neighbour (NN family were used in the simulations. Simulations were performed in the simulation model created in MATLAB environment.

  2. Impact Analysis of Flow Shaping in Ethernet-AVB/TSN and AFDX from Network Calculus and Simulation Perspective

    National Research Council Canada - National Science Library

    Feng He; Lin Zhao; Ershuai Li

    2017-01-01

    .... AFDX implements a fixed priority scheduling strategy with two priority levels. Ethernet-AVB/TSN supports a similar fixed priority scheduling with an additional Credit-Based Shaper (CBS) mechanism...

  3. Free WiFi as Strategic Competitive Advantage for Fast-Food Outlet in the Knowledge Era

    Directory of Open Access Journals (Sweden)

    N. I. Yusop

    2011-01-01

    Full Text Available Problem statement: The growth of food outlets in Malaysia brings about the stiff competition among the players in food industry. To remain competitive, each outlet needs to adopt its own strategy in order to secure their return on investment and profitability. In knowledge era, technology has become an added value in achieving competitive advantage. The aim of this research is to assess whether providing free WiFi can be a strategy to remain competitive. Porter's 5forces competitive model is adopted as the basis for the assessment. Approach: Two phases of data collection using qualitative methodology were planned and rolled out. The first phase involved surveying and observing three regions within a selected state, while the second phase involved interviewing the identified food outlet’s manager. A set of interview questions was formulated based on the 5 areas of porter's model which includes bargaining power of suppliers, bargaining power of customers, threat of substitutions, threat of new entrants and existing rivalries. In addition to the existing five forces, information regarding government policy and initiatives was also collected. Results: Result has shown that by that offering free WiFi to meet the customers' needs, it can help to generate revenue increase of as high as 50% thus ensuring the food outlet to stay competitive. Conclusion: This is more visible when dealing with case of food outlets at same area are targeting the same group of customers as what had been observed in this research. This research provides a good reference to other food outlets that yet to adopt any strategy in order to stay competitive.

  4. Synchronization and NRZ-to-RZ format conversion of 10 G Ethernet packet based on a time lens

    DEFF Research Database (Denmark)

    Hu, Hao; Laguardia Areal, Janaina; Palushani, Evarist;

    2010-01-01

    10 G Ethernet packet with maximum frame size of 1518 bytes is synchronized to a global clock using a time lens. The 10 Gb/s NRZ signal is converted into RZ signal at the same time.......10 G Ethernet packet with maximum frame size of 1518 bytes is synchronized to a global clock using a time lens. The 10 Gb/s NRZ signal is converted into RZ signal at the same time....

  5. Synchronization and NRZ-to-RZ format conversion of 10 G Ethernet packet based on a time lens

    DEFF Research Database (Denmark)

    Hu, Hao; Laguardia Areal, Janaina; Palushani, Evarist

    2010-01-01

    10 G Ethernet packet with maximum frame size of 1518 bytes is synchronized to a global clock using a time lens. The 10 Gb/s NRZ signal is converted into RZ signal at the same time.......10 G Ethernet packet with maximum frame size of 1518 bytes is synchronized to a global clock using a time lens. The 10 Gb/s NRZ signal is converted into RZ signal at the same time....

  6. RSSI BASED LOCATION ESTIMATION IN A WI-FI ENVIRONMENT: AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    M. Ganesh Madhan

    2014-12-01

    Full Text Available In real life situations, location estimation of moving objects, armed personnel are of great importance. In this paper, we have attempted to locate targets which are mobile in a Wi-Fi environment. Radio Frequency (RF localization techniques based on Received Signal Strength Indication (RSSI algorithms are used. This study utilises Wireless Mon tool, software to provide complete technical information regarding received signal strength obtained from different wireless access points available in a campus Wi-Fi environment, considered for the study. All simulations have been done in MATLAB. The target location estimated by this approach agrees well with the actual GPS data.

  7. Passive Wi-Fi Link Capacity Estimation on Commodity Access Points

    OpenAIRE

    Neves da Hora, Diego; Van Doorselaer, Karel; Van Oost, Koen; Teixeira, Renata; Diot, Christophe

    2016-01-01

    International audience; Wi-Fi is the preferred way of accessing the internet for many devices at home, but it is vulnerable to performance problems. In this work, we propose a method to estimate the link capacity of a Wi-Fi link using physical layer metrics passively sampled on commodity access points. We build a model that predicts the maximum UDP throughput a device can sustain, which extends previous models to consider IEEE 802.11n optimizations such as frame aggregation. We validate our m...

  8. ONU WIFI 802.1x认证功能的实现

    Institute of Scientific and Technical Information of China (English)

    胡培

    2015-01-01

    本文详细描述了ONU WIFI 802.1x认证功能的系统模型,并以PEAP认证为例,以FreeRadius搭建Radius认证服务器,使用Windows无线网卡作为WIFI客户端,阐述了ONU WIFI 802.1x认证功能的实现。最后,展望了其他EAP认证方式的实现。

  9. Cognitive radio-based transmission energy management in Wi-Fi nodes

    CSIR Research Space (South Africa)

    Olwal, TO

    2012-10-01

    Full Text Available -services. To solve such problems, in part, this study addresses the transmission energy management in Wi-Fi networks. Figure 1: Internet needs of rural communities PROPOSAL A cognitive radio-based transmission energy management (CR-TEM) solution for Wi... The CSIR has developed a cognitive radio-based transmission energy management algorithm that can be used to manage the energy consumption of Wi-Fi networks in rural and remote communities in South Africa. The project demonstrates the application...

  10. Sensor Fused Indoor Positioning Using Dual Band WiFi Signal Measurements

    OpenAIRE

    Karlsson, Fredrik; Karlsson, Martin; Bernhardsson, Bo; Tufvesson, Fredrik; Persson, Magnus

    2015-01-01

    In this paper, signal strengths from known WiFi access points are used together with a particle filter to perform indoor navigation. It is shown that more information is obtained by using signals of both 2.4 and 5.0 GHz, compared to using only one frequency. Thus, using both frequencies provides a more accurate positioning. The second contribution is an algorithm where WiFi measurements are combined with pedestrian dead reckoning (PDR), which is based on step counting using an accelerometer a...

  11. Experimental Evaluation of a Scalable WiFi Multicast Scheme in the ORBIT Testbed

    OpenAIRE

    Bejerano, Yigal; Ferragut, Jaime; Guo, Katherine; Gupta, Varun; Gutterman, Craig; Nandagopal, Thyaga; Zussman, Gil

    2014-01-01

    IEEE 802.11-based wireless local area networks, referred to as WiFi, have been globally deployed and the vast majority of the mobile devices are currently WiFi-enabled. While WiFi has been proposed for multimedia content distribution, its lack of adequate support for multicast services hinders its ability to provide multimedia content distribution to a large number of devices. In earlier work, we proposed a dynamic scheme called AMuSe that selects a subset of the multicast receivers as feedba...

  12. Radiation-Hard SpaceWire/Gigabit Ethernet-Compatible Transponder

    Science.gov (United States)

    Katzman, Vladimir

    2012-01-01

    A radiation-hard transponder was developed utilizing submicron/nanotechnology from IBM. The device consumes low power and has a low fabrication cost. This device utilizes a Plug-and-Play concept, and can be integrated into intra-satellite networks, supporting SpaceWire and Gigabit Ethernet I/O. A space-qualified, 100-pin package also was developed, allowing space-qualified (class K) transponders to be delivered within a six-month time frame. The novel, optical, radiation-tolerant transponder was implemented as a standalone board, containing the transponder ASIC (application specific integrated circuit) and optical module, with an FPGA (field-programmable gate array) friendly parallel interface. It features improved radiation tolerance; high-data-rate, low-power consumption; and advanced functionality. The transponder utilizes a patented current mode logic library of radiation-hardened-by-architecture cells. The transponder was developed, fabricated, and radhard tested up to 1 MRad. It was fabricated using 90-nm CMOS (complementary metal oxide semiconductor) 9 SF process from IBM, and incorporates full BIT circuitry, allowing a loop back test. The low-speed parallel LVCMOS (lowvoltage complementary metal oxide semiconductor) bus is compatible with Actel FPGA. The output LVDS (low-voltage differential signaling) interface operates up to 1.5 Gb/s. Built-in CDR (clock-data recovery) circuitry provides robust synchronization and incorporates two alarm signals such as synch loss and signal loss. The ultra-linear peak detector scheme allows on-line control of the amplitude of the input signal. Power consumption is less than 300 mW. The developed transponder with a 1.25 Gb/s serial data rate incorporates a 10-to-1 serializer with an internal clock multiplication unit and a 10-1 deserializer with internal clock and data recovery block, which can operate with 8B10B encoded signals. Three loop-back test modes are provided to facilitate the built-in-test functionality. The

  13. Integration of VICbus, FDL, SCI and Ethernet in the CERN CASCADE data acquisition system

    CERN Document Server

    Petersen, J; Bogaerts, A; Burckhart, Doris; Divià, R; Ingebritsen, L; Joos, M; Liebhart, M; Niewold, J; Parkman, C; Perrin, Yves; Thiercelin, B; Tremblet, L J; Vascotto, Alessandro; Werner, P

    1995-01-01

    Cascade is a multi-processor real-time data-acquisition system for HEP experiments developed at CERN by the ECP-DS group. Configurations supported today include VMEbus processors running OS-9 and UNIX workstations. The CASCADE data acquisition processes, called stages communicate via links, at present VICbus between VME crates and Ethernet between VMEbus processors and workstations. Work is in progress to introduce new inter-stage links based on the Fast Data Link between VME crates and on SCI for data exchange between SUN stations. The paper gives a short description of the architecture of CASCADE with emphasis on the link aspects. The implementation and current status of the inter-stage links based on VICbus, Ethernet, FDI, and SCI will be described and results on the performances presented.

  14. Scheduling queues in the Ethernet switch, considering the waiting time of frames

    Directory of Open Access Journals (Sweden)

    Kizilov Evgeniy

    2016-01-01

    Full Text Available Authors proposes an algorithm to scheduling queues with temporal selection of frames in the Ethernet switches with QoS support, which is based on the waiting time of frames in the queues of different classes. Evaluation of the effectiveness of this algorithm compared to the classical cyclic algorithms by simulation with hierarchical temporal coloured Petri nets using CPN Tools package was conducte.

  15. Reliance communications' flag telecom to provide ethernet link between CERN and TIFR

    CERN Document Server

    2007-01-01

    "Flag Telecom Group Limited (Flag), the undersea cable network arm of Anil Ambani-le Reliance Communications, has announced a landmark deal with CERn (Conseil Européen pour la Recheche Nucléaire), the European organisation for nuclear research based in Geneva, Switzerland and the Tata institute of Fundamental Research (TIFR) in Mumbai to provide gigabit Ethernet connectivity between the two." (1 page)

  16. Comparison between Networked Control System behaviour based on CAN and Switched Ethernet networks

    OpenAIRE

    Brahimi, Belynda; Rondeau, Eric; Aubrun, Christophe

    2006-01-01

    7 pages; International audience; The distributed control systems are more and more used in many industrial applications. These systems are often referred as “Networked control systems”. The goal of this paper is to show the network influence on feedback control systems. Two networks are considered: Switched Ethernet network and CAN fieldbus. The first one represents the non deterministic network and second one represents the deterministic one. Several scenarii are studied to analyse the stabi...

  17. Design and implementation of a clock recovery circuit for fast Ethernet applications

    Institute of Scientific and Technical Information of China (English)

    朱全庆; 邹雪城; 沈绪榜

    2004-01-01

    A circuit architechure to realize clock recovery for fast Ethernet applications is presented, whick includies system architecture, modified Mueller Muller algorithm for 100BASE-TX, phase detector for 100BASE-TX and multiple output charge pump PLL. The clock recovery circuit is verified by TSMC 0.35um 1P5M CMOS process. The results show that this clock recovery circuit exactly extracts the timing information. It has advantages over others for simple and easy implementation.

  18. Ethernet Time Transfer through a U.S. Commercial Optical Telecommunications Network

    Science.gov (United States)

    2014-12-01

    Ethernet Time Transfer through a U.S. Commercial Optical Telecommunications Network M. Weiss, NIST Time and Frequency Division, mweiss... telecommunications and data networks through precision synchronization.” Marc founded and has led WSTS, the Workshop on Sync in Telecom Systems...signals through a telecommunication network. This experiment connects UTC(NIST) in Boulder, Colorado with UTC(USNO) at the Alternate Master Clock at

  19. Ein Framework für echtzeitfähige Ethernet-Netzwerke

    Science.gov (United States)

    Dopatka, Frank

    Im Rahmen dieser Arbeit wird die Entwicklung eines formalen Framewoks vorgestellt, mit dessen Hilfe zwischen der Kompatibilität zum verbreiteten baumförmigen Standard-Ethernet und der Einhaltung von Echtzeitanforderungen einer automatisierten Anlage variiert werden kann. Damit kann bereits vor der Auswahl einer bestimmten Technologie eine Schedule der Echtzeit-Übertragungen offline kalkuliert und simuliert werden, sobald die Anforderungen der Geräte im industriellen Echtzeit-Netzwerk bekannt sind.

