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Sample records for ieee national telesystems

  1. An Italian Education: IEEE Pulse talks with Riccardo Pietrabissa, president of Italy's National Bioengineering Group, about Italian progress and challenges in biomedical engineering education.

    Science.gov (United States)

    Pietrabissa, Riccardo; Reynolds, Pamela

    2015-01-01

    From Leonardo da Vinci's designs for ball bearings to the incredible engineering wizardry behind the Ferrari, the inventive, inquisitive, and ingenious spirit of the engineer has always lived--and thrived--in Italy. From education to research to product development, Italy has always been regarded as an engineering leader. But does this apply to biomedical engineering (BME)? Despite many successes, questions loom, as they do at engineering schools worldwide. Concerns such as whether BME programs are providing students with enough focused, practical, hands-on training remain at the forefront, as does the question of whether graduates will be able to find jobs in industry after university studies are over. Here, IEEE Pulse explores these topics with Riccardo Pietrabissa, president of the Gruppo Nazionale di Bioingegneria (National Bioengineering Group) and a full professor in the Department of Chemistry, Materials, and Chemical Engineering at Politecnico di Milano.

  2. IEEE Prize for Lucio Rossi

    CERN Multimedia

    IEEE Council on Superconductivity

    2007-01-01

    Lucio Rossi receives his prize from John Spargo, Chairman of the IEEE Council on Superconductivity (left), and Martin Nisenoff, Chairman of the Council on Superconductivity's Awards Committee (right).

  3. Access to IEEE Electronic Library

    CERN Multimedia

    2007-01-01

    From 2007, the CERN Library now offers readers online access to the complete IEEE Electronic Library (Institute of Electrical and Electronics Engineers). This new licence gives unlimited online access to all IEEE and IET (previously IEE) journals and proceedings as well as all current IEEE standards and selected archived ones. Some of the titles offer volumes back to 1913. This service currently represents more than 1,400,000 full-text articles! This leading engineering information resource replaces the previous service, a sub-product of the IEEE database called 'IEEE Enterprise', which offered online access to the complete collection of IEEE journals and proceedings, but with limited features. The service had become so popular that the CERN Working Group for Acquisitions recommended that the Library subscribe to the complete IEEE Electronic Library for 2007. Usage statistics for recent months showed there was a demand for the service from a large community of CERN users and we were aware that many users h...

  4. IEEE Conference Publications in Libraries.

    Science.gov (United States)

    Johnson, Karl E.

    1984-01-01

    Conclusions of surveys (63 libraries, OCLC database, University of Rhode Island users) assessing handling of Institute of Electrical and Electronics Engineers (IEEE) conference publications indicate that most libraries fully catalog these publications using LC cataloging, and library patrons frequently require series access to publications. Eight…

  5. IEEE Conference Publications in Libraries.

    Science.gov (United States)

    Johnson, Karl E.

    1984-01-01

    Conclusions of surveys (63 libraries, OCLC database, University of Rhode Island users) assessing handling of Institute of Electrical and Electronics Engineers (IEEE) conference publications indicate that most libraries fully catalog these publications using LC cataloging, and library patrons frequently require series access to publications. Eight…

  6. Specialty and Systems Engineering Supplement to IEEE 15288.1

    Science.gov (United States)

    2017-08-28

    15288.1 Tailoring Language ............................................................................ 2 3.2.1 Specialty Engineering Analysis and...believed necessary to maintain the level or rigor required by national security space acquisitions . 2. Context IEEE-15288.1: 2014, Standard for...be: 1. Normative (requirements rather than informative guidance), 2. Tailored appropriately for specific acquisition /contract considerations, and 3

  7. IEEE Prize for Lucio Rossi

    CERN Multimedia

    2007-01-01

    Lucio Rossi receives his prize from John Spargo, Chairman of the IEEE Council on Superconductivity (left), and Martin Nisenoff, Chairman of the Council on Superconductivity’s Awards Committee (right). (Photo: IEEE Council on Superconductivity)With the magnets installed in the tunnel and work on the interconnections almost completed, Lucio Rossi has reaped the rewards of fifteen years of work. And yet, when the physicist from Milan arrived to take charge of the group responsible for the superconducting magnets in 2001, success seemed far from assured. Endowed with surprising levels of energy, Lucio Rossi, together with his team, ensured that production of these highly complex magnets got underway. Today, that achievement earns them the recognition not only of CERN but also of the international superconducting community. It is for this achievement that Lucio Rossi was awarded the prize by the IEEE’s (Institute of Electrical an...

  8. Throughput Limits of IEEE 802.11 and IEEE 802.15.3

    OpenAIRE

    Ullah, Sana; Zhong, Yingji; Islam, S. M. Riazul; Nessa, Ahasanun; Kwak, Kyung Sup

    2009-01-01

    IEEE 802.11 and IEEE 802.15.3 are wireless standards originally designed for wireless local area network (WLAN) and wireless personal area network (WPAN). This paper studies MAC throughput analysis of both standards. We present a comparative analysis of both standards in terms of MAC throughput and bandwidth efficiency. Numerical results show that the performance of IEEE 802.15.3 transcends IEEE 802.11 in all cases.

  9. IEEE WEA 2012 - Mejores Trabajos

    Directory of Open Access Journals (Sweden)

    Miguel Alberto Melgarejo Rey

    2013-06-01

    Full Text Available El 2012 Workshop on Engineering Applications (WEA 2012 realizado porla Facultad de Ingeniería de la Universidad Distrital Francisco José deCaldas y su rama estudiantil IEEE (Institute for Electrical and ElectronicsEngineers, del 2 al 4 de mayo de 2012, fue un espacio académico dondeconvergieron academia e industria alrededor de áreas tan diversas comoel control, las comunicaciones, la electrónica de potencia, el procesamientode señales entre otras .A pesar de ser la primera edición delWEA, esta se caracterizó por una nutrida participación, se recibieron 69artículos, 49 provenientes de Colombia y 20 de otros países.

  10. The IEEE Milestone event at CERN

    CERN Multimedia

    2005-01-01

    On the initiative of its French and Swiss Sections, the IEEE has honoured CERN with an 'IEEE Milestone in the history of electricity and electronics' for the invention of the multi-wire proportional chamber in 1968. The IEEE established the Electrical Engineering Milestones programe in 1983 to honour significant achievements in the history of electrical and electronics engineering. To be designated, an achievement must be at least 25 years old, must have involved a unique solution to an engineering problem, and must have had at least regional impact. Currently there are more than  50 IEEE Milestones around the world. http://www.ieee.org/organizations/history_center/cern.html The installation and unveiling of this IEEE Milestone will provide the opportunity to emphasize the close relationship between science, technology, industry and well-being in society.  A ceremony, organised with the support of a group of IEEE members working at CERN, will be held at the CERN Globe of Science and Inn...

  11. TCP over IEEE 802.11

    Directory of Open Access Journals (Sweden)

    P. Chenna Reddy

    2009-01-01

    Full Text Available IEEE 802.11 is a widely used wireless LAN standard for medium access control. TCP is a prominent transport protocol originally designed for wired networks. TCP treats packet loss as congestion and reduces the data rate. In wireless networks packets are lost not only due to congestion but also due to various other reasons. Hence there is need for making TCP adaptable to wireless networks. Various parameters of TCP and IEEE 802.11 can be set to appropriate values to achieve optimum performance results. In this paper optimum values for various parameters of IEEE 802.11 are determined. Network simulator NS2 is used for simulation.

  12. CERN receives prestigious Milestone recognition from IEEE

    CERN Multimedia

    2005-01-01

    At a ceremony at CERN, Mr W. Cleon Anderson, President of the Institute of Electrical and Electronics Engineers (IEEE) formally a Milestone plaque in recognition of the invention of electronic particle detectors at CERN

  13. IEEE International Symposium on Biomedical Imaging.

    Science.gov (United States)

    2017-01-01

    The IEEE International Symposium on Biomedical Imaging (ISBI) is a scientific conference dedicated to mathematical, algorithmic, and computational aspects of biological and biomedical imaging, across all scales of observation. It fosters knowledge transfer among different imaging communities and contributes to an integrative approach to biomedical imaging. ISBI is a joint initiative from the IEEE Signal Processing Society (SPS) and the IEEE Engineering in Medicine and Biology Society (EMBS). The 2018 meeting will include tutorials, and a scientific program composed of plenary talks, invited special sessions, challenges, as well as oral and poster presentations of peer-reviewed papers. High-quality papers are requested containing original contributions to the topics of interest including image formation and reconstruction, computational and statistical image processing and analysis, dynamic imaging, visualization, image quality assessment, and physical, biological, and statistical modeling. Accepted 4-page regular papers will be published in the symposium proceedings published by IEEE and included in IEEE Xplore. To encourage attendance by a broader audience of imaging scientists and offer additional presentation opportunities, ISBI 2018 will continue to have a second track featuring posters selected from 1-page abstract submissions without subsequent archival publication.

  14. CERN receives prestigious Milestone recognition from IEEE

    CERN Multimedia

    2005-01-01

    The Nobel prize winner Georges Charpak and W. Cleon Anderson, IEEE President, unveil the Milestone bronze plaques. At a ceremony on 26 September at the Globe of Science and Innovation, Mr W. Cleon Anderson, President of the Institute of Electrical and Electronics Engineers (IEEE) formally dedicated Milestone plaques recognising the invention of electronic particle detectors at CERN. The plaque were unveiled by Mr Anderson and Georges Charpak, the Nobel-prize winning inventor of wire chamber technology at CERN in 1968. The IEEE is the world's largest professional association dedicated to the advancement of technology with 365,000 individual members in over 150 countries. Established in 1983, there are currently over 60 Milestones around the world. They honour momentous achievements in the history of electrical and electronics engineering, such as the landing of the first transatlantic cable, code breaking at Bletchley Park during World War II, and the development of the Japanese Bullet train, the Tokaido Shin...

  15. Notice of Violation of IEEE Publication Principles

    DEFF Research Database (Denmark)

    Memon, Nasrullah; Qureshi, Abdul Rasool; Wiil, Uffe Kock

    2009-01-01

    Notice of Violation of IEEE Publication Principles "Novel Algorithms for Subgroup Detection in Terrorist Networks" by Nasrullah Memon, Abdul Rasool Qureshi, Uffe Kock Wiil, and David L. Hicks in the Proceedings of the 2009 International Conference on Availability, Reliability and Security, March...... 2009, pp. 572-577 After careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication Principles. This paper contains significant portions of original text from the papers cited below...... be made to the following articles: "Balancing Systematic and Flexible Exploration of Social Networks" by Adam Perer, Ben Shneiderman in the IEEE Transactions on Visualization and Computer Graphics, Vol. 12, No. 5 Sept/Oct 2006, pp. 693-700 "Mining for Offender Group Detection and Story of a Police...

  16. Editorial for IEEE Transactions on Power Electronics

    DEFF Research Database (Denmark)

    Blaabjerg, Frede

    2007-01-01

    Our IEEE transactions on power electronics has had some very positive progress these past years under the leadership of Dr. Daan van Wyk. Papers have been processed efficiently both in review time and publication time. This success has spread throughout the whole power electronics community which...

  17. Editorial for IEEE Transactions on Power Electronics

    DEFF Research Database (Denmark)

    Blaabjerg, Frede

    2007-01-01

    Our IEEE transactions on power electronics has had some very positive progress these past years under the leadership of Dr. Daan van Wyk. Papers have been processed efficiently both in review time and publication time. This success has spread throughout the whole power electronics community which...

  18. IEEE 1547 and 2030 Standards for Distributed Energy Resources Interconnection and Interoperability with the Electricity Grid

    Energy Technology Data Exchange (ETDEWEB)

    Basso, T.

    2014-12-01

    Public-private partnerships have been a mainstay of the U.S. Department of Energy and the National Renewable Energy Laboratory (DOE/NREL) approach to research and development. These partnerships also include technology development that enables grid modernization and distributed energy resources (DER) advancement, especially renewable energy systems integration with the grid. Through DOE/NREL and industry support of Institute of Electrical and Electronics Engineers (IEEE) standards development, the IEEE 1547 series of standards has helped shape the way utilities and other businesses have worked together to realize increasing amounts of DER interconnected with the distribution grid. And more recently, the IEEE 2030 series of standards is helping to further realize greater implementation of communications and information technologies that provide interoperability solutions for enhanced integration of DER and loads with the grid. For these standards development partnerships, for approximately $1 of federal funding, industry partnering has contributed $5. In this report, the status update is presented for the American National Standards IEEE 1547 and IEEE 2030 series of standards. A short synopsis of the history of the 1547 standards is first presented, then the current status and future direction of the ongoing standards development activities are discussed.

  19. Risk Management Supplement to IEEE-15288.1

    Science.gov (United States)

    2015-05-15

    AND MISSILE SYSTEMS CENTER TAILORING RISK MANAGEMENT SUPPLEMENT TO IEEE -15288.1 APPROVED FOR PUBLIC RELEASE...IEC- IEEE -15288: 2015, SYSTEMS AND SOFTWARE ENGINEERING — SYSTEM LIFE CYCLE PROCESSES...1 2.2. IEEE -15288.1: 2015, STANDARD FOR APPLICATION OF SYSTEMS ENGINEERING ON DEFENSE PROGRAMS

  20. Impact of IEEE 1609.4 channel switching on the IEEE 802.11p beaconing performance

    NARCIS (Netherlands)

    Eenennaam, van Martijn; Venis, van de Anne; Karagiannis, Georgios

    2012-01-01

    The IEEE 802.11p Wireless Access in Vehicular Environment (WAVE) protocol can only transmit packets on one channel. To support multi-channel operations, channel switching procedures have been proposed in IEEE 1609.4. This paper provides an analysis of the beaconing performance of IEEE 802.11p when t

  1. Specialty Engineering Supplement to IEEE-15288.1

    Science.gov (United States)

    2015-05-15

    MISSILE SYSTEMS CENTER TAILORING SPECIALTY ENGINEERING SUPPLEMENT TO IEEE -15288.1 APPROVED FOR PUBLIC RELEASE; DISTRIBUTION...IS UNLIMITED 1 Tailoring of IEEE 15288.1: Specialty Engineering Supplement. 1. Intent of this Tailoring Document This tailoring document is...historically deemed valuable to mission assurance/success of high-reliability space systems. This tailoring document supplements IEEE 15288.1-2015 Annex E

  2. Proceedings of IEEE Machine Learning for Signal Processing Workshop XVI

    DEFF Research Database (Denmark)

    Larsen, Jan

    These proceedings contains refereed papers presented at the sixteenth IEEE Workshop on Machine Learning for Signal Processing (MLSP'2006), held in Maynooth, Co. Kildare, Ireland, September 6-8, 2006. This is a continuation of the IEEE Workshops on Neural Networks for Signal Processing (NNSP...... with sponsorship of the IEEE Signal Processing Society. Following the practice started three years ago, the bound volume of the proceedings is going to be published by IEEE following the Workshop, and we are pleased to offer to conference attendees the proceeding in a CDROM electronic format, which maintains...

  3. Proceedings of IEEE Machine Learning for Signal Processing Workshop XVI

    DEFF Research Database (Denmark)

    Larsen, Jan

    These proceedings contains refereed papers presented at the sixteenth IEEE Workshop on Machine Learning for Signal Processing (MLSP'2006), held in Maynooth, Co. Kildare, Ireland, September 6-8, 2006. This is a continuation of the IEEE Workshops on Neural Networks for Signal Processing (NNSP...... with sponsorship of the IEEE Signal Processing Society. Following the practice started three years ago, the bound volume of the proceedings is going to be published by IEEE following the Workshop, and we are pleased to offer to conference attendees the proceeding in a CDROM electronic format, which maintains...

  4. IEEE北京分会召开IEEE Fellow座谈会并举力IEEE Fellow讲坐

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ 2006年8月29日下午,IEEE北京分会(Beijing Section),在中国科学院自动化研究所召开IEEE Fellow座谈会.座谈会的主要议题是如何发挥我国IEEE Fellow的作用.会议由IEEE北京分会现任主席谭铁牛博士(自动化研究所所长,IEEE Fellow)主持,他向到会的IEEE Fellow,介绍了IEEE北京分会2006-2007年度的工作计划设想.

  5. IEEE 802.11 ECG monitoring system.

    Science.gov (United States)

    Tejero-Calado, Juan; Lopez-Casado, Carmen; Bernal-Martin, Antonio; Lopez-Gomez, Miguel; Romero-Romero, Marco; Quesada, Guillermo; Lorca, Julio; Rivas, Ramon

    2005-01-01

    New wireless technologies make possible the implementation of high level integration wireless devices which allow the replacement of traditional large wired monitoring devices. This kind of devices favours at-home hospitalization, reducing the affluence to sanitary assistance centers to make routine controls. This fact causes a really favourable social impact, especially for elder people, rural-zone inhabitant, chronic patients and handicapped people. Furthermore, it offers new functionalities to physicians and will reduce the sanitary cost. Among these functionalities, biomedical signals can be sent to other devices (screen, PDA, PC...) or processing centers, without restricting the patients' mobility. The aim of this project is the development and implementation of a reduced size multi-channel electrocardiograph based on IEEE 802.11, which allows wireless monitoring of patients, and the insertion of the information into the TCP/IP Hospital network.

  6. 7th IEEE International Conference Intelligent Systems

    CERN Document Server

    Atanassov, KT; Doukovska, L; Hadjiski, M; Jotsov, V; Kacprzyk, J; Kasabov, N; Sotirov, S; Szmidt, E; Zadrożny, S; Filev, D; Jabłkowski, J; Kacprzyk, J; Krawczak, M; Popchev, I; Rutkowski, L; Sgurev, V; Sotirova, E; Szynkarczyk, P

    2015-01-01

    This two volume set of books constitutes the proceedings of the 2014  7th IEEE International Conference Intelligent Systems (IS), or IEEE IS’2014 for short, held on September 24‐26, 2014 in Warsaw, Poland. Moreover, it contains some selected papers from the collocated IWIFSGN'2014-Thirteenth International Workshop on Intuitionistic Fuzzy Sets and Generalized Nets.The conference was organized by the Systems Research Institute, Polish Academy of Sciences, Department IV of Engineering Sciences, Polish Academy of Sciences, and Industrial Institute of Automation and Measurements - PIAP.The papers included in the two proceedings volumes have been subject to a thorough review process by three highly qualified peer reviewers.Comments and suggestions from them have considerable helped improve the quality of the papers but also the division of the volumes into parts, and assignment of the papers to the best suited parts.  

  7. 2012 IEEE Vehicular Networking Conference (VNC): Demo Summaries

    NARCIS (Netherlands)

    Altintas, Onur; Chen, Wai; Heijenk, Geert; Oh, Hyun Seo; Chung, Jong-Moon; Dressler, Falko; Kargl, Frank; Pau, Giovanni; Schoch, Elmar

    2012-01-01

    Preface Last year’s edition of IEEE VNC in Amsterdam included a very successful demonstration session in its program. Therefore, demonstrations are again part of the program of IEEE VNC 2012 in Seoul, Republic of Korea. Demonstrations play an important role to expose the research community to practi

  8. IEEE International Workshop on Machine Learning for Signal Processing: Preface

    DEFF Research Database (Denmark)

    Tao, Jianhua

    The 21st IEEE International Workshop on Machine Learning for Signal Processing will be held in Beijing, China, on September 18–21, 2011. The workshop series is the major annual technical event of the IEEE Signal Processing Society's Technical Committee on Machine Learning for Signal Processing...

  9. IEEE Standard Dictionary of Electrical and Electronics Terms.

    Science.gov (United States)

    Institute of Electrical and Electronics Engineers, Inc., New York, NY.

    This dictionary, prepared by the Institute of Electrical and Electronics Engineers, Inc. (IEEE), defines 13,000 technical words from every area of electrical and electronics engineering. The dictionary contains hundreds of new terms as well as revisions of earlier ones. Each definition is an official standard of IEEE. The definitions are arranged…

  10. IEEE International Workshop on Machine Learning for Signal Processing: Preface

    DEFF Research Database (Denmark)

    Tao, Jianhua

    The 21st IEEE International Workshop on Machine Learning for Signal Processing will be held in Beijing, China, on September 18–21, 2011. The workshop series is the major annual technical event of the IEEE Signal Processing Society's Technical Committee on Machine Learning for Signal Processing...

  11. IEEE Standard Dictionary of Electrical and Electronics Terms.

    Science.gov (United States)

    Institute of Electrical and Electronics Engineers, Inc., New York, NY.

    This dictionary, prepared by the Institute of Electrical and Electronics Engineers, Inc. (IEEE), defines 13,000 technical words from every area of electrical and electronics engineering. The dictionary contains hundreds of new terms as well as revisions of earlier ones. Each definition is an official standard of IEEE. The definitions are arranged…

  12. Proceedings of IEEE Machine Learning for Signal Processing Workshop XV

    DEFF Research Database (Denmark)

    Larsen, Jan

    These proceedings contains refereed papers presented at the Fifteenth IEEE Workshop on Machine Learning for Signal Processing (MLSP’2005), held in Mystic, Connecticut, USA, September 28-30, 2005. This is a continuation of the IEEE Workshops on Neural Networks for Signal Processing (NNSP) organized...... by the NNSP Technical Committee of the IEEE Signal Processing Society. The name of the Technical Committee, hence of the Workshop, was changed to Machine Learning for Signal Processing in September 2003 to better reflect the areas represented by the Technical Committee. The conference is organized...... by the Machine Learning for Signal Processing Technical Committee with sponsorship of the IEEE Signal Processing Society. Following the practice started two years ago, the bound volume of the proceedings is going to be published by IEEE following the Workshop, and we are pleased to offer to conference attendees...

  13. Proceedings of IEEE Machine Learning for Signal Processing Workshop XV

    DEFF Research Database (Denmark)

    Larsen, Jan

    These proceedings contains refereed papers presented at the Fifteenth IEEE Workshop on Machine Learning for Signal Processing (MLSP’2005), held in Mystic, Connecticut, USA, September 28-30, 2005. This is a continuation of the IEEE Workshops on Neural Networks for Signal Processing (NNSP) organized...... by the NNSP Technical Committee of the IEEE Signal Processing Society. The name of the Technical Committee, hence of the Workshop, was changed to Machine Learning for Signal Processing in September 2003 to better reflect the areas represented by the Technical Committee. The conference is organized...... by the Machine Learning for Signal Processing Technical Committee with sponsorship of the IEEE Signal Processing Society. Following the practice started two years ago, the bound volume of the proceedings is going to be published by IEEE following the Workshop, and we are pleased to offer to conference attendees...

  14. Performance comparison of IEEE 802.11g and IEEE 802.11n in the presence of interference from 802.15.4 networks

    OpenAIRE

    Masood, Syed Haani

    2013-01-01

    In this paper we compare the packet error rate (PER) and maximum throughput of IEEE 802.11n and IEEE 802.11g under interference from IEEE 802.15.4 by using MATLAB to simulate the IEEE PHY for 802.11n and 802.11g networks.

  15. Performance comparison of IEEE 802.11g and IEEE 802.11n in the presence of interference from 802.15.4 networks

    OpenAIRE

    Masood, Syed Haani

    2013-01-01

    In this paper we compare the packet error rate (PER) and maximum throughput of IEEE 802.11n and IEEE 802.11g under interference from IEEE 802.15.4 by using MATLAB to simulate the IEEE PHY for 802.11n and 802.11g networks.

  16. A versatile trigger and synchronization module with IEEE1588 capabilities and EPICS support

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, J.M., E-mail: juanmanuel.lopez@upm.e [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Universidad Politecnica de Madrid, Crta. Valencia Km-7, Madrid 28031 (Spain); Ruiz, M.; Borrego, J.; Arcas, G. de; Barrera, E. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Universidad Politecnica de Madrid, Crta. Valencia Km-7, Madrid 28031 (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain)

    2010-07-15

    Event timing and synchronization are two key aspects to improve in the implementation of distributed data acquisition (dDAQ) systems such as the ones used in fusion experiments. It is also of great importance the integration of dDAQ in control and measurement networks. This paper analyzes the applicability of the IEEE1588 and EPICS standards to solve these problems, and presents a hardware module implementation based in both of them that allow adding these functionalities to any DAQ. The IEEE1588 standard facilitates the integration of event timing and synchronization mechanisms in distributed data acquisition systems based on IEEE 803.3 (Ethernet). An optimal implementation of such system requires the use of network interface devices which include specific hardware resources devoted to the IEE1588 functionalities. Unfortunately, this is not the approach followed in most of the large number of applications available nowadays. Therefore, most solutions are based in software and use standard hardware network interfaces. This paper presents the development of a hardware module (GI2E) with IEEE1588 capabilities which includes USB, RS232, RS485 and CAN interfaces. This permits to integrate any DAQ element that uses these interfaces in dDAQ systems in an efficient and simple way. The module has been developed with Motorola's Coldfire MCF5234 processor and National Semiconductors's PHY DP83640T, providing it with the possibility to implement the PTP protocol of IEEE1588 by hardware, and therefore increasing its performance over other implementations based in software. To facilitate the integration of the dDAQ system in control and measurement networks the module includes a basic Input/Output Controller (IOC) functionality of the Experimental Physics and Industrial Control System (EPICS) architecture. The paper discusses the implementation details of this module and presents its applications in advanced dDAQ applications in the fusion community.

  17. A versatile trigger and synchronization module with IEEE1588 capabilities and Epics support

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, J.M.; Ruiz, M.; Borrego, J.; Arcas, G. de; Barrera, E. [Universidad Politecnica de Madrid, Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Madrid (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion. Madrid (Spain)

    2009-07-01

    Event timing and synchronization are two key aspects to improve the implementation of distributed data acquisition (dDAQ) systems such as the ones used in fusion experiments. It is very important to integrate dDAQ in control and measurement networks. This poster analyzes the applicability of the IEEE 1588 and EPICS standards to solve these problems, and presents a hardware module implementation based in both of them that allow adding these functionalities to any DAQ. The IEEE1588 standard facilitates the integration of event timing and synchronization mechanisms in distributed data acquisition systems based on IEEE 803.3 (Ethernet). An optimal implementation of such system requires the use of network interface devices which include specific hardware resources devoted to the IEE1588 functionalities. Unfortunately, this is not the approach followed in most of the large number of applications available nowadays. Therefore, most solutions are based in software and use standard hardware network interfaces. This paper presents the development of a hardware module (GI2E) with IEEE 1588 capabilities which includes USB, RS232, RS485 and CAN interfaces. This permits the integration of any DAQ element that uses these interfaces in dDAQ systems in an efficient and simple way. The module has been developed with Motorola's Coldfire MCF5234 processor and National Semiconductors's PHY DP83640T, providing it with the possibility to implement the PTP protocol of IEEE 1588 by hardware, and therefore increasing its performance over other implementations based in software. To facilitate the integration of the dDAQ system in control and measurement networks the module includes a basic IOC (Input Output Controller) functionality of the EPICS (Experimental Physics and Industrial Control System) architecture. This document is a poster. (authors)

  18. Active Channel Reservation for Coexistence Mechanism (ACROS) for IEEE 802.15.4 and IEEE 802.11

    Science.gov (United States)

    Shin, Soo Young; Woo, Dong Hyuk; Lee, Jong Wook; Park, Hong Seong; Kwon, Wook Hyun

    In this paper, a coexistence mechanism between IEEE 802.15.4 and IEEE 802.11b, Active Channel Reservation for cOexiStence (ACROS), is proposed. The key idea underlining ACROS is to reserve the channel for IEEE 802.15.4 transmission, where IEEE 802.11 transmissions are forbidden. The request-to-send (RTS)/clear-to send (CTS) mechanism within IEEE 802.11 is used to reserve a channel. The proposed ACROS mechanism is implemented into a PC based prototype. The embedded version of ACROS is also developed to mitigate the timing drift problem in the PC-based ACROS. The efficiency of ACROS is shown using the throughput and packet error rate achieved in actual experiments.

  19. Application of IEEE 1588 in LXI testing system%LXI测试系统中IEEE 1588的应用

    Institute of Scientific and Technical Information of China (English)

    Bob Rennard; Agilent Technologies

    2009-01-01

    LXI联盟是主要测试和测量厂商的一个组织,负责开拓基于LAN通信和融合IEEE 1588的模块化、分布式的仪器体系结构.本文将概要说明与 IEEE 1588相关的LXI规范,以及如何在基于LXI测试和测最系统中用IEEE 1588建立时基.

  20. A COMPARISON OF IMPROVED AODV ROUTING PROTOCOL BASED ON IEEE 802.11 AND IEEE 802.15.4

    OpenAIRE

    2009-01-01

    Recently, wireless network industry for the ubiquitous generation is growing quickly. Especially, IEEE 802.15.4 is one of special issues of the networking technology for sensor network. Then, many researchers are studying it for enhanced performance. But many researchers are not focusing on developing routing protocol. So we had proposed improved AODV routing protocol in previous research. But it had studied about performance analysis based on IEEE 802.11. In this paper, we proposed improved ...

  1. Delay Analysis of GTS Bridging between IEEE 802.15.4 and IEEE 802.11 Networks for Healthcare Applications.

    Science.gov (United States)

    Misić, Jelena; Sherman Shen, Xuemin

    2009-01-01

    We consider interconnection of IEEE 802.15.4 beacon-enabled network cluster with IEEE 802.11b network. This scenario is important in healthcare applications where IEEE 802.15.4 nodes comprise patient's body area network (BAN) and are involved in sensing some health-related data. BAN nodes have very short communication range in order to avoid harming patient's health and save energy. Sensed data needs to be transmitted to an access point in the ward room using wireless technology with higher transmission range and rate such as IEEE 802.11b. We model the interconnected network where IEEE 802.15.4-based BAN operates in guaranteed time slot (GTS) mode, and IEEE 802.11b part of the bridge conveys GTS superframe to the 802.11b access point. We then analyze the network delays. Performance analysis is performed using EKG traffic from continuous telemetry, and we discuss the delays of communication due the increasing number of patients.

  2. Simulasi Kinerja Jaringan Nirkabel IEEE-802.11a dan IEEE-802.11g Menggunakan NS-2

    Directory of Open Access Journals (Sweden)

    Helm Fitriawan

    2014-03-01

    Full Text Available Wireless network uses transmission media based on radio waves. This type of networks is mainly useddue to its efficiency and mobility in data exchanging. This paper reports the modeling and simulation of wirelessnetworks based on Cisco Aironet 1130ag access point devices with IEEE 802.11a and IEEE 802.11g standards. Themodeling and simulation are performed using network simulator version 2 (NS-2 that is installed on operationsystem Linux Ubuntu v.10.10. The NS-2 is commonly used and works well in numerous types of network simulation. From simulation, we obtain quality of service parameters by employing several simulation scenarios in terms ofnumber of nodes, distances, and packet data sizes. It can be concluded from simulation results that the IEEE 802.11gnetworks transfer data with better quality than those of IEEE 802.11a networks.  Furthermore, the IEEE 802.11gnetworks provide a higher throughput, with smaller amount of delay and packet loss percentage compared to thoseof IEEE 802.11a networks.

  3. A Kennedy Space Center implementation of IEEE 1451

    Science.gov (United States)

    Oostdyk, Rebecca L.; Mata, Carlos T.; Perotti, José M.; Lucena, Angel R.; Mullenix, Pamela A.

    2006-05-01

    To meet the demand for more reliable sensory data, longer sensor calibration cycles, and more useful information for operators at NASA's Kennedy Space Center (KSC), NASA's Instrumentation Branch and ASRC's Advanced Electronics and Technology Development Laboratory at the KSC are developing custom intelligent sensors based on the IEEE 1451 family of smart-sensor standards. The KSC intelligent sensors are known as Smart Networked Elements (SNEs), and each SNE includes transducers and their associated Transducer Electronic Data Sheets (TEDS), signal conditioning, analog-to-digital conversion, software algorithms for performing health checks on the data, and a network connection for sending data to other SNEs and higher-level systems. The development of the SNE has led to the definition of custom architectures, protocols, IEEE 1451 implementations, and TEDS, which are presented in this paper. The IEEE 1451 standards describe the architecture, message formats, software objects, and communication protocols within the smart sensor. Because of the standard's complexity, KSC has simplified the IEEE 1451 architecture and narrowed the scope of software objects to be included in the SNE to create a "light" IEEE 1451 implementation, and has used the manufacturer-defined TEDS to customize the SNE with health indicators. Furthermore, KSC has developed a protocol that allows the SNEs to communicate over an Ethernet network while reducing bandwidth requirements.

  4. Implicit Block ACK Scheme for IEEE 802.11 WLANs

    Science.gov (United States)

    Sthapit, Pranesh; Pyun, Jae-Young

    2016-01-01

    The throughput of IEEE 802.11 standard is significantly bounded by the associated Medium Access Control (MAC) overhead. Because of the overhead, an upper limit exists for throughput, which is bounded, including situations where data rates are extremely high. Therefore, an overhead reduction is necessary to achieve higher throughput. The IEEE 802.11e amendment introduced the block ACK mechanism, to reduce the number of control messages in MAC. Although the block ACK scheme greatly reduces overhead, further improvements are possible. In this letter, we propose an implicit block ACK method that further reduces the overhead associated with IEEE 802.11e’s block ACK scheme. The mathematical analysis results are presented for both the original protocol and the proposed scheme. A performance improvement of greater than 10% was achieved with the proposed implementation.

  5. Design and implementation of IEEE 802.11ac MAC controller in 65 nm CMOS process

    Science.gov (United States)

    Peng, Cheng; Bin, Wu; Yong, Hei

    2016-02-01

    An IEEE-802.11ac-1*1 wireless LAN system-on-a-chip (SoC) that integrates an analog front end, a digital base-band processor and a media access controller has been implemented in 65 nm CMOS technology. It can provide significantly increased throughput, high efficiency rate selection, and fully backward compatibility with the existing 802.11a/n WLAN protocols. Especially the measured maximum throughput of UDP traffic can be up to 267 Mbps. Project supported by the National Great Specific Project of China (No. 2012ZX03004004_001).

  6. New IEEE standard enables data collection for medical applications.

    Science.gov (United States)

    Kennelly, R J; Wittenber, J

    1994-01-01

    The IEEE has gone to ballot on a "Standard for Medical Device Communications", IEEE P1073. The lower layer, hardware portions of the standard are expected to be approved by the IEEE Standards Board at their December 11-13, 1994 meeting. Other portions of the standard are in the initial stages of the IEEE ballot process. The intent of the standard is to allow hospitals and other users to interface medical electronic devices to host computer systems in a standard, interchangeable manner. The standard is optimized for acute care environments such as ICU's, operating rooms, and emergency rooms. [1] IEEE General Committee and Subcommittee work has been on-going since 1984. Significant amounts of work have been done to discover and meet the needs of the patient care setting. Surveys performed in 1989 identified the following four key user requirements for medical device communications: 1) Frequent reconfiguration of the network. 2) Allow "plug and play" operation by users. 3) Associate devices with a specific bed and patient. 4) Support a wide range of hospital computer system topologies. Additionally, the most critical difference in the acute care setting is patient safety, which has an overall effect on the standard. The standard that went to ballot meets these requirements. The standard is based on existing ISO standards. P1073 is compliant with the OSI seven layer model. P1073 specifies the entire communication stack, from object-oriented software to hospital unique connectors. The standard will be able to be put forward as a true international standard, much in the way that the IEEE 802.x family of standards (like Ethernet) were presented as draft ISO standards.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. System Behavior Specification Using IEEE Std 1175.4

    Science.gov (United States)

    2010-04-27

    22nd Annual Systems & Software Technology Conference S stem Beha ior Specification1 7 y v Using IEEE Std 1175.4 e v i e w 5 2 8 1 2 R 27 April...DATE 27 APR 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE System Behavior Specification Using IEEE Std ...RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std

  8. IEEE 802.15.4 Modifications and Their Impact

    Directory of Open Access Journals (Sweden)

    M. Goyal

    2011-01-01

    Full Text Available IEEE 802.15.4 is a popular choice for MAC/PHY protocols in low power and low data rate wireless sensor networks. In this paper, we suggest several modifications to beaconless IEEE 802.15.4 MAC operation and evaluate their impact on the performance via stochastic modeling and simulations. We found that the utility of these modifications is strongly dependent on the traffic load on the network. Accordingly, we make recommendations regarding how these modifications should be used in view of the prevalent traffic load on the network.

  9. IEEE prize awarded to CERN PhD student

    CERN Multimedia

    2006-01-01

    Rafael Ballabriga Suñe is the recipient of the 2006 Institute of Electrical and Electronics Engineers, Inc. (IEEE) Nuclear and Plasma Sciences Society (NPSS)'s Student Paper Award. Ballabriga's winning paper reported on a prototype chip, which belongs to a new generation of single photon counting hybrid pixel detector readout chips - Medipix3. The award was presented by the deputy programme chair Vince Cianciolo (left) at the IEEE Nuclear Science Symposium held in San Diego on 29 October to 4 November.

  10. Research on IEEE 802.11 wireless local area networks standards%IEEE802.11无线局域网标准研究

    Institute of Scientific and Technical Information of China (English)

    李浩; 高泽华; 高峰; 赵荣华

    2009-01-01

    介绍了IEEE 802.11全系列标准,研究了IEEE 802.11系列各标准的发展轨迹和相互关系,建立了该系列标准的层次模型.研究并分析了IEEE 802.11、IEEE 802.11a、IEEE 802.11b、IEEE 802.11g和IEEE 802.11n这几种常见标准,并对相应物理层和媒质访问控制层的关键技术作了重点分析.

  11. 适用于数字化变电站的IEEE1588测试仪的研制%Development of IEEE1588 tester for digital substation

    Institute of Scientific and Technical Information of China (English)

    陈炯聪; 崔全胜; 魏勇; 郑运召

    2012-01-01

    According to IEEE 1588 protocol testing requirements in digital substation, a development scheme of IEEE1588 tester for digital substation is proposed. The scheme analyzes the IEEE1588 tester's system functional requirements, introduces its hardware & software design, and studies the control mode of test cases and test automation implementation. Using the closed loop test system, IEEE1588 conformance testing of intelligent devices in digital substation can be achieved. The practical testing application shows that the tester can correctly perform real-time closed-loop IEEE] 588 conformance testing of intelligent devices, can significantly improve the testing efficiency of IEEE1588 protocol, so it can ensure the accuracy and reliability of IEEE1588 protocol implementation of intelligent devices.%针对数字化变电站中智能设备的IEEE1588协议测试需求,提出了一种适用于数字化变电站的IEEE1588测试仪的研制方案.该方案分析了IEEE1588测试仪的系统功能要求、介绍了其硬件及软件设计,并研究了测试案例控制模式和测试自动化实现.利用该测试仪构成的闭环测试系统,可以实现数字化变电站中智能设备的IEEE1588协议一致性测试.实际应用效果表明该测试仪能正确完成智能设备的IEEE1588协议实时闭环测试,可显著提高智能设备IEEE1588协议测试效率,确保智能设备IEEE1588协议实现的正确性和可靠性.

  12. 基于IEEE1149.1及IEEE1149.4标准的测试技术研究%Study of test techniques based on IEEE1149.1 and IEEE1149.4

    Institute of Scientific and Technical Information of China (English)

    苏波

    2012-01-01

    With rapid development of electronic technology, the integrated degree of circuits has greatly increased) more and more problems have to be faced in the field of test. The technology of DFT( design for testability) is one of the key solutions to deal with the problems of test. And the boundary-scan technology is a kind of the DFT methods, which is used widely. With intensive study on IEEE std 1149. 4 and IEEE std 1149.1 .this paper explores the testability structure based on boundary-scan,the result of the paper has important theory value and practical significance.%随着电子技术的飞速发展,电路的集成度越来越高,使其测试面临越来越多的问题.可测性设计成为解决测试问题的主要手段之一,而边界扫描技术是众多可测性设计方法中使用较为广泛的一种.在深入研究IEEE1149.1及IEEE1149.4标准的基础上,对基于边界扫描可测性结构进行了探索,具有重要的理论价值和实际意义.

  13. Local Positioning Services on IEEE 802.11 Networks

    Directory of Open Access Journals (Sweden)

    A. M. Vegni

    2008-06-01

    Full Text Available This paper deals with localization services in IEEE 802.11 networks, for indoor environment. The proposed solution processes the Time Of Arrival of location packets sent by a Mobile Terminal, that makes access in a IEEE 802.11 network. A set of Location Supporting Nodes and a Location Support Server composes an indoor location services architecture. A fully compatible IEEE 802.11 Localization Services protocol supporting data exchange related to both TOA measurement and processing is reported. Simulation results show the method efficiency in both IEEE 802.11 PCF and DCF modes. Assessment of the maximum number of users for which location services can be provided is also reported. Since high localization accuracy requires large bandwidth, a broadband antenna for LSN and LSS was designed. The related results are reported in the second part of the paper. The antenna works at 5.0 GHz (centre frequency in broadband mode and is matched on the wireless operating frequencies with a percentage more than 8% (1:1.5 VSWR.

  14. Editorial for IEEE Transactions on Power Electronics, January 2013

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Lehman, Brad

    2013-01-01

    should increase the impact factor of the IEEE TRANSACTIONS ON POWER ELECTRONICS (TPEL). In 2007, TPEL published 2600 pages, and it has gradually been increased to 4000 pages in 2011, 5000 pages in 2012, and 5500 pages are projected for 2013. We have decided to publish 12 printed issues so every month...

  15. Eleanor McElwee and the Formation of IEEE PCS

    Science.gov (United States)

    Malone, Edward A.

    2015-01-01

    This article examines the historical professional project that created the Institute of Radio Engineers' Professional Group on Engineering Writing an Speech (IRE PGEWS)--now called the Institute of Electrical and Electronics Engineers' Professional Communication Society (IEEE PCS)--and recounts the group's early history in detail. It also traces…

  16. Editorial for the IEEE Transactions on Power Electronics, January 2009

    DEFF Research Database (Denmark)

    Blaabjerg, Frede

    2009-01-01

    I am entering the fourth year as the Editor in Chief of the IEEE TRANSACTIONS ON POWER ELECTRONICS. A position like this becomes more and more important for the technical field as publishing in a peer-reviewed highly ranked journal has influence on the industrial and academic career. It is a way...

  17. Proceedings of the IEEE Machine Learning for Signal Processing XVII

    DEFF Research Database (Denmark)

    The seventeenth of a series of workshops sponsored by the IEEE Signal Processing Society and organized by the Machine Learning for Signal Processing Technical Committee (MLSP-TC). The field of machine learning has matured considerably in both methodology and real-world application domains and has...

  18. Eleanor McElwee and the Formation of IEEE PCS

    Science.gov (United States)

    Malone, Edward A.

    2015-01-01

    This article examines the historical professional project that created the Institute of Radio Engineers' Professional Group on Engineering Writing an Speech (IRE PGEWS)--now called the Institute of Electrical and Electronics Engineers' Professional Communication Society (IEEE PCS)--and recounts the group's early history in detail. It also traces…

  19. A timed verification of the IEEE 1394 leader election protocol

    NARCIS (Netherlands)

    Romijn, J.M.T.

    1999-01-01

    The IEEE 1394 architecture standard defines a high performance serial multimedia bus that allows several components in a network to communicate with each other at high speed. In the physical layer of the architecture, a leader election protocol is used to find a spanning tree with a unique root in t

  20. Enhancing MAC performance of DCF protocol for IEEE 802.11 wireless LANs

    National Research Council Canada - National Science Library

    Woo-Yong Choi

    2017-01-01

    ...) protocol of IEEE 802.11 wireless LANs and compatible with various IEEE 802.11 PHY extensions. The performance of the DCF degrades exponentially as the number of nodes participating in the DCF transmission procedure increases...

  1. Approximation of the IEEE 802.11p standard using commercial off-the-shelf IEEE 802.11a hardware

    OpenAIRE

    2011-01-01

    IEEE 802.11p hardware is hard to find. Previous research efforts often relied on project-specific prototype implementations which are characterized by a high cost and are not always available to the entire research community. Commercially available turnkey implementations are rare and quite expensive compared to commercial of-the-shelf (COTS) IEEE 802.11a/b/g hardware. However, the difference between the IEEE 802.11p amendment and the other IEEE 802.11 standards is quite small. It can be seen...

  2. RATE ADAPTIVE PROTOCOL FOR MULTIRATE IEEE 802.11 NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Xi Yong; Huang Qingyan; Wei Jibo; Zhao Haitao

    2007-01-01

    In this paper,a rate adaptive protocol AMARF(Adaptive Multirate Auto Rate Fallback)for multirate IEEE 802.11 networks is proposed.In AMARF,each data rate is assigned a unique success threshold,which is a criterion to judge when to switch a rate to the next higher one,and the success thresholds call be adjusted dynamically in an adaptive manner according to the running conditions,such as packet length and channel parameters.Moreover,the proposed protocol can be implemented by software without any change to the current IEEE 802.11 standards.Simulation result shows that AMARF yields significantly higher throughput than other existing schemes including ARF and its variants,in various running conditions.

  3. Performance analysis of IEEE 802.11 DCF networks

    Institute of Scientific and Technical Information of China (English)

    Krzysztof SZCZYPIORSKI; Jázef LUBZCZ

    2008-01-01

    This paper presents an analytical saturation throughput model of IEEE 802.11DCF (distributed coordination function)with basic access in ad hoc mode. The model takes into account freezing of the backoff timer when a station senses busy channel.It is shown that taking into account this feature of DCF is important in modeling saturation throughput by yielding more accurate and realistic results than models known from literature. The proposed analytical model also takes into account the effect of transmission errors. All essential features of the proposed analytical approach are illustrated with numerical results. The presen-tation of the model is proceeded by an overview of approaches to IEEE 802.11 network performance evaluation presented in the literature.