  20. Contribución para QoS en Redes Metropolitanas Ethernet

    Directory of Open Access Journals (Sweden)

    Omar Álvarez

    2007-11-01

    Full Text Available Los sistemas de control de acceso (ACS permiten apoyar las soluciones actuales de Calidad de Servicio. Éstos consideran entre sus variables el retardo, variación de retardo, pérdida de paquetes o una combinación para asegurar los requerimientos de calidad de servicio para sesiones de voz y video. Proponemos un ACS basado en la pérdida de paquetes de prueba extremo a extremo para la decisión de aceptar nuevas sesiones. La red de transporte será la familia Ethernet, la cual ha incursionado de manera importante en los ámbitos metropolitanos (802.3ae. El presente trabajo muestra la interoperatividad y ventajas de ME-ACS con MPLS./ The access control systems (ACS are useful to improve the Quality of Service solutions. These systems are generally based on delay, jitter or packet loss, employing more of these criteria to maintain the required quality of service requiring for voice or video sessions. We propose an ACS that employs packet loss between probes that send an end-to-end test stream before accepting additional sessions. We used Ethernet as our transport network because the 803.3ae is widely used in metropolitan area networks. This paper presents how the ACS will interoperate with MPLS and describe the improvements related to its use in a metropolitan Ethernet network.

  1. A New Solution of Multicast Packets Management for Managed Ethernet Switch

    Directory of Open Access Journals (Sweden)

    Sheng LU

    2012-12-01

    Full Text Available This paper has a discussion on the new solution of IGMP management for multicast message in industrial Ethernet. It proposed a new mechanism to minimize the congestion which is based on the taking an adaptive decision during transferring multicast messages. Proposed approach is that a device requesting to start and stop the reception of the multicast streams is accomplished through IGMP join and Leave message requests. Quality of Service (QOS as a component is supported by the Switch Manager as well as features built into the micro chip. The IGMP Snooping component monitors (snoops these join and leave messages to allow it to know which streams to prune from which ports. it is a service provided by most managed Ethernet switches. However, the ICIE (Intelligent Controller for Industrial Ethernet does not provide this capability and requires that another device in the network supports the querier functionality. It is through the external devices solicitation of join messages that allow the IGMP Snooping component to correctly decipher on which ports the downstream listeners are connected.

  2. Design and implementation of digital television over ethernet PON transmission system

    Science.gov (United States)

    Lu, Xi; Liu, Deming; Mao, Minjing; Wang, Jinjuan

    2005-11-01

    There are two primary methods of transmitting signal of digital television to the home in China. The first one is HFC mode, which is widely used. The other is IPTV mode, which is emerging. In this paper, the scheme of digital television over Ethernet PON is proposed. There are several differences from this system to IPTV and Video over LAN: the real-time transmission of equal-bandwidth based on statistical multiplexing, channel switching based on multicast and IP CA system, etc.. And these are also the key techniques used in this system. The architecture of DTV over EPON system, the function of every component, the framing process and the multiplexing of Ethernet frame are described. The implementation procedure of the system is shown. The mechanism of channel switching using multicast technique is designed and realized. We also present the method of using static VLAN and IGMP snooping mechanism to implement statistical multiplexing on Ethernet layer, and put forward the concept of IP Conditional Access System and define it. An experimental system of DTV over EPON is set up and the experimental result is significant.

  3. A Data Transmission Method Based on Ethernet Physical Layer for Particle Physics Experiment

    CERN Document Server

    Xi-Ru, Huang; Jia-Jun, Zheng

    2015-01-01

    Due to the advantages of universality, flexibility and high performance, fast Ethernet is widely used in readout system design of modern particle physics experiments. However, Ethernet is usually used together with TCP/IP protocol stack, which makes it difficult to be implemented because designers have to use operating system to process this protocol. Furthermore, TCP/IP protocol degrades the transmission efficiency and real-time performance. To maximize the performance of Ethernet in physics experiment applications, a data readout method based on physical layer (PHY) is proposed in this paper. In this method, TCP/IP protocol is forsaken and replaced with a customized and simple protocol, which make it easier to be implemented. On each readout module, data from front-end electronics is first fed into an FPGA for protocol processing and then sent out to a PHY chip controlled by this FPGA for transmission. This kind of data path is fully implemented by hardware. While from the side of data acquisition system (D...

  4. Ethernet-based mobility architecture for 5G

    DEFF Research Database (Denmark)

    Cattoni, Andrea Fabio; Mogensen, Preben; Vesterinen, Seppo

    2014-01-01

    of mobile devices and sensors. In this paper we propose a paradigm shift for the evolved Packet Core for the future 5G system. By leveraging on the economy of scale of software–based ICT technologies, namely Software Defined Networking and cloud computing, we propose a hierarchically cloudified mobile...

  5. Design and Implementation of WiFi Based Power Regulation System%WiFi控制的功率调节系统设计与实现

    Institute of Scientific and Technical Information of China (English)

    李俐萍; 陈金鹰; 孙宇; 魏万迎

    2014-01-01

    针对目前接触式电源开关存在的问题,在对WiFi技术进行研究的基础上,提出了一种基于Android手机和WiFi的遥控电源开关实现方案。通过对负载功率相关要素的分析,采用受WiFi无线模块控制的PWM信号来改变可控硅导通角的大小,从而利用具有Android操作系统的手机,实现对负载的通断控制和输出功率大小的控制。测试结果表明该方案达到预定要求。%Aiming at the problems existing in contact type switches of power supply, on the basis of researching WiFi technology, the implementing scheme based on mobile phone and WiFi for remote control switch of power supply is proposed. Through analyzing the relevant essential factors about the load power, by using pulse-width modulator( PWM) signal controlled by WiFi wireless module, the conduction angle of silicon controlled rectifier( SCR) can be changed, thus the ON/OFF control of the load and the control for amount of output power can be realized by adopting the mobile phone with Android operating system. The test result shows that this scheme reaches predetermined requirements.

  6. 矿用低功耗Wi—Fi移动终端设计%Design of Mining Low-power Wi-Fi Mobile Terminal

    Institute of Scientific and Technical Information of China (English)

    张科帆

    2012-01-01

    采用低功耗的Cortex—MO内核处理器作为嵌入式开发平台的微处理器,设计了基于Wi—Fi技术的矿用移动终端。在软件设计上,根据应用和实时任务要求进行工作模式切换,在完成Wi—Fi数据传输功能的同时,有效地降低了终端的系统功耗。重点分析了Wi-Fi移动终端的软硬件设计思路,尤其是在降低功耗上采取的措施。最后,给出了终端传输功能和功耗的实际测试结果。%Using low-power Cortex-M0 core processor as the microprocessor of embedded development platform, a mining mobile termi- nal based on Wi-Fi technology is designed. In the software design, the system switches operating modes according to the requirements of applications and real-time tasks, realizes Wi-Fi data transmission function and at the same time effectively reduces power consumption of the terminal. This paper focuses on the hardware and software design ideas of the Wi-Fi mobile terminal, especially the measures of re-ducing power consumption. The actual test results of data transmission function and power consumption are given in the end.

  7. 基于直接连接的无线投影网关的研究与设计%Research and design of wireless projector gateway on Wi-Fi Direct

    Institute of Scientific and Technical Information of China (English)

    吴鹏展; 龙昭华; 张林

    2013-01-01

    Wi-Fi Direct是Wi-Fi联盟新推出的一项无线局域网认证商标,它可使无线设备在无AP时直接建立连接.为解决现有投影仪因需通过线缆传输数据而给用户的使用带来不便的问题,在分析Wi-Fi Direct技术的基础上,设计了无线投影网关嵌入式系统,并采用H.264编码技术及多进程设计方法来分别解决大数据量传输及多用户投影切换问题,从而使无线设备与投影仪的连接摆脱了线缆的束缚.经测试,该无线投影网关系统可给用户带来了极大的便利.%Wi-Fi Direct is a new WLAN certification trademark of Wi-Fi Alliance,it will enable Wi-Fi devices to connect directly without AP.To solve the existing projector for transmission of data through the cable to the inconvenience to the customer,on the basis of the analysis of Wi-Fi Direct technology,a new wireless projection gateway embedded system is designed,which using the H.264 encoding technology and multi-process design method to solve the problem of large amounts of data translation and users switching,allowing the wireless device and the projector connected to get rid of the shackles of cable.The test show,that great convenience to users is brought.

  8. FPGA-based 10-Gbit Ethernet Data Acquisition Interface for the Upgraded Electronics of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Grohs, J P; The ATLAS collaboration

    2013-01-01

    The readout of the trigger signals of the ATLAS Liquid Argon (LAr) calorimeters is foreseen to be upgraded in order to prepare for operation during the first high-luminosity phase of the Large Hadron Collider (LHC). Signals with improved spatial granularity are planned to be received from the detector by a Digitial Processing System (DPS) in ATCA technology and will be sent in real-time to the ATLAS trigger system using custom optical links. These data are also sampled by the DPS for monitoring and will be read out by the regular Data Acquisition (DAQ) system of ATLAS which is a network-based PC-farm. The bandwidth between DPS module and DAQ system is expected to be in the order of 10 Gbit/s per module and a standard Ethernet protocol is foreseen to be used. DSP data will be prepared and sent by a modern FPGA either through a switch or directly to a Read-Out System (ROS) PC serving as buffer interface of the ATLAS DAQ. In a prototype setup, an ATCA blade equipped with a Xilinx Virtex-5 FPGA is used to send da...

  9. A 0.18 μm CMOS transmit physical coding sublayer IC for 100G Ethernet

    Science.gov (United States)

    Weihua, Ruan; Qingsheng, Hu

    2016-03-01

    This paper presents a transmit physical coding sublayer (PCS) circuit for 100G Ethernet. Based on the 4 × 25 Gb/s architecture according to the IEEE P802.3ba and IEEE P802.3bmTM/D1.1 standards, this PCS circuit is designed using a semi-custom design method and consists of 4 modules including 64B/66B encoder, scrambler, multiple lanes distribution and 66 : 8 gearbox. By using the pipeline structure and several optimization techniques, the working speed of the circuit is increased significantly. The parallel scrambling combined with logic optimization also improve the performance. In addition, a kind of phase-independent structure is employed in the design of the gearbox to ensure it can work stably and reliably at high frequency. This PCS circuit has been fabricated based on 0.18 μm CMOS technology and the total area is 1.7 × 1.7 mm2. Measured results show that the circuit can work properly at 100 Gb/s and the power consumption is about 284 mW with a 1.8 V supply. Project supported by the National Natural Science Foundation of China (No. 6504000129) and the National Basic Research Program of China (No. 6504000052).

  10. A novel particle filter approach for indoor positioning by fusing WiFi and inertial sensors

    Institute of Scientific and Technical Information of China (English)

    Zhu Nan; Zhao Hongbo; Feng Wenquan; Wang Zulin

    2015-01-01

    WiFi fingerprinting is the method of recording WiFi signal strength from access points (AP) along with the positions at which they were recorded, and later matching those to new mea-surements for indoor positioning. Inertial positioning utilizes the accelerometer and gyroscopes for pedestrian positioning. However, both methods have their limitations, such as the WiFi fluctuations and the accumulative error of inertial sensors. Usually, the filtering method is used for integrating the two approaches to achieve better location accuracy. In the real environments, especially in the indoor field, the APs could be sparse and short range. To overcome the limitations, a novel particle filter approach based on Rao Blackwellized particle filter (RBPF) is presented in this paper. The indoor environment is divided into several local maps, which are assumed to be independent of each other. The local areas are estimated by the local particle filter, whereas the global areas are com-bined by the global particle filter. The algorithm has been investigated by real field trials using a WiFi tablet on hand with an inertial sensor on foot. It could be concluded that the proposed method reduces the complexity of the positioning algorithm obviously, as well as offers a significant improvement in position accuracy compared to other conventional algorithms, allowing indoor positioning error below 1.2 m.

  11. An investigation of scalable anomaly detection techniques for a large network of Wi-Fi hotspots

    CSIR Research Space (South Africa)

    Machaka, P

    2015-01-01

    Full Text Available The paper seeks to investigate the use of scalable machine learning techniques to address anomaly detection problem in a large Wi-Fi network. This was in the efforts of achieving a highly scalable preemptive monitoring tool for wireless networks...

  12. A novel particle filter approach for indoor positioning by fusing WiFi and inertial sensors

    Directory of Open Access Journals (Sweden)

    Zhu Nan

    2015-12-01

    Full Text Available WiFi fingerprinting is the method of recording WiFi signal strength from access points (AP along with the positions at which they were recorded, and later matching those to new measurements for indoor positioning. Inertial positioning utilizes the accelerometer and gyroscopes for pedestrian positioning. However, both methods have their limitations, such as the WiFi fluctuations and the accumulative error of inertial sensors. Usually, the filtering method is used for integrating the two approaches to achieve better location accuracy. In the real environments, especially in the indoor field, the APs could be sparse and short range. To overcome the limitations, a novel particle filter approach based on Rao Blackwellized particle filter (RBPF is presented in this paper. The indoor environment is divided into several local maps, which are assumed to be independent of each other. The local areas are estimated by the local particle filter, whereas the global areas are combined by the global particle filter. The algorithm has been investigated by real field trials using a WiFi tablet on hand with an inertial sensor on foot. It could be concluded that the proposed method reduces the complexity of the positioning algorithm obviously, as well as offers a significant improvement in position accuracy compared to other conventional algorithms, allowing indoor positioning error below 1.2 m.

  13. Insecure Network, Unknown Connection: Understanding Wi-Fi Privacy Assumptions of Mobile Device Users

    Directory of Open Access Journals (Sweden)

    Bram Bonné

    2017-07-01

    Full Text Available Smartphones and other mobile devices have proliferated in the past five years. The expectation of mobile device users to always be online has led to Wi-Fi networks being offered by a variety of providers. Using these networks introduces multiple security risks. In this work, we assess to what extent the privacy stance of mobile device users corresponds with their actual behavior by conducting a study with 108 participants. Our methodology consists of monitoring Wi-Fi networks that the participants’ devices connect to and the connections made by apps on these devices, for a period of 30 days. Afterwards, participants are surveyed about their awareness and privacy sensitiveness. We show that while a higher expertise in computer networks corresponds to more awareness about the connections made by apps, neither this expertise nor the actual privacy stance of the participant translates to better security habits. Moreover, participants in general were unaware about a significant part of connections made by apps on their devices, a matter that is worsened by the fact that one third of Wi-Fi networks that participants connect to do not have any security enabled. Based on our results, we provide recommendations to network providers, developers and users on how to improve Wi-Fi security for mobile devices.

  14. Mobile Sensing of Pedestrian Flocks in Indoor Environments using WiFi Signals

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Wirz, Martin; Roggen, Daniel

    2012-01-01

    a cohesive whole - specifically flocks - with clustering approaches operating on three different feature sets derived from WiFi signals which are comparatively analysed. Automatic detection of flocks has several important applications, including social and psychological sensing and emergency research studies...

  15. Friend-to-friend short message service with opportunistic Wi-Fi beacons

    NARCIS (Netherlands)

    Türkes, Okan; Scholten, Johan; Havinga, Paul J.M.

    2016-01-01

    This study introduces Oppline, an ad hoc opportunistic short message service that can be collaboratively used by everyone who has a smart mobile device. The data exchange method of Oppline is built on top of the universal Wi-Fi standard, thus expedites platform-independent integration of related

  16. Calculation of radio energy of Wi-fi signal in the railway coach

    Directory of Open Access Journals (Sweden)

    A. A. Bezgin

    2013-09-01

    Full Text Available Introduction. Access to the Internet through mobile networks 3G, compared with other systems, has considerably lower cost of the implementation, and the best speed characteristics that makes its use more efficient. Modern Wi-Fi router has multiple USB ports that enable to connect the additional 3G modems directly to them. The main part. For the organization of the wireless Internet access in the railway transport it is necessary to use Wi-Fi network in the rail coach. Users will connect to this network. To install the equipment we calculate radio energy of the channel. The level of Wi-Fi signal power increases by using several antennas spaced on the rail coach. The optimal distance between the outer antennas for standard rail coaches is 7 meters. In this case the minimum level of power in the free space is -35 dB. The operation of any user’s devices will be stable with such a high signal level. The calculations take into account the effect of the iron walls of the rail coaches, interference and loss RF cable. Conclusions. Calculation power of Wi-Fi signal is performed in a railway coach.

  17. PILA: Sub-Meter Localization Using CSI from Commodity Wi-Fi Devices

    Directory of Open Access Journals (Sweden)

    Zengshan Tian

    2016-10-01

    Full Text Available The aim of this paper is to present a new indoor localization approach by employing the Angle-of-arrival (AOA and Received Signal Strength (RSS measurements in Wi-Fi network. To achieve this goal, we first collect the Channel State Information (CSI by using the commodity Wi-Fi devices with our designed three antennas to estimate the AOA of Wi-Fi signal. Second, we propose a direct path identification algorithm to obtain the direct signal path for the sake of reducing the interference of multipath effect on the AOA estimation. Third, we construct a new objective function to solve the localization problem by integrating the AOA and RSS information. Although the localization problem is non-convex, we use the Second-order Cone Programming (SOCP relaxation approach to transform it into a convex problem. Finally, the effectiveness of our approach is verified based on the prototype implementation by using the commodity Wi-Fi devices. The experimental results show that our approach can achieve the median error 0.7 m in the actual indoor environment.

  18. TCP Performance over Wi-Fi: Joint Impact of Buffer and Channel Losses

    NARCIS (Netherlands)

    Pokhrel, S.R.; Panda, M.; Vu, H.L.; Mandjes, M.

    2016-01-01

    We propose an analytical model for a Wi-Fi network acting as a last-mile Internet access with multiple long-lived TCP connections on both the up and down links. Our model considers the joint impact of buffer losses at the access point, contention at the medium access control layer, and packet losses

  19. 基于WiFi的楼宇环境监测系统%Building environmental monitoring system based on WiFi

    Institute of Scientific and Technical Information of China (English)

    张秀再; 范江棋; 陈彭鑫; 吴华娟; 赵益波

    2016-01-01

    A building environmental monitoring system based on WiFi technology was designed for monitoring of tempera⁃ture,humidity,natural gas,coal gas and air pressure in the building. The system is composed of monitoring center and monitoring node to realize data transmission between them through WiFi. The monitoring node is composed of STM32 MCU,temperature and humidity sensor,combustible gas sensor,air pressure sensor,and WiFi module. The detected data is transferred to the STM32 MCU through the three sensors,and transmitted to the monitoring center through the WiFi module to realize the real⁃time monitoring of the building environment. The system has detection performance of diverse targets and strong expansibility, and is suitable for building environmental detection.%在此设计基于WiFi技术的楼宇环境监测系统,用于监测楼宇内温湿度、天然气、煤气和气压监测。系统分为监测中心和监测节点,监测中心与监测节点之间通过WiFi实现数据传输。监测节点由STM32单片机、温湿度传感器、可燃气体传感器、气压传感器和WiFi模块组成,3个传感器把检测的数据传到STM32单片机中,然后STM32单片机通过WiFi模块把检测数据传输到监测中心,从而实现对楼宇环境的实时监测。该系统检测目标多样且扩充性强,适用于楼宇环境检测,具有一定的实际意义。

  20. An Ethernet LAN based distributed generation system load shedding strategy

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2011-01-01

    This paper firstly analyzes and compares various communication technologies, and proposes a communication system for a distributed generation system (DGS) with wind turbines. Then the paper presents a novel simulation method of considering the interactions between the communication system and power...... system, by using two software platforms: OPNET and EMTDC/PSCAD. A control method based on the communication technique has been designed to stabilize the DG system during power system disturbances. A case study is presented to demonstrate the effectiveness of the proposed communication system, simulation...... method and control strategy....

  1. Supporting Multi-hop Device-to-Device Networks Through WiFi Direct Multi-group Networking

    OpenAIRE

    Funai, Colin; Tapparello, Cristiano; Heinzelman, Wendi

    2015-01-01

    With the increasing availability of mobile devices that natively support Device-to-Device (D2D) communication protocols, we are presented with a unique opportunity to realize large scale ad hoc wireless networks. Recently, a novel D2D protocol named WiFi Direct has been proposed and standardized by the WiFi Alliance with the objective of facilitating the interconnection of nearby devices. However, WiFi Direct has been designed following a client-server hierarchical architecture, where a singl...

  2. A Wi-Fi Union Mechanism for Internet Advertising Reciprocal Platform in Microenterprises

    Directory of Open Access Journals (Sweden)

    Thi Thanh An Nguyen

    2017-07-01

    Full Text Available With the evolution of the Internet and smartphone devices, Internet advertising has become one of the most important methods for delivering promotional marketing messages to customers. However, the efficiency of Internet advertising for microenterprise is not very high, since Wi-Fi advertising—which is limited by a small router coverage area—is mainly used. Moreover, because of the lack of money, microenterprises have been using low-cost methods to promote their products. Thus, enhancing the effectiveness of Wi-Fi advertising, and solving the problem of cost and the range of the views are now an essential investigation in this study. In this paper, we propose a reciprocal model with Wi-Fi union mechanism for Internet advertising based on fog computing architecture to enhance the efficiency of advertisement, reduce the cost, and increase the range of the views for microenterprise by using the Internet. In particular, the system was built in advertisers’, publishers’, and consumers’ sides. In our system, we use contribution point (CP as an exchange value among the participants. Advertisers and publishers can get CP by helping the others in the system to promote their advertisements, increasing their CP by one unit. Similarly, advertisers and publishers can use their CP to ask for assistance from the others, decreasing their CP by one unit. The result shows that the system in a Wi-Fi union is easy to use, and advertisements can be seen by all customers who are using free Wi-Fi from the stores of the union. This method can solve the problem of cost and fixed consumer groups.

  3. A Wi-Fi Union Mechanism for Internet Advertising Reciprocal Platform in Microenterprises.

    Science.gov (United States)

    Nguyen, Thi Thanh An; Chang, Che-Pin; Yuan, Shyan-Ming

    2017-07-13

    With the evolution of the Internet and smartphone devices, Internet advertising has become one of the most important methods for delivering promotional marketing messages to customers. However, the efficiency of Internet advertising for microenterprise is not very high, since Wi-Fi advertising-which is limited by a small router coverage area-is mainly used. Moreover, because of the lack of money, microenterprises have been using low-cost methods to promote their products. Thus, enhancing the effectiveness of Wi-Fi advertising, and solving the problem of cost and the range of the views are now an essential investigation in this study. In this paper, we propose a reciprocal model with Wi-Fi union mechanism for Internet advertising based on fog computing architecture to enhance the efficiency of advertisement, reduce the cost, and increase the range of the views for microenterprise by using the Internet. In particular, the system was built in advertisers', publishers', and consumers' sides. In our system, we use contribution point (CP) as an exchange value among the participants. Advertisers and publishers can get CP by helping the others in the system to promote their advertisements, increasing their CP by one unit. Similarly, advertisers and publishers can use their CP to ask for assistance from the others, decreasing their CP by one unit. The result shows that the system in a Wi-Fi union is easy to use, and advertisements can be seen by all customers who are using free Wi-Fi from the stores of the union. This method can solve the problem of cost and fixed consumer groups.

  4. A Framework for Optimizing IP over Ethernet Naming System

    Directory of Open Access Journals (Sweden)

    Waleed Alzubaidi

    2012-11-01

    Full Text Available Due to the rapid expansion of the technology field. Developing the Internet has become more urgent to meet the needs of the expansion. TCP/IP is the most protocol used in the Internet. It consists from layers, Each layer done its job separately. However these layers susceptible to different attacks and data link layer one of the most layers targeted by attacker, Attack at lower layer may lead to more sophisticated attacks to upper layers like Man in The Middle (MiTM, DNS spoofing and Denial of Service (DoS. Even with encrypted protocols such as HTTPS and SSL. In this paper we discuss security at the Data Link Layer and the attacks depend on the Address resolution protocol (ARP. Moreover proposed an approach to prevent address resolution protocol attacks, finally, we conclude at section 5.

  5. 嵌入式WI-FI路由网关的实现%Realization and Analysis of Embedded WI-FI Route Gateway

    Institute of Scientific and Technical Information of China (English)

    黄乔勇; 刘云; 张晓萌

    2011-01-01

    设计了一种WI-FI路由网关,使用的模式为点对点模式,即Ad-Hoc模式。在无线网卡上添加了基于最小负载路径优先的Ah-Hoc路由协议,结合嵌入式Linux系统实现WI-FI路由网关。对网关的性能进行分析,根据分析结果得出网关的性能在设定场景中的可行性与有效性。%WI-FI technology has advantages of wide coverage,transmission speed,implementation of low cost.Mainly it is used for wireless data communications,and is a universal network interface.It has two kinds of communication mode,one is basic mode,and another is peer-to-peer namely Ad-Hoc mode.The paper designed a WI-FI route gateway used in point to point mode or Ad-Hoc mode added in wireless card based on least load path first Ad-Hoc routing protocols,and combined embedded Linux system to realize the WI-FI route gateway,and analyzed the performance of the gateway.The analysis results showed that the gateway performance owned the feasibility and effectiveness in setting scene.

  6. 基于 WiFi 网络的可视化遥控搬运机器人设计%Design of Visual Remote Control Handl ing Robot Based on WiFi Network

    Institute of Scientific and Technical Information of China (English)

    杨军

    2014-01-01

    Visualization of wireless remote control handling robot based on WiFi network can collect the data by the sensor installed in the robot,and then transmits the real-time video image through WiFi wireless network.Using WiFi network communication makes the con-trol ends varied,you can use cellphone or computer and so on which has WiFi function.In addition,robot can be connected to the Internet to realize longer distance control.This design transplants the Linux operating system on S3C6410 platform to receive commands and con-trol hardware devices,including MJPGstreamer as the video server and BOA as the WEB server.%基于 WiFi 网络的可视化无线遥控搬运机器人,通过机器人安装的传感器实现数据采集,利用 WiFi 网络高速传输实时视频图像。采用 WiFi 网络通信可使控制端多样化,可用手机、电脑等具备 WiFi 功能的设备进行控制,此外,还可将机器人接入 Internet 实现更远距离的控制。本设计在 S3C6410平台上移植了 Linux 操作系统,用于接收命令并对硬件设备进行控制,其中移植了 MJPGstreamer 作为视频服务器,BOA 作为 WEB 服务器。

  7. 100G Ethernet in the wild - first experiences

    Science.gov (United States)

    Hoeft, Bruno; Stoy, Robert; Schröder, Frank; Reymund, Aurelie; Niederberger, Ralf; Mextorf, Olaf; Werner, Sabine

    2011-12-01

    A 100 Gigabit Testbed was established in a collaboration of 6 partners. Three industry partners have contributed the fiber infrastructure, the DWDM equipment, as well as the required routers. 447 kilometer was the distance of the wide area testbed established in collaboration with the German NREN DFN between Karlsruhe Institute of Technology and Forschungszentrum Jülich Before starting, DFN assured the quality of the fiber infrastructure, the operation of the DWDM systems at both locations, as well as the connection of the routers to this WAN link with a bandwidth of 100GE. 12*10GE interfaces were available at each site for connecting the local testnodes to the routers. A monitoring and measurement framework was installed for recording the most important IP network performance metrics, among them the One Way Delay (OWD) and its Variation, Packet Loss and Packet Reordering. The delay measurements were conducted between the GPS time synchronized Hades[1]measurement nodes at each location. Additionally all relevant counters at the routers have been recorded using a SNMP based Network Manangement Station and supplemented special command line interface output gathering and parsing scripts. The interfaces statistics were stored in 60 second intervals. The aim of the testbed was to demonstrate a failure-free transmission of one or more IP datastreams over 100GE during the whole period of 4 weeks.This included the evaluation of the 100 Gbit/s optical transmission system, the 100GE interfaces between the routers and the optical system, and the evaluation of a sustained 100GE transmission as well as the evaluation of the use of 100GE in a production like environment. The evaluation included a circulated (in a routing loop) tunable load between 1 and 100 Gbit/s, measurement of transmission quality of TCP and UDP datastreams between the endsystems, measurements of one way latency, a ramping up data transmission from approx. 8 Gbit/s up to 96 Gbit/s.