  4. Avago首席科学家荣获IEEE Fellow奖

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Avago Technologies(安华高科技)宣布John Larson Ⅲ博士在英国哥伦比亚范库弗峰州举办的2006年国际超声波研讨会上荣获知名的IEEE Fellow奖。IEEE Fellow奖由专业人员提名产生,旨在表彰在各个工程设计领域中取得杰出成绩的人才。Avago Technologies(安华高科技)是为先进的通信、工业和商业等应用领域提供创新的半导体解决方案的领导厂商。

  5. IEEE prize awarded to CERN PhD student

    CERN Multimedia

    2006-01-01

    Rafael Ballabriga Suñe (right) receives the Student Paper Award. Rafael Ballabriga Suñe is the recipient of the 2006 Institute of Electrical and Electronics Engineers, Inc. (IEEE) Nuclear and Plasma Sciences Society (NPSS)'s Student Paper Award. Ballabriga's winning paper reported on a prototype chip, which belongs to a new generation of single photon counting hybrid pixel detector readout chips - Medipix3. The NPSS established this award in 2005 to encourage outstanding student contributions and greater student participation as principle or sole authors of papers. The prizes were presented at the IEEE Nuclear Science Symposium held in San Diego on 29 October to 4 November. The prototype chip was designed by Ballabriga based on ideas generated within the CERN Medipix team - part of the PH Microelectronics group. It could be used in various fields in the future, including medical imaging, neutron imaging, electron microscopy, radiation monitoring and other applications in high-energy physics. The novel aspe...

  6. Interoperability in wireless sensor networks based on IEEE 1451 standard

    OpenAIRE

    Higuera Portilla, Jorge Eduardo; Polo Cantero, José

    2012-01-01

    The syntactic and semantic interoperability is a challenge of the Wireless Sensor Networks (WSN) with smart sensors in pervasive computing environments to increase their harmonization in a wide variety of applications. This chapter contains a detailed description of interoperability in heterogeneous WSN using the IEEE 1451 standard. This work focuses on personal area networks (PAN) with smart sensors and actuators. Also, a technical, syntactic and semantic levels of interoperability based on ...

  7. Interoperability in wireless sensor networks based on IEEE 1451 standard

    OpenAIRE

    Higuera Portilla, Jorge Eduardo; Polo Cantero, José

    2012-01-01

    The syntactic and semantic interoperability is a challenge of the Wireless Sensor Networks (WSN) with smart sensors in pervasive computing environments to increase their harmonization in a wide variety of applications. This chapter contains a detailed description of interoperability in heterogeneous WSN using the IEEE 1451 standard. This work focuses on personal area networks (PAN) with smart sensors and actuators. Also, a technical, syntactic and semantic levels of interoperability based on ...

  8. 认识IEEE1394端口

    Institute of Scientific and Technical Information of China (English)

    王玉岭

    2005-01-01

    Apple称之为FireWire(火线)Sony称之为i.Link Texas Instruments称之为Lynx。尽管各厂商注册的商标名称不同,但实质都是一项技术,那就是IEEE1394。为什么PC业界对其会如此着迷呢?

  9. 17th IEEE NPSS Real Time Conference – RT-2010

    CERN Multimedia

    Carlos Varandas

    2010-01-01

    Congress Centre of “Instituto Superior Técnico”, Lisboa, Portugal, 24-28 May, 2010 ABSTRACT SUBMISSION OPEN Abstract Submission Deadline: March 1st, 2010 Dear Sir/Madam, We are pleased to announce that abstract submission for the 17th IEEE NPSS Real Time Conference is now open on our web site. The deadline for submitting an abstract is 1st March 2010. Full conference details General Chairman

  10. Performance Analysis of the IEEE 802.11s PSM

    Directory of Open Access Journals (Sweden)

    Mirza Nazrul Alam

    2012-01-01

    Full Text Available With the introduction of IEEE 802.11 power save mode (PSM, a lot of work has been done to enhance the energy saving ability of the wireless nodes. The ultimate goal of the research is to make the networking equipment carbon neutral and prolong the lifetime of the energy limited device for various applications; in some cases it is a trade-off between energy efficiency and delay. However, few studies have been made until now in the area of IEEE 802.11s based link specific power mode. The essence of this method is the ability of a node to maintain different power modes with its different peer nodes at the same time. A new peer service period (PSP mechanism is also proposed in IEEE 802.11s amendment for transmitting to a receiver operating in PSM. In this paper the performance of the link specific power mode is studied for a single- and a multilink network in terms of energy, delay throughput, and sleep duration. It is found that at small load the energy saving could be as high as eighty percent when compared with the active mode operation. A stochastic model, based on discrete time discrete state Markov chain, is developed for one peer link operation to study the system behavior closely during PSM operation.

  11. FIRST CALL FOR PAPERS The Second IEEE Pacific-Rim Conference on Multimedia

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Oct. 24~26, 2001, Beijing, China http://research.microsoft.com/~PCM2001. IEEE Signal Processing Society, IEEE Circuits and Systems Society National Science Foundation of China IEEE China, Electronics Society Of China, China Society of Electronics China Society of Computers, China Society of Image and Graphics   The second IEEE Pacific-Rim Conference on Multimedia will be held in Beijing in the next “golden autumn”. Beijing has been the culture capital of Chinese for near one thousand years with many historical palaces, magnificent museums and beautiful parks, as well as rich culture activities. In the last decade, Beijing has also witnessed spectacular growth of hi-tech industry, especially in the Internet and multimedia applications areas. The conference site, Zhongguangchun, known as China's Silicon Valley, is the national center of research, development and education with hundreds of universities and research institutions, and many successful companies providing both multimedia content and systems expertise. The conference complements this wonderful setting by providing a forum to presenting and exploring technological and artistic advancements in multimedia. Technical issues, theory and practice, artistic and consumer innovations will bring together researchers, artists, developers, educators, performers, and practitioners of multimedia from Pacific-Rim and the world. Present your work at PCM2001 and define the future of multimedia in the next millennium!   The technical program will feature keynote addresses, tutorials, special sessions, panels, technical demonstrations, in addition to technical presentations of refereed papers. We cordially invite you to submit your work in one or more of about forms for, but not limited to, the following three areas:   Multimedia processing and coding, including multimedia processing and compression, content analysis, content-based retrieval, watermarking and security;   Multimedia system support and

  12. 基于IEEE802.11p/1609标准的路车互联网的初步实现%Preliminary implementation of road-car network based on IEEE 802.11 p/1609

    Institute of Scientific and Technical Information of China (English)

    金纯; 徐洪刚; 魏星; 罗志峰; 何山

    2011-01-01

    To improve passenger safety, reduce traffic congestion, this paper proposed road-car network which was able to communicate with each other through the vehicles based on IEEE 802. 11p/1609 , and simulated and analysed the communication between the OBU and RSU, As a result, the communication between RSU and OBU seemed relatively stable, low packet loss rate. This result shows good performance under the standard of IEEE 802.11p/1609 which is also a step forward for the future popularity and the industrialization of the national intelligent transportation syslem( ITS).%为了能够通过车辆之间的相互通信来提高旅客的安全性、减少交通拥堵等,基于IEEE 802.11p/1609标准,提出了路车互联网的概念,并对路车互联网中RSU(路边单元)和OBU(车载单元)之间的通信进行了仿真和分析.仿真结果表明,RSU和OBU之间的通信比较稳定,丢包率也较低,显示在车载环境下IEEE 802.11p/1609协议较好的性能,这也为未来国家智能交通系统的普及和产业化发展迈进了一步.

  13. Coexistence of IEEE 802.11b/g WLANs and IEEE 802.15.4 WSNs: Modeling and Protocol Enhancements

    NARCIS (Netherlands)

    Yuan, W.

    2011-01-01

    As an emerging short-range wireless technology, IEEE 802.15.4/ZigBee Wireless Sensor Networks (WSNs) are increasingly used in the fields of home control, industrial control, consumer electronics, energy management, building automation, telecom services, personal healthcare, etc. IEEE

  14. Coexistence of IEEE 802.11b/g WLANs and IEEE 802.15.4 WSNs: Modeling and Protocol Enhancements

    NARCIS (Netherlands)

    Yuan, W.

    2011-01-01

    As an emerging short-range wireless technology, IEEE 802.15.4/ZigBee Wireless Sensor Networks (WSNs) are increasingly used in the fields of home control, industrial control, consumer electronics, energy management, building automation, telecom services, personal healthcare, etc. IEEE 802.15.4/Zig-Be

  15. PRIORITY BASED UPLINK SCHEDULER FOR IEEE 802.16 NETWORKS

    Directory of Open Access Journals (Sweden)

    Gurpreet Singh,

    2011-06-01

    Full Text Available IEEE 802.16, the standard for fixed, portable and mobile Broadband Wireless Access (BWA systems, is promising to support different classes of traffic with Quality of Service (QoS. The Medium Access Control (MAC protocol defines a wide variety of mechanisms for bandwidth allocation and QoS provision. However, the details of how to schedule traffic are left unspecified. In this paper, we propose ascheduling strategy for uplink traffic. Simulation results show that our scheme is capable to provide required QoS.

  16. 15th IEEE International Conference on Intelligent Engineering Systems

    CERN Document Server

    Živčák, Jozef; Aspects of Computational Intelligence Theory and Applications

    2013-01-01

    This volume covers the state-of-the art of the research and development in various aspects of computational intelligence and gives some perspective directions of development. Except the traditional engineering areas that contain theoretical knowledge, applications, designs and projects, the book includes the area of use of computational intelligence in biomedical engineering. „Aspects of Computational Intelligence: Theory and Applications” is a compilation of carefully selected extended papers written on the basis of original contributions presented at the 15th IEEE International Conference on Intelligent Engineering Systems 2011, INES 2011 held at June 23.-26. 2011 in AquaCity Poprad, Slovakia.    

  17. 基于IEEE1149.7的TAP控制器命令研究%Commands of TAP controller based on IEEE1149.7

    Institute of Scientific and Technical Information of China (English)

    江坤; 高俊强

    2013-01-01

    随着待测芯片的集成度越来越高,IEEE 1149.1标准已很难满足芯片设计对测试与调试的要求.IEEE1149.7标准在保持与IEEE1149.1兼容的基础上增加了新功能,提供了一种全新的双引脚测试与调试方法.目前对IEEE1149.7的研究处于起步阶段,所以研究支持其的控制器命令对今后的发展具有重要的意义.本文在深入研究IEEE 1149.7标准的基础上,利用Quartus Ⅱ开发平台设计了基于TAP控制器命令的测试控制器,并进行了仿真验证.结果表明产生的命令测试信号符合IEEE 1149.7标准对TAP控制器命令的规定.%With the increasing integration of test chip,IEEE 1149.1 has been difficult to meet the requirements of the chip testing and designing.Being compatible with IEEE 1149.1,IEEE 1149.7 provides a new two-pin test and debug methods.Because IEEE 1149.7 is still in the initial stage,to study its commands of controller is of great significance on the future development of IEEE 1149.7.This paper is based on the deep study of IEEE 1149.7 standard,to design a test controller based on the commands of TAP controller by using QuartusⅡ platform and perform simulation verification.The result shows that the test signal generated by the controller can meet the requirements of IEEE 1149.7.

  18. Extending Service Area of IEEE 802.11 Ad Hoc Networks

    Science.gov (United States)

    Choi, Woo-Yong

    2012-06-01

    According to the current IEEE 802.11 wireless LAN standards, IEEE 802.11 ad hoc networks have the limitation that all STAs (Stations) are in the one-hop transmission range of each other. In this paper, to alleviate the limitation of IEEE 802.11 ad hoc networks we propose the efficient method for selecting the most appropriate pseudo AP (Access Point) from among the set of ad hoc STAs and extending the service area of IEEE 802.11 ad hoc networks by the pseudo AP's relaying the internal traffic of IEEE 802.11 ad hoc networks. Numerical examples show that the proposed method significantly extends the service area of IEEE 802.11 ad hoc networks.

  19. The First IEEE International Symposium On Industrial Electronics Held in Xi'an

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    The First IEEE International symposium on Industrial Electronics (ISIE) was held at Holiday Inn,xian, P.R.China on May 25-29,1992. The symposium was jointly sponsored by the IEEE Industrial Electronics Society(IES), the IEEE Beijing Section, the Society of Instrument and Control Engineers((?)pan), and the Shaanxi Provincial science and Technology Commission, in cooperation with Northwestern Polytechnieal University(NPU), Xian Jiaotong University and Xidian University.

  20. Wireless Coexistence between IEEE 802.11- and IEEE 802.15.4-Based Networks: A Survey

    OpenAIRE

    2011-01-01

    As more and more wireless devices use the 2.4 GHz radio spectrum, the coexistence of 2.4 GHz wireless devices operating in one place has become a hot topic. With low transmit power, the widely deployed IEEE 802.15.4-based networks are easily interfered with by other 2.4 GHz wireless networks, such as IEEE 802.11. IEEE 802.15.4-based wireless networks have paid great attention to the coexistence between themselves and with other non-IEEE 802.15.4 wireless networks. This problem has been furthe...

  1. Effective Bandwidth Utilization in IEEE802.11 for VOIP

    CERN Document Server

    Bhanu, S Vijay; Balakrishnan, V

    2010-01-01

    Voice over Internet protocol (VoIP) is one of the most important applications for the IEEE 802.11 wireless local area networks (WLANs). For network planners who are deploying VoIP over WLANs, one of the important issues is the VoIP capacity. VoIP bandwidth consumption over a WAN is one of the most important factors to consider when building a VoIP infrastructure. Failure to account for VoIP bandwidth requirements will severely limit the reliability of a VoIP system and place a huge burden on the WAN infrastructure. Less bandwidth utilization is the key reasons for reduced number of channel accesses in VOIP. But in the QoS point of view the free bandwidth of atleast 1-5% will improve the voice quality. This proposal utilizes the maximum bandwidth by leaving 1-5% free bandwidth. A Bandwidth Data rate Moderation (BDM) algorithm has been proposed which correlates the data rate specified in IEEE802.11b with the free bandwidth. At each time BDM will calculate the bandwidth utilization before sending the packet to i...

  2. Vulnerability and Attack of Routing Protocol in IEEE 802.11s%IEEE802.11s路由协议漏洞与攻击

    Institute of Scientific and Technical Information of China (English)

    杜尚鑫; 易平; 罗庆华

    2012-01-01

    IEEE802.11s是IEEE关于无线Mesh网络的规范。802.1ls虽然沿用了IEEE802.11i的安全规范,但是对于路由协议的安全并没有做过多的定义,由此产生了一定的安全隐患。文章分析了IEEE802.11s标准f草案)中的路由协议的漏洞,并针对IEEE802.1ls中使用的混合无线网状网协议(Hybrid WirelessMesh Protocol,HWMP)设计了两种攻击方式,从而破坏无线网状网络的可用性。通过在自行设计的路由器平台上实现无线攻击,并分析攻击对网络造成的影响来验证安全漏洞的存在性和可利用性。%IEEE802.1 l s is the IEEE specification of wireless Mesh network. Although 802.11s follows the IEEE 802.11i security specification, there is no much specification for routing protocol security. The routing protocol vulnerabilities in IEEE802.1 Is standard(draft) are analyzed, and two kinds of attacks aiming at HWMP(Hybrid Wireless Mesh Protocol) routing protocol used in the IEEE 802.11s are designed, thus to undermine the availability of wireless Mesh network. This paper analyzes the impact of attacks on wireless network and tells of the existence and utilizability of security vulnerability.

  3. Capacity and performance study of IEEE 802.11e in WLANs and ad hoc networks

    OpenAIRE

    Mjøberg, Frank Roar

    2007-01-01

    This master thesis focuses on the IEEE 802.11e Enhanced Distribution Channel Access (EDCA). The IEEE 802.11e protocol became an IEEE standard in November 2005 and is a very popular research topic. Even though the protocol has been tested for faults and errors a long time there are still research topics to explore. This thesis will try to answer some of those topics. The main topic in this thesis is how the IEEE 802.11e MAC operates in a multihop ad hoc network. We discuss and evaluated th...

  4. Capacity and performance study of IEEE 802.11e in WLANs and ad hoc networks

    OpenAIRE

    Mjøberg, Frank Roar

    2007-01-01

    This master thesis focuses on the IEEE 802.11e Enhanced Distribution Channel Access (EDCA). The IEEE 802.11e protocol became an IEEE standard in November 2005 and is a very popular research topic. Even though the protocol has been tested for faults and errors a long time there are still research topics to explore. This thesis will try to answer some of those topics. The main topic in this thesis is how the IEEE 802.11e MAC operates in a multihop ad hoc network. We discuss and evaluated th...

  5. Proceedings of IEEE Workshop on Machine Learning for Signal Processing XIV

    DEFF Research Database (Denmark)

    Larsen, Jan

    This proceeding contains refereed papers presented at the fourteenth IEEE Workshop on Machine for Signal Processing (MLSP’2004), held at S\\~ao Luís, Maranh\\~ao, Brazil, September 29-October 1, 2004. This is a continuation of the IEEE workshops on Neural Networks for Signal Processing (NNSP...... by the Machine Learning for Signal Processing Technical Committee with sponsorship of the IEEE Signal Processing Society. Following the practice started last year, the bound volume of the proceedings is going to be published by IEEE following the workshop, and we are pleased to offer to conference attendees...

  6. Proceedings of IEEE Workshop on Machine Learning for Signal Processing XIV

    DEFF Research Database (Denmark)

    Larsen, Jan

    This proceeding contains refereed papers presented at the fourteenth IEEE Workshop on Machine for Signal Processing (MLSP’2004), held at S\\~ao Luís, Maranh\\~ao, Brazil, September 29-October 1, 2004. This is a continuation of the IEEE workshops on Neural Networks for Signal Processing (NNSP...... by the Machine Learning for Signal Processing Technical Committee with sponsorship of the IEEE Signal Processing Society. Following the practice started last year, the bound volume of the proceedings is going to be published by IEEE following the workshop, and we are pleased to offer to conference attendees...

  7. IEEE 802.11 5GHz标准物理层研究

    Institute of Scientific and Technical Information of China (English)

    潘翔; 欧阳红升; 高泽华; 高峰

    2013-01-01

    IEEE 802.115GHz技术标准及相关设备的逐步成熟,使得5GHz WLAN网络建设成为可能.文章研究并分析了IEEE 802.11a、IEEE 802.11n、IEEE 802.11ac等5GHz WLAN标准的技术发展路径,并对其物理层关键技术及各标准所支持的最高数据速率作了重点分析.

  8. Coexistence of IEEE 802.11b/g WLANs and IEEE 802.15.4 WSNs: Modeling and Protocol Enhancements

    OpenAIRE

    Yuan, W.

    2011-01-01

    As an emerging short-range wireless technology, IEEE 802.15.4/ZigBee Wireless Sensor Networks (WSNs) are increasingly used in the fields of home control, industrial control, consumer electronics, energy management, building automation, telecom services, personal healthcare, etc. IEEE 802.15.4/Zig-Bee WSNs share the same 2.4 GHz license-free Industrial, Scientific, and Medical (ISM) band with many other wireless systems such as IEEE 802.11b/g WLANs, Bluetooth, cordless phones, etc. Due to the ...

  9. Coexistence of IEEE 802.11b/g WLANs and IEEE 802.15.4 WSNs: Modeling and Protocol Enhancements

    OpenAIRE

    Yuan, W.

    2011-01-01

    As an emerging short-range wireless technology, IEEE 802.15.4/ZigBee Wireless Sensor Networks (WSNs) are increasingly used in the fields of home control, industrial control, consumer electronics, energy management, building automation, telecom services, personal healthcare, etc. IEEE 802.15.4/Zig-Bee WSNs share the same 2.4 GHz license-free Industrial, Scientific, and Medical (ISM) band with many other wireless systems such as IEEE 802.11b/g WLANs, Bluetooth, cordless phones, etc. Due to the ...

  10. Implementation of CRC in IEEE1394 Based on Verilog HDL%基于Verilog HDL的IEEE1394协议中CRC校验的实现

    Institute of Scientific and Technical Information of China (English)

    张艳; 李现国

    2009-01-01

    CRC是IEEE1394协议中重要的错误检测和恢复机制.介绍循环冗余校验的基本原理,根据IEEE1394协议中CRC码的产生原理,分析CRC校验的具体计算过程,讨论IEEE1394协议中CRC的FPGA实现.借助EDA工具和Verilog HDL语言实现了对这种算法的仿真和验证.

  11. IEEE-PSES中国首届研讨会在京举行%IEEE PSES first seminar was held in Beijing

    Institute of Scientific and Technical Information of China (English)

    郝丽娟

    2010-01-01

    @@ 近日,IEEE-PSES(电气电子工程师学会,产品安全工程师分会)中国首届研讨会在京举行.本次会议由IEEE-PSES主办,中国质量认证中心(CQC)承办.来自IEEE-PSES、IECTC108及检测、认证等相关行业的有关领导和专家共计百余人出席了本次会议.

  12. Benefits of IEEE-754 features in modern symmetric tridiagonaleigensolvers

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Osni; Riedy, Jason E.; Vomel, Christof

    2006-03-12

    Bisection is one of the most common methods used to compute the eigenvalues of symmetric tridiagonal matrices. Bisection relies on the Sturm count: For a given shift a, the number of negative pivots in the factorization T - {sigma}I = LDL{sup T} equals the number of eigenvalues of T that are smaller than a. In IEEE-754 arithmetic, the value oo permits the computation to continue past a zero pivot, producing a correct Sturm count when T is unreduced. Demmel and Li showed that using oo rather than testing for zero pivots within the loop could significantly improve performance on certain architectures. When eigenvalues are to be computed to high relative accuracy, it is often preferable to work with LDL{sup T} factorizations instead of the original tridiagonal T. One important example is the MRRR algorithm. When bisection is applied to the factored matrix, the Sturm count is computed from LDL{sup T} which makes differential stationary and progressive qds algorithms the methods of choice. While it seems trivial to replace T by LDL{sup T}, in reality these algorithms are more complicated: In IEEE-754 arithmetic, a zero pivot produces an overflow followed by an invalid exception (NaN, or 'Not a Number') that renders the Sturm count incorrect. We present alternative, safe formulations that are guaranteed to produce the correct result. Benchmarking these algorithms on a variety of platforms shows that the original formulation without tests is always faster provided that no exception occurs. The transforms see speed-ups of up to 2.6x over the careful formulations. Tests on industrial matrices show that encountering exceptions in practice is rare. This leads to the following design: First, compute the Sturm count by the fast but unsafe algorithm. Then, if an exception occurs, recompute the count by a safe, slower alternative. The new Sturm count algorithms improve the speed of bisection by up to 2x on our test matrices. Furthermore, unlike the traditional tiny

  13. 基于IEEE P1687的可变扫描链设计%Design of Flexible Scan-chain Based on IEEE P1687

    Institute of Scientific and Technical Information of China (English)

    刘洋; 颜学龙

    2012-01-01

    在系统芯片SoC中,嵌入式仪器的应用越来越广泛;如何利用已经获得广泛应用的IEEE 1149.1测试访问端口(TAP)实现对嵌入式仪器的访问成为一个新的问题;IEEE P1687 (IJTAG)建议标准提供了一个连接TAP与片上嵌入式仪器的界面标准;其特点是在扫描链中插入SIB使得在嵌入式仪器网络设计和嵌入式仪器的访问中扫描链具有灵活可变的特性;介绍了IEEE P1687标准,分析了IEEE 1149.1在嵌入式仪器访问应用中的缺点及IEEE P1687的优势,并设计实现了SIB的功能,给出了P1687的单层与多层网络结构,并对所需功能进行了仿真验证证明方案可行.%In the testing of .system on chips (SoC) , Embedded instrument are becoming more widely used in test, debug and monitoring. How to use the widespread IEEE 1149. 1 Standard Test Access Port as the interface for accessing embedded instrument becomes a new issue. The IEEE P1687 (IJTAG) standard proposal aims at providing a standardized interface between the IEEE Standard 1149. 1 test access port (TAP) and on -chip embedded instrument. A key feature in P1687 is to include Segment Insertion Bits (SIBs) in the scan-path to allow flexibility both in designing the instrument access network and in scheduling the access to instruments. This paper presents the IEEE P1687 standard, analyses the background of IEEE 1149. 1 and prior work of IEEE P1687, designed the SIB, the flat and hierarchical architecture.

  14. 利用CSP方法对IEEE802.11w形式化分析%Using CSP for formal analysis of IEEE 802.11w protocol

    Institute of Scientific and Technical Information of China (English)

    吴名欢; 程小辉; 李雄伟

    2015-01-01

    IEEE 802.11w authentication protocol based on the IEEE 802.11i enhances the IEEE 802.11i security for man-agement frames.In order to study the safety of the protocol, this paper modeled the protocol by formal analysis using communi-cating sequential processes (CSP ).This paper chosed the role of protocol and the attacker for modelling and verification.It used CSP for modelling and performed the verification using FDR.In the experiments, it found an attack in this protocol.It checked authentication and security attributes and discovered the middleman attack case.It can provide a reference to improve the safety of IEEE 802.11w help.%运行在 IEEE 802.11i 基础上的 IEEE 802.11w 增加了对无线网络管理帧的保护,针对 IEEE 802.11w 协议的安全性问题,利用了通信顺序进程(CSP)对其进行形式化分析。对协议运行在恶意环境中,存在攻击者的情况下,利用 CSP 方法建立了攻击者和协议主体的 CSP 进程模型。使用模型检测工具故障发散改进器(FDR)进行仿真实验,对协议的认证和安全属性进行了校验,发现该协议存在中间人攻击情况,为提高 IEEE 802.11w的安全性提供了帮助。

  15. WIH-based IEEE 802.11 ECG monitoring implementation.

    Science.gov (United States)

    Moein, A; Pouladian, M

    2007-01-01

    New wireless technologies make possible the implementation of high level integration wireless devices which allow the replacement of traditional large wired monitoring devices. It offers new functionalities to physicians and will reduce the costs. Among these functionalities, biomedical signals can be sent to other devices (PDA, PC . . . ) or processing centers, without restricting the patients' mobility. This article discusses the WIH (Ward-In-Hand) structure and the software required for its implementation before an operational example is presented with its results. The aim of this project is the development and implementation of a reduced size electrocardiograph based on IEEE 802.11 with high speed and more accuracy, which allows wireless monitoring of patients, and the insertion of the information into the Wi-Fi hospital networks.

  16. The New Standard IEEE 1599, Introduction and Examples

    Directory of Open Access Journals (Sweden)

    Denis L. Baggi

    2009-02-01

    Full Text Available IEEE 1599 is a new standard to encode music with XML symbols. It offers two important original characteristics compared to existing standards of the worlds of music, musicology and computer applications to this art and science. On one side, the encoding is in the form of symbols that can be read both by machines and humans. On the other, it allows the realization of applications in which all aspects of music, such as audio and sound, graphical representation, historical data, performance indications, represented thanks to the new concept of layers, are fully integrated, synchronized and can be accessed both individually and as parts of a whole. The article will give a brief description of the standard and of applications that have been built to show its power.

  17. Proceedings of the IEEE Machine Learning for Signal Processing XVII

    DEFF Research Database (Denmark)

    , and two papers from the winners of the Data Analysis Competition. The program included papers in the following areas: genomic signal processing, pattern recognition and classification, image and video processing, blind signal processing, models, learning algorithms, and applications of machine learning......The seventeenth of a series of workshops sponsored by the IEEE Signal Processing Society and organized by the Machine Learning for Signal Processing Technical Committee (MLSP-TC). The field of machine learning has matured considerably in both methodology and real-world application domains and has....... The program featured a Special Session on Genomic Signal Processing, chaired by Prof. Man-Wai Mak from Hong Kong Polytechnic University, Hong Kong. The session included four refereed papers by leading experts in the field. We also continued the tradition of the Data Analysis Competition thanks to the efforts...

  18. IEEE 802.11 Wireless LAN Security White Paper

    Energy Technology Data Exchange (ETDEWEB)

    King, J

    2001-10-22

    Given the increased productivity and growing popularity of wireless communications in general, and wireless data communications in particular, this paper outlines the protocols, security implications, and architectures of IEEE Std. 802.11-1999 wireless LANs (WLANs) and makes recommendations regarding a phased implementation of WLANs at LLNL. This project is driven by the need for convenient and secure access to the Internet for Laboratory visitors and to the internal network for Laboratory employees. A solid architecture designed with a priority on security will allow LLNL to offer network access in areas where it is traditionally hard to deploy wired networks. It will also enable such services as wireless access for inventory control and convenient network access for conference rooms around LLNL. Wireless network access has the potential to increase productivity by enabling instant access to information.

  19. Basic security measures for IEEE 802.11 wireless networks

    Directory of Open Access Journals (Sweden)

    Oscar P. Sarmiento

    2010-05-01

    Full Text Available This article presents a tutorial/discussion of three commonly-used IEEE 802.11 wireless network security standards: WEP, WPA and WPA2. A detailed analysis of the RC4 algorithm supporting WEP is presented, including its vulnera-bilities. The WPA and WPA2 encryption protocols’ most relevant aspects and technical characteristics are reviewed for a comparative analysis of the three standards in terms of the security they provide. Special attention has been paid to WEP encryption by using an educational simulation tool written in C++ Builder for facilitating the unders-tanding of this protocol at academic level. Two practical cases of wireless security configurations using Cisco net-working equipment are also presented: configuring and enabling WPA-Personal and WPA2-Personal (these being security options used by TKIP and AES, respectively.

  20. Review of the IEEE Standard for Computerized Operating Procedure Systems

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, J.; Higgins, J.

    2010-02-26

    Increasingly nuclear power plant procedures, such as emergency operating procedures, are being presented in computer form with functionality to support operator use and management of the procedures. The U.S. Nuclear Regulatory Commission (NRC) currently has guidance for the review of computer-based procedures (CBPs); however, there remain CBP functions and human performance issues for which up-to-date guidance is lacking. The Institute of Electrical and Electronics Engineers (IEEE) has initiated a standard development effort to address the human factors engineering (HFE) aspects of CBP systems. When completed, it may provide guidance to supplement the NRC staff's review criteria. The purpose of our study was to evaluate the suitability of the IEEE Standard for use in the NRC's HFE safety reviews of CBP systems and to ensure that the guidance meets the NRC's standard for scientific and engineering rigor used in its own guidance development efforts. We established the following criteria with which to evaluate the Standard: (1) it should meet an existing need of NRC reviewers, (2) it should be based in sound HFE principles, (3) it should be thoroughly peer-reviewed, and (4) it should address CBP-related human performance issues identified in the literature. This report describes the methodology we used to evaluate each criterion. Our evaluation concluded that the Standard generally does meet these criteria, however several areas were identified for which additional clarifications are needed. Thus consideration of the Standard's use by the NRC is supported. The standard evaluation methodology developed in this study can be generally applied to the review of other HFE standards being considered for possible use or endorsement by the NRC.

  1. 基于IEEE 1588时间同步系统的硬件实现%Hardware Implementation of Time Synchronization System Based on IEEE 1588

    Institute of Scientific and Technical Information of China (English)

    曹禹; 邹磊; 时维铎; 周国平

    2013-01-01

      IEEE 1588是关于网络测量和控制系统的高精度时间协议标准,其时间同步精度能够达到次微秒级。首先分析了IEEE 1588时间同步原理,然后以LPC1768+DP83640的硬件结构实现了IEEE 1588时间同步系统,最后利用示波器测试了主从时钟的时间同步精度。设计结果表明可以满足当今电力系统对高精度时间同步的要求。%IEEE 1588 is a high precision time protocol standards about network measurement and control system, its time synchronization precision can reach sub-microsecond level. This paper first analyzes the principle of IEEE 1588 time synchronization, then realizes the IEEE 1588 time synchronization system with LPC1768 +DP83640. Finally, uses the oscilloscope to test the master -slave clock time synchronization precision. Its results show that it can meet the need of the current electric power system to realize high accuracy time synchronization.

  2. Research on IEEE 802.22.1 Beacon Networks Application%IEEE 802.22.1信标网络应用研究

    Institute of Scientific and Technical Information of China (English)

    杨大全

    2012-01-01

    Several IEEE 802.22.1 beacon devices are used to build beacon network by self-organization. IEEE 802.22.1 beacon protocol is introduced, and the decision strategies of beacon networks in the process of establishing and maintenance are discussed. IEEE 802.22.1 beacon networks sensing and information detection in WRAN device are introduced. The maximum latency before scheduling a quiet period that will ensure to capture the full information of the beacon network is given.%多个IEEE 802.22.1信标设备将自组织成信标网络.介绍了IEEE 802.22.1标准中定义的自组织方案;讨论了信标网络建立与维持过程中的判决策略;介绍了无线区域网络(WRAN)设备对IEEE 802.22.1信标网络的识别与信息获取机制;给出了确保实现对信标网络信息解析所需要安排的最大时延.

  3. Attacks on IEEE 802.11 wireless networks

    Directory of Open Access Journals (Sweden)

    Dejan Milan Tepšić

    2013-06-01

    Full Text Available Security of wireless computer networks was initially secured with the WEP security protocol, which relies on the RC4 encryption algorithm and the CRC algorithm to check the integrity. The basic problems of the WEP are a short initialization vector, unsafe data integrity checking, using a common key, the lack of mechanisms for management and exchange of keys, the lack of protection from the endless insertion of the same package into the network, the lack of authentication of access points and the like. The consequences of these failures are easy attacks against the WEP network, namely their complete insecurity. Therefore, the work began on the IEEE 802.11i protocol, which should radically improve the security of wireless networks. Since the development of a protocol lasted, the WPA standard was released to offset the security gap caused by the WEP. The WPA also relies on RC4 and CRC algorithms, but brings temporary keys and the MIC algorithm for data integrity. The 802.1X authentication was introduced and common keys are no longer needed, since it is possible to use an authentication server. The length of the initialization vector was increased and the vector is obtained based on the packet serial number, in order to prevent the insertion of the same packet into the network. The weakness of the WPA security mechanism is the use of a common key. WPA2 (802.11i later appeared. Unlike the WPA mechanism that worked on old devices with the replacement of software, WPA2 requires new network devices that can perform AES encryption. AES replaces the RC4 algorithm and delivers much greater security. Data integrity is protected by encryption. Despite progress, there are still weaknesses in wireless networks. Attacks for denial of service are possible as well as spoofing package headers attacks. For now, it is not advisable to use wireless networks in environments where unreliability and unavailability are not tolerated. Introduction In the entire history of

  4. A formal analysis of ISO/IEEE P11073-20601 standard of medical device communication

    NARCIS (Netherlands)

    Goga, Nicolae; Costache, Stefania; Moldoveanu, Florica

    2009-01-01

    This article presents the formal work done for the ISO/IEEE P11073-20601 Draft Standard for Health informatics - Personal health device communication - Application profile Optimized exchange protocol. ISO/IEEE 11073 family defines standards for device communication between agents (e.g. blood pressur

  5. Design Optimization of Cyber-Physical Distributed Systems using IEEE Time-sensitive Networks (TSN)

    DEFF Research Database (Denmark)

    Pop, Paul; Lander Raagaard, Michael; Craciunas, Silviu S.

    2016-01-01

    In this paper we are interested in safety-critical real-time applications implemented on distributed architectures supporting the Time-SensitiveNetworking (TSN) standard. The ongoing standardization of TSN is an IEEE effort to bring deterministic real-time capabilities into the IEEE 802.1 Ethernet...

  6. Proceedings of the IEEE 2003 Neural Networks for Signal Processing Workshop

    DEFF Research Database (Denmark)

    Larsen, Jan

    This proceeding contains refereed papers presented at the thirteenth IEEE Workshop on Neural Networks for Signal Processing (NNSP’2003), held at the Atria-Mercure Conference Center, Toulouse, France, September 17-19, 2003. The Neural Networks for Signal Processing Technical Committee of the IEEE...... Signal Processing Society organized the workshop with sponsorship of the Signal Processing Society and the co-operation of the IEEE Neural Networks Society. The IEEE Press published the previous twelve volumes of the NNSP Workshop proceedings in a hardbound volume. This year, the bound volume...... is to be published by IEEE following the workshop, and we are pleased to inaugurate a new CDROM electronic format, which maintains the same standard as the printed version and facilitates the reading and searching of the papers. In recent years, the field of neural networks has matured considerably in both...

  7. Proceedings of the IEEE 2003 Neural Networks for Signal Processing Workshop

    DEFF Research Database (Denmark)

    Larsen, Jan

    This proceeding contains refereed papers presented at the thirteenth IEEE Workshop on Neural Networks for Signal Processing (NNSP’2003), held at the Atria-Mercure Conference Center, Toulouse, France, September 17-19, 2003. The Neural Networks for Signal Processing Technical Committee of the IEEE...... Signal Processing Society organized the workshop with sponsorship of the Signal Processing Society and the co-operation of the IEEE Neural Networks Society. The IEEE Press published the previous twelve volumes of the NNSP Workshop proceedings in a hardbound volume. This year, the bound volume...... is to be published by IEEE following the workshop, and we are pleased to inaugurate a new CDROM electronic format, which maintains the same standard as the printed version and facilitates the reading and searching of the papers. In recent years, the field of neural networks has matured considerably in both...

  8. Performance Analysis of IEEE 802.11 DCF and IEEE 802.11e EDCA in Non-saturation Condition

    Science.gov (United States)

    Kim, Tae Ok; Kim, Kyung Jae; Choi, Bong Dae

    We analyze the MAC performance of the IEEE 802.11 DCF and 802.11e EDCA in non-saturation condition where device does not have packets to transmit sometimes. We assume that a flow is not generated while the previous flow is in service and the number of packets in a flow is geometrically distributed. In this paper, we take into account the feature of non-saturation condition in standards: possibility of transmission performed without preceding backoff procedure for the first packet arriving at the idle station. Our approach is to model a stochastic behavior of one station as a discrete time Markov chain. We obtain four performance measures: normalized channel throughput, average packet HoL (head of line) delay, expected time to complete transmission of a flow and packet loss probability. Our results can be used for admission control to find the optimal number of stations with some constraints on these measures.

  9. Validation testing of ANSI/IEEE n42.49 standard requirements for personal emergency radiation detectors.

    Science.gov (United States)

    Pibida, L; Minniti, R; O'Brien, M

    2010-04-01

    Various radiation detectors including electronic personal emergency radiation detectors (PERDs), radiochromic film cards and thermoluminescent dosimeters (TLDs) were used to validate a subset of the radiological test requirements listed in the American National Standards Institute/The Institute of Electrical and Electronic Engineers (ANSI/IEEE) N42.49 standard. The subset of tests included the following: comparing the readout of the detectors with the value given at the National Institute of Standards and Technology (NIST); testing of the alarm settings (when applicable) in air-kerma (or exposure) and air-kerma rate (or exposure rate) mode; and investigating the effect of testing the detectors mounted on a phantom and free in air. The purpose of this work was not to test the performance of the sample of detectors used. Instead, the detectors were used to validate the requirements of the written standard being developed. For this purpose, the performance and response of these instruments were recorded when placed in (137)Cs, and x-ray beams at different air-kerma rates and test conditions. The measurements described in this report were performed at the NIST x-ray and gamma-ray radiation calibration facilities. The data in this report provide a benchmark in support of the development of the ANSI/IEEE N42.49 standard.

  10. IEEE 1588 Clock Synchroniz ation in Distributed Systems%IEEE 1588时钟同步技术在分布式系统中的研究*

    Institute of Scientific and Technical Information of China (English)

    徐晓霞; 丁建功

    2014-01-01

    In order to realize high accuracy synchronous data acquisition and control in distributed system ,a distributed system clock synchronization method based on IEEE 1588 protocol is proposed .This paper analyzes the principle of master clock algorithm and the time synchronization process of local clock and master clock ,puts forward a IEEE 1588 realization scheme ,provides a hardware design method ,and elaborates the master‐slave clock software design process .On the basis of the work ,verifies the master‐slave clock synchronization .The experiments show that the method is feasible ,clock synchro‐nization precision can reach microsecond ,and may serve as a reference ,when the further application of IEEE 1588 in distrib‐uted industrial control systems is concerned .%为实现分布式系统高精度同步数据采集及实时控制,提出一种基于 IEEE 1588协议的分布式系统时钟同步方法。论文深入分析了IEEE 1588协议的算法原理和本地时钟同步主时钟的过程,提出了时间戳的IEEE 1588实现方案,提供了硬件设计方法,阐述了主从时钟的软件设计流程,在此基础上对主从时钟的同步进行了验证。实验证明:该方法是切实可行的,同步结果达到了10μs同步,为下一步将IEEE 1588大规模应用到分布式工业控制系统中起到了借鉴的作用。

  11. 48 CFR 52.223-16 - IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false IEEE 1680 Standard for the... CONTRACT CLAUSES Text of Provisions and Clauses 52.223-16 IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products. As prescribed in 23.706(b)(1), insert the following clause: IEEE...

  12. IEEE 802.11ah: A Technology to Face the IoT Challenge

    Directory of Open Access Journals (Sweden)

    Victor Baños-Gonzalez

    2016-11-01

    Full Text Available Since the conception of the Internet of things (IoT, a large number of promising applications and technologies have been developed, which will change different aspects in our daily life. This paper explores the key characteristics of the forthcoming IEEE 802.11ah specification. This future IEEE 802.11 standard aims to amend the IEEE 802.11 legacy specification to support IoT requirements. We present a thorough evaluation of the foregoing amendment in comparison to the most notable IEEE 802.11 standards. In addition, we expose the capabilities of future IEEE 802.11ah in supporting different IoT applications. Also, we provide a brief overview of the technology contenders that are competing to cover the IoT communications framework. Numerical results are presented showing how the future IEEE 802.11ah specification offers the features required by IoT communications, thus putting forward IEEE 802.11ah as a technology to cater the needs of the Internet of Things paradigm.

  13. IEEE 802.11ah: A Technology to Face the IoT Challenge.

    Science.gov (United States)

    Baños-Gonzalez, Victor; Afaqui, M Shahwaiz; Lopez-Aguilera, Elena; Garcia-Villegas, Eduard

    2016-11-22

    Since the conception of the Internet of things (IoT), a large number of promising applications and technologies have been developed, which will change different aspects in our daily life. This paper explores the key characteristics of the forthcoming IEEE 802.11ah specification. This future IEEE 802.11 standard aims to amend the IEEE 802.11 legacy specification to support IoT requirements. We present a thorough evaluation of the foregoing amendment in comparison to the most notable IEEE 802.11 standards. In addition, we expose the capabilities of future IEEE 802.11ah in supporting different IoT applications. Also, we provide a brief overview of the technology contenders that are competing to cover the IoT communications framework. Numerical results are presented showing how the future IEEE 802.11ah specification offers the features required by IoT communications, thus putting forward IEEE 802.11ah as a technology to cater the needs of the Internet of Things paradigm.

  14. An Asynchronous IEEE Floating-Point Arithmetic Unit

    Directory of Open Access Journals (Sweden)

    Joel R. Noche

    2007-12-01

    Full Text Available An asynchronous floating-point arithmetic unit is designed and tested at the transistor level usingCadence software. It uses CMOS (complementary metal oxide semiconductor and DCVS (differentialcascode voltage switch logic in a 0.35 µm process using a 3.3 V supply voltage, with dual-rail data andsingle-rail control signals using four-phase handshaking.Using 17,085 transistors, the unit handles single-precision (32-bit addition/subtraction, multiplication,division, and remainder using the IEEE 754-1985 Standard for Binary Floating-Point Arithmetic, withrounding and other operations to be handled by separate hardware or software. Division and remainderare done using a restoring subtractive algorithm; multiplication uses an additive algorithm. Exceptionsare noted by flags (and not trap handlers and the output is in single-precision.Previous work on asynchronous floating-point arithmetic units have mostly focused on single operationssuch as division. This is the first work to the authors' knowledge that can perform floating-point addition,multiplication, division, and remainder using a common datapath.

  15. Throughput Analysis of IEEE 802.11 Multirate WLANs with Collision Aware Rate Adaptation Algorithm

    Institute of Scientific and Technical Information of China (English)

    Dhanasekaran Senthilkumar; A. Krishnan

    2010-01-01

    This paper presents a mathematical model that analyzes the throughput of the IEEE 802.11b distributed coordination function (DCF) with the collision aware rate adaptation (CARA) algorithm. IEEE 802.11 WLANs provide multiple transmission rates to improve system throughput by adapting the transmission rate to the current channel conditions. The system throughput is determined by some stations using low transmission rates due to bad channel conditions. CARA algorithm does not disturb the existing IEEE 802.1 lb formats and it can be easily incorporated into the commercial wireless local area networks (WLAN) devices. Finally, we verify our findings with simulation.

  16. Fuzzy logic congestion control in IEEE 802.11 wireless local area networks: A performance evaluation

    CSIR Research Space (South Africa)

    Nyirenda, CN

    2007-09-01

    Full Text Available networks because they are Clement .N. Nyirenda is with the Meraka Institute, Centre for Scientific and Industrial Research, Pretoria, South Africa (+27 72 1404564; e-mail: nyirendac@ ieee.org). Dawoud S. Dawoud is with the Radio Access Technologies... heavily depends on the frame payload size. When only frames are sent, the maximum throughput on the wireless channel on the wireless channel can drop below 1Mbps even at a data rate of 11 Mbps. At present, an IEEE working group (IEEE802.11n...

  17. Energy Harvesting - Wireless Sensor Networks for Indoors Applications Using IEEE 802.11

    DEFF Research Database (Denmark)

    Fafoutis, Xenofon; Sørensen, Thomas; Madsen, Jan

    2014-01-01

    The paper investigates the feasibility of using IEEE 802.11 in energy harvesting low-power sensing applications. The investigation is based on a prototype carbon dioxide sensor node that is powered by artificial indoors light. The wireless communication module of the sensor node is based on the RTX......4100 module. RTX4100 incorporates a wireless protocol that duty-cycles the radio while being compatible with IEEE 802.11 access points. The presented experiments demonstrate sustainable operation but indicate a trade-off between the benefits of using IEEE 802.11 in energy harvesting applications...

  18. Performance Analysis of IEEE 802.11e (EDCF) and IEEE 802.11(DCF) WLAN Incorporating Different Physical Layer Standards

    Science.gov (United States)

    Sharma, V.; Singh, H.; Malhotra, J.

    2012-12-01

    Medium access coordination function basically implements the distributed coordination function (DCF) which provides support to best effort services but limited to QoS services. Subsequently, a new standard, namely enhanced distributed channel access (EDCA) is reported. The IEEE 802.11e (EDCA) defines MAC procedures to support QoS requirements which specifies distributed contention based access scheme to access the shared wireless media. This paper evaluates the performance of EDCA based IEEE 802.11 WLAN for various access categories (ACs) using OPNET™ Modeller 14.5. Further, the computed results are compared with DCF protocols in terms of QoS parameters. Furthermore, the simulative observation is reported at data rate of 54 Mbps using different physical layer protocols such as IEEE 802.11a/b/g to stumble on the best one to be implemented with EDCF to achieve improved QoS.

  19. 基于OFDM的IEEE802.16a物理层简介%Introduction of IEEE802.16a Physical Layer Based on OFDM

    Institute of Scientific and Technical Information of China (English)

    许云东; 潘志文

    2006-01-01

    简要介绍了IEEE802.16的基本概况,描述了IEEE802.16a标准采用的几种物理层方案.IEEE802.16a协议物理层支持的主流技术就是OFDM技术,重点介绍了OFDM的基本原理,采用OFDM调制技术的WirelessMAN-OFDM系统,以及其物理层的一些参数及性能.最后介绍了2种双工方式的帧结构及其工作原理.

  20. Analysis of Adaptive Control Scheme in IEEE 802.11 and IEEE 802.11e Wireless LANs

    Science.gov (United States)

    Lee, Bih-Hwang; Lai, Hui-Cheng

    In order to achieve the prioritized quality of service (QoS) guarantee, the IEEE 802.11e EDCAF (the enhanced distributed channel access function) provides the distinguished services by configuring the different QoS parameters to different access categories (ACs). An admission control scheme is needed to maximize the utilization of wireless channel. Most of papers study throughput improvement by solving the complicated multidimensional Markov-chain model. In this paper, we introduce a back-off model to study the transmission probability of the different arbitration interframe space number (AIFSN) and the minimum contention window size (CWmin). We propose an adaptive control scheme (ACS) to dynamically update AIFSN and CWmin based on the periodical monitoring of current channel status and QoS requirements to achieve the specific service differentiation at access points (AP). This paper provides an effective tuning mechanism for improving QoS in WLAN. Analytical and simulation results show that the proposed scheme outperforms the basic EDCAF in terms of throughput and service differentiation especially at high collision rate.

  1. Langattoman lähiverkon päivitys IEEE 802.11g -laitteista IEEE 802.11n -laitteisiin

    OpenAIRE

    Kokkonen, Janne

    2009-01-01

    Insinöörityössä tutkittiin langattoman lähiverkon vaiheittaista päivittämistä IEEE 802.11g -standardin laitteista IEEE 802.11n -standardin laitteisiin. Tavoitteena oli tutkia teorian ja käytännön mittauksien pohjalta paras mahdollinen vaihtoehto verkon päivityksen toteuttamiseksi. Työhön liittyvät mittaukset suoritettiin Metropolia Ammattikorkeakoulun tiloissa ja laitteilla. Työn alussa selvitettiin langattomiin lähiverkkoihin liittyviä teoreettisia yksityiskohtia, joiden perusteella rake...

  2. Langattoman lähiverkon päivitys IEEE 802.11g -laitteista IEEE 802.11n -laitteisiin

    OpenAIRE

    Kokkonen, Janne

    2009-01-01

    Insinöörityössä tutkittiin langattoman lähiverkon vaiheittaista päivittämistä IEEE 802.11g -standardin laitteista IEEE 802.11n -standardin laitteisiin. Tavoitteena oli tutkia teorian ja käytännön mittauksien pohjalta paras mahdollinen vaihtoehto verkon päivityksen toteuttamiseksi. Työhön liittyvät mittaukset suoritettiin Metropolia Ammattikorkeakoulun tiloissa ja laitteilla. Työn alussa selvitettiin langattomiin lähiverkkoihin liittyviä teoreettisia yksityiskohtia, joiden perusteella rake...

  3. 高速接口USB与IEEE1394的性能分析%Performance Analysis of High-Speed Digital Interface USB and IEEE 1394

    Institute of Scientific and Technical Information of China (English)

    李洋; 邹建华

    2001-01-01

    The basic features of Universal Serial BusUSB and IEEE 1394 are analyzed and compared in this paper and the foreground of the two interfaces are described.%对计算机外设高速接口USB和IEEE 1394的技术特点和数据传输机制进行了较详细的分析,比较了两种接口的性能,并对其应用前景进行了展望。

  4. Corrections to "Connectivity-Based Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs"

    Directory of Open Access Journals (Sweden)

    Choi Woo-Yong

    2010-01-01

    Full Text Available We have found the errors in the throughput formulae presented in our paper "Connectivity-based reliable multicast MAC protocol for IEEE 802.11 wireless LANs". We provide the corrected formulae and numerical results.

  5. Throughput Analysis Model for IEEE 802.11e EDCA with Multiple Access Categories

    Directory of Open Access Journals (Sweden)

    Y. Lee

    2013-08-01

    Full Text Available IEEE 802.11e standard has been specified to support differentiated quality of service (QoS, one of the critical issues on the conventional IEEE 802.11 wireless local area networks (WLANs. Enhanced Distributed Channel Access (EDCA is the fundamental and mandatory contention-based channel access method of IEEE 802.11e, and delivers traffic based on differentiated Access Categories (ACs. A general three dimensional Markov chain model of IEEE 802.11e EDCA for performance analysis is proposed in this paper. The analytical model considers multiple stations with an arbitrary number of different ACs. It also differentiates the contention window (CW sizes and the arbitration interframe spaces (AIFSs, and considers virtual collision mechanism. Based on the model, the saturation throughput of EDCA is derived, and the accuracy of the proposed model is validated via simulations.

  6. Developing IEEE medical device standards: a case study, wearable cuffless blood pressure measuring devices.

    Science.gov (United States)

    Carey, Carole C; Zhang, Yuang-Ting

    2010-01-01

    The Institute of Electrical and Electronics Engineers Standards Association (IEEE-SA) is a leading standards developing organization of global industry standards in a wide-range of industries, including biomedical and healthcare.

  7. Access Point Selection for Multi-Rate IEEE 802.11 Wireless LANs

    Science.gov (United States)

    2014-05-16

    Feb 2010. [ 11 ] Y. Bejerano, S. jae Han, and L. Li, “Fairness and Load Balancing in Wireless LANs Using Association Control,” Networking, IEEE /ACM...Steenkiste, “Fixing 802 . 11 access point selection,” ACM SIGCOMM Computer Communication Review, 2002. [15] J. C. Chen, T. C. Chen, T. Zhang, and E. van...Access Point Selection for Multi-Rate IEEE 802.11 Wireless LANs Shicong Yang Avideh Zakhor Electrical Engineering and Computer Sciences University of

  8. Algorithm XXX : functions to support the IEEE standard for binary floating-point arithmetic.

    Energy Technology Data Exchange (ETDEWEB)

    Cody, W. J.; Mathematics and Computer Science

    1993-12-01

    This paper describes C programs for the support functions copysign(x,y), logb(x), scalb(x,n), nextafter(x,y), finite(x), and isnan(x) recommended in the Appendix to the IEEE Standard for Binary Floating-Point Arithmetic. In the case of logb, the modified definition given in the later IEEE Standard for Radix-Independent Floating-Point Arithmetic is followed. These programs should run without modification on most systems conforming to the binary standard.

  9. The Unum Number Format: Mathematical Foundations, Implementation and Comparison to IEEE 754 Floating-Point Numbers

    OpenAIRE

    Hunhold, Laslo

    2017-01-01

    This thesis examines a modern concept for machine numbers based on interval arithmetic called 'Unums' and compares it to IEEE 754 floating-point arithmetic, evaluating possible uses of this format where floating-point numbers are inadequate. In the course of this examination, this thesis builds theoretical foundations for IEEE 754 floating-point numbers, interval arithmetic based on the projectively extended real numbers and Unums.

  10. Improving Security Levels Of IEEE802.16e Authentication By Diffie-Hellman Method

    Directory of Open Access Journals (Sweden)

    Mohammad Zabihi

    2011-11-01

    Full Text Available In this paper, we proposed an authentication method according to Diffie-Hellman. First, we introduce different methods for authentication in IEEE.802.16 then we proposed an authentication method according to Diffie-Hellman and in the last we compare different methods for authentication to improve security in IEEE802.16e. CPN is a useful for simulation and compare protocol together so we use CPN tools in this paper.

  11. A Unified Computational Framework for Real-Time Optimal Control , IEEE (42nd; 2003; Maui, Hawaii)

    OpenAIRE

    Ross, I. Michael; Fahroo, Fariba

    2003-01-01

    The article of record as published may be located at http://ieeexplore.ieee.org Approved for public display, distribution unlimited Proceedings of the 42nd IEEE ; Conference on Decision and Control ; Maui, Hawaii USA, December 2003 The dynamics of each agent of a multi-agent controlled dynamical system can be formulated in several possible ways: differential inclusion, flatness parameterization, higher-order inclusions and so on. A plethora of techniques have been proposed for each o...

  12. IEEE 802.16协议及其应用

    Institute of Scientific and Technical Information of China (English)

    张云飞

    2009-01-01

    IEEE 802.16协议由于具有广阔的应用前景,目前受到了国内外学术界和产业界的广泛关注.本文首先介绍了IEEE 802.16协议系列的现状及其进展,然后叙述了其应用情况.

  13. Enhancing MAC performance of DCF protocol for IEEE 802.11 wireless LANs

    Science.gov (United States)

    Choi, Woo-Yong

    2017-01-01

    The DCF (Distributed Coordination Function) is the basic MAC (Medium Access Control) protocol of IEEE 802.11 wireless LANs and compatible with various IEEE 802.11 PHY extensions. The performance of the DCF degrades exponentially as the number of nodes participating in the DCF transmission procedure increases. To deal with this problem, we propose a simple, however efficient modification of the DCF by which the performance of the DCF is greatly enhanced.

  14. Method of Testing High Speed Digital Network Based on IEEE 1149. 6 Standard%基于IEEE 1149.6标准的高速数字网络测试方法

    Institute of Scientific and Technical Information of China (English)

    尤路

    2015-01-01

    As requirement of high speed signal testing increases gradually, the application prospect of the IEEE 1149. 6 standard becomes more and more extensively. Starting from generation of IEEE 1149. 6 standard, the difference between the IEEE 1149. 1 and IEEE 1149. 6 standards is introduced. The fault type of the IEEE 1149. 6 standard is introduced in detail by way of test verification example. This method is functioned obviously in testing high speed digital circuit channel.%随着高速信号测试需求的逐渐增加,IEEE 1149.6标准的应用前景越来越广,本文从IEEE 1149.6标准的产生入手,主要介绍了IEEE 1149.6标准与IEEE 1149.1标准的区别,后文中通过测试验证实例,详细介绍了IEEE 1149.6标准中的故障类型,该方法目前已在数字电路高速通道测试中凸显作用。

  15. IEEE Xplore® Digital Library. Quick user guides

    OpenAIRE

    2014-01-01

    Представлены руководства по работе с платформой IEEE Xplore® Digital Library, содержащей ресурсы в области электроники, радиосвязи, вычислительной техники, информационных технологий, энергетики, машиностроения, физики, химии, геологии, нанотехнологий на английском языке. Руководства: 1) Started with Your Search - Поиск, уточнение результатов, доступ к полнотекстовым документам, сохранение поисковых резкльтатов, расширенные функции; 2) Search and Save with Your File Cabinet - Поиск, уточнен...

  16. Nation

    DEFF Research Database (Denmark)

    Østergaard, Uffe

    2014-01-01

    Nation er et gammelt begreb, som kommer af det latinske ord for fødsel, natio. Nationalisme bygger på forestillingen om, at mennesker har én og kun én national identitet og har ret til deres egen nationalstat. Ordet og forestillingen er kun godt 200 år gammel, og i 1900-tallet har ideologien bredt...... sig over hele verden. Nationalisme er blevet global....

  17. Endlessly Circulating Messages in IEEE 1588-2008 Systems

    Science.gov (United States)

    2014-05-13

    National Science Foundation, NSF awards #0720882 ( CSR -EHS: PRET) and #0931843 (ActionWebs), the Naval Research Laboratory (NRL #N0013-12- 1-G015), and...Software Systems (CHESS) at UC Berkeley (supported by the National Science Founda- tion, NSF awards #0720882 ( CSR -EHS: PRET) and #0931843 (ActionWebs), the...IV-B the following observations can be made on the disconnect models shown: • There are definitely conditions that spawn rogue mes- sages. For the

  18. 2001年IEEE MTT-S介绍

    Institute of Scientific and Technical Information of China (English)

    洪伟

    2001-01-01

    @@ 2001年IEEE微波理论与技术国际会议(IEEE MTT-S)于5月20~25日在美国的凤凰城(Phoenix) 召开.其中,20、21和25日安排的是专题讨论会(Workshops)等,22~24日为分组学术报告. 本次会议共收到学术论文930篇,其中学生投稿论文242篇,这两项都刷新了MTT-S的记录. 经过250位专家的评审,从中录用了511篇论文,录用率为55%.这些学术论文安排在22~24三天的65个分组内进行学术交流,其中除了论文宣读(presentation)之外还在每天的下午安排了论文张贴交流(interactive forum).根据当前的热门研究领域,会议安排了20个专题讨论会(Workshop)和5个短课程(Short courses).此外,针对一些浮现出来的技术领域还设了 5个焦点分组(Focused sessions)、4个专题讨论会(Panel sessions)和1个辩论会(Rump s ession).与MTT-S联合召开的还有射频集成电路(RFIC)和自动射频技术组(ARFTG: Automat ic RF Technology Group)两个专门会议.在会议期间还举办了规模巨大的微波工业展览, 有800多家公司参展,展出的产品涉及微波毫米波元器件、模块、系统、芯片、测量设备、加工设备、设计软件等等.下面就这次会议的主要内容作简要介绍.一、分组学术交流 (Technique Sessions) 学术论文分65个组(Sessions)进行交流,内容涉及电磁场边值问题的分析方法、微波传输线与无源元件、封装与互连技术、非线性分析、微波有源器件、天线、智能天线、通信系统、卫星互连网、微波生物效应与医学应用、微波超导等.

  19. Performance Analysis of Sleep Mode Operation in IEEE 802.16m Mobile WiMAX

    Science.gov (United States)

    Baek, Sangkyu; Son, Jung Je; Choi, Bong Dae

    We mathematically analyze the sleep mode operation of IEEE 802.16m. The sleep mode operation for downlink traffic is modeled as a 3-dimensional discrete time Markov chain. We obtain the average power consumption of a mobile station and the average delay of a message. Numerical results match simulations very well. Numerical results show that there is a tradeoff between power consumption and message delay. We find the optimal lengths of sleep cycle and close-down time that minimize the power consumption while satisfying the quality of service (QoS) constraint on message delay. The power consumption of the sleep mode in IEEE 802.16m is better than that of sleep modes in legacy IEEE 802.16e standard under the same delay bound.

  20. Design of handoff procedures for broadband wireless access IEEE 802.16 based networks

    Directory of Open Access Journals (Sweden)

    V. Rangel–Licea

    2008-01-01

    Full Text Available IEEE 802.16 is a protocol for fixed broad band wire less access that is currently trying to add mobility among mobile users in the standard. However, mobility adds some technical barriers that should be solved first, this is the case of HO "handoff" (change of connection between two base stations "BS" by a mobile user. In this paper, the problem of HO in IEEE 802.16 is approached try ing to maintain the quality of service (QoS of mobile users. A mechanism for changing connection during HO is pre sented. A simulation model based on OPNET MODELER1 was developed to evaluate the performance of the proposed HO mechanism. Finally, this paper demonstrates that it is possible to implement a seam less HO mech a nism over IEEE 802.16 even for users with de manding applications such as voice over IP.

  1. An Analytical Model for the Performance Analysis of Concurrent Transmission in IEEE 802.15.4

    Directory of Open Access Journals (Sweden)

    Cengiz Gezer

    2014-03-01

    Full Text Available Interference is a serious cause of performance degradation for IEEE802.15.4 devices. The effect of concurrent transmissions in IEEE 802.15.4 has been generally investigated by means of simulation or experimental activities. In this paper, a mathematical framework for the derivation of chip, symbol and packet error probability of a typical IEEE 802.15.4 receiver in the presence of interference is proposed. Both non-coherent and coherent demodulation schemes are considered by our model under the assumption of the absence of thermal noise. Simulation results are also added to assess the validity of the mathematical framework when the effect of thermal noise cannot be neglected. Numerical results show that the proposed analysis is in agreement with the measurement results on the literature under realistic working conditions.

  2. Improving IEEE 802.15.4 for Low-Latency Energy-Efficient Industrial Applications

    Science.gov (United States)

    Chen, Feng

    The IEEE 802.15.4 standard for LR-WPAXs is becoming a de-facto standard for Wireless Sensor Xetworks (WSXs) applications in industrial fields. In this paper, we evaluate the latency performance of the IEEE 802.15.4 protocol based on a typical industrial scenario: a star network with 20 devices that send short messages (1 Byte) to the PAX coordinator. We analyzed the behavior of the GTS mechanism in the standard analytically. The results reveal essential limitations of the standard for low-latency applications in automation environments. According to our findings, we propose an enhanced protocol version that fully supports industry demands on low-latency communication. Our protocol version uses the original physical layer and, thus, can be implemented conveniently using cheap IEEE 802.15.4 hardware. The analytical results prove that we are able to meet the guaranteed low latency of 10 ms as specified by typical automation environments.

  3. The scalable coherent interface, IEEE P1596, status and possible applications to data acquisition and physics

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, D.B.

    1990-01-01

    IEEE P1596, the Scalable Coherent Interface (formerly known as SuperBus) is based on experience gained while developing Fastbus (ANSI/IEEE 960-1986, IEC 935), Futurebus (IEEE P896.x) and other modern 32-bit buses. SCI goals include a minimum bandwidth of 1 GByte/sec per processor in multiprocessor systems with thousands of processors; efficient support of a coherent distributed-cache image of distributed shared memory; support for repeaters which interface to existing or future buses; and support for inexpensive small rings as well as for general switched interconnections like Banyan, Omega, or crossbar networks. This paper presents a summary of current directions, reports the status of the work in progress, and suggests some applications in data acquisition and physics. 7 refs.

  4. An Analytical Model for the Performance Analysis of Concurrent Transmission in IEEE 802.15.4

    Science.gov (United States)

    Gezer, Cengiz; Zanella, Alberto; Verdone, Roberto

    2014-01-01

    Interference is a serious cause of performance degradation for IEEE802.15.4 devices. The effect of concurrent transmissions in IEEE 802.15.4 has been generally investigated by means of simulation or experimental activities. In this paper, a mathematical framework for the derivation of chip, symbol and packet error probability of a typical IEEE 802.15.4 receiver in the presence of interference is proposed. Both non-coherent and coherent demodulation schemes are considered by our model under the assumption of the absence of thermal noise. Simulation results are also added to assess the validity of the mathematical framework when the effect of thermal noise cannot be neglected. Numerical results show that the proposed analysis is in agreement with the measurement results on the literature under realistic working conditions. PMID:24658624

  5. IEEE 1451.2 based Smart sensor system using ADuc847

    Science.gov (United States)

    Sreejithlal, A.; Ajith, Jose

    IEEE 1451 standard defines a standard interface for connecting transducers to microprocessor based data acquisition systems, instrumentation systems, control and field networks. Smart transducer interface module (STIM) acts as a unit which provides signal conditioning, digitization and data packet generation functions to the transducers connected to it. This paper describes the implementation of a microcontroller based smart transducer interface module based on IEEE 1451.2 standard. The module, implemented using ADuc847 microcontroller has 2 transducer channels and is programmed using Embedded C language. The Sensor system consists of a Network Controlled Application Processor (NCAP) module which controls the Smart transducer interface module (STIM) over an IEEE1451.2-RS232 bus. The NCAP module is implemented as a software module in C# language. The hardware details, control principles involved and the software implementation for the STIM are described in detail.

  6. A 1-GHz charge pump PLL frequency synthesizer for IEEE 1394b PHY

    DEFF Research Database (Denmark)

    Ji, J.; Liu, H.; Li, Q.

    2012-01-01

    This paper presents an implementation of multi-rate SerDes transceiver for IEEE 1394b applications. Simple and effective pre-emphasis and equalizer circuits are used at transmitter and receiver, respectively. A phase interpolator based clock and data recovery circuit with optimized linearity...... is also described. With an on-chip fully integrated phase locked loop, the transceiver works at data rates of 100Mb/s, 400Mb/s and 800Mb/s, supporting three different operating modes of S100b, S400b and S800b for IEEE 1394b. The chip has been fabricated using 0.13μm technology. The die area of transceiver...... is 2.9*1.6 mm including bonding pads and the total power dissipation is 284 mW with 1.2V and 3.3V supply voltages. © 2012 IEEE....

  7. Throughput and delay analysis of IEEE 802.15.6-based CSMA/CA protocol.

    Science.gov (United States)

    Ullah, Sana; Chen, Min; Kwak, Kyung Sup

    2012-12-01

    The IEEE 802.15.6 is a new communication standard on Wireless Body Area Network (WBAN) that focuses on a variety of medical, Consumer Electronics (CE) and entertainment applications. In this paper, the throughput and delay performance of the IEEE 802.15.6 is presented. Numerical formulas are derived to determine the maximum throughput and minimum delay limits of the IEEE 802.15.6 for an ideal channel with no transmission errors. These limits are derived for different frequency bands and data rates. Our analysis is validated by extensive simulations using a custom C+ + simulator. Based on analytical and simulation results, useful conclusions are derived for network provisioning and packet size optimization for different applications.

  8. An analytical model for the performance analysis of concurrent transmission in IEEE 802.15.4.

    Science.gov (United States)

    Gezer, Cengiz; Zanella, Alberto; Verdone, Roberto

    2014-03-20

    Interference is a serious cause of performance degradation for IEEE802.15.4 devices. The effect of concurrent transmissions in IEEE 802.15.4 has been generally investigated by means of simulation or experimental activities. In this paper, a mathematical framework for the derivation of chip, symbol and packet error probability of a typical IEEE 802.15.4 receiver in the presence of interference is proposed. Both non-coherent and coherent demodulation schemes are considered by our model under the assumption of the absence of thermal noise. Simulation results are also added to assess the validity of the mathematical framework when the effect of thermal noise cannot be neglected. Numerical results show that the proposed analysis is in agreement with the measurement results on the literature under realistic working conditions.

  9. Design and Implementation of IEEE 802.15.4 Mac Protocol on FPGA

    CERN Document Server

    Bhat, Naagesh S

    2012-01-01

    The IEEE 802.15.4 is a wireless standard introduced for low power, low cost wireless communication with moderate data rates. In the next few years, it is expected that Low Rate Wireless Personal Area Networks (LR-WPAN) will be used in a wide variety of embedded applications, including home automation, industrial sensing and control, environmental monitoring and sensing. In these applications, numerous embedded devices running on batteries are distributed in an area communicating via wireless radios. This work presents a method which can be used for comparing current consumption of wireless data transfer embedded systems. This paper implements a small subset of the IEEE 802.15.4 protocol to achieve a point to point communication. The implemented protocol uses 802.15.4 MAC compliant data and acknowledgment packets. Current consumption is measured while doing one data packet transmission. Measurements are compared with existing work. IEEE 802.15.4 protocol implementation is done using Verilog language. Code impl...

  10. PERFORMANCE STUDY OF DISTRIBUTED COORDINATION FUNCTION OVER IEEE 802.11A PHYSICAL LAYER

    Directory of Open Access Journals (Sweden)

    S. SELVAKENEDDY

    2006-06-01

    Full Text Available IEEE 802.11a is one of the latest standards to be released by the IEEE Project 802 for wireless LANs. It has specified an additional physical layer (PHY to support higher data rates, and is termed as the orthogonal frequency division multiplexing (OFDM. In order to exploit its benefits, one of the medium access control (MAC protocols specified in the IEEE 802.11 specification is called distributed coordination function (DCF. DCF is a carrier sense multiple access with collision avoidance (CSMA/CA scheme with slotted binary exponential backoff. The frames can be transmitted using the basic access scheme or the RTS/CTS scheme in DCF. It was demonstrated previously that the RTS/CTS mechanism works well in most scenarios for the previously specified PHYs. In this work, a simple simulator is developed to verify the scalability of the RTS/CTS mechanism over OFDM PHY, which supports much higher data rates.

  11. 基于IEEE 1149.X标准的测试技术研究%Research of the Test Techniques Based on IEEE 1149.X

    Institute of Scientific and Technical Information of China (English)

    姜鹏; 沈绪榜

    2004-01-01

    IEEE1149标准及其子标准是基于边界扫描的测试技术,它们针对不同的应用环境采用相应的技术标准.它们所提供的解决方案极大地方便了芯片级、板级、系统级及数字网络的测试.本文讨论了IEEE1149.X中各标准的原理、结构,分析了各项技术的发展及应用,并举例说明了在实际中的测试应用.

  12. 结合案例探讨IEEE 802.X协议检索策略%Analysis of Search of IEEE 802.X Protocol Associated with Actual Cases

    Institute of Scientific and Technical Information of China (English)

    李玉萍

    2015-01-01

    在涉及IEEE 802.X的发明专利申请的检索过程中,仅在专利数据库中很难检索到与专利申请最接近的现有技术,常常需要转到非专利数据库进行检索,通过两个实际案例,探讨了如何对涉及IEEE 802.X协议的发明专利申请进行有效检索,从而提出一种准确、快速、高效地检索现有技术的方法,为审查工作提供参考,也为该领域的发明人、申请人提供更多的现有技术检索思路和方式.

  13. 基于IEEE802.16e睡眠模式的研究%Performance analysis of sleep mode operation in IEEE802.16e

    Institute of Scientific and Technical Information of China (English)

    顾俊杰; 杨宇航

    2009-01-01

    The IEEE802.16e is a standard of emerging broadband wireless access system which supports the mobility. The mobile subscribers (MSS) are mainly powered by the batteries, so the sleep mode mechanism becomes an important component for the MSS which can effectively manage the limited energy, and prolong the using time of the once-charged batteries.This paper introduced the standardized sleep mode in IEEE802.16e,then it analyzed the average energy consumption and the average packet delay under sleep mode by building a semi-Markov chain,and gave the simulation results by NS2 at last.%IEEE802.16e标准是支持终端移动性的无线城域网接人标准.由于移动终端是由电池供电的,而休眠模式作为其必备功能,能有效管理其有限的电池容量,延长其单次充电使用时间.首先介绍了IEEE802.16e标准建议的睡眠模式,然后通过建立马尔可夫链模型对睡眠模式下的平均能量消耗及平均包延迟进行分析,最后NS2工具对分析结果进行NS2仿真和讨论.

  14. IEEE 802.11 DCF协议性能分析模型%Performance Analysis Model for IEEE 802.11 Distributed Coordination Function Protocol

    Institute of Scientific and Technical Information of China (English)

    钟萍; 施海彬; 庄玉祥; 石江宏; 陈辉煌

    2013-01-01

    提出了一种改进的二维Markov链模型用于分析IEEE 802.11 DCF协议.该模型不仅考虑实际应用中饱和业务量和非饱和业务量的情况,而且考虑DCF协议的退避计时器的冻结状态和有限的重传次数.通过对该Markov链模型稳定状态的求解并结合M/M/1/K排队模型,导出了DCF系统性能的理论模型.仿真结果表明,该理论模型能够精确地预测广义IEEE 802.11 DCF协议的系统性能.%This paper proposes an improved two-dimensional Markov chain model for the performance analysis of the IEEE 802.11 DCF protocol. The model is applicable to both saturated and unsaturated traffic conditions. Moreover, it extends the existing models to take into account previously-ignored MAC layer factors such as backoff freezing and limited times of retry. In addition, by deriving the stationary state of the Markov model and considering an M/M/1/K queuing model, we further derive a theoretical model for evaluating performance of the general IEEE 802.11 DCF protocols. Accuracy of the proposed theoretical model is validated with simulation results.

  15. Research of Bus Signals Extension in IEEE Std 1641-2010%IEEE Std 1641中总线类信号扩展方法研究

    Institute of Scientific and Technical Information of China (English)

    陈育良; 牛双诚; 曲晓燕

    2012-01-01

    With a 4 layers model, IEEE Std 1641 - 2010 provides the capability to describe and control signals, but not include one of the most important signal, bus signals. After researching way of bus signals extension in C/ATLAS, this paper gives an model of bus instruments using the reference of its designing idea, and accomplish bus signals extension by extending new signals. It also gives TPL statement of new signals. Using this method, it fulfill test well in an ATS.%IEEE Std 1641-2010中提出STD四层结构模型,完成信号的描述和控制功能,但没有提供总线信号定义和描述,而总线信号则是自动测试中最重要信号之一;针对此问题,文中通过深入研究C/ATLAS中总线类信号的扩展方法,借鉴其设计思想,提出了满足IEEE Std 1641设计思想和原则的总线信号仪器模型,通过扩展新信号的方法完成多种总线信号扩展,并给出其TPL语言支持,经实际系统中使用,很好地完成了测试测量功能.

  16. 面向IEEE 802.16e的高效LDPC编码器设计%Design of High Efficient LDPC Encoder in IEEE 802.16e

    Institute of Scientific and Technical Information of China (English)

    李书洋; 胡剑浩; 陈杰男

    2012-01-01

    基于矩阵乘法的高斯消元法提出了一种通用的LDPC编码器结构,该结构使用移位寄存器和简单的选线实现了复杂的矩阵向量相乘运算并且不需要存储庞大的校验矩阵.然后根据IEEE 802.16e标准中对校验矩阵的定义,利用FPGA实现了编码器的硬件结构,并且由仿真结果可知这种LDPC编码器结构降低了逻辑资源开销,提高了编码速度.%In this paper, a high efficient LDPC encoder structure is proposed for IEEE 802. 16e with Gaussian elimination algorithm based on matrix multiplication. The matrix-vector multiplication is implemented with a shift register and a simple line selection in the proposed encoder, which is memory free structure for check matrix. According to IEEE 802.16e, the proposed encoder is implemented with FPGA. Compared with existing LDPC encoder, the proposed scheme can provide higher speed of encoding with less logic resources.

  17. Test-Driven Development of IEEE 1451 Transducer Services and Application

    Directory of Open Access Journals (Sweden)

    S. Ranđić

    2012-06-01

    Full Text Available IEEE 1451 standard defines the methods of integrating smart transducers into communicating networks. Interface between a user application and a field of transducers, known as Transducer Services API is defined by standrad IEEE 1451.0. This paper presents the use of Test- Driven Design (TDD in developing methods for accessing transducer services using Transducer Services API and developing web applications which access this services over the network. The characteristics of TDD and its benefits are presented and the way of realization for one method is shown using Java and JUnit framework to run tests.

  18. IEEE 802.11e (EDCA analysis in the presence of hidden stations

    Directory of Open Access Journals (Sweden)

    Xijie Liu

    2011-07-01

    Full Text Available The key contribution of this paper is the combined analytical analysis of both saturated and non-saturated throughput of IEEE 802.11e networks in the presence of hidden stations. This approach is an extension to earlier works by other authors which provided Markov chain analysis to the IEEE 802.11 family under various assumptions. Our approach also modifies earlier expressions for the probability that a station transmits a packet in a vulnerable period. The numerical results provide the impact of the access categories on the channel throughput. Various throughput results under different mechanisms are presented.

  19. A New Analytic Method for IEEE 802.11 Distributed Coordination Function

    Science.gov (United States)

    Hwang, Gang Uk; Chung, Min Young; Lee, Yutae

    In this paper, we consider a network of N identical IEEE 802.11 DCF (Distributed Coordination Function) terminals with RTS/CTS mechanism, each of which is assumed to be saturated. For performance analysis, we propose a simple and efficient mathematical model to derive the statistical characteristics of the network such as the inter-transmission time of packets in the network and the service time (the inter-transmission time of successful packet transmissions) of the network. Numerical results and simulations are provided to validate the accuracy of our model and to study the performance of the IEEE 802.11 DCF network.

  20. International Conference on Grey Systems and intelligent Services (IEEE GSIS 2009)

    CERN Document Server

    Liu, Sifeng; Advances in Grey Systems Research

    2010-01-01

    This book contains contributions by some of the leading researchers in the area of grey systems theory and applications. All the papers included in this volume are selected from the contributions physically presented at the 2009 IEEE International Conference on Grey Systems and Intelligent Services, November 11 – 12, 2009, Nanjing, Jiangsu, People’s Republic of China. This event was jointly sponsored by IEEE Systems, Man, and Cybernetics Society, Natural Science Foundation of China, and Grey Systems Society of China. Additionally, Nanjing University of Aeronautics and Astronautics also invested heavily in this event with its direct and indirect financial and administrative supports.

  1. BER Analysis Of IEEE802.11n MIMO System Using MMSE And ZF Detectors

    Directory of Open Access Journals (Sweden)

    Ye Lwin Oo

    2015-06-01

    Full Text Available Abstract With the increasing demand of higher data rate for telecommunication the IEEE802.11n standard was constituted in 2009. The most important character of the standard is MIMO-OFDM which not only improves the throughput but also the spectrum efficiency and channel capacity. And in wireless communication the role of MIMO detectors plays an important part to remove inter-symbol interference ISI caused by multipath fading channel. In this paper the BER performance of IEEE 802.11n for 3x2 4x2 and 4x3 antennas are compared using MMSE and ZF detectors in Matlab Simulink.

  2. Direct Sequence Spread Spectrum Steganographic Scheme for IEEE 802.15.4

    CERN Document Server

    Zielinska, Elzbieta

    2011-01-01

    This work addresses the issues related to network steganography in IEEE 802.15.4 Wireless Personal Area Networks (WPAN). The proposed communication scheme employs illicit Direct Sequence Spread Spectrum code sequences for the transmission of steganographic data. The presented approach is a compromise between minimising the probability of covert channel disclosure and providing robustness against random errors and a high steganographic data rate. The conducted analyses show that it is possible to create a covert channel with a data rate comparable to the raw data rate of IEEE 802.15.4 without much impact on the perceived receiver sensitivity, the Chip Error Rate and the Bit Error Rate.

  3. GE networked mass storage solutions supporting IEEE network mass storage model

    Science.gov (United States)

    Herzog, Donald

    1993-01-01

    The General Electric Government Communications Systems Department (GE/GCSD) has developed a near real time digital data storage and retrieval system that extends the capabilities currently available in today's marketplace. This system called DuraStore uses commercially available rotary tape drive technology with ANSI/IEEE standards for automated magnetic tape based data storage. It uses a nonproprietary approach to satisfy a wide range of data rates and storage capabilities requirements and is compliant with the IEEE Network Storage Model. Rotary tape drives, standard interfaces, application specific hardware/software, networked automated tape libraries, library administrator, write protection, volume/physical media linkages, and maximum resource utilization are addressed.

  4. IEEE 802.17与弹性分组环

    Institute of Scientific and Technical Information of China (English)

    马上; 马立香

    2004-01-01

    2004年6月发布的IEEE802.1 7标准规范了弹性分组环(RPR)技术.RPR针对承载IP业务进行优化,是构建IP城域网极具潜力的技术.本文概述IEEE 802.17/RPR技术,重点概述RPR的带宽分配、空间重用、自动拓扑发现及保护等关键技术,比较分析RPR相对其它城域网技术的优势.

  5. Chair's Introduction to 2009 IEEE Circuits and Systems International Conference on Testing and Diagnosis

    Institute of Scientific and Technical Information of China (English)

    Rueywen Liu

    2009-01-01

    @@ Based on the recommendation of ICTD'09 TPC members, this Special Issue of the Journal of Electronic Science & Technology of China (JESTC) contained 22 high quality papers selected from the Proceedings of 2009 IEEE Circuits and Systems International Conference on Testing and Diagnosis (ICTD'09) which is fully sponsored by the IEEE Circuits and Systems Society (CASS), and is technically co-sponsored by the University of Electronic Science and Technology of China (UESTC), the Chinese Institute of Electronics (CIE), the China Instrument & Control Society (CIS), and organized by UESTC.

  6. Queuing Analysis for IEEE 802.11e Networks in Non-Saturation Environments

    Directory of Open Access Journals (Sweden)

    Eui-Jik Kim

    2012-04-01

    Full Text Available This paper presents an analytical model for the performance evaluation of an IEEE 802.11e network in non‐saturation environments. We first characterize the probability distribution of the MAC layer packet service time. Based on the probability distribution model of the MAC layer packet service time, we then study the queuing performance of the wireless local area networks (WLANs at different traffic loads based on the IEEE 802.11e MAC protocol. The numerical results show that we can choose a feasible number and bandwidth of the node which determines the system performance that a user demands.

  7. Analysis Of Impact Of Various Parameters On BER Performance For IEEE 802.11b

    Directory of Open Access Journals (Sweden)

    Nilesh B. Kalani

    2015-08-01

    Full Text Available Abstract This paper discusses about IEEE 802.11b simulation model implemented using LabVIEW software and its analyses for impact on bit error rate BER for different parameters as channel type channel number data transmission rate and packet size. Audio file is being transmitted processed and analyzed using the model for various parameters. This paper gives analysis of BER verses ESN0 for various parameter like data rate packet size and communication channel for the IEEE 802.11b simulation model generated using LabVIEW. It is proved that BER can be optimized by tweaking different parameters of wireless communication system.

  8. Reactive GTS Allocation Protocol for Sporadic Events Using the IEEE 802.15.4

    Directory of Open Access Journals (Sweden)

    Mukhtar Azeem

    2014-01-01

    by the IEEE 802.15.4 standard. The proposed control protocol ensures that a given offline sporadic schedule can be adapted online in a timely manner such that the static periodic schedule has not been disturbed and the IEEE 802.15.4 standard compliance remains intact. The proposed protocol is simulated in OPNET. The simulation results are analyzed and presented in this paper to prove the correctness of the proposed protocol regarding the efficient real-time sporadic event delivery along with the periodic event propagation.

  9. IEEE802.15.4协议性能分析实验设计与实现%Experimental Design and Implementation of IEEE 802.15.4 Protocol Performance Analysis

    Institute of Scientific and Technical Information of China (English)

    欧阳国军; 赵艳玲

    2016-01-01

    为了探索IEEE802.15.4协议实验教学,首先对实验内容进行了归纳,然后应用IEEE802.15.4/ZigBee仿真模型设计了IEEE802.15.4协议性能分析实验方案,详细给出IEEE802.15.4/ZigBee仿真模型的参数配置,最后分析了参数SO、BO、NB、BE和负载对网络性能的影响.该实验方案应用到教学中,加强了学生对抽象、复杂知识的理解,填补了IEEE802.15.4协议教学中的一项空白.

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

    Directory of Open Access Journals (Sweden)

    Foh ChuanHeng

    2010-01-01

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

  11. Comparison of QoS guarantee techniques for VoIP over IEEE802.11 wireless LAN

    Science.gov (United States)

    Guo, Fanglu; Chiueh, Tzi-cker

    2008-01-01

    An emerging killer application for enterprise wireless LANs (WLANs) is voice over IP (VoIP) telephony, which promises to greatly improve the reachability and mobility of enterprise telephony service at low cost. None of the commercial IEEE 802.11 WLAN-based VoIP products can support more than ten G.729-quality voice conversations over a single IEEE 802.11b channel on real-world WLANs, even though the physical transmission rate is more than two orders of magnitude higher than an individual VoIP connection's bandwidth requirement. There are two main reasons why these VoIP systems' effective throughput is significantly lower than expected: VoIP's stringent latency requirement and substantial per-WLAN-packet overhead. Time-Division Multiple Access (TDMA) is a well-known technique that provides per-connection QoS guarantee as well as improves the radio channel utilization efficiency. This paper compares the effective throughput of IEEE 802.11, IEEE 802.11e and a software-based TDMA (STDMA) protocol that is specifically designed to support WLAN-based VoIP applications, on the same commodity IEEE 802.11 WLAN hardware. Empirical measurements from a VOIP over WLAN testbed show that the numbers of G.729-quality voice conversations that IEEE 802.11, IEEE 802.11e and STDMA can support over a single IEEE 802.11b channel are 18, 22 and 50, respectively.

  12. Evaluation of the Effects of Hidden Node Problems in IEEE 802.15.7 Uplink Performance

    Directory of Open Access Journals (Sweden)

    Carlos Ley-Bosch

    2016-02-01

    Full Text Available In the last few years, the increasing use of LEDs in illumination systems has been conducted due to the emergence of Visible Light Communication (VLC technologies, in which data communication is performed by transmitting through the visible band of the electromagnetic spectrum. In 2011, the Institute of Electrical and Electronics Engineers (IEEE published the IEEE 802.15.7 standard for Wireless Personal Area Networks based on VLC. Due to limitations in the coverage of the transmitted signal, wireless networks can suffer from the hidden node problems, when there are nodes in the network whose transmissions are not detected by other nodes. This problem can cause an important degradation in communications when they are made by means of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA access control method, which is used in IEEE 802.15.7 This research work evaluates the effects of the hidden node problem in the performance of the IEEE 802.15.7 standard We implement a simulator and analyze VLC performance in terms of parameters like end-to-end goodput and message loss rate. As part of this research work, a solution to the hidden node problem is proposed, based on the use of idle patterns defined in the standard. Idle patterns are sent by the network coordinator node to communicate to the other nodes that there is an ongoing transmission. The validity of the proposed solution is demonstrated with simulation results.

  13. Performance Analysis of Non-saturated IEEE 802.11 DCF Networks

    Science.gov (United States)

    Zhai, Linbo; Zhang, Xiaomin; Xie, Gang

    This letter presents a model with queueing theory to analyze the performance of non-saturated IEEE 802.11 DCF networks. We use the closed queueing network model and derive an approximate representation of throughput which can reveal the relationship between the throughput and the total offered load under finite traffic load conditions. The accuracy of the model is verified by extensive simulations.

  14. Evaluation of H.264/AVC over IEEE 802.11p vehicular networks

    Science.gov (United States)

    Rozas-Ramallal, Ismael; Fernández-Caramés, Tiago M.; Dapena, Adriana; García-Naya, José Antonio

    2013-12-01

    The capacity of vehicular networks to offer non-safety services, like infotainment applications or the exchange of multimedia information between vehicles, have attracted a great deal of attention to the field of Intelligent Transport Systems (ITS). In particular, in this article we focus our attention on IEEE 802.11p which defines enhancements to IEEE 802.11 required to support ITS applications. We present an FPGA-based testbed developed to evaluate H.264/AVC (Advanced Video Coding) video transmission over vehicular networks. The testbed covers some of the most common situations in vehicle-to-vehicle and roadside-to-vehicle communications and it is highly flexible, allowing the performance evaluation of different vehicular standard configurations. We also show several experimental results to illustrate the quality obtained when H.264/AVC encoded video is transmitted over IEEE 802.11p networks. The quality is measured considering two important parameters: the percentage of recovered group of pictures and the frame quality. In order to improve performance, we propose to substitute the convolutional channel encoder used in IEEE 802.11p for a low-density parity-check code encoder. In addition, we suggest a simple strategy to decide the optimum number of iterations needed to decode each packet received.

  15. IEEE 802.11 Wireless LANs: Performance Analysis and Protocol Refinement

    Directory of Open Access Journals (Sweden)

    Chatzimisios P.

    2005-01-01

    Full Text Available The IEEE 802.11 protocol is emerging as a widely used standard and has become the most mature technology for wireless local area networks (WLANs. In this paper, we focus on the tuning of the IEEE 802.11 protocol parameters taking into consideration, in addition to throughput efficiency, performance metrics such as the average packet delay, the probability of a packet being discarded when it reaches the maximum retransmission limit, the average time to drop a packet, and the packet interarrival time. We present an analysis, which has been validated by simulation that is based on a Markov chain model commonly used in the literature. We further study the improvement on these performance metrics by employing suitable protocol parameters according to the specific communication needs of the IEEE 802.11 protocol for both basic access and RTS/CTS access schemes. We show that the use of a higher initial contention window size does not considerably degrade performance in small networks and performs significantly better in any other scenario. Moreover, we conclude that the combination of a lower maximum contention window size and a higher retry limit considerably improves performance. Results indicate that the appropriate adjustment of the protocol parameters enhances performance and improves the services that the IEEE 802.11 protocol provides to various communication applications.

  16. Performance characterization of the IEEE 802.11 signal transmission over a multimode fiber PON

    Science.gov (United States)

    Maksymiuk, L.; Siuzdak, J.

    2014-11-01

    In this paper there are presented measurements concerning performance analysis of the IEEE 802.11 signal distribution over multimode fiber based passive optical network. In the paper there are addressed three main sources of impairments: modal noise, frequency response fluctuation of the multimode fiber and non-linear distortion of the signal in the receiver.

  17. Some problems of implementation: ANSI/IEEE Std 1149.1 in microcontroller design

    Science.gov (United States)

    Adamkiewicz, Hubert; Glinski, Krzysztof; Lewandowski, Artur

    1992-08-01

    The paper presents some problems of implementation ANSI/IEEE Std 1149.1 worked out in the Industrial Institute of Electronics (PIE) microcontroller board. Diagnostic properties of some special hardware solutions and examples of testing procedures are described. Testing was performed with the help of the PIE diagnostic bus analyzer.