  8. A data transmission method for particle physics experiments based on Ethernet physical layer

    Science.gov (United States)

    Huang, Xi-Ru; Cao, Ping; Zheng, Jia-Jun

    2015-11-01

    Due to its advantages of universality, flexibility and high performance, fast Ethernet is widely used in readout system design for modern particle physics experiments. However, Ethernet is usually used together with the TCP/IP protocol stack, which makes it difficult to implement readout systems because designers have to use the operating system to process this protocol. Furthermore, TCP/IP degrades the transmission efficiency and real-time performance. To maximize the performance of Ethernet in physics experiment applications, a data readout method based on the physical layer (PHY) is proposed. In this method, TCP/IP is replaced with a customized and simple protocol, which makes it easier to implement. On each readout module, data from the front-end electronics is first fed into an FPGA for protocol processing and then sent out to a PHY chip controlled by this FPGA for transmission. This kind of data path is fully implemented by hardware. From the side of the data acquisition system (DAQ), however, the absence of a standard protocol causes problems for the network related applications. To solve this problem, in the operating system kernel space, data received by the network interface card is redirected from the traditional flow to a specified memory space by a customized program. This memory space can easily be accessed by applications in user space. For the purpose of verification, a prototype system has been designed and implemented. Preliminary test results show that this method can meet the requirements of data transmission from the readout module to the DAQ with an efficient and simple manner. Supported by National Natural Science Foundation of China (11005107) and Independent Projects of State Key Laboratory of Particle Detection and Electronics (201301)

  9. Optical local area network emulations over Ethernet passive optical networks: A survey

    Institute of Scientific and Technical Information of China (English)

    PENG YunFeng; KUANG YuJun; LONG KePing

    2008-01-01

    As a promising solution to efficiently achieving fiber to the home (FTTH), Ethernet passive optical network (EPON) is currently improved to provide intercommunica-tion among customers, together with normal traffic delivery, via optical local area network emulation. It is a new research direction and expected to enhance the normal EPON performances. The purpose of this article is to review the state-of-the-art solutions to emulating optical local area networks (OLANs) over EPON. We discuss the major problems involved, e.g., network architecture, control mecha-nisms, and other potential enhancements. We also outline areas for future re-searches.

  10. Control PID de un secador mediante autómatas programables conectados por ethernet

    OpenAIRE

    Carrillo Valencia, Víctor

    2012-01-01

    Este proyecto final de carrera se centra en el control PID de temperatura de un secador convencional mediante autómatas programables conectados por Ethernet. Se busca con ello la configuración de un red de comunicaciones entre dos PLC’s industriales (Programmable Logic Controller en sus siglas en inglés) y el control de temperatura mediante un controlador PID. Los controladores lógicos programables o PLC’s son dispositivos electrónicos muy usados en automatización industrial...

  11. Control PID de un secador mediante autómatas programables conectados por ethernet

    OpenAIRE

    Carrillo Valencia, Víctor

    2012-01-01

    Este proyecto final de carrera se centra en el control PID de temperatura de un secador convencional mediante autómatas programables conectados por Ethernet. Se busca con ello la configuración de un red de comunicaciones entre dos PLC’s industriales (Programmable Logic Controller en sus siglas en inglés) y el control de temperatura mediante un controlador PID. Los controladores lógicos programables o PLC’s son dispositivos electrónicos muy usados en automatización industrial...

  12. Reliability of datagram transmission on Gigabit Ethernet at full link load

    CERN Document Server

    Barczyk, A; Dufey, J P; Galli, D; Jost, B; Marconi, U; Neufeld, N; Peco, G; Vagnoni, V M

    2004-01-01

    The reliability of datagram transmission over Copper Gigabit Ethernet using commodity hardware at sustained Gb/s rate is crucial for the functioning of the software trigger layers of the LHCb experiment. We aim to demonstrate that a nowadays available high-end commodity PC can be employed to achieve the required network performance, in particular to implement a sub-farm controller node. To evaluate all components ranging from the physical medium up to the operating system running on the sub-farm controllers, several issues are addressed, such as transmission error rate, packet drop in switching hardware, protocol handling on reception.

  13. Case study of mission-critical smart grid remedial action schemes via Ethernet

    Energy Technology Data Exchange (ETDEWEB)

    Dolezilek, David

    2010-09-15

    At Southern California Edison (SCE), RAS systems are implemented to mitigate thermal overloads and system instability upon the loss of one or more transmission lines. RAS automatic protection eliminates expensive alternative measures, including reconductoring transmission lines, building new lines, and/or adding new transformers. SCE has demonstrated successful use of IEC 61850 GOOSE messages over distances up to 460 miles to collect analysis and arming data and transfer status and control indications. This paper explains methods to perform mission-critical RAS and other smart grid actions via nondeterministic bandwidth sharing Ethernet being promoted to move smart grid information.

  14. Performance evaluation of 10GBASE optical transceivers for Cisco 10-gigabit Ethernet switching architecture

    Science.gov (United States)

    Zhang, Xiaojing; Cain, Jeff C.

    2002-09-01

    This paper presents the process and methodology employed to perform evaluation and analyses for the optical interface that delivers and receives 10Gb/s Ethernet traffic on Cisco's industrial leading switching architecture. Especially, we examined in detail the optical properties for commercially available 10GBASE-LR transceiver modules, with respect to IEEE 802.3ae specifications. The sampled results under room temperature are listed for comparison. Eye diagrams were recorded as a function of transmission distance, as well as temperature variation. System stability issues are also studied following a brief introduction to Cisco standard ODVT (Optical Design Verification Test) procedure.

  15. Evaluating Opportunistic Delivery of Large Content with TCP over WiFi in I2V Communication

    OpenAIRE

    Mukherjee, Shreyasee; Su, Kai; Mandayam, Narayan B.; Ramakrishnan, K. K.; Raychaudhuri, Dipankar; Seskar, Ivan

    2014-01-01

    With the increasing interest in connected vehicles, it is useful to evaluate the capability of delivering large content over a WiFi infrastructure to vehicles. The throughput achieved over WiFi channels can be highly variable and also rapidly degrades as the distance from the access point increases. While this behavior is well understood at the data link layer, the interactions across the various protocol layers (data link and up through the transport layer) and the effect of mobility may red...

  16. Návrh rozšíření WiFi sítě

    OpenAIRE

    Zahradník, Tomáš

    2008-01-01

    Tato bakalářská práce se zabývá rozsáhlou WiFi sítí společnosti VIVO CONNECTION s.r.o. a návrhem jejího rozšíření. The Bachelor work deals with the project of WiFi network expansion for VIVO CONNECTION s.r.o. company. B

  17. Simultaneous transmission of the IEEE 802.11 radio signal and optical Gbit Ethernet over the multimode fiber link

    Science.gov (United States)

    Maksymiuk, L.; Podziewski, A.

    2015-09-01

    In the paper we present a successful joint transmission of the IEEE 802.11 signal and an optical Gbit Ethernet over a multimode fiber based link. Most importantly, the multiplexation of both signals was performed in the optical domain. Due to the utilization of the multimode fiber the OBI noise was avoided and both channels were able to operate at the same wavelength. We prove that potential RoF link for IEEE 802.11 signal distribution may be used to additionally transmit other signals as Gbit Ethernet and therefore utilize the fiber infrastructure installed more effectively. The qualities of both the IEEE 802.11 and Ethernet transmissions fulfilled the requirements imposed by appropriate standards.

  18. The current state of evidence regarding the health effects of wifi communication systems Sistemas de comunicación wifi y efectos sobre la salud. El estado de las evidencias actuales Sistemas de comunicação wifi e efeitos na saúde: O estado atual da evidência

    National Research Council Canada - National Science Library

    Francisco Vargas Marcos

    2012-01-01

    ...) emitted by wifi telecommunication systems. These reports have generated demands for information, which the relevant environmental health authorities have to deal with in a transparent, clear and effective way, based on current scientific evidence...

  19. Effects of acute exposure to WIFI signals (2.45GHz) on heart variability and blood pressure in Albinos rabbit.

    Science.gov (United States)

    Saili, Linda; Hanini, Amel; Smirani, Chiraz; Azzouz, Ines; Azzouz, Amina; Sakly, Mohsen; Abdelmelek, Hafedh; Bouslama, Zihad

    2015-09-01

    Electrocardiogram and arterial pressure measurements were studied under acute exposures to WIFI (2.45GHz) during one hour in adult male rabbits. Antennas of WIFI were placed at 25cm at the right side near the heart. Acute exposure of rabbits to WIFI increased heart frequency (+22%) and arterial blood pressure (+14%). Moreover, analysis of ECG revealed that WIFI induced a combined increase of PR and QT intervals. By contrast, the same exposure failed to alter maximum amplitude and P waves. After intravenously injection of dopamine (0.50ml/kg) and epinephrine (0.50ml/kg) under acute exposure to RF we found that, WIFI alter catecholamines (dopamine, epinephrine) action on heart variability and blood pressure compared to control. These results suggest for the first time, as far as we know, that exposure to WIFI affect heart rhythm, blood pressure, and catecholamines efficacy on cardiovascular system; indicating that radiofrequency can act directly and/or indirectly on cardiovascular system.

  20. Fast optical channel recovery in field demonstration of 100-Gbit/s Ethernet over OTN using real-time DSP.

    Science.gov (United States)

    Yamazaki, Etsushi; Yamanaka, Shogo; Kisaka, Yoshiaki; Nakagawa, Tadao; Murata, Koichi; Yoshida, Eiji; Sakano, Toshikazu; Tomizawa, Masahito; Miyamoto, Yutaka; Matsuoka, Shinji; Matsui, Junichiro; Shibayama, Atsufumi; Abe, Jun-ichi; Nakamura, Yuichi; Noguchi, Hidemi; Fukuchi, Kiyoshi; Onaka, Hiroshi; Fukumitsu, Katsumi; Komaki, Kousuke; Takeuchi, Osamu; Sakamoto, Yuichiro; Nakashima, Hisao; Mizuochi, Takashi; Kubo, Kazuo; Miyata, Yoshikuni; Nishimoto, Hiroshi; Hirano, Susumu; Onohara, Kiyoshi

    2011-07-04

    A field trial of 100-Gbit/s Ethernet over an optical transport network (OTN) is conducted using a real-time digital coherent signal processor. Error free operation with the Q-margin of 3.2 dB is confirmed at a 100 Gbit/s Ethernet analyzer by concatenating a low-density parity-check code with a OTN framer forward error correction, after 80-ch WDM transmission through 6 spans x 70 km of dispersion shifted fiber without inline-dispersion compensation. Also, the recovery time of 12 msec is observed in an optical route switching experiment, which is achieved through fast chromatic dispersion estimation functionality.

  1. The Design of Passive Optical Networking+Ethernet over Coaxial Cable Access Networking and Video-on-Demand Services Carrying

    Science.gov (United States)

    Ji, Wei

    2013-07-01

    Video on demand is a very attractive service used for entertainment, education, and other purposes. The design of passive optical networking+Ethernet over coaxial cable accessing and a home gateway system is proposed. The network integrates the passive optical networking and Ethernet over coaxial cable to provide high dedicated bandwidth for the metropolitan video-on-demand services. Using digital video broadcasting, IP television protocol, unicasting, and broadcasting mechanisms maximizes the system throughput. The home gateway finishes radio frequency signal receiving and provides three kinds of interfaces for high-definition video, voice, and data, which achieves triple-play and wire/wireless access synchronously.

  2. Crowdsource Based Indoor Localization by Uncalibrated Heterogeneous Wi-Fi Devices

    Directory of Open Access Journals (Sweden)

    Wooseong Kim

    2016-01-01

    Full Text Available Many indoor localization techniques that rely on received signals from Wi-Fi access points have been explored in the last decade. Recently, crowdsourced Wi-Fi fingerprint attracts much attention, which leads to a self-organized localization system avoiding painful survey efforts. However, this participatory approach introduces new challenges with no previously proposed techniques such as heterogeneous devices, short measurement time, and multiple values for a single position. This paper proposes an efficient localization method combating the three major technical issues in the crowdsourcing based systems. We evaluate our indoor positioning method using 5 places with different radio environment and 8 different mobile phones. The experimental results show that the proposed approach provides consistent localization accuracy and outperforms existing localization algorithms.

  3. A comparative analysis of Indoor WiFi Positioning at a large building complex

    DEFF Research Database (Denmark)

    Mathisen, Andreas; Krogh, Søren; Stisen, Allan

    2016-01-01

    Indoor Positioning based on WiFi has received extensive focus from research communities, owing its promises of ubiquitous positioning indoors for a variety of applications. The majority of the existing research on WiFi positioning centers around the improvement of positioning accuracy. However......, as only few experimental evaluations have been reported in such environments. This paper presents a comparative evaluation of several indoor positioning techniques set at a large university hospital spanning 160, 000m2—an environment where several location and context-aware logistic applications...... with implementing and using indoor positioning solutions in a highly diverse environment, in which building types and materials, as well as building use differ across the complex. Correspondingly, the evaluation data we use is gathered at different complex parts, days, and daytimes, and both at static locations...