  18. Interference Measurements in IEEE 802.11 Communication Links Due to Different Types of Interference Sources

    NARCIS (Netherlands)

    Bloem, van Jan-Willem; Schiphorst, Roel; Kluwer, Taco; Slump, Cornelis H.

    2012-01-01

    The number of wireless devices (smartphones, laptops, sensors) that use the 2.4 GHz ISM band is rapidly increasing. The most common communication system in this band is Wi-Fi (IEEE 802.11b/g/n). For that reason coexistence between Wi-Fi and other systems becomes more and more important. In this pape

  19. Analysis of the IEEE 802.20 norm as the standard for developing new wireless technologies

    Directory of Open Access Journals (Sweden)

    Danilo A López Sarmiento

    2015-10-01

    Full Text Available This paper aims to compile existing information on the IEEE 802.20 standard and unify it in a document that will serve as support for parties interested in conducting research and / or projects related to wireless technologies.

  20. Interference Mitigation in IEEE 802.15.4-A Cluster Based Scheduling Approach

    Directory of Open Access Journals (Sweden)

    G. M. Tamilselvan

    2011-01-01

    Full Text Available Problem statement: In universal networking environments; two or more heterogeneous communication systems coexisting in a single place. Especially, Wireless Local Area Networks (WLANs based on IEEE 802.11b specifications and Wireless Personal Area Networks (WPANs based on IEEE 802.15.4 specifications need to coexist in the same Industrial, Science and Medial (ISM band. If the WPAN communication coverage is expanded using a cluster-tree network topology, then the 802.15.4 network is more susceptible to interference from neighboring WLANs. Approach: In this study, we propose an adaptive transmission power aware cluster scheduling algorithm using multiple channels in a WPAN in the presence of WLAN interference. Results: The algorithm includes node identification, channel allocation, clustering and time scheduling. To evaluate the performance of the proposed algorithm, the performance metrics such as Bit error, Packet Error Rate (PER, Throughput, Average End-End Delay and Average Jitter is measured through Qualnet simulation. PER is calculated from bit error rate. The simulation results are compared with the conventional TDMA scheme. Conclusion/Recommendations: The measurement result shows that the proposed algorithm is effective in an IEEE 802.15.4 cluster-tree network in the presence of multiple IEEE 802.11 interferers.

  1. Performance Evaluations for IEEE 802.15.4-based IoT Smart Home Solution

    Directory of Open Access Journals (Sweden)

    Nga Dinh

    2016-09-01

    Full Text Available The Internet of Things (IoT is going to be a market-changing force for a variety of real-time applications such as e-healthcare, home automation, environmental monitoring, and industrial automation. Low power wireless communication protocols offering long lifetime and high reliability such as the IEEE 802.15.4 standard have been a key enabling technology for IoT deployments and are deployed for home automation recently. The issues of the IEEE 802.15.4 networks have moved from theory to real world deployments. The work presented herein intends to demonstrate the use of the IEEE 802.15.4 standard in recent IoT commercial products for smart home applications: the Smart Home Starter Kit. The contributions of the paper are twofold. First, the paper presents how the IEEE 802.15.4 standard is employed in Smart Home Starter Kit. In particular, network topology, network operations, and data transfer mode are investigated. Second, network performance metrics such as end-to-end (E2E delay and frame reception ratio (FRR are evaluated by experiments. In addition, the paper discusses several directions for future improvements of home automation commercial products.

  2. Analyzing Performance for Mutual Authentication Mechanism for Wimax: IEEE 802.16e

    Directory of Open Access Journals (Sweden)

    Mrs. R. C. Roychaudhary

    2014-02-01

    Full Text Available The IEEE 802.16 designed to operate in the 10-66 GHz spectrum and it specifies the physical layer (PHY and medium access control layer (MAC of the air interface BWA systems. At 10-66 GHz range, transmission requires Line-of-Sight (LOS. IEEE 802.16 is working group number 16 of IEEE 802, specializing in point-tomultipoint broadband wireless access. The IEEE 802.16 Working Group created a new standard, commonly known as WiMAX, for broadband wireless access at high speed and low cost, which is easy to deploy, and which provides a scalable solution for extension of a fiber-optic backbone. WiMAX base stations can offer greater wireless coverage of about 5 miles, with LOS (line of sight transmission within bandwidth of up to 70 Mbps. WiMAX operates on the same general principles as WiFi -- it sends data from one computer to another via radio signals. A computer (either a desktop or a laptop equipped with WiMAX would receive data from the WiMAX transmitting station, probably using encrypted data keys to prevent unauthorized users from stealing access. The fastest WiFi connection can transmit up to 54 megabits per second under optimal conditions. WiMAX should be able to handle up to 70 megabits per second.

  3. Implementation of IEEE 802.15.4a Based UWB Systems for Coexistence with Primary Users

    Directory of Open Access Journals (Sweden)

    Caglar Findikli

    2016-03-01

    Full Text Available Peaceful coexistence is a major implementation issuefor both cognitive radios and ultra wideband (UWB systems.Accordingly, the UWB impulse radio (UWB-IR based WirelessPersonal Area Network (WPAN standard IEEE 802.15.4a hassuggested using linear combination of pulse to limit interfer-ence to coexisting primary systems. In this paper, motivatedby implementing the IEEE 802.15.4a based UWB-IR systemsfor peaceful coexistence, we consider the implementation oflinear combination of pulses as suggested by the standard.Accordingly, we (i design possible linearly combined pulses thatconform to the standard requirements, (ii consider coherentand noncoherent receiver structures that can be adapted for thephysical layer of the IEEE 802.15.4a standard, (iii investigatethe effect of channel models on the system performance, and(iv study the UWB-IR system performance in the presenceof narrowband and orthogonal frequency division multiplexing(OFDM based wideband primary systems with various band-widths and subcarriers. The study shows that the UWB-IR systemperformance can be significantly improved by selecting suitablepulses for transmission and employing appropriate filteringtechniques at the receiver when the primary system is active.For the implementation of IEEE 802.15.4a based UWB systemscomplying with coexistence requirements, the results of this studyshould be carefully considered.

  4. IEEE Radio and Wireless Symposium Student Awards Support Request: 2010-2012

    Science.gov (United States)

    2012-01-01

    Trasser, Sebastien Chartier , Hermann Schumacher. Analog Synchronous Receiver for Multi-Gigabit Wireless Communications, IEEE Radio and Wireless...Receiver for Multi-Gigabit Wireless Communications Cagri Ulusoy*, Gang Liu*, Andreas Trasser*, S´ebastien Chartier # and Hermann Schumacher* Ulm University

  5. Analysis and design of an on-chip retargeting engine for IEEE 1687 networks

    NARCIS (Netherlands)

    Ibrahim, Ahmed; Kerkhoff, Hans G.

    2016-01-01

    IEEE 1687 (iJTAG) standard introduces a methodology for accessing the increasing number of embedded instruments found in modern System-on-Chips. Retargeting is defined by iJTAG as the procedure of translating instrument-level patterns to system-level scan vectors for a certain network organization.

  6. Analysis of Throughput GTS and SDS in IEEE 802.15.4

    Directory of Open Access Journals (Sweden)

    Abhinav Singh

    2012-03-01

    Full Text Available the current IEEE 802.15.4 standard restricts the beacon enabled approach to star networks, while they support multi-hop networking in mesh but with no synchronization. In this paper there is proposal of a GTS with superframe scheduling for the chain network and throughput is observed.

  7. Performance Modeling of a Bottleneck Node in an IEEE 802.11 Ad-hoc Network

    NARCIS (Netherlands)

    Berg, van den Hans; Roijers, Frank; Mandjes, Michel R.H.; Kunz, T.; Ravi, S.S.

    2006-01-01

    The IEEE 802.11 MAC protocol, often used in ad-hoc networks, has the tendency to share the capacity equally amongst the active nodes, irrespective of their loads. An inherent drawback of this fair-sharing policy is that a node that serves as a relay-node for multiple flows is likely to become a bott

  8. Performance modelieg of a bottleneck node in an IEEE 802.11 ad-hoc network

    NARCIS (Netherlands)

    Berg, J.L. van den; Mandjes, M.; Roijers, F.

    2006-01-01

    The IEEE 802.11 MAC-protocol, often used in ad-hoc networks, has the tendency to share the capacity equally amongst the active nodes, irrespective of their loads. An inherent drawback of this fair-sharing policy is that a node that serves as a relay-node for multiple flows is likely to become a bott

  9. A Carrier Synchronization Algorithm for IEEE 802.11a System

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-guang; ZHOU Zheng

    2004-01-01

    A new Carrier Frequency Offset (CFO) estimation algorithm for IEEE 80211a system is proposed. The extended Kalman filter (EKF) is applied to estimate the frequency offset in the acquisition stage and the cyclic prefix (CP) is used to correct the residual CFO in the tracking stage. Simulation results demonstrate the super performance of the proposed algorithm compared to Maximum-Likelihood (ML) approach.

  10. IEEE802.15.6 -based multi-accelerometer WBAN system for monitoring Parkinson's disease.

    Science.gov (United States)

    Keränen, Niina; Särestöniemi, Mariella; Partala, Juha; Hämäläinen, Matti; Reponen, Jarmo; Seppänen, Tapio; Iinatti, Jari; Jämsä, Timo

    2013-01-01

    In this paper we present a detailed example of a wireless body area network (WBAN) scenario utilizing the recent IEEE802.15.6 standard as applied to a multi-accelerometer system for monitoring Parkinson's disease and fall detection. Ultra wideband physical layer and standard security protocols are applied to meet application requirements for data rate and security.

  11. Adaptability of IEEE 802.15.4(Zigbee Protocol for Wireless Sensor network

    Directory of Open Access Journals (Sweden)

    Lalit Saraswat

    2010-05-01

    Full Text Available The IEEE 802.15.4/Zigbee protocol stack has been considered as a promising technology for Wireless Sensor Networks (WSN. IEEE 802.15.4 Low-Rate Wireless Personal Area Network (WPAN standardspecifies the lower protocol layers—the physical layer (PHY, and the media access control (MAC portion of the data link layer (DLL and Network layer(NWK Wireless sensor network provide the low rate, wireless interconnection of ultra low cost sensor/actuator devices to enable the cyber world to sense and affect the real physical environment. The IEEE 802.15.4/Zigbee protocol stack provide selectable levels of security using AES-128 mechanism for privacy, sender authentication, message integrity. It uses fully handshake protocol for transfer reliability. In business applications where WSN are applied, failures in essential parts of the sensor network must beefficiently detected and automatically recovered. ZigBee is targeted at radio-frequency (RF applications that require a low data rate, long battery life, and secure networking.This paper will analyze theadaptability features of IEEE802.15.4[3] at Physical, MAC and Network layer and various mode of operation at MAC layer.

  12. A Secure Simplification of the PKMv2 Protocol in IEEE 802.16e-2005

    DEFF Research Database (Denmark)

    Yuksel, Ender; Nielson, Hanne Riis; Nielsen, Christoffer Rosenkilde

    2007-01-01

    for IEEE 802.16e, PKMv2. This protocol seems to have an exaggerated mixture of security features. Thus, we iteratively investigate which components are necessary for upholding the security properties and which can be omitted safely. This approach is based on the LySa process calculus and employs...

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

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2007-01-01

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

  14. Computer Controlled Test Systems. Introduction. A Course Based on the IEEE 488 Bus.

    Science.gov (United States)

    Herrmann, Eric J.

    An introductory course in computer automated tests and measurement systems based on the International Test Instrument-Computer Interface Standard, the IEEE (Institute of Electrical and Electronics Engineers)-488, is presented in this study guide. This course is designed to: (1) introduce the electronics engineering technician to the functional…

  15. Energy optimization based path selection algorithm for IEEE 802.11s wireless mesh networks

    CSIR Research Space (South Africa)

    Mhlanga, MM

    2011-09-01

    Full Text Available when the network is deployed in rural areas where electricity is a scarce resource. This research therefore presents an energy optimization based path selection algorithm for IEEE 802.11s WMNs which is aimed at addressing the above mentioned constrains...

  16. Evaluation of the Effects of Hidden Node Problems in IEEE 802.15.7 Uplink Performance.

    Science.gov (United States)

    Ley-Bosch, Carlos; Alonso-González, Itziar; Sánchez-Rodríguez, David; Ramírez-Casañas, Carlos

    2016-02-06

    In the last few years, the increasing use of LEDs in illumination systems has been conducted due to the emergence of Visible Light Communication (VLC) technologies, in which data communication is performed by transmitting through the visible band of the electromagnetic spectrum. In 2011, the Institute of Electrical and Electronics Engineers (IEEE) published the IEEE 802.15.7 standard for Wireless Personal Area Networks based on VLC. Due to limitations in the coverage of the transmitted signal, wireless networks can suffer from the hidden node problems, when there are nodes in the network whose transmissions are not detected by other nodes. This problem can cause an important degradation in communications when they are made by means of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) access control method, which is used in IEEE 802.15.7 This research work evaluates the effects of the hidden node problem in the performance of the IEEE 802.15.7 standard We implement a simulator and analyze VLC performance in terms of parameters like end-to-end goodput and message loss rate. As part of this research work, a solution to the hidden node problem is proposed, based on the use of idle patterns defined in the standard. Idle patterns are sent by the network coordinator node to communicate to the other nodes that there is an ongoing transmission. The validity of the proposed solution is demonstrated with simulation results.

  17. Energy-aware path selection metric for IEEE 802.11s wireless mesh networking

    CSIR Research Space (South Africa)

    Mhlanga, MM

    2009-01-01

    Full Text Available The IEEE 802.11s working group has commenced activities, which would lead to the development of a standard for wireless mesh networks (WMNs). The draft of 802.11s introduces a new path selection metric called airtime link metric. However...

  18. The IEEE-SA patent policy update under the lens of EU competition law

    NARCIS (Netherlands)

    Kanevskaia, Olia; Zingales, Nicolo

    2016-01-01

    In 2015, the Institute of Electrical and Electronics Engineers (IEEE) Standardization Association made some controversial changes to its patent policy. The changes include a recommended method of calculation of FRAND royalty rates, and a request to members holding a standard-essential patent to fore

  19. The IEEE-SA patent policy update under the lens of EU competition law

    NARCIS (Netherlands)

    Kanevskaia, Olia; Zingales, Nicolo

    2016-01-01

    In 2015, the Institute of Electrical and Electronics Engineers (IEEE) Standardization Association made some controversial changes to its patent policy. The changes include a recommended method of calculation of FRAND royalty rates, and a request to members holding a standard essential patent (SEP) t

  20. A Secure Simplification of the PKMv2 Protocol in IEEE 802.16e-2005

    DEFF Research Database (Denmark)

    Yuksel, Ender; Nielson, Hanne Riis; Nielsen, Christoffer Rosenkilde

    2007-01-01

    for IEEE 802.16e, PKMv2. This protocol seems to have an exaggerated mixture of security features. Thus, we iteratively investigate which components are necessary for upholding the security properties and which can be omitted safely. This approach is based on the LySa process calculus and employs...

  1. Computer Controlled Test Systems. Introduction. A Course Based on the IEEE 488 Bus.

    Science.gov (United States)

    Herrmann, Eric J.

    An introductory course in computer automated tests and measurement systems based on the International Test Instrument-Computer Interface Standard, the IEEE (Institute of Electrical and Electronics Engineers)-488, is presented in this study guide. This course is designed to: (1) introduce the electronics engineering technician to the functional…

  2. IEEE 802.11ac sebagai Standar Pertama untuk Gigabit Wireless LAN

    Directory of Open Access Journals (Sweden)

    Afdhal Afdhal

    2014-04-01

    Full Text Available WLAN is a technology that currently has been used widely. This technology is considered as a data transferring media technology within the LAN/MAN. To ensure that WLAN technology can be used widely in the whole world, the IEEE has set a standard known as 802.11 to be an international standard for the WLAN technology. This standard was appeared in 1997, and has been revised and improved for several times. This improvement is done to anticipate the rapidly grown WLAN market as well as to keep this technology remains effective, efficient, and reliable at any time. At the beginning of 2014, the IEEE has set 802.11ac-2013 as a new standard for WLANs that operate below 6 GHz to achieve a data rate for up to 7 Gbps. The purpose of this article is to describe comprehensively the IEEE 802.11ac standard as a result of recent changes to the regulatory for WLAN technology which is known as the first standard issued by the IEEE for the gigabit WLANs. This article discusses the goals and objectives to be achieved by 802.11ac standard as well as the parts that have been enhanced significantly both in its PHY and MAC layers. This article will also contrast the differences between the 802.11ac standard and previous WLAN standards. Finally it will also explain the level of compatibility and interoperability of 802.11ac standards with some of previous WLAN standard.Keywords: IEEE, 802.11, 802.11ac, Gigabit WLAN

  3. IEEE 802.16J-Relay Fortified Aeromacs Networks; Benefits and Challenges

    Science.gov (United States)

    Kamali, Behnam; Apaza, Rafael D.

    2014-01-01

    Aeronautical Mobile Airport Communications System (AeroMACS) is an IEEE 802.16 standard-based (WiMAX) broadband aviation transmission technology, developed to provide safety critical communications coverage for airport surface in support of fixed and mobile ground to ground applications and services. We have previously demonstrated that IEEE 802.16j-amendment-based WiMAX is most feasible for AeroMACS applications. The principal argument in favor of application of IEEE 802.16j technology is the flexible and cost effective extension of radio coverage that is afforded by relay fortified WiMAX networks, with virtually no increase in the power requirements. In this article, following introductory remarks on airport surface communications, WiMAX and AeroMACS; the IEEE 802.16j-based WiMAX technology and multihop relay systems are briefly described. The two modes of relay operation supported by IEEE 802.16j amendment; i.e., transparent (TRS) and non-transparent (NTRS) modes, are discussed in some detail. Advantages and disadvantages of using TRS and NTRS in AeroMACS networks are summarized in a table. Practical issues vis--vis the inclusion of relays in AeroMACS networks are addressed. It is argued that the selection of relay type may affect a number of network parameters. A discussion on specific benefits and challenges of inclusion of relays in AeroMACS networks is provided. The article concludes that in case it is desired or necessary to exclusively employ one type of relay mode for all applications throughout an AeroMACS network, the proper selection would be the non-transparent mode.

  4. IEEE1588协议在工业以太网中的实现%Implementation of IEEE 1588 Protocol over Industrial Ethernet

    Institute of Scientific and Technical Information of China (English)

    关松青; 肖昌炎; 夏晓荣

    2011-01-01

    An IEEE 1588 server, which is based on the foreground/background system with the priorities of interrupts, is designed and implemented to meet the high precision requirement of time synchronization in distributed power systems by using an ARM(@)CortexTM-M3 based microcontroller, which supports IEEE 1588 protocol. The burden of microcontroller is reduced and the real-time performance is further improved as a result of adopting the lightweight TCP/IP stack and simplifying the protocol's complexity to program the bottom communication software. It is shown in test experiments that this server characterizes high clock-synchronizatiun accuracy, excellent stability and low cost, and it has a bright prosperity to be applied into practice.%为满足电力等分布式测控系统对时钟同步的高精度要求,采用TI公司支持IEEE 1588协议的Cortex-M3核ARM芯片作为微处理器,设计并实现一种基于中断优先级的前/后台框架的精密时钟网络服务器.由于选用轻量级TCP/IP协议栈(LwIP)和简化同步协议设计底层通信软件,能减轻处理器负担,实时性能得到改善.测试实验结果表明,该设备同步精度高、稳定性好、成本低,具有较好的应用前景.

  5. SELF-POWERED WIRELESS SENSOR NODE POWER MODELING BASED ON IEEE 802.11 COMMUNICATION PROTOCOL

    Energy Technology Data Exchange (ETDEWEB)

    Vivek Agarwal; Raymond A. DeCarlo; Lefteri H. Tsoukalas

    2016-04-01

    Design and technical advancements in sensing, processing, and wireless communication capabilities of small, portable devices known as wireless sensor nodes (WSNs) have drawn extensive research attention and are vastly applied in science and engineering applications. The WSNs are typically powered by a chemical battery source that has a load dependent finite lifetime. Most applications, including the nuclear industry applications, require WSNs to operate for an extended period of time beginning with their deployment. To ensure longevity, it is important to develop self-powered WSNs. The benefit of self-powered WSNs goes far beyond the cost savings of removing the need for cable installation and maintenance. Self-powered WSNs will potentially offer significant expansion in remote monitoring of nuclear facilities, and provide important data on plant equipment and component status during normal operation, as well as in case of abnormal operation, station blackouts or post-accident evaluation. Advancements in power harvesting technologies enable electric energy generation from many sources, including kinetic, thermal, and radiated energy. For the ongoing research at Idaho National Laboratory, a solid-state thermoelectric-based technology, the thermoelectric generator (TEG), is used to convert thermal energy to power a WSN. The design and development of TEGs to power WSNs that would remain active for a long period of time requires comprehensive understanding of WSN operational. This motivates the research in modeling the lifetime, i.e., power consumption, of a WSN by taking into consideration various node and network level activities. A WSN must perform three essential tasks: sense events, perform quick local information processing of sensed events, and wirelessly exchange locally processed data with the base station or with other WSNs in the network. Each task has a power cost per unit tine and an additional cost when switching between tasks. There are number of other

  6. Next generation WLAN technology--IEEE 802.11ac%下一代WLAN技术IEEE 802.11ac

    Institute of Scientific and Technical Information of China (English)

    郭正跃

    2013-01-01

    IEEE 802.11ac是继802.11n的下一代无线局域网新技术标准,本文主要介绍了802.11ac在新技术方面的特性,重点介绍了MU-MIMO系统在802.11ac中的应用,包括MU-MIMO中多用户调度公平性问题的解决及目前最新的SLNR波束成形技术对多用户间干扰问题的解决方案。%IEEE 802.11ac is the second generation of 802.11n wireless LAN technical standard. The paper mainly introduces the features in new technical aspect and highlights the MU-MIMO system in the application of 802.11ac including the solution of multi-user scheduling fairness problem in MU-MIMO and the latest SLNR beam-forming techniques for multi-user interference.

  7. The National Ignition Facility (NIF) and High Energy Density Science Research at LLNL (Briefing Charts)

    Science.gov (United States)

    2013-06-21

    The National Ignition Facility ( NIF ) and High Energy Density Science Research at LLNL Presentation to: IEEE Pulsed Power and Plasma Science...Conference C. J. Keane Director, NIF User Office June 21, 2013 1491978-1-4673-5168-3/13/$31.00 ©2013 IEEE Report Documentation Page Form ApprovedOMB No...4. TITLE AND SUBTITLE The National Ignition Facility ( NIF ) and High Energy Density Science Research at LLNL 5a. CONTRACT NUMBER 5b. GRANT

  8. A network architecture for precision formation flying using the IEEE 802.11 MAC Protocol

    Science.gov (United States)

    Clare, Loren P.; Gao, Jay L.; Jennings, Esther H.; Okino, Clayton

    2005-01-01

    Precision Formation Flying missions involve the tracking and maintenance of spacecraft in a desired geometric formation. The strong coupling of spacecraft in formation flying control requires inter-spacecraft communication to exchange information. In this paper, we present a network architecture that supports PFF control, from the initial random deployment phase to the final formation. We show that a suitable MAC layer for the application protocol is IEEE's 802.11 MAC protocol. IEEE 802.11 MAC has two modes of operations: DCF and PCF. We show that DCF is suitable for the initial deployment phase while switching to PCF when the spacecraft are in formation improves jitter and throughput. We also consider the effect of routing on protocol performance and suggest when it is profitable to turn off route discovery to achieve better network performance.

  9. Capacity Evaluation for IEEE 802.16e Mobile WiMAX

    Directory of Open Access Journals (Sweden)

    Chakchai So-In

    2010-01-01

    Full Text Available We present a simple analytical method for capacity evaluation of IEEE 802.16e Mobile WiMAX networks. Various overheads that impact the capacity are explained and methods to reduce these overheads are also presented. The advantage of a simple model is that the effect of each decision and sensitivity to various parameters can be seen easily. We illustrate the model by estimating the capacity for three sample applications—Mobile TV, VoIP, and data. The analysis process helps explain various features of IEEE 802.16e Mobile WiMAX. It is shown that proper use of overhead reducing mechanisms and proper scheduling can make an order of magnitude difference in performance. This capacity evaluation method can also be used for validation of simulation models.

  10. RSAD: A Robust Distributed Contention-Based Adaptive Mechanism for IEEE 802.11 Wireless LANs

    Institute of Scientific and Technical Information of China (English)

    Yong Peng; Shi-Duan Cheng; Jun-Liang Chen

    2005-01-01

    Previous researches have shown that Distributed Coordination Function (DCF) access mode of IEEE 802.11 has lower performance in heavy contention environment. Based on the in-depth analysis of IEEE 802.11 DCF, NSAD (New Self-adapt DCF-based protocol) has been proposed to improve system saturation throughput in heavy contention condition.The initial contention window tuning algorithm of NSAD is proved effective in error-free environment. However, problems concerning the exchanging of initial contention window occur in error-prone environment. Based on the analysis of NSAD's performance in error-prone environment, RSAD is proposed to further enhance the performance. Simulation in a more real shadowing error-prone environment is done to compare the performance of NSAD and RSAD and results have shown that RSAD can achieve further performance improvement as expected in the error-prone environment than NSAD (i.e., better goodput and fairness index).

  11. Performance evaluation on IEEE 802.11e considering emergency calls in congested situation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To enhance the quality of service (QoS) support in IEE 802.11, IEEE 802.11e has been studied, which introduces the so-called hybrid coordination function (HCF). HCF includes two medium access mechanisms: contention-based channel access (EDCA), and contention-free channel access (HCCA). Although IEEE 802.11e has provided differentiated channel access mechanism, when call demand rises for important festivals such as New Year's Day or large scale natural disasters such as earthquakes, the delay of voice will increase and the QoS of voice nodes will drop down rapidly. Through our simulation study, in order to guarantee the QoS of emergency voice calls in congested situation, a higher priority for these calls will be required.

  12. Performance Analysis of IEEE 802.16e Wimax Physical Layer

    Directory of Open Access Journals (Sweden)

    Dr. Vineeta Saxena Nigam *,

    2014-05-01

    Full Text Available WiMAX (worldwide inter-operability for microwave access is an emerging technology for global broadband wireless system offering high speed access to mobile and broadband services. It is based on IEEE 802.16e standard. This standard only deals with MAC and PHY layer specification of network architecture. Considerable research has been done on performance analysis of PHY layer model of WiMAX system over AWGN channel model. This paper attempts performance analysis of IEEE 802.16e PHY layer model over AWGN as well as SUI channel models as SUI channel models are more realistic models based on empirical results. Different modulation schemes, coding rates, and different values of cyclic prefix are considered for comparison using BER (Bit error rate ratio and SNR (Signal to Noise ratio as performance parameters.

  13. Real-Time Performance Analysis of Infrastructure-based IEEE 802.11 Distributed Coordination Function

    CERN Document Server

    Xia, Feng; Wang, Linqiang; Hao, Ruonan

    2012-01-01

    With the increasing popularity of wireless networks, wireless local area networks (WLANs) have attracted significant research interest, which play a critical role in providing anywhere and anytime connectivity. For WLANs the IEEE 802.11 standard is the most mature technology and has been widely adopted for wireless networks. This paper analyzes real-time performance of the IEEE 802.11 standard that adopts the MAC protocol of Distributed Coordination Function (DCF) operating in infrastructure mode. Extensive simulations have been done to examine how the network performance in terms of realtime metrics including effective data rate, latency and packet loss rate will be impacted by some critical parameters (e.g. CWmin and packet payload). The results are presented and analyzed. The analysis of simulation results can provide support for parameter configuration and optimization of WLANs for realtime applications.

  14. Integration of IEEE 1451 and HL7 Exchanging Information for Patients’ Sensor Data

    Science.gov (United States)

    Lim, Suyoung; Ahn, Jinsoo; Nah, Jiyoung; Kim, Namhyun

    2009-01-01

    HL7 (Health Level 7) is a standard developed for exchanging incompatible healthcare information generated from programs or devices among heterogenous medical information systems. At present, HL7 is growing as a global standard. However, the HL7 standard does not support effective methods for treating data from various medical sensors, especially from mobile sensors. As ubiquitous systems are growing, HL7 must communicate with various medical transducers. In the area of sensor fields, IEEE 1451 is a group of standards for controlling transducers and for communicating data from/to various transducers. In this paper, we present the possibility of interoperability between the two standards, i.e., HL7 and IEEE 1451. After we present a method to integrate them and show the preliminary results of this approach. PMID:20703604

  15. Performance Analytical Model of IEEE 802.11 Distributed Coordination Function

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    IEEE 802.11 distributed coordination function (DCF) is a distributed medium access scheme based on carrier sense multiple access with collision avoidance (CSMA/CA) protocol. Many literatures have analyzed the performance of IEEE 802.11 DCF. However, such literatures either used simulation methods or built the analytical models under the assumption that the saturation condition was satisfied. To overcome such a problem, in this paper, a bi-dimensional Markovian model has been introduced to depict the DCF mechanism. The proposed model introduced an idle stage and a discrete time M/G/1 queue to deduce the channel throughput under finite load traffic. Simulation results proved the accuracy of the proposed model.

  16. An Improved Markov Model for IEEE 802.15.4 Slotted CSMA/CA Mechanism

    Institute of Scientific and Technical Information of China (English)

    Hao Wen; Chuang Lin; Zhi-Jia Chen; Hao Yin; Tao He; Eryk Dutkiewicz

    2009-01-01

    IEEE 802.15.4 protocol is proposed to meet the low latency and energy consumption needs in low-rate wireless applications, however, few analytical models are tractable enough for comprehensive evaluation of the protocol. To evaluate the IEEE 802.15.4 slotted CSMA/CA channel access mechanism in this paper, we propose a practical and accurate discrete Markov chain model, which can dynamically represent different network loads. By computing the steady-state distribution probability of the Markov chain, we obtain an evaluation formula for throughput, energy consumption, and access latency. Then we further analyze the parameters that influence performance including packet arrival rate, initial backoff exponent and maximum backoff number. Finally, NS2 simulator has been used to evaluate the performance of the 802.15.4 CSMA/CA mechanism under different scenarios and to validate the accuracy of the proposed model.

  17. The Research of ST-OFDM in Physical Layer of IEEE 802.16a

    Institute of Scientific and Technical Information of China (English)

    JU Mei-yan; ZHU Qi; FENG Guang-zeng

    2004-01-01

    This paper briefly introduces one of the three physical layer implementations of IEEE 802.16a[1], Wireless MAN-OFDM PHY. Based on the implementation, the combination of Orthogonal Frequency Division Multiplexing (OFDM) and Space-Time Coding ( STC ) which is briefly called ST-OFDM in IEEE 802.16a, is investigated under the channel provided in Ref . [ 2 ]. Especially, this paper is focused on the influence of the optimal decision threshold on the system Bit-Error-Rate ( BER ) performance based on unequal probabilities of sources. The simulations show that when SignalNoise-Ratio ( SNR ) is low the optimal decision threshold is obviously superior to the usual one; when SNR is high to some extent, such as 10 dB for 4QAM and 16 dB for 16QAM, we can use the usual decision threshold instead of the optimal one .

  18. Pilot Based Channel Estimation in IEEE 802.16a OFDM System

    Institute of Scientific and Technical Information of China (English)

    ZHU Qi; LU Hao

    2005-01-01

    Orthogonal Frequency Division Multiplexing(OFDM)is a kind of transmission techniques with high frequency efficiency,which will be widely used in next-generation wireless communication systems.In this paper,pilot-based channel estimation for IEEE 802.16a OFDM system is studied.By comparing the performance of LS(least squares)estimator and Linear Minimum Mean-Square Error(LMMSE)estimator using Preamble 1 and Preamble 2 suggested by IEEE 802.16a standard in slow fading channel,we propose that Preamble 1 can be used in small multipath delay spread channel and Preamble 2 can be used in large multipath delay spread channel.Considering the tradeoff between performance and complexity,the LS estimator is suggested.

  19. A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks

    Science.gov (United States)

    Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

    2017-01-01

    IEEE 802.15.4e standard proposes Deterministic and Synchronous Multichannel Extension (DSME) mode for wireless sensor networks (WSNs) to support industrial, commercial and health care applications. In this paper, a new channel access scheme and beacon scheduling schemes are designed for the IEEE 802.15.4e enabled WSNs in star topology to reduce the network discovery time and energy consumption. In addition, a new dynamic guaranteed retransmission slot allocation scheme is designed for devices with the failure Guaranteed Time Slot (GTS) transmission to reduce the retransmission delay. To evaluate our schemes, analytical models are designed to analyze the performance of WSNs in terms of reliability, delay, throughput and energy consumption. Our schemes are validated with simulation and analytical results and are observed that simulation results well match with the analytical one. The evaluated results of our designed schemes can improve the reliability, throughput, delay, and energy consumptions significantly.

  20. A Priority and SDB based Admission Control in IEEE 802.16 Systems

    Directory of Open Access Journals (Sweden)

    Xiu-ying Sun

    2010-09-01

    Full Text Available In IEEE 802.16 systems, the algorithm of admission control (AC is very important in guaranteeing the Quality of Service (QoS and managing service flows. However, the IEEE 802.16 standards do not specify any related strategies or algorithms on AC. In order to improve the system performance and satisfy the QoS of stations to the max, we propose a new AC strategy, which includes a weighted blocking rate based priority strategy and a satisfaction-degree based bandwidth-borrowing strategy named SDB in this paper. The simulation results show that the proposed strategy improves the overall performance of system in terms of weighted blocking rate. Furthermore, our strategy enhances the QoS in comparison with the strategy adopting conventional bandwidth-borrowing algorithm.

  1. Securing IEEE 802.11g WLAN Using Open VPN and its Impact Analysis

    Directory of Open Access Journals (Sweden)

    Praveen Likhar

    2011-12-01

    Full Text Available Like most advances, wireless LAN poses both opportunities and risks. The evolution of wireless networking in recent years has raised many serious security issues. These security issues are of greatconcern for this technology as it is being subjected to numerous attacks. Because of the free-space radio transmission in wireless networks, eavesdropping becomes easy and consequently a security breach may result in unauthorized access, information theft, interference and service degradation. Virtual Private Networks (VPNs have emerged as an important solution to security threats surrounding the use of public networks for private communications. While VPNs for wired line networks have matured in both research and commercial environments, the design and deployment of VPNs for WLAN is still an evolving field. This paper presents an approach to secure IEEE 802.11g WLAN using OpenVPN, a transport layer VPN solution and its impact on performance of IEEE 802.11g WLAN.

  2. Performance evaluation of beacon enabled IEEE 802.15.4 under NS2

    CERN Document Server

    Charfi, Faiza

    2012-01-01

    The increasing demand for real-time applications has made the Quality of Service (Qos) support for wireless sensor networks (WSN) a fairly new research framework. In this paper, we propose an extended model of the Beacon enabled IEEE 802.15.4 including the Guaranteed Time Slot GTS allocation mechanism in the aim to analyze and evaluate network performances. Series of extensive simulations were performed to analyze the impact of the Beacon Order BO and the Superframe Order SO on the network performance based on commonly known metrics. In particular, we examine data packet delivery performance and the throughput for different duty cycle rates. Also, we analyze the impact of the number of nodes on collision probability. Thus, for high number of nodes, collision becomes higher and the reachability begins to decline slightly. We discuss and compare simulation results conducted under various parameter settings to the IEEE 802.11 network.

  3. Transient Stability Improvement of IEEE 9 Bus System Using Power World Simulator

    Directory of Open Access Journals (Sweden)

    Kaur Ramandeep

    2016-01-01

    Full Text Available The improvement of transient stability of power system was one of the most challenging research areas in power engineer.The main aim of this paper was transient stability analysis and improvement of IEEE 9 bus system. These studies were computed using POWER WORLD SIMULATOR. The IEEE 9 bus system was modelled in power world simulator and load flow studies were performed to determine pre-fault conditions in the system using Newton-Raphson method. The transient stability analysis was carried out using Runga method during three-phase balanced fault. For the improvement transient stability, the general methods adopted were fast acting exciters, FACT devices and addition of parallel transmission line. These techniques play an important role in improving the transient stability, increasing transmission capacity and damping low frequency oscillations.

  4. Securing IEEE 802.11G WLAN Using OpenVPN and Its Impact Analysis

    CERN Document Server

    Likhar, Praveen; M, Keshava Rao; 10.5121/ijnsa.2011.3607

    2012-01-01

    Like most advances, wireless LAN poses both opportunities and risks. The evolution of wireless networking in recent years has raised many serious security issues. These security issues are of great concern for this technology as it is being subjected to numerous attacks. Because of the free-space radio transmission in wireless networks, eavesdropping becomes easy and consequently a security breach may result in unauthorized access, information theft, interference and service degradation. Virtual Private Networks (VPNs) have emerged as an important solution to security threats surrounding the use of public networks for private communications. While VPNs for wired line networks have matured in both research and commercial environments, the design and deployment of VPNs for WLAN is still an evolving field. This paper presents an approach to secure IEEE 802.11g WLAN using OpenVPN, a transport layer VPN solution and its impact on performance of IEEE 802.11g WLAN.

  5. A Fast MAC-Layer Handover for an IEEE 802.16e-Based WMAN

    Science.gov (United States)

    Ray, Sayan K.; Pawlikowski, Krzysztof; Sirisena, Harsha

    We propose a modification of the IEEE 802.16e hard handover (HHO) procedure, which significantly reduces the handover latency constraint of the original HHO procedure in IEEE 802.16e networks. It allows a better handling of the delay-sensitive traffic by avoiding unnecessary time-consuming scanning and synchronization activity as well as simplifies the network re-entry procedure. With the help of the backhaul network, it reduces the number of control messages in the original handover policy, making the handover latency acceptable also for real-time streaming traffic. Preliminary performance evaluation studies show that the modified handover procedure is able to reduce the total handover latency by about 50%.

  6. Uplink Scheduling for Supporting Real Time Voice Traffic in IEEE 802.16 Backhaul Networks

    Institute of Scientific and Technical Information of China (English)

    Lizhong Dai; Dongmei Zhao

    2008-01-01

    In this paper we propose simple enhancements to the bandwidth (BW) request messages in IEEE 802.16 for supporting real-time packet voice traffic. Three different BW request formats are proposed, each requiring a different amount of latency information about the buffered packets at the SS. On this basis, packet scheduling schemes are proposed for the BS to make resource allocations for real-time traffic. Our results show that the proposed BW request and scheduling schemes achieve significantly lower packet loss probability than the standard IEEE 802.16 BW request with round robin scheduling.The results further show that there is an optimum point about how much delay information the SS should report to the BS in order to best utilize the uplink resources while the SS provides satisfactory real-time performance for the voice traffic.

  7. Performance Evaluation Of BEACON-ENABLED IEEE 802.15.4 Under NS2

    Directory of Open Access Journals (Sweden)

    Faiza Charfi

    2012-04-01

    Full Text Available The increasing demand for real-time applications has made the Quality of Service (Qos support for wireless sensor networks (WSN a fairly new research framework. In this paper, we propose an extended model of the Beacon enabled IEEE 802.15.4 including the Guaranteed Time Slot GTS allocation mechanism in the aim to analyze and evaluate network performances. Series of extensive simulations were performed to analyze the impact of the Beacon Order BO and the Superframe Order SO on the network performance based on commonly known metrics. In particular, we examine data packet delivery performance and the throughput for different duty cycle rates. Also, we analyze the impact of the number of nodes on collision probability. Thus, for high number of nodes, collision becomes higher and the reachability begins to decline slightly. We discuss and compare simulation results conducted under various parameter settings to the IEEE 802.11network.

  8. A Survey of Mobile WiMAX IEEE 802.16m Standard

    CERN Document Server

    Rakesh, Jha; Dalal, Upena

    2010-01-01

    IEEE 802.16m amends the IEEE 802.16 Wireless MAN-OFDMA specification to provide an advanced air interface for operation in licenced bands. It will meet the cellular layer requirements of IMT-Advanced next generation mobile networks. It will be designed to provide significantly improved performance compared to other high rate broadband cellular network systems. For the next generation mobile networks, it is important to consider increasing peak, sustained data reates, corresponding spectral efficiencies, system capacity and cell coverage as well as decreasing latency and providing QoS while carefully considering overall system complexity. In this paper we provide an overview of the state-of-the-art mobile WiMAX technology and its development. We focus our discussion on Physical Layer, MAC Layer, Schedular,QoS provisioning and mobile WiMAX specification.

  9. A nomadic access mechanism for enabling dynamic video surveillance over IEEE 802.15.4 networks

    Science.gov (United States)

    Garcia-Sanchez, Felipe; Garcia-Sanchez, Antonio-Javier; Losilla, Fernando; Garcia-Haro, Joan

    2010-12-01

    IEEE 802.15.4 networking technology is designed to be the common standard for integrating WSN applications in heterogeneous environments. However, applications considering mobile nodes along with strict temporal requirements, such as those required for video transmission, are an unexplored field for this technology. These applications involve different challenges and issues that the direct employment of the IEEE 802.15.4 standard does not resolve. Therefore, in this paper a cross-layer mechanism consisting of application and medium access arbitration is presented, enabling the efficient connection and operation of mobile nodes together with the transmission of video flows. The proposed mechanism is evaluated via simulation and its feasibility checked by means of a first prototype. The study of power consumption is also taken into account and so are the quality of service parameters and the human quality perception of the received video stream. The results obtained are presented and further discussed.

  10. Hybrid Polling Method for Direct Link Communication for IEEE 802.11 Wireless LANs

    Directory of Open Access Journals (Sweden)

    Woo-Yong Choi

    2008-10-01

    Full Text Available The direct link communication between STAtions (STAs is one of the techniques to improve the MAC performance of IEEE 802.11 infrastructure networks. For the efficient direct link communication, in the literature, the simultaneous polling method was proposed to allow the multiple direct data communication to be performed simultaneously. However, the efficiency of the simultaneous polling method is affected by the interference condition. To alleviate the problem of the lower polling efficiency with the larger interference range, the hybrid polling method is proposed for the direct link communication between STAs in IEEE 802.11 infrastructure networks. By the proposed polling method, we can integrate the sequential and simultaneous polling methods properly according to the interference condition. Numerical examples are also presented to show the medium access control (MAC performance improvement by the proposed polling method.

  11. A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks.

    Science.gov (United States)

    Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

    2017-01-16

    IEEE 802.15.4e standard proposes Deterministic and Synchronous Multichannel Extension (DSME) mode for wireless sensor networks (WSNs) to support industrial, commercial and health care applications. In this paper, a new channel access scheme and beacon scheduling schemes are designed for the IEEE 802.15.4e enabled WSNs in star topology to reduce the network discovery time and energy consumption. In addition, a new dynamic guaranteed retransmission slot allocation scheme is designed for devices with the failure Guaranteed Time Slot (GTS) transmission to reduce the retransmission delay. To evaluate our schemes, analytical models are designed to analyze the performance of WSNs in terms of reliability, delay, throughput and energy consumption. Our schemes are validated with simulation and analytical results and are observed that simulation results well match with the analytical one. The evaluated results of our designed schemes can improve the reliability, throughput, delay, and energy consumptions significantly.

  12. A note on bound constraints handling for the IEEE CEC'05 benchmark function suite.

    Science.gov (United States)

    Liao, Tianjun; Molina, Daniel; de Oca, Marco A Montes; Stützle, Thomas

    2014-01-01

    The benchmark functions and some of the algorithms proposed for the special session on real parameter optimization of the 2005 IEEE Congress on Evolutionary Computation (CEC'05) have played and still play an important role in the assessment of the state of the art in continuous optimization. In this article, we show that if bound constraints are not enforced for the final reported solutions, state-of-the-art algorithms produce infeasible best candidate solutions for the majority of functions of the IEEE CEC'05 benchmark function suite. This occurs even though the optima of the CEC'05 functions are within the specified bounds. This phenomenon has important implications on algorithm comparisons, and therefore on algorithm designs. This article's goal is to draw the attention of the community to the fact that some authors might have drawn wrong conclusions from experiments using the CEC'05 problems.

  13. 2011 IEEE Visualization Contest Winner: Visualizing Unsteady Vortical Behavior of a Centrifugal Pump

    KAUST Repository

    Otto, Mathias

    2012-09-01

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump\\'s effectiveness. The winning entry split analysis of the pump into three parts based on the pump\\'s functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/ oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump. © 2012 IEEE.

  14. Performance analysis of IEEE 802.11n network under unsaturated conditions

    Science.gov (United States)

    Lang, Gaiping; Ma, Lin; Xu, Yubin

    2017-07-01

    Frame aggregation is the most important medium access control (MAC) enhancement of IEEE 802.11n. In frame aggregation, multiple frames are encapsulated into a single frame. In the analysis of 802.11n performance, the existing researches assumed that each station always had a packet for transmission. But actually, sometimes stations may have no packet to transmit. In this paper, we develop an analytical model for IEEE 802.11n in unsaturated conditions. Therefore, the transmission of the station is assumed to be a bulk service queue system. Bulk size is aggregation size. According to the 802.11n standard, when the number of packets in the buffer is smaller than the aggregation size, we can also transmit all the packets in the buffer using A-MPDU. Therefore, bulk size is variable. The throughput and mean access delay are achieved. Numerical results show that the proposed algorithm can effectively increase the throughput and lower the access delay.