  4. Communication Network Architectures Based on Ethernet Passive Optical Network for Offshore Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2016-03-01

    Full Text Available Nowadays, with large-scale offshore wind power farms (WPFs becoming a reality, more efforts are needed to maintain a reliable communication network for WPF monitoring. Deployment topologies, redundancy, and network availability are the main items to enhance the communication reliability between wind turbines (WTs and control centers. Traditional communication networks for monitoring and control (i.e., supervisory control and data acquisition (SCADA systems using switched gigabit Ethernet will not be sufficient for the huge amount of data passing through the network. In this paper, the optical power budget, optical path loss, reliability, and network cost of the proposed Ethernet Passive Optical Network (EPON-based communication network for small-size offshore WPFs have been evaluated for five different network architectures. The proposed network model consists of an optical network unit device (ONU deployed on the WT side for collecting data from different internal networks. All ONUs from different WTs are connected to a central optical line terminal (OLT, placed in the control center. There are no active electronic elements used between the ONUs and the OLT, which reduces the costs and complexity of maintenance and deployment. As fiber access networks without any protection are characterized by poor reliability, three different protection schemes have been configured, explained, and discussed. Considering the cost of network components, the total implementation expense of different architectures with, or without, protection have been calculated and compared. The proposed network model can significantly contribute to the communication network architecture for next generation WPFs.

  5. A Multiservice Voice, Data, and Video Network Enabled by Optical Ethernet

    Science.gov (United States)

    Simcoe, Mitchell

    With data now approaching 60% of all aggregate traffic and expected to grow to 90% of all traffic by 2004, networks designed around all-packet architectures are being envisioned. Within this timeframe, a network vision is to deliver voice, video, and data services over a single packet-oriented network. Some entrepreneurial network providers are pursuing this vision in an even earlier timeframe. This article introduces a multiservices voice, data, and multicast video network over an Optical Ethernet architecture for residents of multidwelling units (MDU). This article reviews the network architecture for delivering these services over Optical Ethernet and addresses the challenges of handling service types with different bandwidths and latencies over a common packet-oriented infrastructure. As an example, it addresses the challenge of managing latency-intolerant traffic such as voice over IP over a common architecture as Internet data. Furthermore, it discusses the challenges of delivering over 100 channels of broadcast video as well as video on demand over the same infrastructure.

  6. Přenos informací po síti Ethernet

    OpenAIRE

    Kutílek, Miloš

    2013-01-01

    Tato diplomová práce se zabývá přenosem informací po síti Ethernet. V této práci byl vybrán vhodný mikrokontrolér a komunikační modul, který zajištuje přenos dat z Ethernetu na SPI sběrnici, dále bylo zvoleno optimální digitální teplotní čidlo DS1820. Teoreticky popisuje model TCP/IP a síť typu Ethernet. V práci je vytvořeno blokové schéma zapojení, dále bylo vytvořeno elektrické schéma zapojení a deska plošných spojů. V prostředí BascomAVR je naprogramován program, který slouží pro přenos in...

  7. Modeling and Algorithm for Multiple Spanning Tree Provisioning in Resilient and Load Balanced Ethernet Networks

    Directory of Open Access Journals (Sweden)

    Steven S. W. Lee

    2015-01-01

    Full Text Available We propose a multitree based fast failover scheme for Ethernet networks. In our system, only few spanning trees are used to carry working traffic in the normal state. As a failure happens, the nodes adjacent to the failure redirect traffic to the preplanned backup VLAN trees to realize fast failure recovery. In the proposed scheme, a new leaf constraint is enforced on the backup trees. It enables the network being able to provide 100% survivability against any single link and any single node failure. Besides fast failover, we also take load balancing into consideration. We model an Ethernet network as a twolayered graph and propose an Integer Linear Programming (ILP formulation for the problem. We further propose a heuristic algorithm to provide solutions to large networks. The simulation results show that the proposed scheme can achieve high survivability while maintaining load balancing at the same time. In addition, we have implemented the proposed scheme in an FPGA system. The experimental results show that it takes only few μsec to recover a network failure. This is far beyond the 50 msec requirement used in telecommunication networks for network protection.

  8. Readout electronics for CBM-TOF super module quality evaluation based on 10 Gbps ethernet

    Science.gov (United States)

    Jiang, D.; Cao, P.; Huang, X.; Zheng, J.; Wang, Q.; Li, B.; Li, J.; Liu, S.; An, Q.

    2017-07-01

    The Compressed Baryonic Matter-Time of Flight (CBM-TOF) wall uses high performance of Multi-gap Resistive Plate Chambers (MRPC) assembled in super modules to identify charged particles with high channel density and high measurement precision at high event rate. Electronics meet the challenge for reading data out from a super module at high speed of about 6 Gbps in real time. In this paper, the readout electronics for CBM-TOF super module quality evaluation is proposed based on 10 Gigabit Ethernet. The digitized TOF data from one super module will be concentrated at the front-end electronics residing on the side of the super module and transmitted to an extreme speed readout module (XSRM) housed in the backend crate through the PCI Express (PCIe) protocol via optic channels. Eventually, the XSRM transmits data to the data acquisition (DAQ) system through four 10 Gbps Ethernet ports in real time. This readout structure has advantages of high performance and expansibility. Furthermore, it is easy to operate. Test results on the prototype show that the overall data readout performance for each XSRM can reach up to 28.8 Gbps, which means XSRM can meet the requirement of reading data out from 4 super modules with 1280 channels in real time.

  9. Coexistence of Wi-Fi and heterogeneous small cell networks sharing unlicensed spectrum

    OpenAIRE

    Zhang, H.; Chu, X.; Guo, W; Wang, S.

    2015-01-01

    As two major players in terrestrial wireless communications, Wi-Fi systems and cellular networks have different origins and have largely evolved separately. Motivated by the exponentially increasing wireless data demand, cellular networks are evolving towards a heterogeneous and small cell network architecture, wherein small cells are expected to provide very high capacity. However, due to the limited licensed spectrum for cellular networks, any effort to achieve capacity growth through netwo...

  10. Received Signal Strength Database Interpolation by Kriging for a Wi-Fi Indoor Positioning System.

    Science.gov (United States)

    Jan, Shau-Shiun; Yeh, Shuo-Ju; Liu, Ya-Wen

    2015-08-28

    The main approach for a Wi-Fi indoor positioning system is based on the received signal strength (RSS) measurements, and the fingerprinting method is utilized to determine the user position by matching the RSS values with the pre-surveyed RSS database. To build a RSS fingerprint database is essential for an RSS based indoor positioning system, and building such a RSS fingerprint database requires lots of time and effort. As the range of the indoor environment becomes larger, labor is increased. To provide better indoor positioning services and to reduce the labor required for the establishment of the positioning system at the same time, an indoor positioning system with an appropriate spatial interpolation method is needed. In addition, the advantage of the RSS approach is that the signal strength decays as the transmission distance increases, and this signal propagation characteristic is applied to an interpolated database with the Kriging algorithm in this paper. Using the distribution of reference points (RPs) at measured points, the signal propagation model of the Wi-Fi access point (AP) in the building can be built and expressed as a function. The function, as the spatial structure of the environment, can create the RSS database quickly in different indoor environments. Thus, in this paper, a Wi-Fi indoor positioning system based on the Kriging fingerprinting method is developed. As shown in the experiment results, with a 72.2% probability, the error of the extended RSS database with Kriging is less than 3 dBm compared to the surveyed RSS database. Importantly, the positioning error of the developed Wi-Fi indoor positioning system with Kriging is reduced by 17.9% in average than that without Kriging.

  11. RF Exposure Analysis for Multiple Wi-Fi Devices In Enclosed Environment

    Science.gov (United States)

    Hwu, Shian U.; Rhodes, Bryan A.; deSilva, B. Kanishka; Sham, Catherine C.; Keiser, James R.

    2013-01-01

    Wi-Fi devices operated inside a metallic enclosure have been investigation in the recent years. A motivation for this study is to investigate wave propagation inside an enclosed environment such as elevator, car, aircraft, and spacecraft. There are performances and safety concerned that when the RF transmitters are used in the metallic enclosed environments. In this paper, the field distributions inside a confined room were investigated with multiple portable Wi-Fi devices. Computer simulations were performed using the rigorous computational electromagnetics (CEM). The method of moments (MoM) was used to model the mutual coupling among antennas. The geometrical theory of diffraction (GTD) was applied for the multiple reflections off the ground and walls. The prediction of the field distribution inside such environment is useful for the planning and deployment of a wireless radio and sensor system. Factors that affect the field strengths and distributions of radio waves in confined space were analyzed. The results could be used to evaluate the RF exposure safety in confined environment. By comparing the field distributions for various scenarios, it was observed that the Wi-Fi device counts, spacing and relative locations in the room are important factors in such environments. The RF Keep Out Zone (KOZ), where the electric field strengths exceed the permissible RF exposure limit, could be used to assess the RF human exposure compliance. As shown in this study, it s possible to maximize or minimize field intensity in specific area by arranging the Wi-Fi devices as a function of the relative location and spacing in a calculated manner.

  12. Studying the Impact of LTE-U on Wi-Fi Downlink Performance

    OpenAIRE

    2016-01-01

    International audience; To address the mobile data growth challenges, mobile operators need to access more spectrum resources. LTE in unlicensed spectrum (LTE-U) has been proposed to extend the usual operation of LTE in licensed spectrum to cover also unlicensed spectrum, mainly at 5 GHz band due to its wide spectrum availability. However, this extension poses significant challenges especially regarding the coexistence between LTE-U and legacy systems like Wi-Fi. In case of LTE-U adopts Time-...

  13. Received Signal Strength Database Interpolation by Kriging for a Wi-Fi Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Shau-Shiun Jan

    2015-08-01

    Full Text Available The main approach for a Wi-Fi indoor positioning system is based on the received signal strength (RSS measurements, and the fingerprinting method is utilized to determine the user position by matching the RSS values with the pre-surveyed RSS database. To build a RSS fingerprint database is essential for an RSS based indoor positioning system, and building such a RSS fingerprint database requires lots of time and effort. As the range of the indoor environment becomes larger, labor is increased. To provide better indoor positioning services and to reduce the labor required for the establishment of the positioning system at the same time, an indoor positioning system with an appropriate spatial interpolation method is needed. In addition, the advantage of the RSS approach is that the signal strength decays as the transmission distance increases, and this signal propagation characteristic is applied to an interpolated database with the Kriging algorithm in this paper. Using the distribution of reference points (RPs at measured points, the signal propagation model of the Wi-Fi access point (AP in the building can be built and expressed as a function. The function, as the spatial structure of the environment, can create the RSS database quickly in different indoor environments. Thus, in this paper, a Wi-Fi indoor positioning system based on the Kriging fingerprinting method is developed. As shown in the experiment results, with a 72.2% probability, the error of the extended RSS database with Kriging is less than 3 dBm compared to the surveyed RSS database. Importantly, the positioning error of the developed Wi-Fi indoor positioning system with Kriging is reduced by 17.9% in average than that without Kriging.

  14. Low Speed Vehicle Localization using WiFi FingerPrinting

    OpenAIRE

    Nguyen, Dinh-Van; Vaca Recalde, Myriam; Nashashibi, Fawzi

    2016-01-01

    International audience; Recently, the problem of fully autonomous navigation of vehicle has gained major interest from research institutes and private companies. In general, these researches rely on GPS in fusion with other sensors to track vehicle in outdoor environment. However, as indoor environment such as car park is also an important scenario for vehicle navigation, the lack of GPS poses a serious problem. This study presents an approach to use WiFi Fingerprinting as a replacement for G...

  15. Autonomous WiFi Sensor for Heating Systems in the Internet of Things

    OpenAIRE

    C. A. Trasviña-Moreno; Blasco, R; Casas, R.; Marco, A.

    2016-01-01

    In smart cities and home applications, the use of Wireless Sensor Networks to extract environmental data becomes more common with the passing of time. These sensors are used for a wide array of applications, but mainly to manage energy consumption in domestic buildings. One of the key energy consumers in households is heating systems. To monitor them, sensors are used with wireless communication protocols, like ZigBee, to transmit data to a central processing unit (CPU). WiFi communications, ...

  16. Passive Radar based on WiFi transmissions: signal processing schemes and experimental results

    OpenAIRE

    Falcone, Paolo

    2013-01-01

    Aim of this work is to study innovative techniques and processing strategies for a new passive sensor for short range surveillance. The principle of work of the sensor will be based on the passive radar principle, and WiFi transmissions - which usually provide Internet access within local areas - will be exploited by the passive sensor to detect, localize and classify targets. EU ATOM Project (FP7)

  17. Collaborative WiFi Fingerprinting Using Sensor-Based Navigation on Smartphones

    OpenAIRE

    Peng Zhang; Qile Zhao; You Li; Xiaoji Niu; Yuan Zhuang; Jingnan Liu

    2015-01-01

    This paper presents a method that trains the WiFi fingerprint database using sensor-based navigation solutions. Since micro-electromechanical systems (MEMS) sensors provide only a short-term accuracy but suffer from the accuracy degradation with time, we restrict the time length of available indoor navigation trajectories, and conduct post-processing to improve the sensor-based navigation solution. Different middle-term navigation trajectories that move in and out of an indoor area are com...

  18. WIPP: Wi-Fi Compass for Indoor Passive Positioning with Decimeter Accuracy

    Directory of Open Access Journals (Sweden)

    Zhenyuan Zhang

    2016-04-01

    Full Text Available In recent decades, the proliferation of smart phones, tablets, and wireless networks has fostered a growing interest in indoor passive positioning. The Wi-Fi-based passive positioning systems can provide Location-Based Services (LBSs to the third party such as market and security departments. Most of the existing systems are based on the Receive Signal Strength Indication (RSSI information, which are generally time-consuming and susceptible to environmental change. To overcome this problem, we propose the Wi-Fi compass for indoor passive positioning system (WIPP, an Angle of Arrival (AOA based passive positioning system using the existing commodity Wi-Fi network. In this paper, we first propose a new algorithm for the joint estimation of AOA and Time of Arrival (TOA measurements based on the fine-grained Channel State Information (CSI, which is collected by an off-the-shelf Wi-Fi device equipped with only three antennas. Second, we use the affinity propagation clustering algorithm to identify the direct signal path from the target to each Wi-Fi Access Point (AP. Finally, we deploy the WIPP in an actual indoor environment to conduct the performance comparison with the well-known radio-frequency (RF based system for locating and tracking users inside buildings (RADAR, as well as the conventional passive positioning system using the AOA solely. The experimental results show that the WIPP is able to achieve the median positioning error 0.7 m, which is much lower than the ones by the RADAR system and the conventional system using the AOA solely.