  15. Integration of IEEE 1451 and HL7 exchanging information for patients' sensor data.

    Science.gov (United States)

    Kim, Wooshik; Lim, Suyoung; Ahn, Jinsoo; Nah, Jiyoung; Kim, Namhyun

    2010-12-01

    HL7 (Health Level 7) is a standard developed for exchanging incompatible healthcare information generated from programs or devices among heterogenous medical information systems. At present, HL7 is growing as a global standard. However, the HL7 standard does not support effective methods for treating data from various medical sensors, especially from mobile sensors. As ubiquitous systems are growing, HL7 must communicate with various medical transducers. In the area of sensor fields, IEEE 1451 is a group of standards for controlling transducers and for communicating data from/to various transducers. In this paper, we present the possibility of interoperability between the two standards, i.e., HL7 and IEEE 1451. After we present a method to integrate them and show the preliminary results of this approach.

  16. AN IMPROVED CHANNEL DETECTION METHOD FOR IEEE 802.11N MIMO SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Yao Xiaocheng; Jian Haifang; Fang Zhi; Shi Yin

    2011-01-01

    Coexistence and interoperability between 20 MHz and 40 MHz device and modes of operations are stressed in standard IEEE 802.11n system.It is mandate to report the both sub-channels states to Medium Access Control (MAC) at receiver,since for 40 MHz device,it should serve not only 20 MHz but also 40 MHz signals receiving.Both energy detection and carrier sense are employed to detect channel state.In the case of 20/40 M mode,the power difference between the two sub-channels is also detected in order to report the channel state accurately.The simulation results demonstrate that the performance of the proposed methods are much better than the methods which just employ energy detection.Besides,the simulation results show that the proposed methods ensure that the channel sensing is not a roadblock of IEEE 802.11n system design.

  17. The Exploration of Network Coding in IEEE 802.15.4 Networks

    Directory of Open Access Journals (Sweden)

    Deze Zeng

    2011-01-01

    communication protocol should be energy efficient. The IEEE 802.15.4 is designed as a standard protocol for low power, low data rate, low complexity, and short range connections in WPANs. The standard supports allocating several numbers of collision-free guarantee time slots (GTSs within a superframe for some time-critical transmissions. Recently, COPE was proposed as a promising network coding architecture to essentially improve the throughput of wireless networks. In this paper, we exploit the network coding technique at coordinators to improve energy efficiency of the WPAN. Some related practical issues, such as GTS allocation and multicast, are also discussed in order to exploit the network coding opportunities efficiently. Since the coding opportunities are mostly exploited, our proposal achieves both higher energy efficiency and throughput performance than the original IEEE 802.15.4.

  18. Research of time synchronization technology based on IEEE 1588v2 in optical communication network%基于IEEE1588v2协议的光网络时间同步技术研究

    Institute of Scientific and Technical Information of China (English)

    李恩; 刘志强; 敬玉乡; 丁明吉

    2011-01-01

    分析了现有光网络中时间同步实现方法的不足,阐述了IEEE 1588v2协议的基本原理,提出了IEEE 1588v2协议在光通信网络中实现时间同步的方法,指出精确时间同步协议在光网络中的应用前景和发展方向.%This paper analyses the disadvantage of time synchronization in the optical communication network, and illustrated the fundamental principle of IEEE 1588v2 protocol, the synchronization method about IEEE 1588v2 protocol in optical communication network time was proposed. Finally,it showed the application and development direction of precision time synchronization protocol in optical communication network.

  19. IEEE 802.15.4: a Federating Communication Protocol for Time-Sensitive Wireless Sensor Networks

    OpenAIRE

    Koubâa, Anis; Alves, Mário; Tovar, Eduardo

    2006-01-01

    Wireless Sensor Networks (WSNs) have been attracting increasing interests for developing a new generation of embedded systems with great potential for many applications such as surveillance, environment monitoring, emergency medical response and home automation. However, the communication paradigms in WSNs differ from the ones attributed to traditional wireless networks, triggering the need for new communication protocols. In this context, the recently standardised IEEE 802.15....

  20. Generalization of the proposed IEEE standard for floating-point arithmetic

    Energy Technology Data Exchange (ETDEWEB)

    Cody, W.J.

    1982-12-10

    Several years ago the Microprocessor Standards Committee of the IEEE Computer Society established a Floating-Point Working Group to draft a standard binary floating-point arithmetic on 32-bit microprocessors. As that task neared completion, a second working group was established to generalize the proposed binary standard for other radices and wordlengths. We discuss the emerging generalization, its influence on final deliberations on the proposed binary standard, and the implications for numerical computation.

  1. An NTP Stratum-One Server Farm Fed By IEEE-1588

    Science.gov (United States)

    2010-01-01

    synchronized to its Master Clocks via IRIG -B time code on a low- frequency RF distribution system. The availability of Precise Time Protocol (PTP, IEEE...forwarding back to the requestor. The farm NTP servers are synchronized to the USNO Master Clocks using IRIG -B time code. The current standard NTP... IRIG -B and provide memory-mappable BCD time clocks. The standard NTP distribution is augmented with a USNO- developed NTP reference clock driver for

  2. Performance Evaluation of IEEE 802.15.4 under Jamming DoS Attack

    OpenAIRE

    2013-01-01

    Wireless Sensor Network (WSN) is a wireless network consisting of small nodes with sensing, computation, and wireless communications capabilities. The design of wireless sensor networks depends of many factors, such as transmission errors, network topology and power consumption. Many routing protocols, protocols for data transmission, are specifically designed for wireless sensor networks where energy consumption is essential. This paper provides a brief description of the IEEE 802.15.4/ZigBe...

  3. Interpretation of IEEE-854 floating-point standard and definition in the HOL system

    Science.gov (United States)

    Carreno, Victor A.

    1995-01-01

    The ANSI/IEEE Standard 854-1987 for floating-point arithmetic is interpreted by converting the lexical descriptions in the standard into mathematical conditional descriptions organized in tables. The standard is represented in higher-order logic within the framework of the HOL (Higher Order Logic) system. The paper is divided in two parts with the first part the interpretation and the second part the description in HOL.

  4. Study of asymmetric traffic influence on IEEE 802.11 WLAN family, enhancement proposals

    OpenAIRE

    López Aguilera, M. Elena; Casademont Serra, Jordi; Cotrina Navau, Josep

    2004-01-01

    This paper is focused on the study of WLAN performance in IEEE 802.11 networks that are in a situation of asymmetric traffic, where the access point (AP) transmits much more than the user stations (US). This situation is very different from the symmetric one, wherein all the stations have the same traffic load. The paper also presents a discussion of the different mechanisms in order to increase AP priority under the asymmetric traffic situation. Peer Reviewed

  5. The Impact of Dynamic RTS Threshold Adjustment for IEEE 802.11 MAC Protocol

    OpenAIRE

    Mostafa Mjidi; Debasish Chakraborty; Naoki Nakamura; Norio Shiratori

    2009-01-01

    In recent years, wireless technologies and application received great attention. The Medium Access Control (MAC) protocol is the main element that determines the efficiency in sharing the limited communication bandwidth of the wireless channel in wireless local area networks (WLANs). IEEE 802.11 introduced the optional RTS/CTS handshaking mechanism to address the hidden terminal problem as well as to reduces the chance of collision in case of higher node density and traffic. RTS Threshold (RT...

  6. [Mobile Health: IEEE Standard for Wearable Cuffless Blood Pressure Measuring Devices].

    Science.gov (United States)

    Zhou, Xia; Wu, Wenli; Bao, Shudi

    2015-07-01

    IEEE Std 1708-2014 breaks through the traditional standards of cuff based blood pressure measuring devices and establishes a normative definition of wearable cuffless blood pressure measuring devices and the objective performance evaluation of this kind of devices. This study firstly introduces the background of the new standard. Then, the standard details will be described, and the impact of cuffless blood pressure measuring devices with the new standard on manufacturers and end users will be addressed.

  7. 基于IEEE802.16的OFDM同步问题分析

    Institute of Scientific and Technical Information of China (English)

    赵莹琦

    2011-01-01

    在OFDM(正交频分复用)系统中,收发双方的同步是决定通信系统性能的重要指标.该文阐述了IEEE802.16中的OFDM同步问题,并对存在的偏差进行分析.对学习OFDM起到了一定的指导作用.

  8. Practical support for Lean Six Sigma software process definition using IEEE software engineering standards

    CERN Document Server

    Land, Susan K; Walz, John W

    2012-01-01

    Practical Support for Lean Six Sigma Software Process Definition: Using IEEE Software Engineering Standards addresses the task of meeting the specific documentation requirements in support of Lean Six Sigma. This book provides a set of templates supporting the documentation required for basic software project control and management and covers the integration of these templates for their entire product development life cycle. Find detailed documentation guidance in the form of organizational policy descriptions, integrated set of deployable document templates, artifacts required in suppo

  9. BER Performance of IEEE 802.11ad for Single Carrier and Multi Carrier

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar Gupta

    2012-05-01

    Full Text Available In present scenario 802.11n is one of the fastest standards which is widely popular. It provides a theoretical maximum of 450 megabits per second (Mbps, with a typical throughput of 100Mbps. As we know, there is high demand for higher speed due to an increasing of high definition (HD video on smart phone usage and home entertainment. As 802.11n is not able to provide the required speed needed for these uses, thus there is need for technologies which can meet therequirement. IEEE 802.11ad is one of such standards which meet the requirement needed for the above. IEEE 802.11ad standard operates at 60 GHz frequency, promise to deliver from 1 to 7 Gbps. 60 GHz band is one of the largest unlicensed bandwidth with availability of at least 5 GHz of continuous bandwidth worldwide. In this paper we have tested the IEEE 802.11ad system model Bits Error Rate (BER for different modulation technique under several coding scheme for both Single Carrier and Multi Carriers. In this model the modulation technique mainly used are Binary Phase Shift Keying (BPSK, Quaternary Phase Shift Keying (QPSK, 16-Quadrature Amplitude Modulation (QAM, 64-Quadrature Amplitude Modulation (QAM and the coding scheme used is Low Density Parity Check (LDPC code with different code rate.

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

    Directory of Open Access Journals (Sweden)

    Navid Tadayon

    2010-01-01

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

  11. An improved IEEE 802.11 protocol for reliable data transmission in power distribution fault diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Campoccia, F.; Di Silvestre, M.L.; Sanseverino, E.R.; Zizzo, G. [Palermo Univ., Palermo (Italy)

    2010-10-15

    In power systems, on-line transmission between local units and the central unit can be done by means of power line communications or wireless technology. During an electrical fault, the reliability of the distribution system depends on the security of the timely protective and restorative actions on the network. This paper focused on the WiFi system because of its economy and ease of installation. However, WiFi systems are typically managed by the IEEE 802.11 protocol, which is not reliable in terms of security in data communication. In WiFi networks, data is divided into packets and sent in succession to reduce errors within the radio channel. The IEEE 802.11 protocol has high probability for loss of packets or delay in their transmission. In order to ensure the reliability of data transmission times between two terminal units connected by WiFi stations, a new protocol was derived by modifying the IEEE 802.11. The improvements of the new protocol were highlighted and its capability for the diagnostic service was verified. The modified protocol eliminates the danger of collisions between packets and optimizes the transmission time for sending information. 6 refs., 7 tabs., 8 figs.

  12. Fairness resource allocation and scheduling for IEEE 802.16 Mesh networks

    Directory of Open Access Journals (Sweden)

    Limin Peng

    2010-06-01

    Full Text Available The IEEE 802.16 standard provides a scheme for creating multi-hop relay networks, which can be deployed as a high speed wide area wireless network at low cost. Although the standard defines signaling mechanisms in mesh mode, however, it doesn’t specify wireless resource management in the protocol. In this paper, we address the problem of resource allocation with the goal of providing fairness access to wireless channel for all the nodes as well as high network throughput in IEEE 802.16 mesh networks. We first define node’s unsatisfactory index and throughput function. Then, a multi-objective programming formulation is proposed for optimizing network performance. Accordingly, a dynamic programming based resource allocation and scheduling algorithm is presented to provide an optimal resource allocation to achieve fairness among different nodes as well as high network throughput in IEEE 802.16 mesh networks. Simulation results show that our proposed algorithm significantly provides both fairness of channel access and optimal network throughput.

  13. Survey of Down Link Data Allocation Algorithms in IEEE 802.16 WiMAX

    Directory of Open Access Journals (Sweden)

    Ahmed M Husein Shabani

    2012-08-01

    Full Text Available IEEE 802.16 standard and its marketing technology Worldwide Interoperability for Microwave Access (WiMAX is one of the leading technology that gain benefit of adopting orthogonal frequency division multiple access (OFDMA as its multiple access technique. OFDMA gives flexibility in resources allocation to accommodate a large number of users supporting several services classes with quality of service (QoS. This loads big challenges on its resource allocation. One of the key performance factors of OFDMA resource allocation is its downlink data packing mechanism. In IEEE802.16 standard based OFDMA the downlink data is packed into down link frames in the form of rectangular slots called burst.The standard leaves details of packing mechanism as an open issue for researchers and manufacturer to implement. Therefore recently several algorithms have been proposed in literature. This paper endeavours to identify key factors and tradeoffs issues associated with designing of downlink data packing algorithm for WiMAX based IEEE802.16 through a competitive survey of recent proposed algorithms.

  14. Segmentized Clear Channel Assessment for IEEE 802.15.4 Networks

    Directory of Open Access Journals (Sweden)

    Kyou Jung Son

    2016-06-01

    Full Text Available This paper proposed segmentized clear channel assessment (CCA which increases the performance of IEEE 802.15.4 networks by improving carrier sense multiple access with collision avoidance (CSMA/CA. Improving CSMA/CA is important because the low-power consumption feature and throughput performance of IEEE 802.15.4 are greatly affected by CSMA/CA behavior. To improve the performance of CSMA/CA, this paper focused on increasing the chance to transmit a packet by assessing precise channel status. The previous method used in CCA, which is employed by CSMA/CA, assesses the channel by measuring the energy level of the channel. However, this method shows limited channel assessing behavior, which comes from simple threshold dependent channel busy evaluation. The proposed method solves this limited channel decision problem by dividing CCA into two groups. Two groups of CCA compare their energy levels to get precise channel status. To evaluate the performance of the segmentized CCA method, a Markov chain model has been developed. The validation of analytic results is confirmed by comparing them with simulation results. Additionally, simulation results show the proposed method is improving a maximum 8.76% of throughput and decreasing a maximum 3.9% of the average number of CCAs per packet transmission than the IEEE 802.15.4 CCA method.

  15. Multi-model Music Content Description and Retrieval Using IEEE 1599 XML Standard

    Directory of Open Access Journals (Sweden)

    Alberto Pinto

    2009-02-01

    Full Text Available The new format IEEE 1599 for music and audio content description defines a standard for the representation of retrieval models within music and music/audio formats that makes use of XML documents as content descriptors. In this article, it is described how music/audio semantics can be actually represented within the Structural Layer of IEEE 1599, thanks to the introduction of novel Music Information Retrieval (MIR objects that can be exploited by music search engines. A complete description of MIR objects is provided and it is shown how they can be used to embed metadata relative to specific music retrieval models, thus allowing for the description of music content in different retrieval contexts. To this aim, a new concept for MIR Model is introduced together with its formalization and tools provided by category theory. The role of MIR objects and morphisms in music content description and retrieval is explained. Furthermore, a concrete example is given with the implementation of a graph-based model within the IEEE 1599 framework.

  16. Performance Evaluation of Beacon-Enabled Mode for IEEE 802.15.4 Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    M. Udin Harun Al Rasyid

    2013-12-01

    Full Text Available IEEE 802.15.5 standard support structure of star and peer-to-peer network formation. Strating from these, the cluster tree network can be built as a special case of peer-to-peer network to increse coverage area. In this paper, we provide an performance evaluation of beacon- enabled mode for IEEE 802.15.4 wireless sensor network on star and cluster topology in order to get the maximum result to apply the appropriate topology model as needed. We conduct analysis on each topology model by using the numbers of nodes from 10 nodes to 100 nodes to analyze throughput, delay, energy consumption, and probability success packet by using NS2 simulator. The simulation results show that the throughput and the probability of success packet of cluster topology are higher than that of star topology, and the energy consumption of cluster topology is lesser than that of star topology. However, cluster topology increases the delay more than star topology. Keywords: IEEE 802.15.4, wireless sensor network, beacon-enabled mode, topology, csma/ca

  17. Analysis and Enhancement of IEEE 802.15.4e DSME Beacon Scheduling Model

    Directory of Open Access Journals (Sweden)

    Kwang-il Hwang

    2014-01-01

    Full Text Available In order to construct a successful Internet of things (IoT, reliable network construction and maintenance in a sensor domain should be supported. However, IEEE 802.15.4, which is the most representative wireless standard for IoT, still has problems in constructing a large-scale sensor network, such as beacon collision. To overcome some problems in IEEE 802.15.4, the 15.4e task group proposed various different modes of operation. Particularly, the IEEE 802.15.4e deterministic and synchronous multichannel extension (DSME mode presents a novel scheduling model to solve beacon collision problems. However, the DSME model specified in the 15.4e draft does not present a concrete design model but a conceptual abstract model. Therefore, in this paper we introduce a DSME beacon scheduling model and present a concrete design model. Furthermore, validity and performance of DSME are evaluated through experiments. Based on experiment results, we analyze the problems and limitations of DSME, present solutions step by step, and finally propose an enhanced DSME beacon scheduling model. Through additional experiments, we prove the performance superiority of enhanced DSME.

  18. A versatile electrical penetration design qualified to IEEE Std. 317-1983

    Energy Technology Data Exchange (ETDEWEB)

    Lankenau, W.; Wetherill, T.M. [Imaging & Sensing Technology Corp., Horseheads, NY (United States)

    1994-12-31

    Although worldwide demand for new construction of nuclear power stations has been on a decline, the available opportunities for the design and construction of qualified electrical penetrations continues to offer challenges, requiring a highly versatile design. Versatility is necessary in order to meet unique customer requirements within the constraints of a design basis qualified to IEEE Std. 317-1983. This paper summarizes such a versatile electrical penetration designed, built and tested to IEEE Std. 317-1983. The principal features are described including major materials of construction. Some of the design constraints such as sealing requirements, and conductor density (including numerical example) are discussed. The requirements for qualification testing of the penetration assembly to IEEE Std. 317-1983 are delineated in a general sense, and some typical test ranges for preconditioning, radiation exposure, and LOCA are provided. The paper concludes by describing ways in which this versatile design has been adapted to meet unique customer requirements in a variety of nuclear power plants.

  19. Strategies for Optimal MAC Parameters Tuning in IEEE 802.15.6 Wearable Wireless Sensor Networks.

    Science.gov (United States)

    Alam, Muhammad Mahtab; Ben Hamida, Elyes

    2015-09-01

    Wireless body area networks (WBAN) has penetrated immensely in revolutionizing the classical heath-care system. Recently, number of WBAN applications has emerged which introduce potential limits to existing solutions. In particular, IEEE 802.15.6 standard has provided great flexibility, provisions and capabilities to deal emerging applications. In this paper, we investigate the application-specific throughput analysis by fine-tuning the physical (PHY) and medium access control (MAC) parameters of the IEEE 802.15.6 standard. Based on PHY characterizations in narrow band, at the MAC layer, carrier sense multiple access collision avoidance (CSMA/CA) and scheduled access protocols are extensively analyzed. It is concluded that, IEEE 802.15.6 standard can satisfy most of the WBANs applications throughput requirements by maximum achieving 680 Kbps. However, those emerging applications which require high quality audio or video transmissions, standard is not able to meet their constraints. Moreover, delay, energy efficiency and successful packet reception are considered as key performance metrics for comparing the MAC protocols. CSMA/CA protocol provides the best results to meet the delay constraints of medical and non-medical WBAN applications. Whereas, the scheduled access approach, performs very well both in energy efficiency and packet reception ratio.

  20. Interoperability in digital electrocardiography: harmonization of ISO/IEEE x73-PHD and SCP-ECG.

    Science.gov (United States)

    Trigo, Jesús D; Chiarugi, Franco; Alesanco, Alvaro; Martínez-Espronceda, Miguel; Serrano, Luis; Chronaki, Catherine E; Escayola, Javier; Martínez, Ignacio; García, José

    2010-11-01

    The ISO/IEEE 11073 (x73) family of standards is a reference frame for medical device interoperability. A draft for an ECG device specialization (ISO/IEEE 11073-10406-d02) has already been presented to the Personal Health Device (PHD) Working Group, and the Standard Communications Protocol for Computer-Assisted ElectroCardioGraphy (SCP-ECG) Standard for short-term diagnostic ECGs (EN1064:2005+A1:2007) has recently been approved as part of the x73 family (ISO 11073-91064:2009). These factors suggest the coordinated use of these two standards in foreseeable telecardiology environments, and hence the need to harmonize them. Such harmonization is the subject of this paper. Thus, a mapping of the mandatory attributes defined in the second draft of the ISO/IEEE 11073-10406-d02 and the minimum SCP-ECG fields is presented, and various other capabilities of the SCP-ECG Standard (such as the messaging part) are also analyzed from an x73-PHD point of view. As a result, this paper addresses and analyzes the implications of some inconsistencies in the coordinated use of these two standards. Finally, a proof-of-concept implementation of the draft x73-PHD ECG device specialization is presented, along with the conversion from x73-PHD to SCP-ECG. This paper, therefore, provides recommendations for future implementations of telecardiology systems that are compliant with both x73-PHD and SCP-ECG.

  1. On IEEE 802.15.6 IR-UWB receivers - simulations for DBPSK modulation.

    Science.gov (United States)

    Niemelä, Ville; Hämäläinen, Matti; Iinatti, Jari

    2013-01-01

    In 2002, Federal Communications Commission (FCC) was the first in defining regulations for ultra wideband (UWB) communications followed by Europe and Japan some years later. Focusing on impulse radio (IR) UWB, in 2007 was the time for the first published standard targeting in personal area networks, released by the IEEE. The second IEEE released standard including UWB definitions is targeted for wireless body area networks (WBAN) and was published in 2012. As the wireless communications has been and will be passing through almost any levels in society, the natural step with WBAN is using it in different medical, healthcare and wellbeing applications. The arguments for these are related to the modern lifestyle, in which people have increasingly more free time and are more interested in taking care of their health and wellbeing. Another challenge is the population composition, i.e., aging in developed countries which call for new solutions and procedures, particularly from cost wise. In this paper, we are evaluating UWB receivers based on the IEEE 802.15.6 physical layer definitions and capable of detecting differentially encoded modulation. The evaluation is performed using two different WBAN channel models.

  2. Segmentized Clear Channel Assessment for IEEE 802.15.4 Networks.

    Science.gov (United States)

    Son, Kyou Jung; Hong, Sung Hyeuck; Moon, Seong-Pil; Chang, Tae Gyu; Cho, Hanjin

    2016-06-03

    This paper proposed segmentized clear channel assessment (CCA) which increases the performance of IEEE 802.15.4 networks by improving carrier sense multiple access with collision avoidance (CSMA/CA). Improving CSMA/CA is important because the low-power consumption feature and throughput performance of IEEE 802.15.4 are greatly affected by CSMA/CA behavior. To improve the performance of CSMA/CA, this paper focused on increasing the chance to transmit a packet by assessing precise channel status. The previous method used in CCA, which is employed by CSMA/CA, assesses the channel by measuring the energy level of the channel. However, this method shows limited channel assessing behavior, which comes from simple threshold dependent channel busy evaluation. The proposed method solves this limited channel decision problem by dividing CCA into two groups. Two groups of CCA compare their energy levels to get precise channel status. To evaluate the performance of the segmentized CCA method, a Markov chain model has been developed. The validation of analytic results is confirmed by comparing them with simulation results. Additionally, simulation results show the proposed method is improving a maximum 8.76% of throughput and decreasing a maximum 3.9% of the average number of CCAs per packet transmission than the IEEE 802.15.4 CCA method.

  3. Study on additional carrier sensing for IEEE 802.15.4 wireless sensor networks.

    Science.gov (United States)

    Lee, Bih-Hwang; Lai, Ruei-Lung; Wu, Huai-Kuei; Wong, Chi-Ming

    2010-01-01

    Wireless sensor networks based on the IEEE 802.15.4 standard are able to achieve low-power transmissions in the guise of low-rate and short-distance wireless personal area networks (WPANs). The slotted carrier sense multiple access with collision avoidance (CSMA/CA) is used for contention mechanism. Sensor nodes perform a backoff process as soon as the clear channel assessment (CCA) detects a busy channel. In doing so they may neglect the implicit information of the failed CCA detection and further cause the redundant sensing. The blind backoff process in the slotted CSMA/CA will cause lower channel utilization. This paper proposes an additional carrier sensing (ACS) algorithm based on IEEE 802.15.4 to enhance the carrier sensing mechanism for the original slotted CSMA/CA. An analytical Markov chain model is developed to evaluate the performance of the ACS algorithm. Both analytical and simulation results show that the proposed algorithm performs better than IEEE 802.15.4, which in turn significantly improves throughput, average medium access control (MAC) delay and power consumption of CCA detection.

  4. Performance Analysis of Proposed Congestion Avoiding Protocol for IEEE 802.11s

    Directory of Open Access Journals (Sweden)

    Kishwer Abdul Khaliq

    2017-02-01

    Full Text Available The wireless technology is one of the core compo-nents of mobile applications with mobility support at low deploy-ment costs. Among these, Wireless Mesh Network (WMN is one of the technologies that supports mobile users for un-disrupted, reliable data connectivity, provides high bandwidth even in areas, where access of such services is difficult. Additionally, it features capabilities like self-configuring, self-healing, and self-organizing. IEEE proposed a MAC standard for WMN enhancements named IEEE 802.11s for multi-hop networks. Within this standard, the mandatory routing protocol called Hybrid Wireless Mesh Protocol (HWMP is proposed for efficient utilization of resources to achieve high bandwidth at MAC layer. To improve this protocol, a congestion avoiding protocol was proposed, which utilizes alternate paths just before the congestion state is reached. The proposed technique does not add any overhead, it utilizes congestion notification frame, which is already part of standard. This paper discusses simulation results of the proposed routing protocol against the existing HWMP protocol for packet delivery fraction, throughput and delay. The results indicate that the proposed technique significantly improves performance of IEEE 802.11s.

  5. Spectrum Hole Identification in IEEE 802.22 WRAN using Unsupervised Learning

    Directory of Open Access Journals (Sweden)

    V. Balaji

    2016-01-01

    Full Text Available In this paper we present a Cooperative Spectrum Sensing (CSS algorithm for Cognitive Radios (CR based on IEEE 802.22Wireless Regional Area Network (WRAN standard. The core objective is to improve cooperative sensing efficiency which specifies how fast a decision can be reached in each round of cooperation (iteration to sense an appropriate number of channels/bands (i.e. 86 channels of 7MHz bandwidth as per IEEE 802.22 within a time constraint (channel sensing time. To meet this objective, we have developed CSS algorithm using unsupervised K-means clustering classification approach. The received energy level of each Secondary User (SU is considered as the parameter for determining channel availability. The performance of proposed algorithm is quantified in terms of detection accuracy, training and classification delay time. Further, the detection accuracy of our proposed scheme meets the requirement of IEEE 802.22 WRAN with the target probability of falsealrm as 0.1. All the simulations are carried out using Matlab tool.

  6. Study on Additional Carrier Sensing for IEEE 802.15.4 Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Bih-Hwang Lee

    2010-06-01

    Full Text Available Wireless sensor networks based on the IEEE 802.15.4 standard are able to achieve low-power transmissions in the guise of low-rate and short-distance wireless personal area networks (WPANs. The slotted carrier sense multiple access with collision avoidance (CSMA/CA is used for contention mechanism. Sensor nodes perform a backoff process as soon as the clear channel assessment (CCA detects a busy channel. In doing so they may neglect the implicit information of the failed CCA detection and further cause the redundant sensing. The blind backoff process in the slotted CSMA/CA will cause lower channel utilization. This paper proposes an additional carrier sensing (ACS algorithm based on IEEE 802.15.4 to enhance the carrier sensing mechanism for the original slotted CSMA/CA. An analytical Markov chain model is developed to evaluate the performance of the ACS algorithm. Both analytical and simulation results show that the proposed algorithm performs better than IEEE 802.15.4, which in turn significantly improves throughput, average medium access control (MAC delay and power consumption of CCA detection.

  7. Experimental study of IEEE 802.15.4 anti-interference ability to WLAN%IEEE802.15.4对WLAN抗干扰性能的实验研究

    Institute of Scientific and Technical Information of China (English)

    王赟; 乐燕芬; 施伟斌

    2012-01-01

    针对2.4 GHz频段内的IEEE 802.15.4,研究其与无线局域网共存时的抗干扰性.实验设定了多种场景并测试了实际应用环境中IEEE 802.15.4的通信质量.实验数据表明,WLAN干扰可使IEEE 802.15.4数据丢包率高达94%.通过实验数据分析得到了IEEE 802.15.4通信节点丢包率与WLAN信道、节点发送功率以及RSSI的相关性,为研究WSN的同频抗干扰技术提供了有价值的实验依据.%An experimental study of IEEE 802.15.4 anti-interference ability when it is coexistent with Wireless Local Area Networks in 2.4 GHz band is carried out. Communication quality of IEEE 802.15.4 is tested in a variety of scenarios and in practical application environment. Packet loss rate of IEEE 802.15.4 reaches as high as 94% due to the interference of WLAN as showed by the experimental data. This paper analyses correlation of packet loss rate of IEEE 802.15.4 communication nodes with WLAN channel, output power of nodes and RSSI and it provides a valuable experimental basis for the study of frequency anti-interference of WSN technology.

  8. Network performance study for mobile node in IEEE 802.15.4%移动节点在IEEE 802.15.4中网络性能的研究

    Institute of Scientific and Technical Information of China (English)

    张宇; 黄刘生

    2007-01-01

    研究并分析了IEEE 802.15.4协议在移动环境下的性能,仿真并分析了IEEE 802.15.4的Beacon和非Beacon两种不同的网络拓扑对移动节点的支持程度,针对存在的问题,提出了进一步改进的意见.

  9. Distributed Continuous Event-Based Data Acquisition Using the IEEE 1588 Synchronization and FlexRIO FPGA

    Science.gov (United States)

    Taliercio, C.; Luchetta, A.; Manduchi, G.; Rigoni, A.

    2017-07-01

    High-speed event driven acquisition is normally performed by analog-to-digital converter (ADC) boards with a given number of pretrigger sample and posttrigger sample that are recorded upon the occurrence of a hardware trigger. A direct physical connection is, therefore, required between the source of event (trigger) and the ADC, because any other software-based communication method would introduce a delay in triggering that would turn out to be not acceptable in many cases. This paper proposes a solution for the relaxation of the event communication time that can be, in this case, carried out by software messaging (e.g., via an LAN), provided that the system components are synchronized in time using the IEEE 1588 synchronization mechanism. The information about the exact event occurrence time is contained in the software packet that is sent to communicate the event and is used by the ADC FPGA to identify the exact sample in the ADC sample queue. The length of the ADC sample queue will depend on the maximum delay in software event message communication time. A prototype implementation using a National FlexRIO FPGA board connected with an ADC device is presented as the proof of concept.

  10. IEEE 1451网络化智能传感器标准的发展及应用探讨%Study of Development and Application of IEEE 1451 Standards for Networked Smart Sensors

    Institute of Scientific and Technical Information of China (English)

    童利标; 徐科军; 梅涛

    2002-01-01

    IEEE 1451标准由IEEE 1451.1、1451.2、P1451.3和P1451.4组成.它定义了一套连接传感器到网络的标准化通用接口,建立了网络化智能传感器的框架,这使得传感器制造商有能力支持多种网络.然而,IEEE1451标准在应用中存在着一些困难.本文简要介绍IEEE 1451标准的内容和发展过程,分析限制该标准应用的一些原因,讨论IEEE1451.x标准之间的关系,给出一个用于机器人手爪的基于IEEE1451.1标准的网络化智能传感器的例子.

  11. 基于IEEE802.11n的无线局域网关键技术研究%Research on Key Technologies of Wireless Local Area Network IEEE802.11n

    Institute of Scientific and Technical Information of China (English)

    伍转华

    2012-01-01

      This paper first introduces several high speed physical layer specifications in the IEEE 802.11 series standards, and makes a brief analysis. Furthermore focuses on the research of the main standard IEEE802.11n from the two aspects of physical layer and media access control layer. It has elaborately analyzed the channel access method of IEEE802.11n and key technologies of physical layer and media access control layer in system throughput.%  文中首先介绍了IEEE 802.11系列标准中的几种高速物理层标准,并进行了简要的分析.接着分别从无线局域网PHY层和MAC层两个层面,重点研究了目前无线局域网领域的主流标准IEEE 802.11n.细致的分析了IEEE 802.11n的信道接入方式以及与系统吞吐量相关的MAC层和PHY层关键技术.

  12. Implementation of DoS attack and mitigation strategies in IEEE 802.11b/g WLAN

    Science.gov (United States)

    Deng, Julia; Meng, Ke; Xiao, Yang; Xu, Roger

    2010-04-01

    IEEE 802.11 wireless Local Area Network (WLAN) becomes very prevalent nowadays. Either as a simple range extender for a home wired Ethernet interface, or as a wireless deployment throughout an enterprise, WLAN provides mobility, convenience, and low cost. However, an IEEE 802.11b/g wireless network uses the frequency of unlicensed 2.4GHz, which makes the network unsafe and more vulnerable than traditional Ethernet networks. As a result, anyone who is familiar with wireless network may initiate a Denial of Service (DoS) attack to influence the common communication of the network or even make it crash. In this paper, we present our studies on the DoS attacks and mitigation strategies for IEEE 802.11b/g WLANs and describe some initial implementations using IEEE 802.11b/g wireless devices.

  13. Empirical Performance Evaluation of Enhanced Throughput Schemes of IEEE802.11 Technology in Wireless Area Networks

    Directory of Open Access Journals (Sweden)

    Femi-Jemilohun Oladunni.Juliet

    2013-08-01

    Full Text Available The success in the growing wireless standards can be measured by the achievement of quality of service(QoS specifications by the designers. The IEEE802.11 wireless standards are widely accepted as wirelesstechnology for wireless LAN. Efforts have been made over the years by the task group to provide adequatenumber of QoS enhancement schemes for the increasing numbers of multimedia applications. This paperexamines the empirical performances of ad hoc wireless networks deployed on IEEE802.11 standardvariants. A survey to some of the QoS schemes incorporated in IEEE802.11 wireless PHY layers werecarried out. Then the effects of this enhancement schemes in relation to data throughput and systemcapacity and reliability in the newest technology deployed on IEEE802.11ac standards was investigatedusing real time applications and simulation based approaches.

  14. NIH-IEEE 2015 Strategic Conference on Healthcare Innovations and Point-of-Care Technologies for Prec

    Science.gov (United States)

    NIH and the Institute for Electrical and Electronics Engineering, Engineering in Medicine and Biology Society (IEEE/EMBS) hosted the third iteration of the Healthcare Innovations and Point-of-Care Technologies Conference last week.

  15. IEEE 1394事务层接口的设计与实现%Design and implementation of IEEE 1394 transaction layer interface

    Institute of Scientific and Technical Information of China (English)

    王佩; 徐进; 张爱林

    2014-01-01

    本文设计的IEEE 1394事物层接口连接了PLB (Processor Local Bus )总线和1394链路层模块,主要实现1394事物层模块数据的发送和接收。首先对事物层接口进行系统结构设计,然后对PLB从接口、FIFO接口和主机访问寄存器接口这3个子模块分别进行逻辑设计,最后采用硬件描述语言对设计进行可综合描述,并使用软件 QuestaSim进行仿真验证。该设计使事务层能够跨时钟域同链路层进行数据包的传输,并进行有效的数据位宽转换,提高传输效率。经过仿真验证,结果满足设计要求,表明IEEE 1394事物层接口能够正常发送和接收等时及异步数据包。%T he design of the IEEE 1394 transaction layer interface connecting the PLB (Processor Local Bus) with the 1394 link layer module ,mainly aims to send and receive 1394 transaction layer module′s data .Firstly ,the system structure of transaction layer interface is designed ,and then the three sub -modules ,including PLB slave interface ,FIFO interface and host interface to access the registers are de‐signed .Finally the hardware description language is used to describe this design ,and the software QuestaSim is used to simulate and verify the result .This design of the transaction layer can transmit da‐ta packet with the link layer across the clock domain ,switch data width effectively and improve the transmission efficiency .The simulation results meet the design requirements and show that the transac‐tion layer can be capable of sending and receiving isochronous and asynchronous data correctly .

  16. Implementation of IEEE-1588 timing and synchronization for ATCA control and data acquisition systems

    Energy Technology Data Exchange (ETDEWEB)

    Correia, Miguel, E-mail: miguelfc@lei.fis.uc.pt [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Lisboa (Portugal); Sousa, Jorge; Combo, Alvaro; Rodrigues, Antonio P.; Carvalho, Bernardo B.; Batista, Antonio J.N.; Goncalves, Bruno [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Lisboa (Portugal); Correia, Carlos M.B.A. [Grupo de Electronica e Instrumentacao do Centro de Instrumentacao, Dept. de Fisica, Universidade de Coimbra, Coimbra (Portugal); Varandas, Carlos A.F. [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Lisboa (Portugal)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer IEEE-1588 over Ethernet protocol is implemented for the synchronization of all clock signals of an ATCA AMC carrier module. Black-Right-Pointing-Pointer The ATCA hardware consists of an AMC quad-carrier main-board with PCI Express switching. Black-Right-Pointing-Pointer IEEE-1588 is to be implemented on a Virtex-6 FPGA. Black-Right-Pointing-Pointer Timing signals on the ATX-AMC4-PTP are managed and routed by a crosspoint-switch implemented on a Virtex-6 FPGA. Black-Right-Pointing-Pointer Each clock signal source may be independently located (on each of the AMC cards, RTM or ATCA backplane). - Abstract: Control and data acquisition (C and DA) systems for Fusion experiments are required to provide accurate timing and synchronization (T and S) signals to all of its components. IPFN adopted PICMG's Advanced Telecommunications Computing Architecture (ATCA) industry standard to develop C and DA instrumentation. ATCA was chosen not only for its high throughput characteristics but also for its high availability (HA) features which become of greater importance in steady-state operation scenarios. However, the specified ATCA clock and synchronization interface may be too limited for the timing and synchronization needs in advanced Physics experiments. Upcoming specification extensions, developed by the 'xTCA for Physics' workgroups, will contemplate, among others, a complementary timing specification, developed by the PICMG xTCA for Physics IO, Timing and Synchronization Technical Committee. The IEEE-1588 Precision Time Protocol (PTP) over Ethernet is one of the protocols, proposed by the Committee, aiming for precise synchronization of clocks in measurement and control systems, based on low jitter and slave-to-slave skew criteria. The paper presents an implementation of IEEE-1588 over Ethernet, in an ATCA hardware platform. The ATCA hardware consists of an Advanced Mezzanine Card (AMC) quad-carrier front board with PCI

  17. IEEE 802.15.4 transceiver for the 868/915 MHz band using Software Defined Radio

    OpenAIRE

    Zitouni, Rafik; Ataman, Stefan; Mathian, Marie; George, Laurent

    2013-01-01

    This paper reports an implementation of the PHY specifications of the IEEE 802.15.4 standard for the frequency band 868 915 MHz on a Software Defined Radio (SDR) platform. This standard is defined for low power, low data rate and low cost wireless networks. These specifications are used by the Zigbee technology for various applications such as home automation, industry monitoring or medical surveillance. Several hardware PHY 868/915 MHz band IEEE 802.15.4 transceiver implementations have been...

  18. Empirical Performance Evaluation of Enhanced Throughput Schemes of IEEE802.11 Technology in Wireless Area Networks

    OpenAIRE

    2013-01-01

    The success in the growing wireless standards can be measured by the achievement of quality of service (QoS) specifications by the designers. The IEEE802.11 wireless standards are widely accepted as wireless technology for wireless LAN. Efforts have been made over the years by the task group to provide adequate number of QoS enhancement schemes for the increasing numbers of multimedia applications. This paper examines the empirical performances of ad hoc wireless networks deployed on IEEE802....

  19. IEEE 802.16e标准中LDPC编码的实现与仿真%The implementation and simulation of IEEE 802.16e LDPC coding

    Institute of Scientific and Technical Information of China (English)

    宁平

    2014-01-01

    根据IEEE802.16e标准中LDPC编码的定义,提出了一种利用高速状态机来实现编码的快速算法.在Quartus Ⅱ下使用Verilog HDL实现了该算法并进行了时序仿真.仿真结果表明,设计具有良好的实时性,克服了以往设计中预处理复杂、消耗逻辑资源多的缺点.最后利用MATLAB对该设计与DVB-S2缩短码的BER性能进行了比较,分析了制约DVB-S2缩短码性能的因素.

  20. IEEE Transactions on Engineering Management的发展历程及研究热点%Development History and Research Focus of IEEE Transactions on Engineering Management

    Institute of Scientific and Technical Information of China (English)

    陈悦; 李瑛

    2011-01-01

    利用知识计量学与知识图谱的方法技术,以SSCI数据库的论文为基础,对美国创新管理期刊IEEE Transactions on Engineering Management发展历程及其研究热点进行计量研究。通过对该期刊三个时间段知识群文献的分析,可看出该刊从侧重于技术管理的定量工具方法,到侧重于产品开发、项目管理与技术转移,再到侧重于组织、战略及政策管理的大致发展脉络。其当前创新管理研究热点,主要围绕“绩效”、“创新”、“管理”、“产品开发”、“系统”和“战略”展开。%Based on registed articles in SSCI, the paper took a metric research on the development history and research focus of ' IEEE Transactions on Engineering Management' by the means of scientometrics and knowledge mapping. The major aspects were the articles analysis in knowledge group of three different periods. The research focus change can be concluded : first, focus on the quantitative tools and methods of technical management; and then turn to product development, project management and technology transfer; at last focus on organization, strategy and policy management. Current innovation management research mainly focuses on the following aspects : performance, innovation, management, product development, system, strategy etc.

  1. 基于IEEE Std 1500标准的SOC可测性设计研究%Research of DFT of SOC based on IEEE Std 1500

    Institute of Scientific and Technical Information of China (English)

    周银; 周浔; 陈圣俭; 王月芳

    2012-01-01

    he technology of IP core based on SOC design is widely used, which is attribute to the rapid development of deep submicron meter manufacture technology and design technology of integrated circuit. Because of the fact that IP cores usually come from different providers and the incompatibility of interface between IP core providers and core users and aims at improving ease of test reuse and test integration with respect to the core based SOC. 1500 standard for embedded core test is presented to solve this problem. The detail includes the test architecture, usage of this standard and core test description language.%集成电路深亚微米制造技术和设计技术的迅速发展,使得基于IP核复用的SOC设计技术得到越来越广泛的应用,但由于IP核的来源不同,设计标准的不兼容等因素,使得SOC的测试变得越来越困难;IEEE为解决SOC的测试问题提出了嵌入式芯核测试标准IEEE Std 1500,致力于建立标准化的IP核供应商和用户之间的测试接口,简化核测试信息的复用;文章详细介绍了IEEE Std 1500标准的测试架构,使用方法和核测试描述语言CTL,同时给出标准中提出的SOC可测性设计方法.

  2. 基于IEEE1588的变电站过程层采样值同步技术研究%Analysis of sample value synchronization in process level based on IEEE 1588

    Institute of Scientific and Technical Information of China (English)

    陈宏辉; 蔡泽祥; 王海柱

    2012-01-01

    为了提高变电站过程层网络采样值的同步精度,详细分析了基于IEEE 1588精确同步协议的变电站过程层采样值同步技术的原理与实现方式.分析对比了瞬时值差动与矢量差动的采样精度,研究了同步误差对差动保护采样值精度的影响;通过分析IEEE 1588协议同步的实现过程,并与毫秒级别对时协议NTP进行对比,指出了IEEE 1588实现所涉及到的关键技术.通过分析基于IEEE 1588过程层采样值同步在实际工程应用中的实现方式,论证了IEEE 1588协议的采样精度达到亚微秒级别,能够有效减小多端同步采样的精度,对于变电站安全稳定运行具有十分重要的意义.%To improve the synchronous accuracy of network sampling values of process level, this paper analyzes the principle and realization way of sample value synchronization in process level based on IEEE 1588 in detail. First, the instantaneous value sampling precision and vector sampling precision are compared and influence of synchronization errors on sample value precision is analyzed. Then, synchronization of IEEE 1588 is expatiated by comparing with NTP of which synchronization precision is in millisecond level and essential parts of IEEE 1588 are studied. Last, realization of sample value synchronization in process level in engineering application based on IEEE 1588 is introduced, which proves that IEEE 1588 protocol can achieve sub-microsecond level of sampling accuracy and effectively reduce the multiport synchronous sampling accuracy, which is very significant for the security and stability of the substation.

  3. DoS detection in IEEE 802.11 with the presence of hidden nodes

    Directory of Open Access Journals (Sweden)

    Joseph Soryal

    2014-07-01

    Full Text Available The paper presents a novel technique to detect Denial of Service (DoS attacks applied by misbehaving nodes in wireless networks with the presence of hidden nodes employing the widely used IEEE 802.11 Distributed Coordination Function (DCF protocols described in the IEEE standard [1]. Attacker nodes alter the IEEE 802.11 DCF firmware to illicitly capture the channel via elevating the probability of the average number of packets transmitted successfully using up the bandwidth share of the innocent nodes that follow the protocol standards. We obtained the theoretical network throughput by solving two-dimensional Markov Chain model as described by Bianchi [2], and Liu and Saadawi [3] to determine the channel capacity. We validated the results obtained via the theoretical computations with the results obtained by OPNET simulator [4] to define the baseline for the average attainable throughput in the channel under standard conditions where all nodes follow the standards. The main goal of the DoS attacker is to prevent the innocent nodes from accessing the channel and by capturing the channel’s bandwidth. In addition, the attacker strives to appear as an innocent node that follows the standards. The protocol resides in every node to enable each node to police other nodes in its immediate wireless coverage area. All innocent nodes are able to detect and identify the DoS attacker in its wireless coverage area. We applied the protocol to two Physical Layer technologies: Direct Sequence Spread Spectrum (DSSS and Frequency Hopping Spread Spectrum (FHSS and the results are presented to validate the algorithm.

  4. DoS detection in IEEE 802.11 with the presence of hidden nodes.

    Science.gov (United States)

    Soryal, Joseph; Liu, Xijie; Saadawi, Tarek

    2014-07-01

    The paper presents a novel technique to detect Denial of Service (DoS) attacks applied by misbehaving nodes in wireless networks with the presence of hidden nodes employing the widely used IEEE 802.11 Distributed Coordination Function (DCF) protocols described in the IEEE standard [1]. Attacker nodes alter the IEEE 802.11 DCF firmware to illicitly capture the channel via elevating the probability of the average number of packets transmitted successfully using up the bandwidth share of the innocent nodes that follow the protocol standards. We obtained the theoretical network throughput by solving two-dimensional Markov Chain model as described by Bianchi [2], and Liu and Saadawi [3] to determine the channel capacity. We validated the results obtained via the theoretical computations with the results obtained by OPNET simulator [4] to define the baseline for the average attainable throughput in the channel under standard conditions where all nodes follow the standards. The main goal of the DoS attacker is to prevent the innocent nodes from accessing the channel and by capturing the channel's bandwidth. In addition, the attacker strives to appear as an innocent node that follows the standards. The protocol resides in every node to enable each node to police other nodes in its immediate wireless coverage area. All innocent nodes are able to detect and identify the DoS attacker in its wireless coverage area. We applied the protocol to two Physical Layer technologies: Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) and the results are presented to validate the algorithm.

  5. Planning of Efficient Wireless Access with IEEE 802.16 for Connecting Home Network to the Internet

    Directory of Open Access Journals (Sweden)

    Krairit Donyaprueth

    2010-01-01

    Full Text Available The emergence of IEEE802.16 wireless standard technology (WiMAX has significantly increased the choice to operators for the provisioning of wireless broadband access network. WiMAX is being deployed to compliment with xDSL in underserved or lack of the broadband network area, in both developed and developing countries. Many incumbent operators in developing countries are considering the deployment of WiMAX as part of their broadband access strategy. This paper presents an efficient and simple method for planning of broadband fixed wireless access (BFWA with IEEE802.16 standard to support home connection to Internet. The study formulates the framework for planning both coverage and capacity designs. The relationship between coverage area and access rate from subscriber in each environment area is presented. The study also presents the throughput and channel capacity of IEEE802.16 in different access rates. An extensive analysis is performed and the results are applied to the real case study to demonstrate the practicality of using IEEE 802.16 for connecting home to Internet. Using empirical data and original subscriber traffic from measurement, it is shown that the BFWA with IEEE802.16 standard is a capacity limited system. The capacity of IEEE802.16 is related to different factors including frequency bandwidth, spectrum allocation, estimation of traffic per subscriber, and choice of adaptive modulation from subscriber terminal. The wireless access methods and procedures evolved in this research work and set out in this paper are shown to be well suited for planning BFWA system based on IEEE802.16 which supports broadband home to Internet connections.

  6. Impact of cell load on 5GHz IEEE 802.11 WLAN

    OpenAIRE

    Abu-Tair, Mamoun; Bhatti, Saleem Noel

    2017-01-01

    We have conducted an empirical study of the latest 5GHz IEEE 802.11 wireless LAN (WLAN) variants of 802.11n (5GHz) and 802.11ac (Wave 1), under different cell load conditions. We have considered typical configurations of both protocols on a Linux testbed. Under light load,there is no clear difference between 802.11n and 802.11ac in terms of performance and energy consumption. However, in some cases of high cell load, we have found that there may be a small advantage with 802.11ac. Overall, we...

  7. Connectivity-Based Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs

    Directory of Open Access Journals (Sweden)

    Woo-Yong Choi

    2009-01-01

    Full Text Available We propose the efficient reliable multicast MAC protocol based on the connectivity information among the recipients. Enhancing the BMMM (Batch Mode Multicast MAC protocol, the reliable multicast MAC protocol significantly reduces the RAK (Request for ACK frame transmissions in a reasonable computational time and enhances the MAC performance. By the analytical performance analysis, the throughputs of the BMMM protocol and our proposed MAC protocol are derived. Numerical examples show that our proposed MAC protocol increases the reliable multicast MAC performance for IEEE 802.11 wireless LANs.

  8. Rate Adaptation Based on Collision Probability for IEEE 802.11 WLANs

    Science.gov (United States)

    Kim, Taejoon; Lim, Jong-Tae

    Nowadays IEEE 802.11 wireless local area networks (WLANs) support multiple transmission rates. To achieve the best performance, transmitting stations adopt the various forms of automatic rate fallback (ARF). However, ARF suffers from severe performance degradation as the number of transmitting stations increases. In this paper, we propose a new rate adaptation scheme which adjusts the ARF's up/down threshold according to the channel contention level. Simulation result shows that the proposed scheme achieves fairly good performance compared with the existing schemes.

  9. Adaptive rate selection scheme for video transmission to resolve IEEE 802.11 performance anomaly

    Science.gov (United States)

    Tang, Guijin; Zhu, Xiuchang

    2011-10-01

    Multi-rate transmission may lead to performance anomaly in an IEEE 802.11 network. It will decrease the throughputs of all the higher rate stations. This paper proposes an adaptive rate selection scheme for video service when performance anomaly occurs. Considering that video has the characteristic of tolerance to packet loss, we actively drop several packets so as to select the rates as high as possible for transmitting packets. Experiment shows our algorithm can decrease the delay and jitter of video, and improve the system throughput as well.

  10. Distributed Fair Access Point Selection for Multi-Rate IEEE 802.11 WLANs

    Science.gov (United States)

    Gong, Huazhi; Nahm, Kitae; Kim, Jongwon

    In IEEE 802.11 networks, the access point (AP) selection based on the strongest signal strength often results in the extremely unfair bandwidth allocation among mobile users (MUs). In this paper, we propose a distributed AP selection algorithm to achieve a fair bandwidth allocation for MUs. The proposed algorithm gradually balances the AP loads based on max-min fairness for the available multiple bit rate choices in a distributed manner. We analyze the stability and overhead of the proposed algorithm, and show the improvement of the fairness via computer simulation.

  11. A Novel Energy Saving Algorithm with Frame Response Delay Constraint in IEEE 802.16e

    Science.gov (United States)

    Nga, Dinh Thi Thuy; Kim, Mingon; Kang, Minho

    Sleep-mode operation of a Mobile Subscriber Station (MSS) in IEEE 802.16e effectively saves energy consumption; however, it induces frame response delay. In this letter, we propose an algorithm to quickly find the optimal value of the final sleep interval in sleep-mode in order to minimize energy consumption with respect to a given frame response delay constraint. The validations of our proposed algorithm through analytical results and simulation results suggest that our algorithm provide a potential guidance to energy saving.

  12. Saturation Throughput - Delay Analysis of IEEE 802.11 DCF in Fading Channel

    CERN Document Server

    Hadzi-Velkov, Zoran

    2010-01-01

    In this paper, we analytically analyzed the impact of an error-prone channel over all performance measures in a trafficsaturated IEEE 802.11 WLAN. We calculated station's transmission probability by using the modified Markov chain model of the backoff window size that considers the frame-error rates and maximal allowable number of retransmission attempts. The frame error rate has a significant impact over theoretical throughput, mean frame delay, and discard probability. The peak throughput of a WLAN is insensitive of the maximal number of retransmissions. Discard probabilities are insensitive to the station access method, Basic or RTS/CTS.

  13. Design and Implementation of DSP——Based IEEE802.16a OFDM System

    Institute of Scientific and Technical Information of China (English)

    QIU Run-he; XIE Ying-hua; SHEN Xiong-wei; HAN Han-guang; LIU Chao

    2009-01-01

    A set of integrated Orthogonal Frequency Division Multiplexing (OFDM) modulation and demodulation system is proposed and its performance is verified in reference to the standard of IEEE802.16a for WMAN. The design, combined with analogy front-end, adopts Texas Instrument ( TI ) Company's 6701 evaluation module (EVM) to construct digital Intermediate Frequency (IF) platform. A DSP-based baseband processing software module is embedded into the system. The proposed scheme makes it possible for users to select various software modules to set up corrections with different throughput performance. Taking into account the given hardware configuration, the design aims to optimize the algorithm modules to accomplish better system performance.

  14. Experimental Performances Analysis of Load Balancing Algorithms in IEEE 802.11

    CERN Document Server

    Salah, Hamdi; Rached, Tourki

    2009-01-01

    In IEEE 802.11, load balancing algorithms (LBA) consider only the associated stations to balance the load of the available access points (APs). However, although the APs are balanced, it causes a bad situation if the AP has a lower signal length (SNR) less than the neighbor APs. So, balance the load and associate one mobile station to an access point without care about the signal to noise ratio (SNR) of the AP cause possibly an unforeseen QoS, such as the bit rate, the end to end delay, the packet loss. In this way, we study an improvement load balancing algorithm with SNR integration at the selection policy.

  15. IEEE 802.11 Distributed Coordination Function:Enhancement and Analysis

    Institute of Scientific and Technical Information of China (English)

    WU HaiTao(邬海涛); LIN Yu(林宇); CHENG ShiDuan(程时端); PENG Yong(彭泳); LONG KePing(隆克平)

    2003-01-01

    IEEE 802.11 Medium Access Control (MAC) is proposed to support asynchronousand time bounded delivery of radio packets. Distributed Coordination Function (DCF), which uses Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) and binary slotted exponent ial backoff, is the basis of the 802.11 MAC. This paper proposes a throughput enhancement forDCF by adjusting the Contention Window (CW) setting scheme. Moreover, an analytical modelbased on Markov chain is introduced to compute the enhanced throughput. The accuracy of themodel and the enhancement of the proposed scheme are verified by elaborate simulations.

  16. Achieving Efficient Channel Utilization for Data Communications in IEEE 802.11 WLAN

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang; SHU Yantai

    2005-01-01

    In the IEEE 802. 11 protocol, the adoption of the exponential backoff technique leads to throughput performance strongly dependent on the initial contention window size and, most importantly, on the number of contending stations considered in the network. This paper proposes a simpie but accurate method to dynamically estimate the number of contending stations in a wireless local area network (WLAN). Based on estimation, all the mobile stations dynamically adjust the initial contention window in medium access control (MAC) layer to avoid collisions. The simulation results show that the proposed algorithm can achieve efficient channel utilization, higher system throughput, and better fairness performance.

  17. Estimation Algorithm of Contending Stations Based on Improved DCF Model in IEEE 802.11

    Institute of Scientific and Technical Information of China (English)

    HU He-fei; LIU Yuan-an; LI Shu-lan

    2004-01-01

    The fundamental access method of IEEE 802.11 is a DCF known as carrier sense multiple access with collision avoidance (CSMA/CA) scheme with exponential back-off. RTS_threshold is used to determine whether to deploy RTS/CTS access method. This threshold should vary with the number of contending stations which contend wireless media to get better throughput. The paper proposes an algorithm which estimates the number of contending stations in BSS. The algorithm is shown to be accurate which is verified by elaborate simulations.

  18. Latency and Jitter Analysis for IEEE 802.11e Wireless LANs

    Directory of Open Access Journals (Sweden)

    Sungkwan Youm

    2013-01-01

    Full Text Available This paper presents a numerical analysis of latency and jitter for IEEE 802.11e wireless local area networks (WLANs in a saturation condition, by using a Markov model. We use this model to explicate how the enhanced distributed coordination function (EDCF differentiates classes of service and to characterize the probability distribution of the medium access control (MAC layer packet latency and jitter, on which the quality of the voice over Internet protocol (VoIP calls is dependent. From the proposed analytic model, we can estimate the available number of nodes determining the system performance, in order to satisfy user demands on the latency and jitter.

  19. Conception and FPGA implementation of IEEE 802.11s mesh network MAC layer transmitter

    CERN Document Server

    Chaari, Lamia; Kamoun, Lotfi

    2010-01-01

    This paper proposes, a hardware implementation of Wireless Mesh Networks (WMN) medium Access Controller (MAC) layer transmitter. In the literature a lot of works are focused on WMN routing protocol as well as performance analysis and software integration of WMN units, however few works deals with WMN hardware implementation. In this field our contribution is to conceive and to implements on FPGA a WMN MAC transmitter module. Our implementation, written in hardware description language (HDL) is based on the IEEE 802.11 s standard. The hardware implementation retains a good performance in speed.

  20. Enhancement of the IEEE 802.11 Power Saving Mode by Prioritized Reservations

    OpenAIRE

    Xiaoying Lei; Seung Hyong Rhee

    2015-01-01

    The increasing demand for real-time applications in WSN has raised the requirement of protocols considering both energy efficiency and end-to-end delay. A PSM is proposed in the IEEE 802.11 protocol to reduce the power consumptions of wireless nodes. Wireless nodes can stay in doze mode and periodically wake up to retrieve the frames buffered in the APs. However, the 802.11 PSM is not such energy efficiency for WSN. First, in the process of the node’s transmitting polling frames to AP, channe...

  1. 4th IEEE/ACIS International Conference on Computer and Information Science

    CERN Document Server

    2016-01-01

    This edited book presents scientific results of the 14th IEEE/ACIS International Conference on Computer and Information Science (ICIS 2015) which was held on June 28 – July 1, 2015 in Las Vegas, USA. The aim of this conference was to bring together researchers and scientists, businessmen and entrepreneurs, teachers, engineers, computer users, and students to discuss the numerous fields of computer science and to share their experiences and exchange new ideas and information in a meaningful way. Research results about all aspects (theory, applications and tools) of computer and information science, and to discuss the practical challenges encountered along the way and the solutions adopted to solve them.

  2. An Effective Capacity Estimation Scheme in IEEE802.11-based Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    H. Zafar

    2012-11-01

    Full Text Available Capacity estimation is a key component of any admission control scheme required to support quality of serviceprovision in mobile ad hoc networks. A range of schemes have been previously proposed to estimate residualcapacity that is derived from window-based measurements of channel estimation. In this paper a simple and improvedmechanism to estimate residual capacity in IEEE802.11-based ad hoc networks is presented. The scheme proposesthe use of a ‘forgiveness’ factor to weight these previous measurements and is shown through simulation-basedevaluation to provide accurate utilizations estimation and improved residual capacity based admission control.

  3. IEEE 1451.0-2007 Compatible Smart Sensor Readout with Error Compensation Using FPGA

    Directory of Open Access Journals (Sweden)

    J. Kamala

    2009-03-01

    Full Text Available This paper deals with effective usage of user TEDS for developing smart sensor readout which is suitable to estimate and compensate the disturbances occurring in the system. The system parameters are incorporated along with other transducer data. Appropriate processing capabilities are built in Transducer Interface Module TIM for disturbance estimation and compensation. A Verilog based single chip module of IEEE 1451.0 smart sensor is proposed incorporating the above mentioned features. The architecture enables reliable and smart readout for sensors at low cost for a given application. The programmable nature of the proposed architecture enables wide usage of the smart sensor for various applications.

  4. Deployment of Directory Service for IEEE N Bus Test System Information

    Science.gov (United States)

    Barman, Amal; Sil, Jaya

    2008-10-01

    Exchanging information over Internet and Intranet becomes a defacto standard in computer applications, among various users and organizations. Distributed system study, e-governance etc require transparent information exchange between applications, constituencies, manufacturers, and vendors. To serve these purposes database system is needed for storing system data and other relevant information. Directory service, which is a specialized database along with access protocol, could be the single solution since it runs over TCP/IP, supported by all POSIX compliance platforms and is based on open standard. This paper describes a way to deploy directory service, to store IEEE n bus test system data and integrating load flow program with it.

  5. Low-frequency electrical dosimetry: research agenda of the IEEE International Committee on Electromagnetic Safety.

    Science.gov (United States)

    Reilly, J Patrick; Hirata, Akimasa

    2016-06-21

    This article treats unsettled issues in the use of numerical models of electrical dosimetry as applied to international limits on human exposure to low-frequency (typically  IEEE-ICES (International Committee on Electromagnetic Safety) Technical Committee 95. The paper discusses 25 issues needing attention, fitting into three general categories: induction models; electrostimulation models; and human exposure limits. Of these, 9 were voted as 'high priority' by members of Subcommittee 6. The list is presented as a research agenda for refinements in numerical modeling with applications to human exposure limits. It is likely that such issues are also important in medical and electrical product safety design applications.

  6. Building smart sensor nodes according to IEEE 1451.3 standard.

    Science.gov (United States)

    da Costa, Murilo N J; Neto, Olegario C S; Ferreira, José O; da Rocha, Adson F; de A Barbosa, Talles M G

    2011-01-01

    A Body Sensor Network (BSN) application requires many software and hardware adaptations to support correctly data exchanges between different sensor node architectures. However, these customizations demand extra time, cost and components. This paper introduces a simple development process in order to customize off-the-shelf BSN sensor nodes according to Transducer Bus Interface Modules (TBIM) standard. IEEE 1451.3 offers technical solutions for interfacing multiple and physically separated transducer allowing self-identification, self-configuration, plug and play and hot swapping capabilities. These are important requirements relating to most BSN applications.

  7. Long-Distance IEEE 802.11 Wireless Mesh Networks: A Survey%基于IEEE 802.11的长距离无线Mesh网络

    Institute of Scientific and Technical Information of China (English)

    赵增华; 王楠; 窦志斌; 张连芳; 舒炎泰

    2012-01-01

    基于IEEE 802.11的长距离无线Mesh网络(LDmesh)的单跳链路长度在几十到上百公里,具有带宽高、成本低、覆盖广等优点,可广泛应用于偏远乡村或人口分布稀疏地区的无线宽带接入等.LDmesh网络是点到点的链路,链路的干扰特性和传输特性与传统无线Mesh网络有显著不同,原有的基于CSMA的MAC协议不再适用,进而影响到上层协议的设计.分析了LDmesh网络的研究进展,从链路性能、MAC协议、路由协议及网络管理等方面深入论述了LDmesh网络面临的挑战和进一步研究方向.%Long-distance IEEE 802. 11 wireless Mesh networks (LDmesh) have been emerged in recent years for its high bandwidth, low cost and large coverage. It can be applied in rural regions or sparse-populated areas to provide high-bandwidth Internet access. In LDmesh networks, links are point-to-point and as long as tens to hundreds of kilometers. To achieve the long range, the wireless nodes are usually equipped with high-power (e. g. 400 mW) 802. 11 wireless cards and high-gain (e. g. 32dBi) directional antennas. The links in one node cannot transmit or receive da-ta simultaneously because of the inter-link interference. The traditional CSMA/CA MAC proto-col suffers poor performance in such a network for its long propagation delay, ACK timeout and inter-link interference. Therefore new TDMA-type MAC protocols have been proposed to solve the above issues, such as 2P MAC, WiLDNet and JazzyMac. The upper layer protocols such as routing and network management thus face great challenges and appeal new design diagram. In this paper, we introduce the fundamental concepts of LDmesh networks, survey the research ac-tivities in recent years, and discuss in depth the challenges in terms of link performance, MAC protocols, routing protocols and network management. The future work is also discussed.

  8. Application and Simulation of OFDM in IEEE 802.16 Networks%正交频分复用技术在IEEE802.16标准中的应用及仿真分析

    Institute of Scientific and Technical Information of China (English)

    马辉; 王兴; 王军

    2012-01-01

    文章介绍了正交频分复用技术在802.16中的应用及802.16的帧结构,并在NS2中对IEEE802.16进行了仿真,接着分析了实验结果,最后提出了下一步研究方向。%This paper introduces the application of Orthogonal Frequency Division Multiplexing (OFDM) in IEEE 802. 16. The frame structure of IEEE 802. 16 PMP was also discussed in the paper. Then the 802. 16 was evaluated using NS2 and the result was analyzed. Fi- nally, the future work was put forward.

  9. Service design projects sponsored by the Kansas State University Student Chapter of the IEEE EMBS.

    Science.gov (United States)

    Griffith, Connor; Gruber, Lucinda; Young, Ethan; Humphrey, Jason; Warren, Steve

    2008-01-01

    Service projects offer volunteer student organizations a means to generate interest and focus activity outside of the context of the classroom. This paper addresses efforts by the Kansas State University (KSU) Student Chapter of the IEEE Engineering in Medicine and Biology Society (EMBS) to initiate and guide service projects in two primary areas: (1) research to aid persons with disabilities (RAPD) and (2) hands-on efforts to interest young women in the quantitative fields of science and engineering. Three RAPD projects are presented: a computer mouse design that helps to alleviate productivity problems associated with Parkinson's tremors, a battery removal tool for arthritic individuals with limited dexterity, and a wireless door control and communication system to assist mobility-limited individuals. Service projects to garner science and engineering interest in young women are co-sponsored by the KSU Women in Engineering and Science Program (WESP). The most recent activity, entitled 'Vital Signs Shirts,' is presented in this paper, along with a summary of pending interactive laboratories designed to interest participants in engineering as applied to the human body. These service projects encourage IEEE EMBS student chapter members to explore their biomedical engineering interests and make a positive impact in the community.

  10. An Adaptive Medium Access Parameter Prediction Scheme for IEEE 802.11 Real-Time Applications

    Directory of Open Access Journals (Sweden)

    Estefanía Coronado

    2017-01-01

    Full Text Available Multimedia communications have experienced an unprecedented growth due mainly to the increase in the content quality and the emergence of smart devices. The demand for these contents is tending towards wireless technologies. However, these transmissions are quite sensitive to network delays. Therefore, ensuring an optimum QoS level becomes of great importance. The IEEE 802.11e amendment was released to address the lack of QoS capabilities in the original IEEE 802.11 standard. Accordingly, the Enhanced Distributed Channel Access (EDCA function was introduced, allowing it to differentiate traffic streams through a group of Medium Access Control (MAC parameters. Although EDCA recommends a default configuration for these parameters, it has been proved that it is not optimum in many scenarios. In this work a dynamic prediction scheme for these parameters is presented. This approach ensures an appropriate traffic differentiation while maintaining compatibility with the stations without QoS support. As the APs are the only devices that use this algorithm, no changes are required to current network cards. The results show improvements in both voice and video transmissions, as well as in the QoS level of the network that the proposal achieves with regard to EDCA.

  11. Adaptive Backoff Algorithm for Contention Window for Dense IEEE 802.11 WLANs

    Directory of Open Access Journals (Sweden)

    Ikram Syed

    2016-01-01

    Full Text Available The performance improvement in IEEE 802.11 WLANs in widely fluctuating network loads is a challenging task. To improve the performance in this saturated state, we develop an adaptive backoff algorithm that maximizes the system throughput, reduces the collision probability, and maintains a high fairness for the IEEE 802.11 DCF under dense network conditions. In this paper, we present two main advantages of the proposed ABA-CW algorithm. First, it estimates the number of active stations and then calculates an optimal contention window based on the active station number. Each station calculates the channel state probabilities by observing the channel for the total backoff period. Based on these channel states probabilities, each station can estimate the number of active stations in the network, after which it calculates the optimal CW utilizing the estimated active number of stations. To evaluate the proposed mechanism, we derive an analytical model to determine the network performance. From our results, the proposed ABA-CW mechanism achieved better system performance compared to fixed-CW (BEB, EIED, LILD, and SETL and adaptive-CW (AMOCW, Idle Sense mechanisms. The simulation results confirmed the outstanding performance of the proposed mechanism in that it led to a lower collision probability, higher throughput, and high fairness.

  12. Dynamic Contention Window Control Scheme in IEEE 802.11e EDCA-Based Wireless LANs

    Science.gov (United States)

    Abeysekera, B. A. Hirantha Sithira; Matsuda, Takahiro; Takine, Tetsuya

    In the IEEE 802.11 MAC protocol, access points (APs) are given the same priority as wireless terminals in terms of acquiring the wireless link, even though they aggregate several downlink flows. This feature leads to a serious throughput degradation of downlink flows, compared with uplink flows. In this paper, we propose a dynamic contention window control scheme for the IEEE 802.11e EDCA-based wireless LANs, in order to achieve fairness between uplink and downlink TCP flows while guaranteeing QoS requirements for real-time traffic. The proposed scheme first determines the minimum contention window size in the best-effort access category at APs, based on the number of TCP flows. It then determines the minimum and maximum contention window sizes in higher priority access categories, such as voice and video, so as to guarantee QoS requirements for these real-time traffic. Note that the proposed scheme does not require any modification to the MAC protocol at wireless terminals. Through simulation experiments, we show the effectiveness of the proposed scheme.

  13. An Efficient Power Saving Mechanism for Delay-Guaranteed Services in IEEE 802.16e

    Science.gov (United States)

    Park, Yunju; Hwang, Gang Uk

    As the IEEE 802.16e Wireless Metropolitan Access Network (WMAN) supports the mobility of a mobile station (MS), increasing MS power efficiency has become an important issue. In this paper, we analyze the sleep-mode operation for an efficient power saving mechanism for delay-guaranteed services in the IEEE 802.16e WMAN and observe the effects of the operating parameters related to this operation. For the analysis we use the M/GI/1/K queueing system with multiple vacations, exhaustive services and setup times. In the analysis, we consider the power consumption during the wake-mode period as well as the sleep-mode period. As a performance measure for the power consumption, we propose the power consumption per unit time per effective arrival which considers the power consumption and the packet blocking probability simultaneously. In addition, since we consider delay-guaranteed services, the average packet response delay is also considered as a performance measure. Based on the performance measures, we obtain the optimal sleep-mode operation which minimizes the power consumption per unit time per effective arrival with a given delay requirement. Numerical studies are also provided to investigate the system performance and to show how to achieve our objective.

  14. Mathematical Analysis of Energy Efficiency in IEEE 802.11 DCF

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The standardized IEEE 802.11 distributed coordination function (DCF) provides a contention-based distributed channel access mechanism for mobile stations to share the wireless medium.However, when stations are mobile or portable units, power consumption becomes a primary issue since terminals are usually battery driven. This paper proposes an analytical model that calculates the energy efficiency of both the basic and the RTS/CTS access mechanisms of the IEEE 802.11 protocol. The model is validated with simulation results using NS-2 simulation package. The effects of the network size, the average packet length, the initial contention window and maximum backoff stages on the energy efficiency of both access mechanisms are also investigated. Results show that the basic scheme has low energy efficiency at large packet length and large network size, and depends strongly on the number of stations and the backoff procedure parameters. Conversely, the RTS/CTS mechanism provides higher energy efficiency when the network size is large, and is more robust to variations in the backoff procedure parameters.

  15. Implementing ISO/IEEE 11073: proposal of two different strategic approaches.

    Science.gov (United States)

    Martínez-Espronceda, M; Serrano, L; Martínez, I; Escayola, J; Led, S; Trigo, J; García, J

    2008-01-01

    This paper explains the challenges encountered during the ISO/IEEE 11073 standard implementation process. The complexity of the standard and the consequent heavy requirements, which have not encouraged software engineers to adopt the standard. The developing complexity evaluation drives us to propose two possible implementation strategies that cover almost all possible use cases and eases handling the standard by non-expert users. The first one is focused on medical devices (MD) and proposes a low-memory and low-processor usage technique. It is based on message patterns that allow simple functions to generate ISO/IEEE 11073 messages and to process them easily. In this way a framework for MDs can be obtained. Second one is focused on more powerful machines such as data loggers or gateways (aka. computer engines (CE)), which do not have the MDs' memory and processor usage constraints. For CEs a more intelligent and adaptative Plug&Play (P&P) solution is provided. It consists on a general platform that can access to any device supported by the standard. Combining both strategies will cut developing time for applications based on ISO/EEE 11073.

  16. A Joint Beamforming based SDMA Protocol for IEEE 802.11n Downlink

    Directory of Open Access Journals (Sweden)

    Cheng Guo

    2015-09-01

    Full Text Available To support space division multiple access (SDMA in the IEEE 802.11n downlink, a joint beamforming based MAC protocol, J-MAC is presented in this paper. An access point (AP follows J-MAC, which employs multiple array antennas, and user equipments (UEs follow the IEEE 802.11x standard which employ omni-directional MIMO antennas. J-MAC maintains full compatibility with 802.11x, and UEs do not change any more. In J-MAC, firstly, the AP achieves the weight vector for the array antenna-based beamforming, and updates it periodically. Secondly, before transmitting any data-frame, the AP achieves the weight vector for the MIMO-based beamforming, which should be updated in each transmission. Finally, after getting the joint beamforming, the AP transmits its data-frames to multiple UEs simultaneously. Simulation results show that J-MAC can support the joint beamforming effectively and provide much higher network throughput, lower delay, jitter and packet-loss-rate than DCF does.

  17. Performance analysis of the IEEE 802.16e power management for the initiations of awakening

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To increase battery life in IEEE 802.16e systems, it is essential to efficiently manage energy in mobile stations. The sleep-mode operation in power management helps to increase the life of a station by saving energy consumption. In power management, there are two important performance metrics: energy consumption and the response delay of awakening medium access control (MAC) service data unit (SDU). While in a base station (BS) initiation of awakening, the two performance metrics should be simultaneously considered, in a mobile subscriber station (MSS) initiation of awakening, the response delay is not considered because it is self-operational. There performance metrics are affected by the minimum sleep interval (Tmin), the maximum sleep interval (Tmax), and the average interarrival time of awakening MAC SDUs (TI) during sleep-mode operation. Therefore, it is imperative to evaluate the two initiations of awakening depending on TI. To reach a fuller understanding of the performance, this paper shows an analytical mode and simulations results for the standard sleep-mode operation in the IEEE 802.16e MAC.

  18. Performance of IEEE 802.15.4 Clusters with Power Management and Key Exchange

    Institute of Scientific and Technical Information of China (English)

    Fereshteh Amini; Moazzam Khan; Jelena Mi(s)i(c); Hossein Pourreza

    2008-01-01

    The IEEE 802.15.4 specification is a recent low data rate wireless personal area network standard. While basic security services are provided for, there is a lack of more advanced techniques which are indispensable in modern personal area network applications. In addition, performance implications of those services are not known. In this paper, we describe a secure data exchange protocol based on the Zig Bee specification and built on top of IEEE 802.15.4 link layer. This protocol includes a key exchange mechanism. We assume that all nodes are applying power management technique based on thecons tant event sensing reliability required by the coordinator. Power management generates random sleep times by every node which in average fairly distributes the sensing load among the nodes. Key exchange is initiated by a cluster coordinator after some given number of sensing packets have been received by the coordinator. We develop and integrate simulation model of the key exchange and power management technique into the cluster's reliable sensing function. We evaluate the impact of security function and its periodicity on cluster performance.

  19. Throughput analysis of the IEEE 802.4 token bus standard under heavy load

    Science.gov (United States)

    Pang, Joseph; Tobagi, Fouad

    1987-03-01

    It has become clear in the last few years that there is a trend towards integrated digital services. Parallel to the development of public Integrated Services Digital Network (ISDN) is service integration in the local area (e.g., a campus, a building, an aircraft). The types of services to be integrated depend very much on the specific local environment. However, applications tend to generate data traffic belonging to one of two classes. According to IEEE 802.4 terminology, the first major class of traffic is termed synchronous, such as packetized voice and data generated from other applications with real-time constraints, and the second class is called asynchronous which includes most computer data traffic such as file transfer or facsimile. The IEEE 802.4 token bus protocol which was designed to support both synchronous and asynchronous traffic is examined. The protocol is basically a timer-controlled token bus access scheme. By a suitable choice of the design parameters, it can be shown that access delay is bounded for synchronous traffic. As well, the bandwidth allocated to asynchronous traffic can be controlled. A throughput analysis of the protocol under heavy load with constant channel occupation of synchronous traffic and constant token-passing times is presented.

  20. A Source-Based Multicast Scheme in IEEE 802.16 Mesh Mode

    Directory of Open Access Journals (Sweden)

    Ali Azarpeyvand

    2012-12-01

    Full Text Available WiMAX based on IEEE 802.16 is known as one of effective technologies for transmission of multimedia to groups of receivers. There are two operational modes in WiMAX: point to multi point (PMP for single hop transmission and a mesh node for multi-hop transmission. The current standard only defines unicast transmission under mesh mode thus the performance is deteriorated for multimedia applications with multicast nature. In this paper, we first propose a mechanism for source-based tree topology construction aiming at facilitating multicast transmission in WiMAX mesh network. In the proposed approach, the multicast tree is constructed considering available link’s bandwidth and multicast group members. After constructing the multicast tree we propose a novel scheduling algorithm to improve the transmission throughout. In the proposed scheduling algorithm a parent node uses broadcasting when the number of its children belonging to a multicast group excesses a threshold. Extensive simulation results show that the proposed multicast mechanism improves multicast transmission efficiency and reduces scheduling time slots noticeably in comparison to the approach mandated by the IEEE 802.16 standard.

  1. BOB-RED queue management for IEEE 802.15.4 wireless sensor networks

    Directory of Open Access Journals (Sweden)

    Wu Jean-Lien

    2011-01-01

    Full Text Available Abstract Multimedia services over resource constrained wireless sensor networks (WSNs face a performance bottleneck issue from the gateway node to the sink node. Therefore, the queue management at the gateway node is crucial for diversified messages conveyed from the front nodes to the sink node. In this article, beacon order-based random early detection (BOB-RED queue management is proposed. BOB-RED is a dynamic adaptation scheme based on adjusting beacon interval and superframe duration in the IEEE 802.15.4 MAC superframe accompanied with RED queue management scheme to increase the transmission efficiency of multimedia over WSNs. We focus on the performance improvement upon different traffic loads over WSNs. Evaluation metrics include end-to-end delay, packet delivery ratio, and energy consumption in IEEE 802.15.4 beacon enabled mode. Simulation results show that BOB-RED can effectively decrease end-to-end delay and energy consumption compared to the DropTail scheme.

  2. On the seamless, harmonized use of ISO/IEEE11073 and openEHR.

    Science.gov (United States)

    Trigo, Jesús D; Kohl, Christian D; Eguzkiza, Aitor; Martínez-Espronceda, Miguel; Alesanco, Álvaro; Serrano, Luis; García, José; Knaup, Petra

    2014-05-01

    Standardized exchange of clinical information is a key factor in the provision of high quality health care systems. In this context, the openEHR specification facilitates the management of health data in electronic health records (EHRs), while the ISO/IEEE11073 (also referred to as X73PHD) family of standards provides a reference framework for medical device interoperability. Hospitals and health care providers using openEHR require flawless integration of data coming from external sources, such as X73PHD. Hence, a harmonization process is crucial for achieving a seamless, coherent use of those specifications in real scenarios. Such harmonization is the aim of this paper. Thus, the classes and attributes of a representative number of X73PHD specializations for medical devices--weight, temperature, blood pressure, pulse and heart rate, oximetry, and electrocardiograph--along with the X73PHD core document--ISO/IEEE11073-20601--have been analyzed and mapped to openEHR archetypes. The proposed methodology reuses the existing archetypes when possible and suggests new ones--or appropriate modifications--otherwise. As a result, this paper analyzes the inconsistencies found and the implications thereof in the coordinated use of these two standards. The procedure has also shown how existing standards are able to influence the archetype development process, enhancing the existing archetype corpus.

  3. Throughput and Delay Analysis of Unslotted IEEE 802.15.4

    Directory of Open Access Journals (Sweden)

    Benoît Latré

    2006-05-01

    Full Text Available The IEEE 802.15.4 standard is designed as a low power and low data rate protocol offering high reliability. It defines a beaconed and unbeaconed version. In this work, we analyze the maximum throughput and minimum delay of the unbeaconed or unslotted version of the protocol. First, the most important features are described. Then the exact formula for the throughput and delay of a direct transmission between one sender and one receiver is given. This is done for the different frequency ranges and address structures used in IEEE 802.15.4. The analysis is limited to the unslotted version as this one experiences the lowest overhead. It is shown that the maximum throughput depends on the packet size. In the 2.4 GHz band, a bandwidth efficiency of 64.9% is reached when the maximum packet size is used. Further we describe the influence of the back off interval. A significant gain is found when the backs off parameters are altered. We have measured the throughput experimentally in order to compare the theoretical analysis with real-life examples.

  4. MAC Security and Security Overhead Analysis in the IEEE 802.15.4 Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sethi Sakshi

    2006-01-01

    Full Text Available Sensor networks have many applications. However, with limited resources such as computation capability and memory, they are vulnerable to many kinds of attacks. The IEEE 802.15.4 specification defines medium access control (MAC layer and physical layer for wireless sensor networks. In this paper, we propose a security overhead analysis for the MAC layer in the IEEE 802.15.4 wireless sensor networks. Furthermore, we survey security mechanisms defined in the specification including security objectives, security suites, security modes, encryption, authentication, and so forth. Then, security vulnerabilities and attacks are identified. Some security enhancements are proposed to improve security and to prevent these attacks such as same-nonce attack, denial-of-service attack, reply-protection attack, ACK attack, and so forth. Our results show that, for example, with 128-bit key length and 100 MIPS, encryption overhead is 10.28 s per block, and with 100 MIPS and 1500-byte payload, the encryption overhead is as high as 5782.5 s.

  5. Investigating the efficiency of IEEE 802.15.4 for medical monitoring applications.

    Science.gov (United States)

    Pelegris, P; Banitsas, K

    2011-01-01

    Recent advancements in wireless communications technologies bring us one step closer to provide reliable Telecare services as an alternative to patients staying in a hospital mainly for monitoring purposes. In this research we investigate the efficiency of IEEE 802.15.4 in a simple scenario where a patient is being monitored using an ECG and a blood analysis module. This approach binds well with assisted living solutions, by sharing the network infrastructure for both monitoring and control while taking advantage of the low power features of the protocol. Such applications are becoming more and more realistic to implement as IEEE 802.15.4 compatible hardware becomes increasingly available. Our aim is to examine the impact of Beacon and Superframe Order in the medium access delay, dropped packets, end to end delay, average retransmission attempts and consumed power focusing on this bandwidth demanding situation where the network load does not allow low duty cycles, in order to draw some conclusions on the effect that this will have to telemonitoring applications.

  6. A Green Media Access Method for IEEE 802.15.6 Wireless Body Area Network.

    Science.gov (United States)

    Jacob, Anil K; Jacob, Lillykutty

    2017-09-30

    It is of utmost importance to conserve battery energy to the maximum possible extent in WBAN nodes while collecting and transferring medical data. The IEEE 802.15.6 WBAN standard does not specify any method to conserve energy. This paper focuses on a method to conserve energy in IEEE 802.15.6 WBAN nodes when using CSMA/CA, while simultaneously restricting data delivery delay to the required value as specified in medical applications. The technique is to allow the nodes to sleep all the times except for receiving beacons and for transmitting data frames whenever a data frame enters an empty buffer. The energy consumed by the nodes and the average latency of data frame for periodical arrival of data are found out analytically. The analytical results are validated and also the proposed method is compared with other energy conserving schemes, using Castalia simulation studies. The proposed method shows superior performance in both device lifetime and latency of emergency medical data.

  7. Predictable and reliable ECG monitoring over IEEE 802.11 WLANs within a hospital.

    Science.gov (United States)

    Park, Juyoung; Kang, Kyungtae

    2014-09-01

    Telecardiology provides mobility for patients who require constant electrocardiogram (ECG) monitoring. However, its safety is dependent on the predictability and robustness of data delivery, which must overcome errors in the wireless channel through which the ECG data are transmitted. We report here a framework that can be used to gauge the applicability of IEEE 802.11 wireless local area network (WLAN) technology to ECG monitoring systems in terms of delay constraints and transmission reliability. For this purpose, a medical-grade WLAN architecture achieved predictable delay through the combination of a medium access control mechanism based on the point coordination function provided by IEEE 802.11 and an error control scheme based on Reed-Solomon coding and block interleaving. The size of the jitter buffer needed was determined by this architecture to avoid service dropout caused by buffer underrun, through analysis of variations in transmission delay. Finally, we assessed this architecture in terms of service latency and reliability by modeling the transmission of uncompressed two-lead electrocardiogram data from the MIT-BIH Arrhythmia Database and highlight the applicability of this wireless technology to telecardiology.

  8. Improving Energy Efficiency in Idle Listening of IEEE 802.11 WLANs

    Directory of Open Access Journals (Sweden)

    Muhammad Adnan

    2016-01-01

    Full Text Available This paper aims to improve energy efficiency of IEEE 802.11 wireless local area networks (WLANs by effectively dealing with idle listening (IL, which is required for channel sensing and is unavoidable in a contention-based channel access mechanism. Firstly, we show that IL is a dominant source of energy drain in WLANs and it cannot be effectively alleviated by the power saving mechanism proposed in the IEEE 802.11 standard. To solve this problem, we propose an energy-efficient mechanism that combines three schemes in a systematic way: downclocking, frame aggregation, and contention window adjustment. The downclocking scheme lets a station remain in a semisleep state when overhearing frames destined to neighbor stations, whereby the station consumes the minimal energy without impairing channel access capability. As well as decreasing the channel access overhead, the frame aggregation scheme prolongs the period of semisleep time. Moreover, by controlling the size of contention window based on the number of stations, the proposed mechanism decreases unnecessary IL time due to collision and retransmission. By deriving an analysis model and performing extensive simulations, we confirm that the proposed mechanism significantly improves the energy efficiency and throughput, by up to 2.8 and 1.8 times, respectively, compared to the conventional power saving mechanisms.

  9. Evaluating IEEE 802.15.4 for Cyber-Physical Systems

    Directory of Open Access Journals (Sweden)

    Vinel Alexey

    2011-01-01

    Full Text Available With rapid advancements in sensing, networking, and computing technologies, recent years have witnessed the emergence of cyber-physical systems (CPS in a broad range of application domains. CPS is a new class of engineered systems that features the integration of computation, communications, and control. In contrast to general-purpose computing systems, many cyber-physical applications are safety critical. These applications impose considerable requirements on quality of service (QoS of the employed networking infrastruture. Since IEEE 802.15.4 has been widely considered as a suitable protocol for CPS over wireless sensor and actuator networks, it is of vital importance to evaluate its performance extensively. Serving for this purpose, this paper will analyze the performance of IEEE 802.15.4 standard operating in different modes respectively. Extensive simulations have been conducted to examine how network QoS will be impacted by some critical parameters. The results are presented and analyzed, which provide some useful insights for network parameter configuration and optimization for CPS design.

  10. Application of IEEE 1588 protocol in protection example value synchronization of distributed generation system%IEEE 1588在分布式发电系统保护采样值同步中的应用

    Institute of Scientific and Technical Information of China (English)

    杨乘胜; 唐立军

    2009-01-01

    The future trend of the distributed automation system is adopting the 1EC 61850 standard to realize seamless communication in the substation and between the substation and every node of the distributed system. The IEC 61850 protocol has very high requirement for sample value synchronization accuracy. The IEEE 1588 protocol was introduced and analyzed. A separate iming index generator was established, and "side-clock" function for exchanger was realized. A new accurate time synchronization scheme was proposed which is in accordance with the IEEE 1588 protocol and can be used in distributed system protection communication, and the software and hardware structure modes were given. The realization of the IEEE 1588 protocol was accomplished by using microcontroller, and the requirement of sample value synchronization of distributed protection communication system based on IEC 61850 protocol should be satisfied.%分布式发电自动化系统未来的趋势是变电站以及变电站到分布式系统的每个节点之间都采用IEC 61850标准实现无缝通信.IEC 61850对采样值同步精确度有着非常高的精确性要求.分析并介绍了IEEE 1588协议.单独设立时标生成器,对交换机实现边界时钟功能.提出了一种符合IEEE 1588协议,可用于分布式系统保护通信中的精确时间同步新方案,并给出了软硬件结构模型.IEEE 1588协议的实现利用微控制器来完成,可以满足基于IEC 61850的分布式保护通信系统的采样值同步要求.

  11. 基于PMP模式的IEEE 802.16 系统中Ranging问题%Ranging problem in IEEE 802.16 system based on PMP mode

    Institute of Scientific and Technical Information of China (English)

    关艳峰; 胡爱群; 王兴建

    2006-01-01

    研究了IEEE 802.16在PMP(点到多点)模式下的Ranging过程中竞争冲突问题.运用生灭过程分析了在确定SS数目的情况下需要Ranging的SS数量模型,并计算出了需要Ranging的SS数量的稳态解.根据随机过程理论提出了SS在Ranging过程中单步竞争转移模型,在此基础上以单位Ranging带宽下SS的 Ranging竞争成功率最大为原则推导出了最优的Ranging带宽.最后,分别在非最优带宽、Sungmin给出的带宽和最优带宽下对Ranging过程进行仿真,结果表明,最优Ranging带宽下比其他2种带宽下的Ranging成功率提高20%,而Ranging的竞争次数和总的Ranging时延分别降低25%和20%.

  12. Algorithms of sleep interval growth in IEEE802.16e sleep mode%IEEE802.16e休眠间隔增长算法

    Institute of Scientific and Technical Information of China (English)

    唐朝伟; 邵艳清; 刘鹏军; 张伟军

    2009-01-01

    为提高移动站点的节能综合性能,构造了两种休眠间隔增长算法,通过减缓休眠间隔的增长速度降低了移动站点的平均能耗,并缩短了其接收数据帧的平均响应时间.通过选取不同的初始休眠间隔值,探讨了休眠间隔增长速度对节能综合性能的影响,仿真实验对比分析了休眠间隔增长算法的节能综合性能.结果表明:两种增长算法均优于IEEE802.16e采用的指数增长算法,其中的步进增长算法的综合性能最优.