  19. Communicating Is Crowdsourcing: Wi-Fi Indoor Localization with CSI-based Speed Estimation

    OpenAIRE

    Jiang, Zhiping; Zhao, Jizhong; Li, Xiang-Yang; XI, WEI; Zhao, Kun; Tang, Shaojie; Han, Jinsong

    2013-01-01

    Numerous indoor localization techniques have been proposed recently to meet the intensive demand for location based service, and Wi-Fi fingerprint-based approaches are the most popular and inexpensive solutions. Among them, one of the main trends is to incorporate the built-in sensors of smartphone and to exploit crowdsourcing potentials. However the noisy built-in sensors and multi-tasking limitation of underline OS often hinder the effectiveness of these schemes. In this work, we propose a ...

  20. Pushing the Limits of Indoor Localization in Today’s Wi-Fi Networks

    OpenAIRE

    XIONG, J.

    2015-01-01

    Wireless networks are ubiquitous nowadays and play an increasingly important role in our everyday lives. Many emerging applications including augmented reality, indoor navigation and human tracking, rely heavily on Wi-Fi, thus requiring an even more sophisticated network. One key component for the success of these applications is accurate localization. While we have GPS in the outdoor environment, indoor localization at a sub-meter granularity remains challenging due to a number of factors, i...

  1. Research and application of EtherCAT based on high speed industrial Ethernet%基于高速工业以太网的EtherCAT应用研究

    Institute of Scientific and Technical Information of China (English)

    叶一枝

    2016-01-01

    随着工业4.0的发展,基于高速工业以太网的工业自动化现场总线(EtherCAT)技术发展迅速,在微电网、机器人和定日镜厂等领域,需要高速高效控制技术,以实现对控制对象的实时操作与控制,基于高速工业以太网的EtherCAT技术可以实现微秒级的实时控制。%Along with the development of industrial 4.0, based on fast industrial Ethernet in industrial automation Fieldbus EtherCAT technology is developing rapidly,in the field of micro grid,robot and a heliostat factory and need to high speed and high efficiency control technology,to achieve the real-time operation and control of the controlled object,based on fast industrial Ethernet EtherCAT technology can realize the real-time control of the microsecond.

  2. Wake-on-a-Schedule: Energy-aware Communication in Wi-Fi Networks

    Directory of Open Access Journals (Sweden)

    PERKOVIC, T.

    2014-02-01

    Full Text Available Excessive energy consumption of mobile device Wi-Fi (IEEE 802.11x interface is limiting its operational time on batteries, and impacts total energy consumption of electronic devices. In recent years research community has invested great effort in better efficiency of energy consumption. However, there is still a space for improvement. Wi-Fi devices connected to the single AP (Access Point compete for the medium during data exchange. However, due to the performance anomaly in 802.11 networks, a low data rate device will force all other devices connected to the AP to communicate at low rate, which will increase the total energy consumption of these devices. Wake-on-a-Schedule algorithm is proposed reducing the energy consumption of devices placed in the area with the weaker signal by scheduling the data packets for each client on the server side which will not allow clients to compete for the Wi-Fi medium. Through extensive measurements we show that our algorithm can save up to 60% of energy consumption on the client side.

  3. WiFi and Measurement%Wi Fi及测量

    Institute of Scientific and Technical Information of China (English)

    向天明

    2015-01-01

    The author introduces the technical parameters,measuring method and relevant equipment of WiFi network quality.It systematically discusses the parameters of WiFi signal intensity and link quality,and puts forward the measuring method in installation and maintenance.In addition,the author explains the method of analyzing spectrum,and further discusses how to set up WiFi frequency points and suppress interference.%介绍WiFi网络质量的技术参数指标、测量方案及相关仪器,详细阐述WiFi信号的强度与链路质量等参数,并提出了安装维护中的测量方法;详细阐述WiFi 频谱的分析方法,提出WiFi 信号的频点设置与排除干扰的方案。

  4. SURVEYING BEST SUITABLE SCHEDULING ALGORITHM FOR WIMAX- WI-FI INTEGRATED HETEROGENEOUS NETWORK

    Directory of Open Access Journals (Sweden)

    Poulomi Das

    2013-02-01

    Full Text Available To provide uninterrupted service to all subscribers in a wireless network, we need to incorporate a low cost, flexible Heterogeneous network which will be able to link with any kind of network for efficient spectrum utilization, hence improved system capacity. In this connection, Wi-Fi/ Wi MAX integrated network seems to be an ideal solution as it is able to provide easy deployment, high speed data rate and wide range coverage with high throughput, low end to end delay, flat and low jitter. Wi-Fi/ WiMAX integrated network provides Quality of Service (QoS that can support all kinds of real-time application in wireless networks that includes priority scheduling and queuing for bandwidth allocation that is based on traffic scheduling algorithms within wireless networks. In this paper, we have designed a Wi-Fi/ WiMAX integrated network and analyze the performance of different scheduling algorithms for that integrated network and highlight our findings on the scheduling algorithm which will give the best performance for a heterogeneous network.

  5. Indoor Map Aided Wi-Fi Integrated Lbs on Smartphone Platforms

    Science.gov (United States)

    Yu, C.; El-Sheimy, N.

    2017-09-01

    In this research, an indoor map aided INS/Wi-Fi integrated location based services (LBS) applications is proposed and implemented on smartphone platforms. Indoor map information together with measurements from an inertial measurement unit (IMU) and Received Signal Strength Indicator (RSSI) value from Wi-Fi are collected to obtain an accurate, continuous, and low-cost position solution. The main challenge of this research is to make effective use of various measurements that complement each other without increasing the computational burden of the system. The integrated system in this paper includes three modules: INS, Wi-Fi (if signal available) and indoor maps. A cascade structure Particle/Kalman filter framework is applied to combine the different modules. Firstly, INS position and Wi-Fi fingerprint position integrated through Kalman filter for estimating positioning information. Then, indoor map information is applied to correct the error of INS/Wi-Fi estimated position through particle filter. Indoor tests show that the proposed method can effectively reduce the accumulation positioning errors of stand-alone INS systems, and provide stable, continuous and reliable indoor location service.

  6. Indoor Location Sensing with Invariant Wi-Fi Received Signal Strength Fingerprinting

    Directory of Open Access Journals (Sweden)

    Mohd Nizam Husen

    2016-11-01

    Full Text Available A method of location fingerprinting based on the Wi-Fi received signal strength (RSS in an indoor environment is presented. The method aims to overcome the RSS instability due to varying channel disturbances in time by introducing the concept of invariant RSS statistics. The invariant RSS statistics represent here the RSS distributions collected at individual calibration locations under minimal random spatiotemporal disturbances in time. The invariant RSS statistics thus collected serve as the reference pattern classes for fingerprinting. Fingerprinting is carried out at an unknown location by identifying the reference pattern class that maximally supports the spontaneous RSS sensed from individual Wi-Fi sources. A design guideline is also presented as a rule of thumb for estimating the number of Wi-Fi signal sources required to be available for any given number of calibration locations under a certain level of random spatiotemporal disturbances. Experimental results show that the proposed method not only provides 17% higher success rate than conventional ones but also removes the need for recalibration. Furthermore, the resolution is shown finer by 40% with the execution time more than an order of magnitude faster than the conventional methods. These results are also backed up by theoretical analysis.

  7. Fusion of WiFi, Smartphone Sensors and Landmarks Using the Kalman Filter for Indoor Localization

    Directory of Open Access Journals (Sweden)

    Zhenghua Chen

    2015-01-01

    Full Text Available Location-based services (LBS have attracted a great deal of attention recently. Outdoor localization can be solved by the GPS technique, but how to accurately and efficiently localize pedestrians in indoor environments is still a challenging problem. Recent techniques based on WiFi or pedestrian dead reckoning (PDR have several limiting problems, such as the variation of WiFi signals and the drift of PDR. An auxiliary tool for indoor localization is landmarks, which can be easily identified based on specific sensor patterns in the environment, and this will be exploited in our proposed approach. In this work, we propose a sensor fusion framework for combining WiFi, PDR and landmarks. Since the whole system is running on a smartphone, which is resource limited, we formulate the sensor fusion problem in a linear perspective, then a Kalman filter is applied instead of a particle filter, which is widely used in the literature. Furthermore, novel techniques to enhance the accuracy of individual approaches are adopted. In the experiments, an Android app is developed for real-time indoor localization and navigation. A comparison has been made between our proposed approach and individual approaches. The results show significant improvement using our proposed framework. Our proposed system can provide an average localization accuracy of 1 m.

  8. Fusion of WiFi, smartphone sensors and landmarks using the Kalman filter for indoor localization.

    Science.gov (United States)

    Chen, Zhenghua; Zou, Han; Jiang, Hao; Zhu, Qingchang; Soh, Yeng Chai; Xie, Lihua

    2015-01-05

    Location-based services (LBS) have attracted a great deal of attention recently. Outdoor localization can be solved by the GPS technique, but how to accurately and efficiently localize pedestrians in indoor environments is still a challenging problem. Recent techniques based on WiFi or pedestrian dead reckoning (PDR) have several limiting problems, such as the variation of WiFi signals and the drift of PDR. An auxiliary tool for indoor localization is landmarks, which can be easily identified based on specific sensor patterns in the environment, and this will be exploited in our proposed approach. In this work, we propose a sensor fusion framework for combining WiFi, PDR and landmarks. Since the whole system is running on a smartphone, which is resource limited, we formulate the sensor fusion problem in a linear perspective, then a Kalman filter is applied instead of a particle filter, which is widely used in the literature. Furthermore, novel techniques to enhance the accuracy of individual approaches are adopted. In the experiments, an Android app is developed for real-time indoor localization and navigation. A comparison has been made between our proposed approach and individual approaches. The results show significant improvement using our proposed framework. Our proposed system can provide an average localization accuracy of 1 m.

  9. Bit error rate analysis of Wi-Fi and bluetooth under the interference of 2.45 GHz RFID

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    IEEE 802.11b WLAN (Wi-Fi) and IEEE 802.15.1 WPAN (bluetooth) are prevalent nowadays, and radio frequency identification (RFID) is an emerging technology which has wider applications. 802.11b occupies unlicensed industrial, scientific and medical (ISM) band (2.4-2.483 5 GHz) and uses direct sequence spread spectrum (DSSS) to alleviate the narrow band interference and fading. Bluetooth is also one user of ISM band and adopts frequency hopping spread spectrum (FHSS) to avoid the mutual interference. RFID can operate on multiple frequency bands, such as 135 KHz, 13.56 MHz and 2.45 GHz. When 2.45 GHz RFID device, which uses FHSS, collocates with 802.11b or bluetooth, the mutual interference is inevitable. Although DSSS and FHSS are applied to mitigate the interference, their performance degradation may be very significant. Therefore, in this article, the impact of 2.45 GHz RFID on 802.11b and bluetooth is investigated. Bit error rate (BER) of 802.11b and bluetooth are analyzed by establishing a mathematical model, and the simula-tion results are compared with the theoretical analysis to justify this mathematical model.

  10. Fault Nodes Localization Algorithms of Wi-Fi Network Under Abnormal Disturbance%Wi-Fi网络非常态干扰下的故障节点定位算法

    Institute of Scientific and Technical Information of China (English)

    张华

    2014-01-01

    当前对Wi-Fi网络节点故障定位方法使用正交频分复用技术,采用直调直检的方法将Wi-Fi节点网络之间高速数据信号转换为分布式载波信号,实现节点故障节点检测,该方法很容易导致相邻节点信道间频谱主瓣重叠,在非常态干扰下定位不准。提出一种基于OFDM技术的Wi-Fi故障节点定位方法,采用同步算法来减小子载波间的正交性抑制,采用信息素更新策略实现在非常态干扰下对故障节点的定位检测。仿真实验表明,该方法能有效定位Wi-Fi故障节点,网络传输误码率降低明显,大幅提高网络传输效率,有效提高了Wi-Fi网络可靠性和应用性。%The current fault nodes location methods of Wi-Fi network use orthogonal frequency division multiplexing tech-nique, the method of straight straightening is used. The high speed data signals between the Wi-Fi network nodes is added with distributed carrier signal, the node fault detection is realized. This method causes the neighboring nodes to inter chan-nel spectral main lobe overlap, and the fault nodes localization is not accurate. A Wi-Fi fault nodes localization method was proposed based on OFDM technology. The information update strategy was designed to realize the detection and location of fault nodes. Simulation results show that, the method can effectively locate Wi-Fi faulty nodes, and the network transmis-sion error rate reduces obviously. The efficiency of network transmission is improved. The reliability of Wi-Fi network is improved effectively.

  11. The effect of Wi-Fi electromagnetic waves in unimodal and multimodal object recognition tasks in male rats.

    Science.gov (United States)

    Hassanshahi, Amin; Shafeie, Seyed Ali; Fatemi, Iman; Hassanshahi, Elham; Allahtavakoli, Mohammad; Shabani, Mohammad; Roohbakhsh, Ali; Shamsizadeh, Ali

    2017-06-01

    Wireless internet (Wi-Fi) electromagnetic waves (2.45 GHz) have widespread usage almost everywhere, especially in our homes. Considering the recent reports about some hazardous effects of Wi-Fi signals on the nervous system, this study aimed to investigate the effect of 2.4 GHz Wi-Fi radiation on multisensory integration in rats. This experimental study was done on 80 male Wistar rats that were allocated into exposure and sham groups. Wi-Fi exposure to 2.4 GHz microwaves [in Service Set Identifier mode (23.6 dBm and 3% for power and duty cycle, respectively)] was done for 30 days (12 h/day). Cross-modal visual-tactile object recognition (CMOR) task was performed by four variations of spontaneous object recognition (SOR) test including standard SOR, tactile SOR, visual SOR, and CMOR tests. A discrimination ratio was calculated to assess the preference of animal to the novel object. The expression levels of M1 and GAT1 mRNA in the hippocampus were assessed by quantitative real-time RT-PCR. Results demonstrated that rats in Wi-Fi exposure groups could not discriminate significantly between the novel and familiar objects in any of the standard SOR, tactile SOR, visual SOR, and CMOR tests. The expression of M1 receptors increased following Wi-Fi exposure. In conclusion, results of this study showed that chronic exposure to Wi-Fi electromagnetic waves might impair both unimodal and cross-modal encoding of information.

  12. Design Tri-band Rectangular Patch Antenna for Wi-Fi, Wi-Max and WLAN in Military Band Applications with Radiation Pattern Suppression

    Directory of Open Access Journals (Sweden)

    Aymen Dheyaa Khaleel

    2015-08-01

    Full Text Available Design tri-band rectangular patch antenna is presented. This research study focuses on designing an antenna that can operate with three bands; 2.4, 3.5 and 4.4 GHz, respectively. These bands are accepted by Wi-Fi, Wi-MAX and WLAN in Military band applications. The shape of the proposed design is based on simple rectangular patches with inset-feed on one surface of the FR4 substrate. On the other surface of FR4 substrate, is the infinite ground plane. Also Computer Simulation Technology (CST microwave studio 2012 is used for the design of antenna. This design is fabricated using photolithographic process.

  13. Industrial communication technology handbook

    CERN Document Server

    Zurawski, Richard

    2005-01-01

    The Industrial Communication Technology Handbook focuses on current and newly emerging communication technologies and systems that are evolving in response to the needs of industry and the demands of industry-led consortia and organizations.Organized into two parts, the text first summarizes the basics of data communications and IP networks, then presents a comprehensive overview of the field of industrial communications. This book extensively covers the areas of fieldbus technology, industrial Ethernet and real-time extensions, wireless and mobile technologies in industrial applications, the

  14. Manufacturability and reliability on 10-Gb/s transponder for ethernet-based applications

    Science.gov (United States)

    Kao, Min-Sheng; Tsai, Cheng-Hung; Chiu, Chia-Hung; Cheng, Shou-Chien; Shen, Kun-Yi; Huang, Min-Fa; Shaw, Cheng-Da; Lee, Shin-Ge

    2004-05-01

    In this paper, manufacturing issues include Optical Sub-Assembly (OSA), Electrical Sub-Assembly (ESA) and reliability considerations of 10 Gb/s Ethernet transponder were studied by using experiments and implementation. In the growing optical communication industry, one of the star products is the Z-axis pluggable optical transceiver module. Under the broad usage of Ethernet means high port density, low cost, high utilities, compact size and still require excellent performance. After standardizing of 10 Gb/s ethernet (IEEE 802.3ae), many transceiver companies, silicon vendors and system vendors reached the agreement and signed up diversity of MSA (Multi-Source Agreement). These MSAs still keep modifying with system demands, customer requirements, cost and performance issue. This paper presents how to achieve these functions description in the MSA and own a highly manufacturability and reliability module design. According to composed block of transponder, we split it into OSA, ESA, mechanical design and related reliability experimental result. In the OSA, traditional TO-CAN package and optical components be introduced. Because the mature manufacture experience, vendor can easy to meet low cost and manufacturability requirements and only need to slightly modifications. A simply solution be implemented to solve this problem and discuss the critical point of the design. Thermal issue on OSA will also be mentioned because of the sensitive of light source and how to calculate the effect to find effective solutions. By the way, some manufacturability criteria will be discussed for OSA characteristics in 10 Gb/s applications. In the ESA, PMD (Physical media dependant) driving methods, Multi-Source Agreement related digital optical monitor function implement and performance comparison will be presented. On the other hand, we will examine the crosstalk effect between transmitter and receiver circuit and impact to the module Optical to Electrical convert interface design. We

  15. Filters for Wi-Fi Generated Crowd Movement Data

    NARCIS (Netherlands)

    Chilipirea, Cristian; Petre, Andreea-Cristina; Dobre, Ciprian; Steen, van Maarten

    2015-01-01

    Cities represent large groups of people that share a common infrastructure, common social groups and/or common interests. With the development of new technologies current cities aim to become what is known as smart cities, in which all the small details of these large constructs are controlled to be

  16. A WiFi Tracking Device Printed Directly on Textile for Wearable Electronics Applications

    KAUST Repository

    Krykpayev, Bauyrzhan

    2015-12-01

    reported which utilize an interface layer [1{13]. No sophisticated circuit or a system level design involving integration of components on textile has been demonstrated in this medium before. This work, for the first time, demonstrates a complete system printed on a polyester/cotton T-shirt, that helps in tracking the person who is wearing that T-shirt through a smart phone or any Internet enabled device. A low cost dielectric material (Creative Materials 116-20 Dielectric ink) is used to print the interface layer through manual screen printing method. The circuit layout and antenna have been ink-jet printed with silver nano-particles based conductive ink. Utilizing WiFi technology, this wearable tracking system can locate the position of lost children, senior citizens, patients or people in uniforms, lab coats, hospital gowns, etc. The device is small enough (55 mm x 45 mm) and light weight (10.5g w/o battery) for people to comfortably wear it and can be easily concealed in case discretion is required. Field tests have revealed that a person can be localized with up to 8 meters accuracy and the device can wirelessly communicate with a hand-held receiver placed 55 meters away. Future development of the method with techniques such as automated screen printing, pick and place components, and digital ink-jet printing can pave the way for mass production.

  17. Research and Application of High Performance Ethernet Switch Chip-BCM56132%高性能以太网交换芯片BCM56132的研究与应用

    Institute of Scientific and Technical Information of China (English)

    孟芳; 邱里鑫

    2012-01-01

    With the development of ethernet switch technology and super large-scale integrated circuit technology, the fuctions and performance of ethernet switch chips are incresingly improved. A multilayer switch chip, BCM56132, whose internal architecture, functions and characteristics, access method, layer 2 and 3 switch dataflow, and so on are detailly introduced in this paper. Then the design of layer 2 and 3 switch platform based on BCM56132 is completed. At the same time, the description of the hardware and soft development process is given. Finally, the conclusion indicates that the design is correct.%随着以太网交换技术的发展和超大规模集成电路技术的进步,以太网交换芯片功能与性能不断提高.详细介绍了以太网交换芯片BCM56132的内部结构、功能特性、访问方式及2,3层交换的数据流程等,并基于该芯片完成了2、3层交换平台设计,同时对软、硬件实现过程进行了描述,最后通过测试验证了设计的正确性.

  18. Outcomes of Critical Limb Ischemia in an Urban, Safety Net Hospital Population with High WIfI Amputation Scores.

    Science.gov (United States)

    Ward, Robert; Dunn, Joie; Clavijo, Leonardo; Shavelle, David; Rowe, Vincent; Woo, Karen

    2017-01-01

    Patients presenting to a public hospital with critical limb ischemia (CLI) typically have advanced disease with significant comorbidities. The purpose of this study was to assess the influence of revascularization on 1-year amputation rate of CLI patients presenting to Los Angeles County USC Medical Center, classified according to the Society for Vascular Surgery Wound, Ischemia and foot Infection (WIfI). A retrospective review of patients who presented to a public hospital with CLI from February 2010 to July 2014 was performed. Patients were classified according to the WIfI system. Only patients with complete data who survived at least 12 months after presentation were included. Ninety-three patients with 98 affected limbs were included. The mean age was 62.8 years. Eighty-two patients (84%) had hypertension and 71 (72%) had diabetes. Fifty (57.5%) limbs had Trans-Atlantic Inter-Society Consensus (TASC) C or D femoral-popliteal lesions and 82 (98%) had significant infrapopliteal disease. The majority had moderate or high WIfI amputation and revascularization scores. Eighty-four (86%) limbs underwent open, endovascular, or hybrid revascularization. Overall, one year major amputation (OYMA) rate was 26.5%. In limbs with high WIfI amputation score, the OYMA was 34.5%: 21.4% in those who were revascularized and 57% in those who were not. On univariable analysis, factors associated with increased risk of OYMA were nonrevascularization (P = 0.005), hyperlipidemia (P = 0.06), hemodialysis (P = 0.005), gangrene (P = 0.02), ulcer classification (P = 0.05), WIfI amputation score (P = 0.026), and WIfI wound grade (P = 0.04). On multivariable analysis, increasing WIfI amputation score (odds ratio [OR] 1.84, 95% confidence interval [CI] 1.0-3.39) was associated with increased risk of OYMA while revascularization (OR 0.24, 95% CI 0.07-0.80) was associated with decreased risk of OYMA. The OYMA rates in this population were consistent with those predicted by the

  19. Evaluation of Giga-bit Ethernet Instrumentation for SalSA Electronics Readout (GEISER)

    CERN Document Server

    Varner, G S; Ridley, D; Zhu, C; Gorham, P; Varner, Gary S.; Murakami, Laine; Ridley, David; Zhu, Chaopin; Gorham, Peter

    2005-01-01

    An instrumentation prototype for acquiring high-speed transient data from an array of high bandwidth antennas is presented. Multi-kilometer cable runs complicate acquisition of such large bandwidth radio signals from an extensive antenna array. Solutions using analog fiber optic links are being explored, though are very expensive. We propose an inexpensive solution that allows for individual operation of each antenna element, operating at potentially high local self-trigger rates. Digitized data packets are transmitted to the surface via commercially available Giga-bit Ethernet hardware. Events are then reconstructed on a computer farm by sorting the received packets using standard networking gear, eliminating the need for custom, very high-speed trigger hardware. Such a system is completely scalable and leverages the hugh capital investment made by the telecommunications industry. Test results from a demonstration prototype are presented.

  20. Evaluation of the Delivery QoS Characteristics of Gigabit Ethernet Switches

    CERN Document Server

    Beuran, Razvan; Davies, Neil; Dobinson, Robert W

    2004-01-01

    The event selection system for ATLAS is designed to perform real-time image processing on particle collision data equivalent to 2 TB/s. This data is filtered by a multi-level architecture, resulting in 200 GB/s of data analysed by a distributed system consisting of several thousand PCs and switches. As part of our ongoing work on this system, we performed tests on several Gigabit Ethernet switches manufactured by market leaders, using our custom-built test equipment. We analysed the implications of running network devices at, and just beyond, saturation while deploying service differentiation mechanisms. We quantified the quality degradation that traffic flows experienced when passing through switches. We focused on emergent properties in saturation, including fairness and fidelity to expectations. We discuss the ideals for switch behaviour and compare them against the observed behaviour of real implementations of differentiation mechanisms in switches. This creates a generic benchmark, which is independent o...

  1. On Application of Least-delay Variation Problem in Ethernet Networks Using SDN Concept

    Directory of Open Access Journals (Sweden)

    Tomas Hegr

    2016-01-01

    Full Text Available The goal of this paper is to present an application idea of SDN in Smart Grids, particularly, in the area of L2 multicast as defined by IEC 61850-9-2. Authors propose an Integer Linear Formulation (ILP dealing with a Least-Delay-Variation multicast forwarding problem that has a potential to utilize Ethernet networks in a new way. The proposed ILP formulation is numerically evaluated on random graph topologies and results are compared to a shortest path tree approach that is traditionally a product of Spanning Tree Protocols. Results confirm the correctness of the ILP formulation and illustrate dependency of a solution quality on the selected graph models, especially, in a case of scale-free topologies.

  2. Evaluation of Giga-bit Ethernet instrumentation for SalSA electronics readout

    Energy Technology Data Exchange (ETDEWEB)

    Varner, Gary S. [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States)]. E-mail: varner@phys.hawaii.edu; Murakami, Laine [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States); Ridley, David [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States); Zhu Chaopin [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States); Gorham, Peter [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States)

    2005-12-01

    An instrumentation prototype for acquiring high-speed transient data from an array of high bandwidth antennas is presented. Multi-kilometer cable runs complicate acquisition of such large bandwidth radio signals from an extensive antenna array. Solutions using analog fiber optic links are being explored though are very expensive. We propose an inexpensive solution that allows for individual operation of each antenna element, operating at potentially high local self-trigger rates. Digitized data packets are transmitted to the surface via commercially available Giga-bit Ethernet hardware. Events are then reconstructed on a computer farm by sorting the received packets using standard networking gear, eliminating the need for custom, very high speed trigger hardware. Such a system is completely scalable and leverages the enormous capital investment made by the telecommunications industry. Test results from a demonstration prototype are presented.

  3. Development of a Beam Loss Measurement System with Gigabit Ethernet Readout at CERN

    CERN Document Server

    Kwiatkowski, M; Angelogiannopoulos, E; Dehning, B; Jackson, S; Vigano, W; Zamantzas, C

    2012-01-01

    The aim of the BLM Dual Polarity module under development at the European Organisation for Nuclear Research (CERN) is to measure and digitise with high precision the current produced by several types of beam loss detectors. In its default configuration, it is expected to provide data to the processing electronics through two point-to-point connections with bidirectional multi-gigabit optical links. For the development phases as well as later serving as a standalone measurement system, its reconfigurable FPGA device is exploited to provide a soft-core CPU with a custom made server. This server, running on the CPU, will expose through the Gigabit Ethernet connection and the TCP/IP protocol different types of data in the network. In this paper the development of the system and of the communication protocol is explored as well as the accompanying client ap- plication that is realised with the purpose of commanding, collecting storing and viewing the different types of data.