  13. Based on IEEE P1901 Standard for Next-.generation EoC Technology%基于IEEE P1901标准的下一代EoC技术

    Institute of Scientific and Technical Information of China (English)

    王洪新

    2011-01-01

    In this paper, Compare Intellons INT6400 Homeplug AV solutions with standards P1901 AR74XX chip, to illustrate the next generation based on P1901 EoC advantages.%以Intellon的HomePlug AV的解决方案INT6400和基于IEEE P1901标准的AR74XX芯片做对比,来说明基于IEEE P1901标准的下一代EoC技术的优点。

  14. 应用于配电网的时钟偏移估计的IEEE 1588改进方案%An improvedIEEE 1588 synchronization schemeon the clock offset estimation applied in distribution network

    Institute of Scientific and Technical Information of China (English)

    梅军; 徐迅; 钱超; 喻洁; 王勇; 嵇文路; 朱红

    2016-01-01

    IEEE 1588 is usedfor clock synchronization in a networked measurement and control system of the distribution grid.It plays an important role in the packet-based network synchronization mechanism. However, the performance of the conventional IEEE 1588 synchronization algorithm is affected by the asymmetric link and random delay problems.This paper proposesan improved IEEE 1588 based synchronization scheme involves two different random delay models: theGaussian random delay modelandtheexponential random delay model.And the time offset andthe maximum likelihood estimators of the two random delay models are derived.The results show that the clock offset estimation performance depends on the ratioof the random delay of the model andthesizeof thedata packet transmitted.As is shown in the simulation results, the solution to the asymmetric links and random delay issuecompared with the traditional IEEE 1588 clock synchronization method and bursttransmission schemeobtains better performance.%IEEE 1588协议实现在配电网中网络测量和控制系统的时钟同步,并在基于分组的网络同步机制中起了重要作用。然而,传统的IEEE 1588同步算法的性能由于非对称链路和随机延迟问题的影响,达不到期望的精度。提出了基于IEEE 1588的时钟同步改进方案涉及到两种不同的随机延迟模型,分别服从高斯延迟模型和指数延迟模型。并分别推导出该方案中两种时间延迟模型的时钟偏移的最大似然估计值。分析结果表明,时钟偏移估计的性能依赖于随机延迟的模型和所发送的数据包大小的比率。仿真结果表明,该方案解决了非对称链路和随机延迟的问题,与传统的IEEE 1588时钟同步方法以及突发脉冲传输方案相比具有更好的性能。

  15. 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.

  16. A Cross-Layer Key Management Scheme for MIPv6 Fast Handover over IEEE 802.11 Wireless LAN

    Directory of Open Access Journals (Sweden)

    Chang-Seop Park

    2015-01-01

    Full Text Available A new key management and security scheme is proposed to integrate Layer Two (L2 and Layer Three (L3 keys for secure and fast Mobile IPv6 handover over IEEE 802.11 Wireless Local Area Network (WLAN. Unlike the original IEEE 802.11-based Mobile IPv6 Fast Handover (FMIPv6 that requires time-consuming IEEE 802.1x-based Extensible Authentication Protocol (EAP authentication on each L3 handover, the newly proposed key management and security scheme requires only one 802.1x-EAP regardless of how many L3 handovers occur. Therefore, the proposed scheme reduces the handover latency that results from a lengthy 802.1x-based EAP. The proposed key management and security scheme is extensively analyzed in terms of security and performance, and the proposed security scheme is shown to be more secure than those that were previously proposed.

  17. ART-GAS: An Adaptive and Real-Time GTS Allocation Scheme for IEEE 802.15.4

    CERN Document Server

    Xia, Feng; Cao, Yang; Xue, Lei

    2012-01-01

    IEEE 802.15.4 supports a Guaranteed Time Slot (GTS) allocation mechanism for time-critical and delay-sensitive data transmissions in Wireless Personal Area Networks (WPANs). However, the inflexible first-come-first-served GTS allocation policy and the passive deallocation mechanism significantly reduce network efficiency. In this paper, we propose an Adaptive and Real-Time GTS Allocation Scheme (ART-GAS) to provide differentiated services for devices with different priorities, which guarantees data transmissions for time-sensitive and high-traffic devices. The bandwidth utilization in IEEE 802.15.4-based PAN is improved. Simulation results show that our ART-GAS algorithm significantly outperforms the existing GTS mechanism specified in IEEE 802.15.4.

  18. A distributed scheme to manage the dynamic coexistence of IEEE 802.15.4-based health-monitoring WBANs.

    Science.gov (United States)

    Deylami, Mohammad N; Jovanov, Emil

    2014-01-01

    The overlap of transmission ranges between wireless networks as a result of mobility is referred to as dynamic coexistence. The interference caused by coexistence may significantly affect the performance of wireless body area networks (WBANs) where reliability is particularly critical for health monitoring applications. In this paper, we analytically study the effects of dynamic coexistence on the operation of IEEE 802.15.4-based health monitoring WBANs. The current IEEE 802.15.4 standard lacks mechanisms for effectively managing the coexistence of mobile WBANs. Considering the specific characteristics and requirements of health monitoring WBANs, we propose the dynamic coexistence management (DCM) mechanism to make IEEE 802.15.4-based WBANs able to detect and mitigate the harmful effects of coexistence. We assess the effectiveness of this scheme using extensive OPNET simulations. Our results indicate that DCM improves the successful transmission rates of dynamically coexisting WBANs by 20%-25% for typical medical monitoring applications.

  19. IEEE Xplore® Digital Library - Evolving to Meet YOUR Changing Needs

    OpenAIRE

    2014-01-01

    Представлена презентация доклада "Использование платформы IEEE Digital Library: уникальные научные публикации в области электроники, радиосвязи, вычислительной техники, информационных технологий, энергетики, машиностроения, физики, химии, геологии, нанотехнологий" Эстер Лукаш, специалиста по обучению IEEE (Германия), на семинаре «Использование платформы IEEE Digital Library», прошедшем 02 октября 2014 года в УрФУ, на английском языке....

  20. IEEE Xplore® Digital Library - Evolving to Meet YOUR Changing Needs

    OpenAIRE

    2014-01-01

    Представлена презентация доклада "Использование платформы IEEE Digital Library: уникальные научные публикации в области электроники, радиосвязи, вычислительной техники, информационных технологий, энергетики, машиностроения, физики, химии, геологии, нанотехнологий" Эстер Лукаш, специалиста по обучению IEEE (Германия), на семинаре «Использование платформы IEEE Digital Library», прошедшем 02 октября 2014 года в УрФУ, на английском языке....

  1. Analysis of performance of wireless sensor networks based on IEEE 802.15.4%基于IEEE802.15.4的无线传感器网络性能分析

    Institute of Scientific and Technical Information of China (English)

    向碧群; 李艳体; 王小平; 李云

    2011-01-01

    通过将IEEE 802.15.4标准中的超帧与无线传感器网络的LEACH协议结合,在星型网络拓扑下,网络节点通过申请超帧中的GTS来进行无冲突的数据通信,对使用GTS传输数据的这一过程进行了研究,从理论上分析了无线传感器网络的网络性能.仿真结果说明了网络控制参数对网络性能的影响,为今后无线传感器网络应用中的参数配置提供了一定的理论基础.%Based on IEEE 802. 15. 4 standard, this paper combined the superframe of IEEE 802. 15. 4 with the LEACH of WSN. In the star topology the nodes would communicate without contention. It researched the communication in the guaran-teed time slot of superframe in IEEE 802.15.4. Then analyzed the performance of WSN theoretically.' The analysis and simu-lation results show the influence of control parameters on the performance of networks, the result will provide certain basement for the application of WSN.

  2. 一种基于IEEE802.16e的新型切换算法研究%Research of New Handover Algorithm for IEEE 802.16e

    Institute of Scientific and Technical Information of China (English)

    孙阳; 曹龙汉; 李平

    2012-01-01

    In this paper, a new handover algorithm for IEEE 802. 16e wirless networks is proposed The algorithm takes into consideration the main behaviors of IEEE 802. 16 operation such as ranging, authorization, and registration. That by using service-flows awareness is to minimize the time spent in handover based on theserviee flows running at the mobile statioa Simulation analysis of the proposed algorithm shows that handover time can be effectively reduced by several folds after taking advantage of different capabilities provided by the standard.%提出一种基于IEEE 802.16e无线网络的新型切换算法.算法充分考虑了IEEE 802.16e的测距、认证、注册等主要使用行为,通过引入业务流(Service Flow)认知,使基于业务流的移动终端处的切换时间达到最小.仿真分析表明,利用标准提出的多种不同能力的交互,算法能够有效降低切换时间.

  3. 无线个域网mesh网络标准——IEEE 802.15.5%Standard of mesh wireless personal area network——IEEE 802.15.5

    Institute of Scientific and Technical Information of China (English)

    史晓晨; 刘凯明; 高锦春; 刘元安

    2011-01-01

    In order to further understand the IEEE 802.15.5 standard, this paper introduced the reference model, key technologies and applications of 802.15.5.It described the ability of IEEE 802.15.5 for supporting mesh fully, then compared the differences of HR-WPAN and LR-WPAN, at last discussed the unresolved topics of WPAN and development trends in this field.%为了进一步理解IEEE 802.15.5标准,对802.15.5的结构模型、关键技术及应用进行了介绍.讨论了IEEE 802.15.5对mesh网络的完全支持能力,并对高速个域网(HR-WPAN)和低速个域网(LR-WPAN)两种情况进行了比较,最后给出了WPAN存在的问题及展望.

  4. A 3-D Markov Chain Model of IEEE 802.11b DCF in Non-saturated Conditions%IEEE 802.11b DCF三维Markov非饱和链路模型

    Institute of Scientific and Technical Information of China (English)

    梁博; 赵成林

    2015-01-01

    为了准确评估实际网络中IEEE 802.11b 分布式协调功能( Distributed Coordination Function, DCF)的系统性能,提出了一种三维Markov链路模型,该模型综合考虑了DCF协议退避计数器冻结状态和有限重传次数,并结合M/M/1/K排队模型给出了在负载有限的情况下DCF系统性能的理论模型。仿真结果表明,该模型能准确地预测IEEE 802.11b DCF协议的系统性能。%A new 3⁃D Markov chain model is proposed for accurately assessing the actual network performance of IEEE 802.11b DCF.The model takes into account DCF protocol backoff counter frozen and limited number of retransmissions.Combined with M/M/1/K queue model,a theoretical model of DCF system performance with finite load is derived.The simulation results show that the model can accurately predict system performance of IEEE 802.11b DCF protocol.

  5. Hierarchical Model of IEEE 802.21 Media Independent Information Service (MIIS

    Directory of Open Access Journals (Sweden)

    Shamsa Gilani

    2013-05-01

    Full Text Available In this era of emerging technologies, the main issue is to discover the appropriate neighbor access network during handoff mechanism for a mobile node. We require handover because in this heterogeneous environment, there can be several networks (Wi-Fi, WIMAX and UMTS in a geographical area which are not so interoperable. For abiding the services we use Media Independent Information Service (MIIS provided by IEEE 802.21 MIH standards (Buiati et al., 2010 to select the most suitable network. This study provides a brief overview of how the challenges associated with the handoff are solved by several proposed schemes. In the introduction, role of MIIS is comprehensively defined to represent its importance followed by issues associated with handoff. Then, it gives an overview of the latest research activities in this field, including all the problems faced during handoff process. The study concludes by giving a new hierarchical scheme presenting implementation of MIIS servers to significantly improve the mobility.

  6. Experimental video signals distribution MMF network based on IEEE 802.11 standard

    Science.gov (United States)

    Kowalczyk, Marcin; Maksymiuk, Lukasz; Siuzdak, Jerzy

    2014-11-01

    The article was focused on presentation the achievements in a scope of experimental research on transmission of digital video streams in the frame of specially realized for this purpose ROF (Radio over Fiber) network. Its construction was based on the merge of wireless IEEE 802.11 network, popularly referred as Wi-Fi, with a passive optical network PON based on multimode fibers MMF. The proposed approach can constitute interesting proposal in area of solutions in the scope of the systems monitoring extensive, within which is required covering of a large area with ensuring of a relatively high degree of immunity on the interferences transmitted signals from video IP cameras to the monitoring center and a high configuration flexibility (easily change the deployment of cameras) of such network.

  7. Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs with Extended Service Range

    Science.gov (United States)

    Choi, Woo-Yong

    2011-11-01

    In this paper, we propose the efficient reliable multicast MAC protocol by which the AP (Access Point) can transmit reliably its multicast data frames to the recipients in the AP's one-hop or two-hop transmission range. The AP uses the STAs (Stations) that are directly associated with itself as the relays for the data delivery to the remote recipients that cannot be reached directly from itself. Based on the connectivity information among the recipients, the reliable multicast MAC protocol optimizes the number of the RAK (Request for ACK) frame transmissions in a reasonable computational time. Numerical examples show that our proposed MAC protocol significantly enhances the MAC performance compared with the BMMM (Batch Mode Multicast MAC) protocol that is extended to support the recipients that are in the AP's one-hop or two-hop transmission range in IEEE 802.11 wireless LANs.

  8. Mobile Device Passive Localization Based on IEEE 802.11 Probe Request Frames

    Directory of Open Access Journals (Sweden)

    Lin Sun

    2017-01-01

    Full Text Available This paper presents a novel passive mobile device localization mode based on IEEE 802.11 Probe Request frames. In this approach, the listener can discover mobile devices by receiving the Probe Request frames and localize them on his walking path. The unique location of the mobile device is estimated on a geometric diagram and right-angled walking path. In model equations, site-related parameter, that is, path loss exponent, is eliminated to make the approach site-independent. To implement unique localization, the right-angled walking path is designed and the optimal location is estimated from the optional points. The performance of our method has been evaluated inside the room, outside the room, and in outdoor scenarios. Three kinds of walking paths, for example, horizontal, vertical, and slanted, are also tested.

  9. IEEE 802.11p Empirical Performance Model from Evaluations on Test Tracks

    Directory of Open Access Journals (Sweden)

    Sébastien Demmel

    2014-06-01

    Full Text Available IEEE 802.11p is the new standard for intervehicular communications (IVC using the 5.9 GHz frequency band; it is planned to be widely deployed to enable cooperative systems. 802.11p uses and performance have been studied theoretically and in simulations over the past years. Unfortunately, many of these results have not been confirmed by on-tracks experimentation. In this paper, we describe field trials of 802.11p technology with our test vehicles; metrics such as maximum range, latency and frame loss are examined. Then, we propose a detailed modelisation of 802.11p that can be used to accurately simulate its performance within Cooperative Systems (CS applications.

  10. Transient Stability Analysis of IEEE 9 Bus System in Power World Simulator x

    Directory of Open Access Journals (Sweden)

    Transient Stability Analysis of IEEE 9 Bus System in Power World Simulator Ramandeep Kaur,

    2016-01-01

    Full Text Available It is widely accepted that transient stability is an important aspect in designing and upgrading electric power system. The objective of this paper was to investigate and understand the stability of power system In this paper, modelling and transient stability analysis of IEEE 9 bus system was performed using POWER WORLD SIMULATOR. The load flow studies were performed to determine pre-fault conditions in the system using Newton-Raphson method. With the help of three-phase balanced fault, the variations in power angle and frequency of the system were studied. Frequency is a reliable indicator if deficiency condition in the power systems exists or not. For three-phase balanced fault, fast fault clearing time was analysed to bring back the system to the stability. Further, comparison between Runga method and Euler method for better results was performed. Hence, impact of load switching on system was also computed so as to bring system to steady state.

  11. Improved Power Saving Mechanism to Increase Unavailability Interval in IEEE 802.16e Networks

    Science.gov (United States)

    Lee, Kyunghye; Mun, Youngsong

    To manage limited energy resources efficiently, IEEE 802.16e specifies sleep mode operation. Since there can be no communication between the mobile station (MS) and the serving base station (BS) during the unavailability interval, the MS can power down its physical operation components. We propose an improved power saving mechanism (iPSM) which effectively increases the unavailability interval of Type I and Type II power saving classes (PSCs) activated in an MS. After investigating the number of frames in the unavailability interval of each Type II PSC when used with Type I PSC, the iPSM chooses the Type II PSC that yields the maximum number of frames in the unavailability interval. Performance evaluation confirms that the proposed scheme is very effective.

  12. IEEE 802.21 Assisted Seamless and Energy Efficient Handovers in Mixed Networks

    Science.gov (United States)

    Liu, Huaiyu; Maciocco, Christian; Kesavan, Vijay; Low, Andy L. Y.

    Network selection is the decision process for a mobile terminal to handoff between homogeneous or heterogeneous networks. With multiple available networks, the selection process must evaluate factors like network services/conditions, monetary cost, system conditions, user preferences etc. In this paper, we investigate network selection using a cost function and information provided by IEEE 802.21. The cost function provides flexibility to balance different factors in decision making and our research is focused on improving both seamlessness and energy efficiency of handovers. Our solution is evaluated using real WiFi, WiMax, and 3G signal strength traces. The results show that appropriate networks were selected based on selection policies, handovers were triggered at optimal times to increase overall network connectivity as compared to traditional triggering schemes, while at the same time the energy consumption of multi-radio devices for both on-going operations as well as during handovers is optimized.

  13. A Novel Pulse Shaping for UWB Impulse Radio IEEE 802.15.4a Communications Systems

    Directory of Open Access Journals (Sweden)

    BARRAJ Imen

    2014-05-01

    Full Text Available This paper presents a novel pulse shape which we call modified triangular pulse (MTri for Impulse Radio-Ultra Wide Band (IR-UWB IEEE 802.15.4a systems. The MTri pulse and UWB shapes previously proposed for low power IR-UWB transceivers topologies are studied and compared. The performance measures considered are compliance with required spectral emission constrains, Mask Loss (ML power and pulse energy. Our theoretical and simulations results show the advantages of the MTri pulse over studies UWB pulses. It presents the lower ML power about 0.45dB and the higher pulse energy of 0.45nJ/p.

  14. Low-frequency electrical dosimetry: research agenda of the IEEE International Committee on Electromagnetic Safety

    Science.gov (United States)

    Reilly, J. Patrick; Hirata, Akimasa

    2016-06-01

    This article treats unsettled issues in the use of numerical models of electrical dosimetry as applied to international limits on human exposure to low-frequency (typically  electromagnetic fields and contact current. The perspective in this publication is that of Subcommittee 6 of IEEE-ICES (International Committee on Electromagnetic Safety) Technical Committee 95. The paper discusses 25 issues needing attention, fitting into three general categories: induction models; electrostimulation models; and human exposure limits. Of these, 9 were voted as ‘high priority’ by members of Subcommittee 6. The list is presented as a research agenda for refinements in numerical modeling with applications to human exposure limits. It is likely that such issues are also important in medical and electrical product safety design applications.

  15. Integration of heterogeneous biomedical sensors into an ISO/IEEE 11073 compliant application.

    Science.gov (United States)

    Fioravanti, A; Fico, G; Arredondo, M T; Salvi, D; Villalar, J L

    2010-01-01

    Current trends in healthcare technology include mobile-based applications. Relevant advances in the integration of vital signs monitoring devices with mobile platforms are widely reported nowadays. In this context, conceiving and designing an interoperable application is essential due to the growing necessity of integrating a huge and heterogeneous amount of biomedical data, coming from a wide range of devices and sensors. In this paper the key research issues associated with such integration are presented as well as a specific proposal to solve these problems. It is based on a middleware architecture for the integration of biomedical sensors with mobile devices, derived from the ISO/IEEE 11073 standards family. The application has been developed in the framework of an EU-funded R&D project called METABO.

  16. A study on IEEE 802. 11 WLAN implementation with embedded microprocessor

    Institute of Scientific and Technical Information of China (English)

    Abdullah A Hussain; LOU Xi-zhong; ZHONG Wei; MAO Zhi-gang

    2005-01-01

    Applying IEEE 802. 11 MAC protocols in battery-powered devices make power consumption critical demand upon implementation. A statistical study on operator/bit usage, the weight of operator and operator type in the programs has been done, including converting the MAC functions from SDL to C to ASM with tow RISC targets. The study shows that implementing MAC functions should consider real-time protocol requirements by dividing MAC functions into sets. We enhance the set of time-critical functions implemented to dedicated hardware and the set of non-time-critical functions implemented to software run with embedded processor. This heterogeneous system is proposed in consideration of our study results to reduce power consumption.

  17. Design and Implementation of a Testbed for IEEE 802.15.4 (Zigbee Performance Measurements

    Directory of Open Access Journals (Sweden)

    Patrick R. Casey

    2010-01-01

    Full Text Available IEEE 802.15.4, commonly known as ZigBee, is a Media Access Control (MAC and physical layer standard specifically designed for short range wireless communication where low rate, low power, and low bandwidth are required. This makes ZigBee an ideal choice when it comes to sensor networks for monitoring data collection and/or triggering process responses. However, these very characteristics bring into question ZigBee's ability to perform reliably in harsh environments. This paper thoroughly explains the experimental testbed setup and execution to demonstrate ZigBee's performance in several practical applications. This testbed is capable of measuring the minimum, maximum, and average received signal strength indicator (RSSI, bit error rate (BER, packet error rate (PER, packet loss rate (PLR, and the bit error locations. Results show that ZigBee has the potential capabilities to be used in all four tested environments.

  18. Performance Improvement of Distributed Coordination Function in IEEE 802.11 Wireless LAN

    Institute of Scientific and Technical Information of China (English)

    SHU Yantai; DONG Linfang; WANG Guanghong; ZHANG Liang

    2006-01-01

    This paper proposes a modification to distributed coordination function (DCF) to improve the channel utilization in IEEE 802.11 wireless local area networks (WLANs). In the modified DCF, when a station has contended for the channel, it may transmit multiple data frames continuously to the same destination, which is called transmission burst(TB). When the maximum number of data packets transmitted continuously in a TB is set to be 2, the performance is expected to be the best. The theoretical analysis and simulation results show that compared with the standard DCF, the modified DCF can increase the throughput and decrease the delay of the WLAN, and the modification does not introduce any additional control overhead.

  19. Supporting service differentiation with enhancements of the IEEE 802.11 MAC protocol: Models and analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As one of the fastest growing wireless access technologies, wireless LANs must evolve to support adequate degrees of service differentiation. Unfortunately, current WLAN standards like IEEE 802.11 Distributed Coordination Function (DCF) lack this ability. Work is in progress to define an enhanced version capable of supporting QoS for multimedia traffic at the MAC layer. In this paper, we aim at gaining insight into three mechanisms to differentiate among traffic categories, i.e., differentiating the minimum contention window size, the Inter-Frame Spacing (IFS), and the length of the packet payload according to the priority of different traffic categories. We propose an analysis model to compute the throughput and packet transmission delays. In addition, we derive approximations to obtain simpler but more meaningful relationships among different parameters. Comparisons with discrete-event simulation results show that good accuracy of performance evaluation can be achieved by using the proposed analysis model.

  20. Performance analysis of IEEE 802.11e EDCA in wireless LANs

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; SUN Jun; LIU Jing; ZHANG Hai-bin

    2007-01-01

    In this paper, we propose an analytical model for the performance evaluation of IEEE 802.11e enhanced distributed channel access (EDCA). Different from most previous analytical studies based on the saturation assumption, we extend the analytical model to non-saturation conditions. An empty state is introduced into the Markov chain to represent the status of transmission queue being empty. This model can be used to calculate the traffic priority, throughput, and MAC layer delay with various configurations of contention parameters. A detailed simulation is provided to validate the proposed model. With the help of this model, the contention parameters can be configured appropriately to achieve specific quality-of-service (QoS) requirements.

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

    Institute of Scientific and Technical Information of China (English)

    YAOZhongbang; CAOZhigang

    2004-01-01

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

  2. Channel Impulse Response Estimation in IEEE 802.11p via Data Fusion and MMSE Estimator

    Directory of Open Access Journals (Sweden)

    Giulio Ministeri

    2015-01-01

    Full Text Available Tracking the channel impulse response in systems based on the IEEE 802.11p standard, the most widely accepted standard for the physical layer in vehicular area networks (VANETs, is still an open research topic. In this paper we aim to improve previously proposed channel estimators by utilizing data aided algorithm that includes the channel decoding to enhance the quality of the estimated data. Moreover we propose a novel technique that exploits information provided by external sensors like GPS or speedometer, usually present in vehicles. The algorithm proposed so far has been analyzed in non-line-of-sight link conditions; in this paper we present an analysis of performances in the line-of-sight condition as well. Simulations show that both proposals give considerable improvements in terms of packet error rate and channel estimation error in the highway scenario which is surely the most stressing environment for the channel response tracker.

  3. Performance Improvement of DCF Supporting Multi-Rate in IEEE 802.11b Wireless LAN

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper proposes a new channel access algorithm based on channel occupancy time (COT) fairness to guarantee fairness and improve the aggregate throughput of 802.11b multi-rate WLANs. In the algorithm, the COT is used as fairness index to analyze the fairness of WLANs instead of the channel access probability (CAP) used in the distributed coordination function (DCF).The standard COT is given by access point (AP) and broadcasted to all wireless stations. The AP and wireless stations in the WLAN can achieve COT-based fairness by adjusting their packet length,sending the multiple back-to-back packets at one time, or giving up an opportunity to access the channel. Analysis and simulations show that our algorithm can provide COT-fairness. Compared with the CAP-based algorithm, the proposed algorithm leads to improvements in aggregate throughput of IEEE 802.11b multi-rate WLANs.

  4. A Fair and Efficient Packet Scheduling Scheme for IEEE 802.16 Broadband Wireless Access Systems

    CERN Document Server

    Chowdhury, Prasun; 10.5121/ijasuc.2010.1308

    2010-01-01

    This paper proposes a fair and efficient QoS scheduling scheme for IEEE 802.16 BWA systems that satisfies both throughput and delay guarantee to various real and non-real time applications. The proposed QoS scheduling scheme is compared with an existing QoS scheduling scheme proposed in literature in recent past. Simulation results show that the proposed scheduling scheme can provide a tight QoS guarantee in terms of delay, delay violation rate and throughput for all types of traffic as defined in the WiMAX standard, thereby maintaining the fairness and helps to eliminate starvation of lower priority class services. Bandwidth utilization of the system and fairness index of the resources are also encountered to validate the QoS provided by our proposed scheduling scheme.

  5. A NOVEL LINK ADAPTATION SCHEME TO ENHANCE PERFORMANCE OF IEEE 802.11G WIRELESS LAN

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel link adaptation scheme using linear Auto Regressive (AR) model channel estimation algorithm to enhance the performance of auto rate selection mechanism in IEEE 802.11g is proposed. This scheme can overcome the low efficiency caused by time interval between the time when Received Signal Strength (RSS) is measured and the time when rate is selected. The best rate is selected based on data payload length, frame retry count and the estimated RSS, which is estimated from recorded RSSs. Simulation results show that the proposed scheme enhances mean throughput performance up to 7%, in saturation state,and up to 24% in finite load state compared with those non-estimation schemes, performance enhancements in average drop rate and average number of transmission attempts per data frame delivery also validate the effectiveness of the proposed scheme.

  6. 3th IEEE/ACIS International Conference on Computer and Information Science

    CERN Document Server

    2015-01-01

    This edited book presents scientific results of the 13th IEEE/ACIS International Conference on Computer and Information Science (ICIS 2014) which was held on June 4-6, 2014 in Taiyuan, China. The aim of this conference was to bring together researchers and scientists, businessmen and entrepreneurs, teachers, engineers, computer users, and students to discuss the numerous fields of computer science and to share their experiences and exchange new ideas and information in a meaningful way. Research results about all aspects (theory, applications and tools) of computer and information science, and to discuss the practical challenges encountered along the way and the solutions adopted to solve them. The conference organizers selected the best papers from those papers accepted for presentation at the conference.  The papers were chosen based on review scores submitted by members of the program committee, and underwent further rigorous rounds of review. This publication captures 14 of the conference’s most promis...

  7. Delay efficient cooperation in public safety vehicular networks using LTE and IEEE 802.11p

    KAUST Repository

    Atat, Rachad

    2012-01-01

    Cooperative schemes for critical content distribution over vehicular networks are presented and analyzed. The first scheme is based on unicasting from the base station, whereas the second is based on threshold based multicasting. Long Term Evolution (LTE) is used for long range communications with the base station (BS) and 802.11p is considered for inter-vehicle collaboration on the short range. A high mobility environment with correlated shadowing is adopted. Both schemes are shown to outperform non-cooperative unicasting and multicasting, respectively, when the appropriate 802.11p power class is used. The first scheme achieves the best performance among the compared methods, and a practical approximation of that scheme is shown to be close to optimal performance. © 2012 IEEE.

  8. Performance Analysis of Beacon-Less IEEE 802.15.4 Multi-Hop Networks

    CERN Document Server

    Srivastava, Rachit

    2012-01-01

    We develop an approximate analytical technique for evaluating the performance of multi-hop networks based on beacon-less CSMA/CA as standardised in IEEE 802.15.4, a popular standard for wireless sensor networks. The network comprises sensor nodes, which generate measurement packets, and relay nodes which only forward packets. We consider a detailed stochastic process at each node, and analyse this process taking into account the interaction with neighbouring nodes via certain unknown variables (e.g., channel sensing rates, collision probabilities, etc.). By coupling these analyses of the various nodes, we obtain fixed point equations that can be solved numerically to obtain the unknown variables, thereby yielding approximations of time average performance measures, such as packet discard probabilities and average queueing delays. Different analyses arise for networks with no hidden nodes and networks with hidden nodes. We apply this approach to the performance analysis of tree networks rooted at a data sink. ...

  9. Performance evaluation of IEEE 802.11 MAC layer in supporting delay sensitive services

    Directory of Open Access Journals (Sweden)

    Jyotsna Sengupta

    2010-02-01

    Full Text Available Providing QoS requirements like good throughput and minimum access delay are challenging tasks with regard to 802.11 WLAN protocols and Medium Access Control (MAC functions. IEEE 802.11 MAC layer supports two main protocols: DCF (Distributed Coordination Function and EDCF (Enhanced Distributed Coordination Function. During the evaluation of EDCF, the performance of various access categories was thedetermining factor. Two scenarios, with same Physical and MAC parameters, one implementing the DCF and other EDCF, were created in the network simulation tool (OPNET MODELER [5] to obtain the results. The results showed that the performance of EDCF was better in providing QoS for real-time interactive services (like video conferencing as compared to DCF, because of its ability to differentiate and prioritize various services. Whereas the DCF’s overall performance was marginally better for all kinds of services taken together.

  10. 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...

  11. A Novel Efficient VLSI Architecture for IEEE 754 Floating point multiplier using Modified CSA

    Directory of Open Access Journals (Sweden)

    Nishi Pandey

    2015-10-01

    Full Text Available Due to advancement of new technology in the field of VLSI and Embedded system, there is an increasing demand of high speed and low power consumption processor. Speed of processor greatly depends on its multiplier as well as adder performance. In spite of complexity involved in floating point arithmetic, its implementation is increasing day by day. Due to which high speed adder architecture become important. Several adder architecture designs have been developed to increase the efficiency of the adder. In this paper, we introduce an architecture that performs high speed IEEE 754 floating point multiplier using modified carry select adder (CSA. Modified CSA depend on booth encoder (BEC Technique. Booth encoder, Mathematics is an ancient Indian system of Mathematics. Here we are introduced two carry select based design. These designs are implementation Xilinx Vertex device family

  12. 12th ACIS/IEEE International Conference on Computer Science and Information Science

    CERN Document Server

    2013-01-01

    This edited book presents scientific results of the 12th IEEE/ACIS International Conference on Computer and Information Science (ICIS 2013) which was held on June 16-20, 2013 in Toki Messe, Niigata, Japan. The aim of this conference was to bring together scientists, engineers, computer users, and students to share their experiences and exchange new ideas, research results about all aspects (theory, applications and tools) of computer and information science, and to discuss the practical challenges encountered along the way and the solutions adopted to solve them The conference organizers selected the best 20 papers from those papers accepted for presentation at the conference. The papers were chosen based on review scores submitted by members of the program committee, and underwent further rigorous rounds of review.    

  13. IEEE802.3工作组批准成立EPoC研究组

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    北京时间11月11日,在美国亚特兰大举行的”2011lEEE局域网/城域网标准委员会全体会议”上,IEEE802.3工作组批准并成立了EPONP HYfor Copper Study Group(面向同轴接入的EPONPHY研究组)。该研究组将致力于同轴专用接入技术EPoC(EPONProtocalover Coaxial Distribution Network.基于EPON协议的同轴分配网络1的市场需求考察、网络兼容性考量、基于现有技术的物理层标准制定。

  14. 浅谈IEEE 802.11、Wi-Fi和Wi-Fi应用

    Institute of Scientific and Technical Information of China (English)

    周善国

    2013-01-01

      随着互联网技术的飞速发展,越来越多的人在生活和工作开始与无线局域网网息息相关,大家都沉寂在无线网络带给我们非凡体验的喜悦当中,同时也对新科技普及带来的新名词IEEE 802.11和Wi-Fi感到陌生,或将Wi-Fi与802.11混为一谈,今天笔者来和大家浅谈下EEE 802.11、Wi-Fi和Wi-Fi应用。

  15. Improving the Bandwidth Utilization by Recycling the Unused Bandwidth in IEEE 802.16 Networks

    Directory of Open Access Journals (Sweden)

    Gowri T

    2012-03-01

    Full Text Available The Physical and MAC layers have been specified in IEEE 802.16 networks. The quality of service is ensured by the bandwidth reservation. The subscriber station should reserve the bandwidth more than its demand. But the bandwidth is fully utilized by SS but not all the time. So the bandwidth has recycled by the process of recycling the unused bandwidth. The main objective of the proposed scheme is to utilize the unused bandwidth by recycling and maintain the QOS service. By recycling the throughput can be improved which maintains the QOS in the proposed scheme. During this recycling process to maintain the QOS services, the amount of reserved bandwidth is not changed. The proposed scheme can utilize the unused bandwidth up to 70% on average. Protocols and the scheduling algorithms are used to improve the utilization and throughput.

  16. IEEE30节点系统电压/无功优化

    Institute of Scientific and Technical Information of China (English)

    张俊; 张安安

    2016-01-01

    文中以IEEE30节点标准电网为基础,用Matpower完成了该电网模型的潮流分析.同时基于潮流分析结果,采取改变网络中无功功率分布调压、改变发电机端电压调压、改变变压器变比调压三种电力系统的主要调压措施来对电压偏移较大的节点进行了无功优化,最后分析了电压调整后的Matpower潮流结果,并得出了定性结论.

  17. Simulation and Analysis of Node Scheduling Schemes in IEEE 802.17 Standard

    Directory of Open Access Journals (Sweden)

    Mohsen Ashourian

    2007-09-01

    Full Text Available The Resilient Packet Ring (RPR architecture, known as the IEEE 802.17 standard, has received attention in the last year. The Priority Queue (PQ algorithm is recommended as the scheduling scheme for RPR, which always gives priority to the transit buffer. Using this scheduling scheme in RPR, the high priority traffic, such as video packets waiting to access the ring at congested node in the transmit buffer, suffer large delays and unsteady delay jitters. In this, we propose new scheduling schemes base on Deficit Round-Robin (DRR algorithm and compare it with the original schemes. To assess the efficiency of the system we simulate the network with 10 node attachments in the OPNET simulator and consider the efficiency of the new scheme. Using this scheme, the QoS of traffic transmission on the congested node can be significantly improved. Real time video traffic can benefit from such schemes.

  18. Dynamic Voltage Stability Studies using a Modified IEEE 30-Bus System

    Directory of Open Access Journals (Sweden)

    Oluwafemi Emmanuel Oni

    2016-09-01

    Full Text Available Power System stability is an essential study in the planning and operation of an efficient, economic, reliable and secure electric power system because it encompasses all the facet of power systems operations, from planning, to conceptual design stages of the project as well as during the systems operating life span. This paper presents different scenario of power system stability studies on a modified IEEE 30-bus system which is subjected to different faults conditions. A scenario whereby the longest high voltage alternating current (HVAC line is replaced with a high voltage direct current (HVDC line was implemented. The results obtained show that the HVDC line enhances system stability more compared to the contemporary HVAC line. Dynamic analysis using RMS simulation tool was used on DigSILENT PowerFactory.

  19. The IEEE guide to writing in the engineering and technical fields

    CERN Document Server

    Kmiec, David

    2017-01-01

    This book introduces students and practicing engineers to all the components of writing in the workplace. It teaches readers how considerations of audience and purpose govern the structure of their documents within particular work settings. The IEEE Guide to Writing in the Engineering and Technical Fields is broken up into two sections: "Writing in Engineering Organizations" and "What Can You Do With Writing?" The first section helps readers approach their writing in a logical and persuasive way as well as analyze their purpose for writing. The second section demonstrates how to distinguish rhetorical situations and the generic forms to inform, train, persuade, and collaborate. The emergence of the global workplace has brought with it an increasingly important role for effective technical communication. Engineers more often need to work in cross-functional teams with people in different disciplines, in different countries, and in different parts of the world. Engineers must know how to communicate in a rapid...

  20. A Study of IEEE 802.15.4 Security Framework for Wireless Body Area Network

    CERN Document Server

    Saleem, Shahnaz; Kwak, Kyung Sup; 10.3390/s110201383

    2011-01-01

    A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a sma...

  1. Application Delay Modelling for Variable Length Packets in Single Cell IEEE 802.11 WLANs

    CERN Document Server

    Sunny, Albert; Aggarwal, Saurabh

    2010-01-01

    In this paper, we consider the problem of modelling the average delay experienced by an application packets of variable length in a single cell IEEE 802.11 DCF wireless local area network. The packet arrival process at each node i is assumed to be a stationary and independent increment random process with mean ai and second moment a(2) i . The packet lengths at node i are assumed to be i.i.d random variables Pi with finite mean and second moment. A closed form expression has been derived for the same. We assume the input arrival process across queues to be uncorrelated Poison processes. As the nodes share a single channel, they have to contend with one another for a successful transmission. The mean delay for a packet has been approximated by modelling the system as a 1-limited Random Polling system with zero switchover times. Extensive simulations are conducted to verify the analytical results.

  2. Development of a low mobility IEEE 802.15.4 compliant VANET system for urban environments.

    Science.gov (United States)

    Nazabal, Juan Antonio; Falcone, Francisco; Fernández-Valdivielso, Carlos; Matías, Ignacio Raúl

    2013-05-29

    The use of Vehicular Ad-Hoc Networks (VANETs) is growing nowadays and it includes both roadside-to-vehicle communication (RVC) and inter-vehicle communication (IVC). The purpose of VANETs is to exchange useful information between vehicles and the roadside infrastructures for making an intelligent use of them. There are several possible applications for this technology like: emergency warning system for vehicles, cooperative adaptive cruise control or collision avoidance, among others. The objective of this work is to develop a VANET prototype system for urban environments using IEEE 802.15.4 compliant devices. Simulation-based values of the estimated signal strength and radio link quality values are obtained and compared with measurements in outdoor conditions to validate an implemented VANET system. The results confirm the possibility of implementing low cost vehicular communication networks operating at moderate vehicular speeds.

  3. 2011 IEEE Visualization Contest winner: Visualizing unsteady vortical behavior of a centrifugal pump.

    Science.gov (United States)

    Otto, Mathias; Kuhn, Alexander; Engelke, Wito; Theisel, Holger

    2012-01-01

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump's effectiveness. The winning entry split analysis of the pump into three parts based on the pump's functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump.

  4. Beamforming transmission in IEEE 802.11ac under time-varying channels.

    Science.gov (United States)

    Yu, Heejung; Kim, Taejoon

    2014-01-01

    The IEEE 802.11ac wireless local area network (WLAN) standard has adopted beamforming (BF) schemes to improve spectral efficiency and throughput with multiple antennas. To design the transmit beam, a channel sounding process to feedback channel state information (CSI) is required. Due to sounding overhead, throughput increases with the amount of transmit data under static channels. Under practical channel conditions with mobility, however, the mismatch between the transmit beam and the channel at transmission time causes performance loss when transmission duration after channel sounding is too long. When the fading rate, payload size, and operating signal-to-noise ratio are given, the optimal transmission duration (i.e., packet length) can be determined to maximize throughput. The relationship between packet length and throughput is also investigated for single-user and multiuser BF modes.

  5. Vispubdata.org: A Metadata Collection About IEEE Visualization (VIS) Publications.

    Science.gov (United States)

    Isenberg, Petra; Heimerl, Florian; Koch, Steffen; Isenberg, Tobias; Xu, Panpan; Stolper, Charles D; Sedlmair, Michael; Chen, Jian; Moller, Torsten; Stasko, John

    2017-09-01

    We have created and made available to all a dataset with information about every paper that has appeared at the IEEE Visualization (VIS) set of conferences: InfoVis, SciVis, VAST, and Vis. The information about each paper includes its title, abstract, authors, and citations to other papers in the conference series, among many other attributes. This article describes the motivation for creating the dataset, as well as our process of coalescing and cleaning the data, and a set of three visualizations we created to facilitate exploration of the data. This data is meant to be useful to the broad data visualization community to help understand the evolution of the field and as an example document collection for text data visualization research.

  6. A New Secure Strategy for Small-Scale IEEE 802.11 Wireless Local Area Networ

    Directory of Open Access Journals (Sweden)

    Yigang Yang

    2012-08-01

    Full Text Available As the main secret-key encryption techniques of the wireless local area network (WLAN have been proven to be unsafe, wireless network security is faced with serious challenges. It is unpractical for home users and small companies to buy expansive network equipments to improve the network security. Therefore, the secure strategy of wireless network needs to be changed. In this paper, we first introduce secure issues of the main secret-key encryption techniques currently adopted by the most popular commercial wireless routers. Then we propose a new strategy for small-scale IEEE 802.11 wireless local area network which can strengthen the network security. The new secure strategy is based on web authentication with unshared key and virtual local area network (VLAN in wireless network. It can provide protection against practical attacks which are popular nowadays. Moreover, it is simple, wieldy and low-cost.

  7. IEEE/NASA Workshop on Leveraging Applications of Formal Methods, Verification, and Validation

    Science.gov (United States)

    Margaria, Tiziana (Editor); Steffen, Bernhard (Editor); Hichey, Michael G.

    2005-01-01

    This volume contains the Preliminary Proceedings of the 2005 IEEE ISoLA Workshop on Leveraging Applications of Formal Methods, Verification, and Validation, with a special track on the theme of Formal Methods in Human and Robotic Space Exploration. The workshop was held on 23-24 September 2005 at the Loyola College Graduate Center, Columbia, MD, USA. The idea behind the Workshop arose from the experience and feedback of ISoLA 2004, the 1st International Symposium on Leveraging Applications of Formal Methods held in Paphos (Cyprus) last October-November. ISoLA 2004 served the need of providing a forum for developers, users, and researchers to discuss issues related to the adoption and use of rigorous tools and methods for the specification, analysis, verification, certification, construction, test, and maintenance of systems from the point of view of their different application domains.

  8. Fair Scheduling and Throughput Maximization for IEEE 802.16 Mesh Mode Broadband Wireless Access Networks

    Science.gov (United States)

    Alam, Muhammad Mahbub; Hamid, Md. Abdul; Razzaque, Md. Abdur; Hong, Choong Seon

    Broadband wireless access networks are promising technology for providing better end user services. For such networks, designing a scheduling algorithm that fairly allocates the available bandwidth to the end users and maximizes the overall network throughput is a challenging task. In this paper, we develop a centralized fair scheduling algorithm for IEEE 802.16 mesh networks that exploits the spatio-temporal bandwidth reuse to further enhance the network throughput. The proposed mechanism reduces the length of a transmission round by increasing the number of non-contending links that can be scheduled simultaneously. We also propose a greedy algorithm that runs in polynomial time. Performance of the proposed algorithms is evaluated by extensive simulations. Results show that our algorithms achieve higher throughput than that of the existing ones and reduce the computational complexity.

  9. A Study of IEEE 802.15.4 Security Framework for Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Kyung Sup Kwak

    2011-01-01

    Full Text Available A Wireless Body Area Network (WBAN is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE applications. Since WBAN nodes are used to collect sensitive (life-critical information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS attacks in WBAN at Physical, Medium Access Control (MAC, Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP and Contention Free Period (CFP parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS in WBAN (since most of the data is carried in CFP period. As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN.

  10. A study of IEEE 802.15.4 security framework for wireless body area networks.

    Science.gov (United States)

    Saleem, Shahnaz; Ullah, Sana; Kwak, Kyung Sup

    2011-01-01

    A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS) in WBAN (since most of the data is carried in CFP period). As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN.

  11. Reliable and Efficient Access for Alarm-initiated and Regular M2M Traffic in IEEE 802.11ah Systems

    DEFF Research Database (Denmark)

    Madueño, Germán Corrales; Stefanovic, Cedomir; Popovski, Petar

    2016-01-01

    IEEE 802.11ah is a novel WiFi-based protocol, aiming to provide an access solution for the machine-to-machine (M2M) communications. In this paper, we propose an adaptive access mechanism that can be seamlessly incorporated into IEEE 802.11ah protocol operation and that supports all potential M2M...

  12. Low-cost RAU with Optical Power Supply Used in a Hybrid RoF IEEE 802.11 Network

    Science.gov (United States)

    Kowalczyk, M.; Siuzdak, J.

    2014-09-01

    The paper presents design and implementation of a low-cost RAU (Remote Antenna Unit) device. It was designed to work in a hybrid Wi-Fi/optical network based on the IEEE 802.11b/g standard. An unique feature of the device is the possibility of optical power supply.

  13. Packet size optimization for goodput and energy efficiency enhancement in slotted IEEE 802.15.4 networks

    NARCIS (Netherlands)

    Zhang, Y.; Shu, F.