  4. Cold front-end electronics and Ethernet-based DAQ systems for large LAr TPC readout

    CERN Document Server

    D.Autiero,; B.Carlus,; Y.Declais,; S.Gardien,; C.Girerd,; J.Marteau; H.Mathez

    2010-01-01

    Large LAr TPCs are among the most powerful detectors to address open problems in particle and astro-particle physics, such as CP violation in leptonic sector, neutrino properties and their astrophysical implications, proton decay search etc. The scale of such detectors implies severe constraints on their readout and DAQ system. We are carrying on a R&D in electronics on a complete readout chain including an ASIC located close to the collecting planes in the argon gas phase and a DAQ system based on smart Ethernet sensors implemented in a µTCA standard. The choice of the latter standard is motivated by the similarity in the constraints with those existing in Network Telecommunication Industry. We also developed a synchronization scheme developed from the IEEE1588 standard integrated by the use of the recovered clock from the Gigabit link

  5. Internetworking technological foundations and applications

    CERN Document Server

    Meinel, Christoph

    2013-01-01

    This book is supposed to serve as a comprehensive and instructive guide through the new world of digital communication. On the physical layer optical and electrical cabling technology are described as well as wireless communication technologies. On the data link layer local area networks (LANs) are introduced together with the most popular LAN technologies such as Ethernet, Token Ring, FDDI, and ATM as well as wireless LAN technologies including IEEE 802.x, Bluetooth, or ZigBee. A wide range of WAN technologies are covered including contemporary high speed technologies like PDH and SDH up to h

  6. Coexistence of WiFi and WiMAX Systems Based on PS-Request Protocols

    Directory of Open Access Journals (Sweden)

    Ho Young Hwang

    2011-10-01

    Full Text Available We introduce both the coexistence zone within the WiMAX frame structure and a PS-Request protocol for the coexistence of WiFi and WiMAX systems sharing a frequency band. Because we know that the PS-Request protocol has drawbacks, we propose a revised PS-Request protocol to improve the performance. Two PS-Request protocols are based on the time division operation (TDO of WiFi system and WiMAX system to avoid the mutual interference, and use the vestigial power management (PwrMgt bit within the Frame Control field of the frames transmitted by a WiFi AP. The performance of the revised PS-Request protocol is evaluated by computer simulation, and compared to those of the cases without a coexistence protocol and to the original PS-Request protocol.

  7. Real-Time and Accurate Indoor Localization with Fusion Model of Wi-Fi Fingerprint and Motion Particle Filter

    Directory of Open Access Journals (Sweden)

    Xinlong Jiang

    2015-01-01

    Full Text Available As the development of Indoor Location Based Service (Indoor LBS, a timely localization and smooth tracking with high accuracy are desperately needed. Unfortunately, any single method cannot meet the requirement of both high accuracy and real-time ability at the same time. In this paper, we propose a fusion location framework with Particle Filter using Wi-Fi signals and motion sensors. In this framework, we use Extreme Learning Machine (ELM regression algorithm to predict position based on motion sensors and use Wi-Fi fingerprint location result to solve the error accumulation of motion sensors based location occasionally with Particle Filter. The experiments show that the trajectory is smoother as the real one than the traditional Wi-Fi fingerprint method.

  8. Multi-Criteria Vertical Handover Comparison between Wimax and Wifi

    Directory of Open Access Journals (Sweden)

    Maroua Drissi

    2015-07-01

    Full Text Available In next generation wireless networks, the most tempting feature is the ability of the user to move smoothly over different access networks regardless of the network access technology. In this paper we study the benefit of Multiple Attribute Decision Making (MADM strategies for network selection. We compare three of these methods naming Simple Additive Weighting (SAW, Multiplicative Exponential Weighting (MEW and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS in a realtime ns-3 simulation. Analytic Hierarchy Process (AHP provides the weights of attributes which allow the comparison in different types of applications. Therefore, we propose a performance evaluation model with a reconfiguration of AHP parameters used in the literature. Simulation results show that the proposed parameters provide an improvement of Delay and offer allowable Packet loss in different types of applications.

  9. xD-Track: Leveraging Multi-Dimensional Information for Passive Wi-Fi Tracking

    OpenAIRE

    Xie, Y.; XIONG, J.; Li, M; Jamieson, K.

    2016-01-01

    We describe the design and implementation of xD-Track, the first practical Wi-Fi based device-free localization system that employs a simultaneous and joint estimation of time-of-flight, angle-of-arrival, angle-of-departure, and Doppler shift to fully characterize the wireless channel between a sender and receiver. Using this full characterization, xD-Track introduces novel methods to measure and isolate the signal path that reflects off a person of interest, allowing it to localize a human w...

  10. No Effects of Acute Exposure to Wi-Fi Electromagnetic Fields on Spontaneous EEG Activity and Psychomotor Vigilance in Healthy Human Volunteers.

    Science.gov (United States)

    Zentai, Norbert; Csathó, Árpád; Trunk, Attila; Fiocchi, Serena; Parazzini, Marta; Ravazzani, Paolo; Thuróczy, György; Hernádi, István

    2015-12-01

    Mobile equipment use of wireless fidelity (Wi-Fi) signal modulation has increased exponentially in the past few decades. However, there is inconclusive scientific evidence concerning the potential risks associated with the energy deposition in the brain from Wi-Fi and whether Wi-Fi electromagnetism interacts with cognitive function. In this study we investigated possible neurocognitive effects caused by Wi-Fi exposure. First, we constructed a Wi-Fi exposure system from commercial parts. Dosimetry was first assessed by free space radiofrequency field measurements. The experimental exposure system was then modeled based on real geometry and physical characteristics. Specific absorption rate (SAR) calculations were performed using a whole-body, realistic human voxel model with values corresponding to conventional everyday Wi-Fi exposure (peak SAR10g level was 99.22 mW/kg with 1 W output power and 100% duty cycle). Then, in two provocation experiments involving healthy human volunteers we tested for two hypotheses: 1. Whether a 60 min long 2.4 GHz Wi-Fi exposure affects the spectral power of spontaneous awake electroencephalographic (sEEG) activity (N = 25); and 2. Whether similar Wi-Fi exposure modulates the sustained attention measured by reaction time in a computerized psychomotor vigilance test (PVT) (N = 19). EEG data were recorded at midline electrode sites while volunteers watched a silent documentary. In the PVT task, button press reaction time was recorded. No measurable effects of acute Wi-Fi exposure were found on spectral power of sEEG or reaction time in the psychomotor vigilance test. These results indicate that a single, 60 min Wi-Fi exposure does not alter human oscillatory brain function or objective measures of sustained attention.

  11. In-building Unlicensed WiFi Band OFDM Signal Distribution over MMF&BIF Using VCSEL

    DEFF Research Database (Denmark)

    Deng, Lei; Jensen, Jesper Bevensee; Yu, Xianbin

    2011-01-01

    For in-building applications, an OFDM-VCSEL RoF system operating in unlicensed WiFi band is experimentally tested using MMF and bend insensitive fiber (BIF). A spectral efficiency of 4.32 bit/s/Hz with 0.9 Gbps data rate is achieved.......For in-building applications, an OFDM-VCSEL RoF system operating in unlicensed WiFi band is experimentally tested using MMF and bend insensitive fiber (BIF). A spectral efficiency of 4.32 bit/s/Hz with 0.9 Gbps data rate is achieved....

  12. Coexistence of WiFi and WiMAX Systems Based on PS-Request Protocols

    OpenAIRE

    Ho Young Hwang; Young-uk Chung; Yong-Hoon Choi; Jongwoo Kim; Suwon Park; Seung Hyong Rhee

    2011-01-01

    We introduce both the coexistence zone within the WiMAX frame structure and a PS-Request protocol for the coexistence of WiFi and WiMAX systems sharing a frequency band. Because we know that the PS-Request protocol has drawbacks, we propose a revised PS-Request protocol to improve the performance. Two PS-Request protocols are based on the time division operation (TDO) of WiFi system and WiMAX system to avoid the mutual interference, and use the vestigial power management (PwrMgt) bit within t...

  13. A Multi-Game Framework for Harmonized LTE-U and WiFi Coexistence over Unlicensed Bands

    OpenAIRE

    2016-01-01

    The introduction of LTE over unlicensed bands (LTE-U) will enable LTE base stations (BSs) to boost their capacity and offload their traffic by exploiting the underused unlicensed bands. However, to reap the benefits of LTE-U, it is necessary to address various new challenges associated with LTE-U and WiFi coexistence. In particular, new resource management techniques must be developed to optimize the usage of the network resources while handling the interdependence between WiFi and LTE users ...

  14. Realistic Indoor Wi-Fi and Femto deployment Study as the Offloading Solutions to LTE Macro Network

    DEFF Research Database (Denmark)

    Hu, Liang; Coletti, Claudio; Nguyen, Huan Cong

    2012-01-01

    that, in a dual-carrier LTE macro case, Wi-Fi access point density of 230/km2 is required to meet the Key Performance Indicator (KPI) - less than 10% of users have a throughput below 1 Mbps whereas out-band Femto access point density of 1200/km2 is required. Furthermore, we show that in-band Femto cell...... cannot meet the network KPI even at a very high access point density. We also show that Wi-Fi and Femto cell offload the same amount of traffic when they are deployed at the same access point density....

  15. L'arrivée du WiFi, technologie de télécommunication radio

    OpenAIRE

    Dumé, Bel; Ubéda, Stéphane

    2012-01-01

    National audience; La technologie radio 802.11, désormais bien connue sous le nom de Wi-Fi, est développée à la fin des années 1990, mais sa mise en oeuvre est assez compliquée et il faudra attendre les années 2002-2003 pour que les vraies cartes Wi-Fi arrivent sur le marché et ouvrent le champ des applications d'objets mobiles communicants.

  16. Perancangan Sistem Informasi Parkir dengan WiFi Berbasis Arduino

    Directory of Open Access Journals (Sweden)

    Novi Yulianto

    2016-12-01

    Full Text Available Now the need for access to information is very important because the information obtained can specify or provide comfort and ease in performing daily activities. One example is to use gadgets such as smartphones, notebooks, tablets and others, we can easily find out information directly without having to come to the venue. This system aims to design information systems in the parking lot. This technology can provide an idea of ??the amount of available parking spots has been filled or empty. By accessing the IP address given earlier, then we will know the availability of parking space directly. From the test results, it can be said that this system has the advantages of easy to use, the application is simple and can help improve the comfort / convenience for users of the car park. But this system also has the disadvantage of a webserver which is used has a very small memory that can not be accessed by many concurrent users in one time.

  17. Conversion of asynchronous 10 Gbit/s Ethernet NRZ frame into a synchronous RZ frame and multiplexing to 170 Gbit/s

    DEFF Research Database (Denmark)

    Laguardia Areal, Janaina; Hu, Hao; Palushani, Evarist

    2010-01-01

    This paper presents an optical circuit for frame synchronization and pulse compression of 10G Ethernet frames with 12000 bits and multiplexing to a 170 Gbit/s optical time division multiplexed data stream.......This paper presents an optical circuit for frame synchronization and pulse compression of 10G Ethernet frames with 12000 bits and multiplexing to a 170 Gbit/s optical time division multiplexed data stream....

  18. 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.

  19. 基于STM8S103和WIFI的智能家居照明系统设计%Design of Smart Home Lighting System Based on STM8S103 and WIFI

    Institute of Scientific and Technical Information of China (English)

    卢林杰; 秦会斌

    2014-01-01

    With ever increasing demand on life experience and more convenient and comfortable operation of android mobile phones,WIFI wireless information transmission technology becomes mature day by day. It is a development trend to apply WIFI wireless transmission to the smart home lighting system controlled by the Android smart phone terminal.STM8S103 microcontroller,as the core controller,combined with WIFI wireless information transmission and mobile phone terminal control program,can realize the design of smart home lighting system,so that Android mobile phone may easily control the switching and dimming of indoor light sources,with excellent effects of application and experience.%人们对生活体验的要求越来越高,Android智能手机带给人们更快捷舒适的操作,WIFI无线信息传输技术日趋成熟。将WIFI无线传输方式用到智能家居照明系统,由Android智能手机终端进行控制成为一种发展趋势。STM8S103单片机作为核心控制器,由WIFI无线方式进行信息传输,结合手机终端控制程序,实现智能家居照明系统的设计。能轻松的利用Android手机对室内灯源进行开关、调光等控制,具有很好的应用和体验效果。

  20. WiFi Localization Based on IEEE 802.11 RTS/CTS Mechanism

    Directory of Open Access Journals (Sweden)

    Zhe Cui

    2015-11-01

    Full Text Available Location Based Services are providing one of the fastest growing market segments today. While the most common technique for location determination is GPS, several alternative approaches have been proposed for Wi-Fi environments, based on time of flight, signal strength, etc. Time based techniques not only require accurate timestamping mechanisms, but also precise and synchronized clocks, which is quite difficult and expensive in industry. On the other hand, signal strength based methods need a lot of ground truth data. These method also require time consuming work and efforts before the system comes into use. In considerations of costs and time consumption, we present in this paper an approach for determining the location of a general Wi-Fi device combining RTS/CTS and TDoA techniques. The proposed model is deployable in various environments and contains two different methods, with clock mapping functions and asynchronized clocks. We also explain limitations of current round trip time (RTT based RTS/CTS systems. Extensive experiments have been conducted and demonstrated how an accuracy of about one foot can be obtained and also the assumption of RTT measurements have been verified.