    2009-01-01

    To address system goodput and energy efficiency enhancement, this paper studies packet size optimization for IEEE 802.15.4 networks. Taking into account of the CSMA-CA contention, protocol overhead, and channel condition, new analytical models are proposed to calculate the goodput and the energy con

  14. Quality of Service Policy for IEEE 802.11 Networks with Service Rate Selection based on Fairness Index

    Directory of Open Access Journals (Sweden)

    L. T.M. Mota

    2011-01-01

    Full Text Available Problem statement: The IEEE802.11 standard states that all stations have the same probability of accessing the network, but does not consider important parameters such as transmission rates and signal-to-noise ratios. However, these networks present an anomaly that allows a station with a low transmission rate to use the communication channel for a long time. Approach: In this context, this study presents a Quality of Service (QoS policy, based on the implementation of the IEEE802.11e standard, that aims to keep or find the most fair scenario for IEEE802.11 networks. Hence, an algorithm for determining a fairness index is proposed based on physical parameters such as connection rates, service types and necessary conditions for the communication service. Results: The results obtained using the NS2 simulation software show that the proposed QoS policy was able to improve the network throughput or, at least, to keep a condition similar to the original one, when the proposed policy was not applied. Conclusion: All simulated scenarios presented a network performance gain or, at least, a similar result when compared to the results obtained when the IEEE802.11 standard was applied.

  15. Architectural and Functional Design and Evaluation of E-Learning VUIS Based on the Proposed IEEE LTSA Reference Model.

    Science.gov (United States)

    O'Droma, Mairtin S.; Ganchev, Ivan; McDonnell, Fergal

    2003-01-01

    Presents a comparative analysis from the Institute of Electrical and Electronics Engineers (IEEE) Learning Technology Standards Committee's (LTSC) of the architectural and functional design of e-learning delivery platforms and applications, e-learning course authoring tools, and learning management systems (LMSs), with a view of assessing how…

  16. Energy Consumption Model and Measurement Results for Network Coding-enabled IEEE 802.11 Meshed Wireless Networks

    DEFF Research Database (Denmark)

    Paramanathan, Achuthan; Rasmussen, Ulrik Wilken; Hundebøll, Martin

    2012-01-01

    This paper presents an energy model and energy measurements for network coding enabled wireless meshed networks based on IEEE 802.11 technology. The energy model and the energy measurement testbed is limited to a simple Alice and Bob scenario. For this toy scenario we compare the energy usages...

  17. IEEE 802.11 Networks: A Simple Model Geared Towards Offloading Studies and Considerations on Future Small Cells

    DEFF Research Database (Denmark)

    Garcia, Luis Guilherme Uzeda; Rodriguez, Ignacio; Catania, Davide

    2013-01-01

    WiFi is the prevalent wireless access technology in local area deployments and is expected to play a major role in a mobile operator’s data offloading strategy. As a result, having simple tools that are able to assess the offloading potential of IEEE 802.11 networks is vital. In this paper, we...

  18. Comparison of Analytical and Measured Performance Results on Network Coding in IEEE 802.11 Ad-Hoc Networks

    DEFF Research Database (Denmark)

    Zhao, Fang; Médard, Muriel; Hundebøll, Martin

    2012-01-01

    Network coding is a promising technology that has been shown to improve throughput in wireless mesh networks. In this paper, we compare the analytical and experimental performance of COPE-style network coding in IEEE 802.11 ad-hoc networks. In the experiments, we use a lightweight scheme called...

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

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2010-01-01

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

  20. AVSS 2007: IEEE International Conference onAdvanced Video and Signal based Surveillance, London, UK, September 2007

    DEFF Research Database (Denmark)

    Fihl, Preben

    This technical report will cover the participation in the IEEE International Conference on Advanced Video and Signal based Surveillance in September 2007. The report will give a concise description of the most relevant topics presented at the conference, focusing on the work related to the HERMES...

  1. Spectrum-efficient multi-channel design for coexisting IEEE 802.15.4 networks: A stochastic geometry approach

    KAUST Repository

    Elsawy, Hesham

    2014-07-01

    For networks with random topologies (e.g., wireless ad-hoc and sensor networks) and dynamically varying channel gains, choosing the long term operating parameters that optimize the network performance metrics is very challenging. In this paper, we use stochastic geometry analysis to develop a novel framework to design spectrum-efficient multi-channel random wireless networks based on the IEEE 802.15.4 standard. The proposed framework maximizes both spatial and time domain frequency utilization under channel gain uncertainties to minimize the number of frequency channels required to accommodate a certain population of coexisting IEEE 802.15.4 networks. The performance metrics are the outage probability and the self admission failure probability. We relax the single channel assumption that has been used traditionally in the stochastic geometry analysis. We show that the intensity of the admitted networks does not increase linearly with the number of channels and the rate of increase of the intensity of the admitted networks decreases with the number of channels. By using graph theory, we obtain the minimum required number of channels to accommodate a certain intensity of coexisting networks under a self admission failure probability constraint. To this end, we design a superframe structure for the coexisting IEEE 802.15.4 networks and a method for time-domain interference alignment. © 2002-2012 IEEE.

  2. Analyzing the Engineering Educational Research in Spain: A Global Vision through the Awards of CESEI-IEEE

    Science.gov (United States)

    Plaza, I.; Arcega, F.; Castro, M.; Llamas, M.

    2011-01-01

    CESEI is the acronym of the Spanish Chapter of the Education Society of IEEE (the Institute of Electric and Electronics Engineers). Every year, the CESEI awards a prize for the best doctoral thesis and FDP (final (master) degree projects) about education. The thesis or the project must be developed in the areas of electrical engineering,…

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

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2009-01-01

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

  4. Uplink capacity of multi-class IEEE 802.16j relay networks with adaptive modulation and coding

    DEFF Research Database (Denmark)

    Wang, Hua; Xiong, C; Iversen, Villy Bæk

    2009-01-01

    The emerging IEEE 802.16j mobile multi-hop relay (MMR) network is currently being developed to increase the user throughput and extend the service coverage as an enhancement of existing 802.16e standard. In 802.16j, the intermediate relay stations (RSs) help the base station (BS) communicate...

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

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2009-01-01

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

  6. Performance evaluation aodv, dymo, olsr and zrpad hoc routing protocol for ieee 802.11 mac and 802.11 dcf in vanet using qualnet

    CERN Document Server

    Sharma, Manish

    2012-01-01

    In VANET high speed is the real characteristics which leads to frequent breakdown, interference etc. Therefore Performance of adhoc routing protocols is helpful to improve the Quality of Service (QOS). In this paper we studied various adhoc routing protocols, Reactive, Proactive & Hybrid, taking in to consideration parameters like speed, altitude, mobility etc in real VANET scenario. The AODV and DYMO (Reactive), OLSR (Proactive) and ZRP (hybrid) protocols are compared for IEEE 802.11(MAC) and IEEE 802.11(DCF) standard using Qualnet as a Simulation tool. Since IEEE 802.11, covers both physical and data link layer. Hence performance of the protocols in these layers helps to make a right selection of Protocol for high speed mobility. Varying parameters of VANET shows that in the real traffic scenarios proactive protocol performs more efficiently for IEEE 802.11 (MAC) and IEEE 802.11(DCF).

  7. Real-Time Station Grouping under Dynamic Traffic for IEEE 802.11ah.

    Science.gov (United States)

    Tian, Le; Khorov, Evgeny; Latré, Steven; Famaey, Jeroen

    2017-07-04

    IEEE 802.11ah, marketed as Wi-Fi HaLow, extends Wi-Fi to the sub-1 GHz spectrum. Through a number of physical layer (PHY) and media access control (MAC) optimizations, it aims to bring greatly increased range, energy-efficiency, and scalability. This makes 802.11ah the perfect candidate for providing connectivity to Internet of Things (IoT) devices. One of these new features, referred to as the Restricted Access Window (RAW), focuses on improving scalability in highly dense deployments. RAW divides stations into groups and reduces contention and collisions by only allowing channel access to one group at a time. However, the standard does not dictate how to determine the optimal RAW grouping parameters. The optimal parameters depend on the current network conditions, and it has been shown that incorrect configuration severely impacts throughput, latency and energy efficiency. In this paper, we propose a traffic-adaptive RAW optimization algorithm (TAROA) to adapt the RAW parameters in real time based on the current traffic conditions, optimized for sensor networks in which each sensor transmits packets with a certain (predictable) frequency and may change the transmission frequency over time. The TAROA algorithm is executed at each target beacon transmission time (TBTT), and it first estimates the packet transmission interval of each station only based on packet transmission information obtained by access point (AP) during the last beacon interval. Then, TAROA determines the RAW parameters and assigns stations to RAW slots based on this estimated transmission frequency. The simulation results show that, compared to enhanced distributed channel access/distributed coordination function (EDCA/DCF), the TAROA algorithm can highly improve the performance of IEEE 802.11ah dense networks in terms of throughput, especially when hidden nodes exist, although it does not always achieve better latency performance. This paper contributes with a practical approach to optimizing

  8. IEEE 802.11p协议数据收发控制器的状态仿真%Simulation of States for Protocol Data Transceiver Controller Based on IEEE 802.11p

    Institute of Scientific and Technical Information of China (English)

    阮峥

    2015-01-01

    无线接入技术应用的广泛拓展,IEEE 802.11p作为针对快速移动环境的无线接入而产生.该文研究了该协议物理层数据帧的组帧原理、收发控制协议,最后使用Verilog硬件描述语言(HDL)在Altera QuartusⅡ环境下仿真实现了该协议下的数据帧收发控制器.%With the expansion of application range of wireless access, IEEE 802.11p emerges as protocol adapted to the environ-ment of fast moving. This paper studies principle of data frame and control protocol of physical layer, and finally simulations for transceiver controller are conducted with Verilog hardware design language under Altera QaurtusⅡ.

  9. 一种IEEE 802.11s树型网络的PREQ广播风暴抑制方案%Scheme to reduce broadcast storm of PREQ in IEEE 802.11 s tree network

    Institute of Scientific and Technical Information of China (English)

    游波; 牟荣增; 阎跃鹏

    2012-01-01

    To reduce the broadcast storm of PREQ caused by simply flooding of PREQ to maintain routes between leaf nodes in tree network based on IEEE 802.11s, this paper proposed a new scheme to limit the broadcast region of PREQ based on the table-driven routing in HWMP. In this scheme, one leaf node set the TTL of PREQ according to the hop count in its route to the root node, which limited the delivery distance of PREQ and decreased the number of redundant PREQ. Experiment shows that compared with IEEE 802. 11s, this new scheme can effectively reduce the costs for routing and increase the network throughput.%在IEEE 802.11s的树型网络中,为了解决子节点之间洪泛PREQ维护路由时引发的PREQ广播风暴问题,基于HWMP的表驱动路由,提出了一种限制PREQ广播范围的广播风暴抑制方案.在该方案中,子节点根据自己到根节点的路由跳数设置PREQ的TTL,缩小了PREQ的传输距离,降低了冗余PREQ的数量.实验结果表明,与IEEE 802.11 s相比,本方案有效地减小了网络中的路由开销,提高了网络吞吐量.

  10. 基于IEEE 802.11n无线局域网系统的符号同步%Symbol timing synchronization for IEEE 802.11n WLAN systems

    Institute of Scientific and Technical Information of China (English)

    方元

    2013-01-01

    IEEE 802.1 1n Wireless LAN standards use the cyclic shift diversity (CSD) scheme in order to avoid unnecessary beamforming,but the scheme makes barriers to the symbol timing synchronization,causes the pseudo multipoth problem in symbol timing synchronization.Aiming at this problem,this paper proposes a novel synchronization method using the local training sequence shift superposition correlation.Through the simulation of IEEE 802.11n Wireless LAN system,to compare the novel method to the previous method.Proving the verification of the synchronization method is practical finally,it can improve the synchronization accuracy greatly,makes the symbol synchronization error in the 2 sample points.%IEEE 802.1 1n无线局域网标准为了避免不必要的波束成型采用了循环移位机制,该机制对符号同步造成障碍,使得符号同步产生所谓的假多径问题.针对这个问题,本文提出了一种采用移位叠加的本地训练序列互相关的同步方法.通过时IEEE 802.11n无线局域网系统进行建模仿真,对新提出的方法和前人所提出的方法进行比较.最终验证该同步方法具有实用性,能够大幅度的提升同步的精度,使得符号同步的定位误差控制在2个采样点之内.

  11. Analysis of Video Transmission Characteristics of Wirelss Local Area Network over IEEE802.11b%IEEE802.11b无线局域网视频传输特性分析

    Institute of Scientific and Technical Information of China (English)

    王峰博; 崔慧娟

    2004-01-01

    论述了目前成熟的无线局域网(WLAN)技术的特点,在此基础上对IEEE802.11b进行IP组播的传输特性进行研究与分析,为在无线局域网上进行视频实时传输提供信道的应用特性.

  12. 计数器驱动的IEEE 802.16e休眠模式研究%Improved counter-driven sleep mode for IEEE 802.16e

    Institute of Scientific and Technical Information of China (English)

    杨磊磊; 黎海涛

    2014-01-01

    为了降低移动终端的能量消耗以及对基站空口资源的占用,IEEE 802.16e标准定义了休眠模式。针对计数器驱动的休眠工作模式与IEEE 802.16e标准不能较好兼容的局限,提出了改进的计数器驱动休眠算法,建立马尔可夫链模型分析其性能,推导出平均时延、平均功耗与计数器门限值等参数之间的内在关系,在此基础上给出了不同QoS要求的连接所对应的参数设置方案。%In order to save the energy consumption of the mobile stations and reduce the air interface resource utilization of serving base stations, the sleep mode is adopted in IEEE 802.16e standard. The counter-driven sleep mode algorithm has the advantage of simple and effectiveness, whereas it is difficult to be implemented in IEEE 802.16e system. To elimi-nate this limitation, the improved counter-driven sleep mode algorithm is proposed. The performance of the improved sleep method is evaluated based on the derivation of Markov’s analysis model. The relationship among the average energy consumption, average delivery latency and the threshold values of counters is investigated. The threshold parameters con-figuration scheme of counter for different QoS connection is presented.

  13. Adaptive Deficit IEEE 802. 11 PCF Polling Scheme Based on NS-2%基于NS-2的自适应差额IEEE 802.11 PCF轮询机制

    Institute of Scientific and Technical Information of China (English)

    廖勇; 杨士中; 徐昌彪

    2009-01-01

    在研究无线局域网IEEE 802.11标准点协调功能PCF(Point Coordination Function)机制不足的情况下,针对其中Round Robin轮询机制存在的QoS(Quality of Service)不能得到有效保障的问题,提出了一套自适应差额轮询调度算法解决方案,阐述了算法的核心思想,介绍了调度机制的执行过程,并且通过修改PCF源代码,在网络模拟器NS-2平台上对算法进行了脚本模拟.实验结果表明,自适应差额IEEE 802.11 PCF轮询算法比传统的Round Robin算法在端到端延迟、系统吞吐量和包延迟等QoS服务性能方面都有显著的提高.%A adaptive deficit polling scheme was put forward which aimed to guarantee the QoS(Quality of Service) of Round Robin polling scheme under the condition of inefficient WLAN IEEE 802.11 PCF (Point Coordination Function) mechanism.The core idea of this scheme was described as well as the processing of adjustment mechanism, and it was simulated on the platform of network simulator NS-2 by revising PCF source code.The results indicated that adaptive deficit IEEE 802.11 PCF polling scheme is prior to Round Robin scheme with its better performance of QoS(Quality of Service)which includes end-to-end delay, system throughput, packet delay, etc.

  14. Adaptive Sleep Scheduling for Health Monitoring System Based on the IEEE 802.15.4 Standard

    Directory of Open Access Journals (Sweden)

    Nurul Fahmi

    2016-08-01

    Full Text Available In the recent years, Wireless Sensor Networks (WSNs have become a very popular technology for research in various fields. One of the technologies which is developed using WSN is environmental health monitoring. However, there is a problem when we want to optimize the performance of the environmental health monitoring such as the limitation of the energy. In this paper, we proposed a method for the environmental health monitoring using the fuzzy logic approach according to the environmental health conditions. We use that condition to determine the sleep time in the system based on IEEE 802.15.4 standard protocol. The main purpose of this method is to extend the life and minimize the energy consumption of the battery. We implemented this system in the real hardware test-bed using temperature, humidity, CO and CO2 sensors. We compared the performance without sleep scheduling, with sleep scheduling and adaptive sleep scheduling. The power consumption spent during the process of testing without sleep scheduling is 52%, for the sleep scheduling is 13%, while using the adaptive sleep scheduling is around 7%. The users also can monitor the health condition via mobile phone or web-based application, in real-time anywhere and anytime.

  15. RWBO(pd, w): A Novel Backoff Algorithm for IEEE 802.11 DCF

    Institute of Scientific and Technical Information of China (English)

    Yun Li; Ke-Ping Long; Wei-Liang Zhao; Feng-Rui Yang

    2005-01-01

    The Probability Distribution of Slot Selection (PDoSS) of IEEE 802.11 DCF is extremely uneven, which makes the packet collision probability very high. In this paper, the authors explore how to make the stations select the slots uniformly, and give an RWBO(pd,w) algorithm for 802.11 DCF to make the PDoSS even and decrease the packet collision probability. A Markov model is given to analyze the PDoSS of RWBO(pd, ω). The performance of RWBO(pd, ω) is evaluated by simulation in terms of saturation throughput and packet collision probability. The simulation results indicate that RWBO(pd, ω) can decrease the packet contention probability to a large extent, and utilize the channel more efficiently as compared to the 802.11 DCF. Moreover, the relation between saturation throughput and walking probability (Pd), the relation between saturation throughput and contention windows (ω), the relation between packet collision probability and walking probability (pd), and the relation between packet collision probability and contention windows (ω) are analyzed.The analysis indicates that RWBO(pd, ω) has some remarkable features: its saturation throughout keeps high and packet collision probability keeps very low (under 0.1) in a large range of pd and ω, which allow users to configure pd and ω more flexibly.

  16. BER IMPROVEMENT OF WIRELESS LAN IEEE 802.11 STANDARD USING WAVELET PACKET TRANSFORMS

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    2012-09-01

    Full Text Available High data rates and spectral efficiency is the main requirements for wireless communication systems. Orthogonal Frequency Division Multiplexing (OFDM is a special form of multi carrier transmission used to achieve high data rates of the various WLAN standards. WLAN uses an Inverse Fast Fourier Transform (IFFT at the transmitter to modulate a high bit-rate signal onto a number of carriers and ensure orthogonality between the carriers. The FFT-OFDM has a disadvantage that it is inherently inflexible and requires a complex IFFT core. Recently, Wavelet Packet Transform is proposed as an alternate to FFT. It is a multiplexing method in which data is assigned to wavelet sub bands having different time and frequency resolutions. This paper presents a BER analysis of Fourier-based OFDM (FFT-OFDM and Wavelet Packet based OFDM (WPT-OFDM in WLAN standard (IEEE 802.11a. The performance of FFT and WPT OFDM for various modulation techniques such as PSK, DPSK and QAM for varying values of M was evaluated in AWGN Channel.

  17. A Client-Assisted and Distributed Channel Assignment Scheme For Dense IEEE 802.11 WLAN

    Directory of Open Access Journals (Sweden)

    Dr. Vineeta Saxena Nigam

    2014-04-01

    Full Text Available Due to huge popularity, the WLANs (Wireless Local Area Networks have gained in recent years, especially based on IEEE 802.11 family of standards, dense deployment of AP (Access Point can be found in many places. However, these dense deployments can severely affect the aggregate throughput of the network due increased contention and interference between different APs using same channel. This often leads to decreased overall throughput of a local wireless network, such as in a university campus or city-wide Wi-Fi network. In this paper, a simple client-assisted and distributed channel assignment scheme has been proposed for minimizing such adverse affects of interference in dense WLANs. Client-assisted means the resources of clients are also used for measurements of some parameters to increase the performance of the scheme. Distributed schemes are those schemes which can easily be used where AP belongs to different owners and administrative domains. This scheme will be shown to have better throughput performance than other prominent distributed schemes through simulation results.

  18. On the Optimization of the IEEE 802.11 DCF: A Cross-Layer Perspective

    Directory of Open Access Journals (Sweden)

    Massimiliano Laddomada

    2010-01-01

    Full Text Available This paper is focused on the problem of optimizing the aggregate throughput of the distributed coordination function (DCF employing the basic access mechanism at the data link layer of IEEE 802.11 protocols. We consider general operating conditions accounting for both nonsaturated and saturated traffic in the presence of transmission channel errors, as exemplified by the packet error rate . The main clue of this work stems from the relation that links the aggregate throughput of the network to the packet rate of the contending stations. In particular, we show that the aggregate throughput ( presents two clearly distinct operating regions that depend on the actual value of the packet rate with respect to a critical value , theoretically derived in this work. The behavior of ( paves the way to a cross-layer optimization algorithm, which proved to be effective for maximizing the aggregate throughput in a variety of network operating conditions. A nice consequence of the proposed optimization framework relies on the fact that the aggregate throughput can be predicted quite accurately with a simple, yet effective, closed-form expression. Finally, theoretical and simulation results are presented in order to unveil, as well as verify, the key ideas.

  19. The Impact of Dynamic RTS Threshold Adjustment for IEEE 802.11 MAC Protocol

    Directory of Open Access Journals (Sweden)

    Mostafa Mjidi

    2009-01-01

    Full Text Available In recent years, wireless technologies and application received great attention. The Medium Access Control (MAC protocol is the main element that determines the efficiency in sharing the limited communication bandwidth of the wireless channel in wireless local area networks (WLANs. IEEE 802.11 introduced the optional RTS/CTS handshaking mechanism to address the hidden terminal problem as well as to reduces the chance of collision in case of higher node density and traffic. RTS Threshold (RT determines when RTS/CTS mechanism should be used and proved to be an important parameter for performance characteristics in data transmission. We first investigate to find a meaningful threshold value according to the network situation and determine the impact of using or disengaging the RTS/CTS optional mechanism and dynamically adjust the RTS Threshold to maximize data transmission. The results show a significant improvement over existing CSMA/CA and RTS/CTS schemes. Our adaptive scheme performed even better when data rate increases. We verify our proposed scheme both analytically and with extensive network simulation using ns-2.

  20. Signaling-Free Max-Min Airtime Fairness in IEEE 802.11 Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Youngsoo Lee

    2016-01-01

    Full Text Available We propose a novel media access control (MAC protocol, referred to as signaling-free max-min airtime fair (SMAF MAC, to improve fairness and channel utilization in ad hoc networks based on IEEE 802.11 wireless local area networks (WLANs. We introduce busy time ratio (BTR as a measure for max-min airtime fairness. Each node estimates its BTR and adjusts the transmission duration by means of frame aggregation and fragmentation, so that it can implicitly announce the BTR to neighbor nodes. Based on the announced BTR, each of the neighbor nodes controls its contention window. In this way, the SMAF MAC works in a distributed manner without the need to know the max-min fair share of airtime, and it does not require exchanging explicit control messages among nodes to attain fairness. Moreover, we successfully incorporate the hidden node detection and resolution mechanisms into the SMAF MAC to deal with the hidden node problem in ad hoc networks. The simulation results confirm that the SMAF MAC enhances airtime fairness without degrading channel utilization, and it effectively resolves several serious problems in ad hoc networks such as the starvation, performance anomaly, and hidden node problems.

  1. Achievable Throughput-Based MAC Layer Handoff in IEEE 802.11 Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Wu Haitao

    2009-01-01

    Full Text Available We propose a MAC layer handoff mechanism for IEEE 802.11 Wireless Local Area Networks (WLAN to give benefit to bandwidth-greedy applications at STAs. The proposed mechanism determines an optimal AP with the maximum achievable throughput rather than the best signal condition by estimating the AP's bandwidth with a new on-the-fly measurement method, Transient Frame Capture (TFC, and predicting the actual throughput could be achieved at STAs. Since the TFC is employed based on the promiscuous mode of WLAN NIC, STAs can avoid the service degradation through the current associated AP. In addition, the proposed mechanism is a client-only solution which does not require any modification of network protocol on APs. To evaluate the performance of the proposed mechanism, we develop an analytic model to estimate reliable and accurate bandwidth of the AP and demonstrate through testbed measurement with various experimental study methods. We also validate the fairness of the proposed mechanism through simulation studies.

  2. Fairness Provision in the IEEE 802.11e Infrastructure Basic Service Set

    CERN Document Server

    Keceli, Feyza; Ayanoglu, Ender

    2007-01-01

    Most of the deployed IEEE 802.11e Wireless Local Area Networks (WLANs) use infrastructure Basic Service Set (BSS) in which an Access Point (AP) serves as a gateway between wired and wireless domains. We present the unfairness problem between the uplink and the downlink flows of any Access Category (AC) in the 802.11e Enhanced Distributed Channel Access (EDCA) when the default settings of the EDCA parameters are used. We propose a simple analytical model to calculate the EDCA parameter settings that achieve weighted fair resource allocation for all uplink and downlink flows. We also propose a simple model-assisted measurement-based dynamic EDCA parameter adaptation algorithm. Moreover, our dynamic solution addresses the differences in the transport layer and the Medium Access Control (MAC) layer interactions of User Datagram Protocol (UDP) and Transmission Control Protocol (TCP). We show that proposed Contention Window (CW) and Transmit Opportunity (TXOP) limit adaptation at the AP provides fair UDP and TCP ac...

  3. Green Frame Aggregation Scheme for IEEE 802.11n Networks

    KAUST Repository

    Alaslani, Maha S.

    2015-04-01

    Frame aggregation is one of the major MAC layer enhancements in the IEEE 802.11 family that boosts the network throughput performance. It aims to achieve higher throughput by transmitting huge amount of data in a single transmit oppor- tunity. With the increasing awareness of energy e ciency, it has become vital to rethink about the design of such frame aggregation protocol. Aggregation techniques help to reduce energy consumption over ideal channel conditions. However, in a noisy channel environment, a new energy-aware frame aggregation scheme is required. In this thesis, a novel Green Frame Aggregation (GFA) scheduling scheme has been proposed and evaluated. GFA optimizes the aggregate size based on channel quality in order to minimize the consumed energy. GFA selects the optimal sub-frame size that satisfies the loss constraint for real-time applications as well as the energy budget of the ideal channel situations. The design, the implementation, and evaluation of GFA using testbed deployment is done. The experimental analysis shows that GFA outperforms the conventional frame aggregation methodology in terms of energy e ciency by about 6⇥ in the presence of severe interference conditions. Moreover, GFA also outperforms the static frame sizing method in terms of network goodput and maintains almost the same end- to-end latency.

  4. Delay Analysis of an Enhancing IEEE 802.11 Point Coordination Function MAC Protocol

    Directory of Open Access Journals (Sweden)

    Zheng Guan

    2014-05-01

    Full Text Available The widespread use of multimedia networking applications has brought more requirements to the network, creating a need for end-to-end Quality of Service (QoS. The contention-free Point Coordination Function (PCF with Round Robin scheme, where the Access Point controls all transmissions based on a polling mechanism, is defined in IEEE 802.11 standard to provide QoS service. This network suffers from inefficiency in the delay sensitive traffic and makes. It is difficult to provide priority-differentiated service. In this paper, a useful enhance mechanism is derived from a two-level-polling model with a parallel scheme between the polling and switch over processes. We consider two different polling schemes according to station classify: key station and normal station. This mechanism allows for a delay guarantee as well as priority service. An analytical is developed for evaluating the queuing length for the station and waiting time for the packets at nodes. Based on this model, we achieve several closed-form expressions for mean cycle time, mean queue length and mean waiting time. To verify the correctness of our analytical model, we also develop a simulator for the 802.11 PCF MAC. The simulation results well match the analytical results.

  5. WiPal: Efficient Offline Merging of IEEE 802.11 Traces

    CERN Document Server

    Claveirole, Thomas

    2008-01-01

    Merging wireless traces is a fundamental step in measurement-based studies involving multiple packet sniffers. Existing merging tools either require a wired infrastructure or are limited in their usability. We propose WiPal, an offline merging tool for IEEE 802.11 traces that has been designed to be efficient and simple to use. WiPal is flexible in the sense that it does not require any specific services, neither from monitors (like synchronization, access to a wired network, or embedding specific software) nor from its software environment (e.g. an SQL server). We present WiPal's operation and show how its features - notably, its modular design - improve both ease of use and efficiency. Experiments on real traces show that WiPal is an order of magnitude faster than other tools providing the same features. To our knowledge, WiPal is the only offline trace merger that can be used by the research community in a straightforward fashion.

  6. Home healthcare settop-box for senior chronic care using ISO/IEEE 11073 PHD standard.

    Science.gov (United States)

    Lim, Joon-Ho; Park, Chanyong; Park, Soo-Jun

    2010-01-01

    As the number of seniors with chronic disease increases, the need of home healthcare settop-box is increased to manage their chronic disease in their home environment. Using the home healthcare settop-box, the patients can regularly check their health data, and finally, it can lead the decrease of medical expenses. For the home healthcare settop-box, the most important factor is the standard compatibility, which can interoperate with standard devices of any other companies. In this paper, we propose a home healthcare settop-box using ISO/IEEE 11073 PHD standard. It collects health data according to the PHD standard, and provides a chronic-care service based on the collected data. The proposed settop-box is connected with 3 devices of weigh scale, blood pressure monitor, and glucose meter, and tested at 10 homes for a month. Lastly, the proposed settop-box can be used for various healthcare services such as Google Health and Telemedicine Services using a healthcare platform server.

  7. Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests

    Directory of Open Access Journals (Sweden)

    Xingjian Ding

    2016-06-01

    Full Text Available Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR, the received signal strength indicator (RSSI and the link quality indicator (LQI under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments.

  8. A Novel Current-Mode Differential Transconductance LNA for IEEE 802.11a Application

    Science.gov (United States)

    Tu, Yuxiang; Wang, Chunhua; Chen, Lei; Wu, Zhangbin; Zhang, Guangxiang

    2012-03-01

    In this paper, a novel current-mode differential transconductance low noise amplifier (LNA) designed in the chartered 0.18 μm CMOS technology is proposed to realize the receiver front-end. The proposed LNA frequency ranges from 4.7 GHz to 6 GHz,mainly targeting at IEEE802.11a application. It utilizes two stage structure, with a PMOS current-mirrorr using inductive series peaking technique to achieve optimized current output. The noise performance is improved through the use of a gm-boosting technique, while the gain performance is improved and power consumption is saved by using current-reused technique. Measured results demonstrate that the circuit provides flat transconductance gain higher than 17.0 dB, noise figure lower than 2.31 dB and low operating voltage of 0.85 V in frequency band. A comparison with other LNAs in similar and nearby frequency bands shows the proposed LNA has advantages of higher gain, lower noise figure and better other performances.

  9. Impact of Vehicle Mobility on Performance of Vehicular Ad Hoc Network IEEE 1609.4

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    M. Ahyar

    2014-01-01

    Full Text Available Vehicular Ad hoc Network (VANET is a new communications system for moving vehicles at high speed, which are equipped with wireless communication devices, together with additional wireless roadside units, enabling communications among nearby vehicles (vehicle-to-vehicle communication as well as between vehicles and nearby fixed equipment (vehicle-to-infrastructure communication. Inter-vehicular communications aim to improve road traffic safety and provide multimedia services. VANET has become an important communication infrastructure for the Intelligent Transportation System (ITS. In this work we have studied the impact of vehicle mobility on the quality of service in VANET based on IEEE 1609.4. The performance of this network is evaluated through exhaustive simulations using the VanetMobiSim and Network Simulator-NS2 under different parameters like delay, packet delivery ratio, packet loss and throughput. The simulation results are obtained when vehicles are moving according to a freeway mobility model is significantly different from results based on Manhattan model. When the Manhattan model is used, there is an increase in the average end-to-end delay and packet loss.

  10. Time allocation scheme in IEEE 802.15.3 TDMA mechanism

    Institute of Scientific and Technical Information of China (English)

    LIU Xin; DAI Qiong-hai; WU Qiu-feng

    2006-01-01

    In network with a shared channel in TDMA mechanism, it is a core issue to effectively allocate channel time to provide service guarantees for flows with QoS requirements. This paper proposes a simple and efficient time allocation scheme called MES-ESRPT (MCTA at the End of Superframe-Enhanced Shortest Remaining Processing Time) for delay-sensitive VBR traffic in accordance with IEEE 802.15.3 standard. In this algorithm, PNC (piconet coordinator) allocates one MCTA (Management Channel Time Allocation) for each stream which is the process of communication at the end of superframe. During the MCTA period, each transmitter should report current fragments number of the first MSDU (MAC Service Data Unit) and the fragments number of the remainder MSDUs to PNC. In the next superframe, PNC firstly allocates part CTAs (Channel Time Allocation) for each stream based on the remainder fragments number of the first MSDU by SRPT rule, then allocates remainder CTAs for each stream based on all fragments number of remainder MSDUs by the same SRPT rule. Simulation results showed that our proposed MES-ESRPT method achieves significantly better performance in QoS for multimedia streams compared to the existing schemes.

  11. An empirical evaluation of bufferbloat in IEEE 802.11n wireless networks

    KAUST Repository

    Showail, Ahmad

    2014-04-06

    In this paper, we analyze the impact of large, persistently-full buffers (`bufferbloat\\') on various network dynamics in IEEE 802.11n wireless networks. Bufferbloat has mostly been studied in the context of wired networks. We study the impact of bufferbloat on a variety of wireless network topologies, including wireless LAN (WLAN) and multi-hop wireless networks. Our results show that a single FTP transfer between two Linux wireless hosts can saturate the buffers in the network stack, leading to RTT delays exceeding 4.5 s in multi-hop configurations. We show that well-designed Aggregate MAC Protocol Data Unit (A-MPDU) MAC-layer frame aggregation can reduce RTT delays while simultaneously increasing network throughput. However, additional measures may still be required to meet the constraints of real-time flows (such as VoIP). Our experiments show that large buffers can deteriorate the fairness in rate allocation in parking lot based multi-hop networks.

  12. IEEE 802.11-Based Wireless Sensor System for Vibration Measurement

    Directory of Open Access Journals (Sweden)

    Yutaka Uchimura

    2010-01-01

    Full Text Available Network-based wireless sensing has become an important area of research and various new applications for remote sensing are expected to emerge. One of the promising applications is structural health monitoring of building or civil engineering structure and it often requires vibration measurement. For the vibration measurement via wireless network, time synchronization is indispensable. In this paper, we introduce a newly developed time synchronized wireless sensor network system. The system employs IEEE 802.11 standard-based TSF-counter and sends the measured data with the counter value. TSF based synchronization enables consistency on common clock among different wireless nodes. We consider the scale effect on synchronization accuracy and evaluated the effect by taking beacon collisions into account. The scalability issue by numerical simulations is also studied. This paper also introduces a newly developed wireless sensing system and the hardware and software specifications are introduced. The experiments were conducted in a reinforced concrete building to evaluate synchronization accuracy. The developed system was also applied for a vibration measurement of a 22-story steel structured high rise building. The experimental results showed that the system performed more than sufficiently.

  13. Adaptive RTS threshold for maximum network throughput in IEEE 802.11 DCF

    Science.gov (United States)

    Yan, Shaohu; Zhuo, Yongning; Wu, Shiqi; Guo, Wei

    2004-04-01

    The IEEE 802.11 medium access control (MAC) protocol provides shared access to wireless channel. Its primary MAC technique is called distributed coordination function (DCF) that includes two packet transmission schemes, namely, basic access and RTS/CTS access mechanisms. In a "hybrid" network combining the two schemes, packets with payload longer than a given threshold (RTS Threshold) are transmitted according to the RTS/CTS mechanism. Based on delicate mathematical model, the average time in a successful and unsuccessful transmission is analyzed in the assumption of idea channel. Then the relation of network saturation throughput and RTS threshold was found and expressed in theoretical formula. We present the numerical techniques to find out the optimum RTS threshold that can maximize the network capacity. An adaptive RTS threshold adjust algorithm (ARTA), with which a station can automatically adjust its RTS threshold to the current optimum value, is also presented in detail. A special procedure is also developed to help ARTA in determination of station numbers. All theoretical analysis and algorithm are validated through computer simulation.

  14. Performance Analysis of IEEE 802.16d using Forward Error Correction

    Directory of Open Access Journals (Sweden)

    Venkatesh Sekar

    2011-01-01

    Full Text Available Problem statement: Worldwide Interoperability for Microwave Access is the broadband wireless technology for terrestrial broadcast services in Metropolitan Area Networks. This BWA technology is based on Orthogonal Frequency Division Multiplex (OFDM technology and considers the radio frequency range up to 2-11 GHz and 10-66 GHz. The objective of this research work is the performance analysis of AWGN, SUI-1 and SUI-2 fading channels in IEEE802.16d using FEC to improving BER at different SNR under QPSK digital modulation technique. Approach: Channel coding part is composed of three steps randomization, Forward Error Correction (FEC and interleaving. FEC is done in two phases through the outer Reed Solomon (RS and inner Convolutional Code (CC. The implementation and analysis will be made on using MATLAB simulation. Results: In this analysis the Bit Error Rate under QPSK modulation technique over AWGN, SUI-1 and SUI-2 fading channel with encoder for a SNR value of 5dB but in the case of without encoder is found SNR value of 9dB,10dB and 8dB respectively. Conclusion: It was concluded that all the three fading channel had same SNR with FEC .The optional Block Turbo Coding (BTC can be implemented to enhance the performance of FEC.

  15. Fair and Efficient TCP Access in the IEEE 802.11 Infrastructure Basic Service Set

    CERN Document Server

    Keceli, Feyza; Ayanoglu, Ender

    2008-01-01

    When the stations in an IEEE 802.11 infrastructure Basic Service Set (BSS) employ Transmission Control Protocol (TCP) in the transport layer, this exacerbates per-flow unfair access which is a direct result of uplink/downlink bandwidth asymmetry in the BSS. We propose a novel and simple analytical model to approximately calculate the per-flow TCP congestion window limit that provides fair and efficient TCP access in a heterogeneous wired-wireless scenario. The proposed analysis is unique in that it considers the effects of varying number of uplink and downlink TCP flows, differing Round Trip Times (RTTs) among TCP connections, and the use of delayed TCP Acknowledgment (ACK) mechanism. Motivated by the findings of this analysis, we design a link layer access control block to be employed only at the Access Point (AP) in order to resolve the unfair access problem. The novel and simple idea of the proposed link layer access control block is employing a congestion control and filtering algorithm on TCP ACK packets...

  16. Optimizing Quality of Service Evaluation in IEEE 802.15.4 Networks

    Directory of Open Access Journals (Sweden)

    Anitha A

    2012-11-01

    Full Text Available Wireless Sensor Networks (WSNs comprise of groups of tiny sensor nodes that are deployed for collaborative missions such as environmental monitoring, target tracking and surveillance. Due to the miniature size of the nodes, they are typically deployed in large numbers and communicate via multiple hops through a wireless shared communication channel. The successful implementation of such networks is dependent on the enabling technologies (such as digital electronics and wireless communications, as well as the provisioning of Quality of Service (QoS in the network. While there have been many efforts in QoS provisioning in traditional networks such as the Internet and Mobile Ad Hoc Networks (MANETs, these networks have very different characteristics from that of WSNs. Consequently, the QoS models and protocols that have been designed for the Internet and MANETs cannot be directly applied to WSNs. The performance evaluation of quality of service parameters for WSNs based on IEEE 802.15.4 star and mesh topology. The performances have evaluated for varying traffic loads using Mobile Adhoc Network (MANET routing protocol in QualNet 4.5. The total energy consumption is used for performance metrics.

  17. Generalized Bianchi's Model of IEEE 802.11 Distributed Coordination Function

    CERN Document Server

    Yin, Dongjie; Lee, Tony T

    2011-01-01

    A widely adopted two-dimensional Markov chain model of the IEEE 802.11 DCF was introduced by Bianchi to characterize the backoff behavior of a single node under a saturated traffic condition. Using this approach, we propose a queuing model for the 802.11 DCF under a non-saturated traffic environment. The input buffer of each node is modeled as a Geo/G/1 queue, and the packet service time distribution is derived from a one-dimensional Markov chain of 802.11 DCF with the underlying scheduling algorithm. The DCF defines two access mechanisms, namely the Basic access mechanism and the request-to-send/clear-to-send (RTS/CTS) access mechanism. Based on our model, performance analyses of both schemes are studied with exponential backoff scheduling. Specifically, we obtain the characteristic equation of network throughput, the stable throughput region, and the bounded delay region. For both access schemes, the bounded delay region is a subset of the stable throughput region. Our results show that the RTS/CTS access m...

  18. An Enhanced Reservation-Based MAC Protocol for IEEE 802.15.4 Networks

    Science.gov (United States)

    Afonso, José A.; Silva, Helder D.; Macedo, Pedro; Rocha, Luis A.

    2011-01-01

    The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and support to a maximum of only seven devices. This paper presents eLPRT (enhanced Low Power Real Time), a new reservation-based MAC protocol that introduces several performance enhancing features in comparison to the GTS scheme. This MAC protocol builds on top of LPRT (Low Power Real Time) and includes various mechanisms designed to increase data transmission reliability against channel errors, improve bandwidth utilization and increase the number of supported devices. A motion capture system based on inertial and magnetic sensors has been used to validate the protocol. The effectiveness of the performance enhancements introduced by each of the new features is demonstrated through the provision of both simulation and experimental results. PMID:22163826

  19. On the Feasibility of Wireless Multimedia Sensor Networks over IEEE 802.15.5 Mesh Topologies.

    Science.gov (United States)

    Garcia-Sanchez, Antonio-Javier; Losilla, Fernando; Rodenas-Herraiz, David; Cruz-Martinez, Felipe; Garcia-Sanchez, Felipe

    2016-05-05

    Wireless Multimedia Sensor Networks (WMSNs) are a special type of Wireless Sensor Network (WSN) where large amounts of multimedia data are transmitted over networks composed of low power devices. Hierarchical routing protocols typically used in WSNs for multi-path communication tend to overload nodes located within radio communication range of the data collection unit or data sink. The battery life of these nodes is therefore reduced considerably, requiring frequent battery replacement work to extend the operational life of the WSN system. In a wireless sensor network with mesh topology, any node may act as a forwarder node, thereby enabling multiple routing paths toward any other node or collection unit. In addition, mesh topologies have proven advantages, such as data transmission reliability, network robustness against node failures, and potential reduction in energy consumption. This work studies the feasibility of implementing WMSNs in mesh topologies and their limitations by means of exhaustive computer simulation experiments. To this end, a module developed for the Synchronous Energy Saving (SES) mode of the IEEE 802.15.5 mesh standard has been integrated with multimedia tools to thoroughly test video sequences encoded using H.264 in mesh networks.

  20. An SNMP-based solution to enable remote ISO/IEEE 11073 technical management.

    Science.gov (United States)

    Lasierra, Nelia; Alesanco, Alvaro; García, José

    2012-07-01

    This paper presents the design and implementation of an architecture based on the integration of simple network management protocol version 3 (SNMPv3) and the standard ISO/IEEE 11073 (X73) to manage technical information in home-based telemonitoring scenarios. This architecture includes the development of an SNMPv3-proxyX73 agent which comprises a management information base (MIB) module adapted to X73. In the proposed scenario, medical devices (MDs) send information to a concentrator device [designated as compute engine (CE)] using the X73 standard. This information together with extra information collected in the CE is stored in the developed MIB. Finally, the information collected is available for remote access via SNMP connection. Moreover, alarms and events can be configured by an external manager in order to provide warnings of irregularities in the MDs' technical performance evaluation. This proposed SNMPv3 agent provides a solution to integrate and unify technical device management in home-based telemonitoring scenarios fully adapted to X73.

  1. Cross-layer TCP Performance Analysis in IEEE 802.11 Vehicular Environments

    Directory of Open Access Journals (Sweden)

    T. Janevski

    2014-06-01

    Full Text Available In this paper we provide a performance analysis of TCP in IEEE 802.11 vehicular environments for different well-known TCP versions, such as Tahoe, Reno, New Reno, Vegas, and Sack. The parameters of interest from the TCP side are the number of Duplicate Acknowledgements - DupAck, and the number of Delayed Acknowledgements - DelAck, while on the wireless network side the analyzed parameter is the interface queue - IFQ. We have made the analysis for the worst-case distance scenario for single-hop and worst-case multihop vehicular environments. The results show that the number of wireless hops in vehicular environments significantly reduces the TCP throughput. The best average performances considering all scenarios were obtained for TCP Vegas. However, the results show that the interface queue at wireless nodes should be at least five packets or more. On the other side, due to shorter distances in the vehicular wireless network, results show possible flexibility of using different values for the DupAck without degradation of the TCP throughput. On the other side, the introduction of the DelAck parameter provides enhancement in the average TCP throughput for all TCP versions.

  2. New IEEE 11073 Standards for interoperable, networked Point-of-Care Medical Devices.

    Science.gov (United States)

    Kasparick, Martin; Schlichting, Stefan; Golatowski, Frank; Timmermann, Dirk

    2015-08-01

    Surgical procedures become more and more complex and the number of medical devices in an operating room (OR) increases continuously. Today's vendor-dependent solutions for integrated ORs are not able to handle this complexity. They can only form isolated solutions. Furthermore, high costs are a result of vendor-dependent approaches. Thus we present a service-oriented device communication for distributed medical systems that enables the integration and interconnection between medical devices among each other and to (medical) information systems, including plug-and-play functionality. This system will improve patient's safety by making technical complexity of a comprehensive integration manageable. It will be available as open standards that are part of the IEEE 11073 family of standards. The solution consists of a service-oriented communication technology, the so called Medical Devices Profile for Web Services (MDPWS), a Domain Information & Service Model, and a binding between the first two mechanisms. A proof of this concept has been done with demonstrators of real world OR devices.

  3. ISO/IEEE 11073 PHD message generation toolkit to standardize healthcare device.

    Science.gov (United States)

    Lim, Joon-Ho; Park, Chanyong; Park, Soo-Jun; Lee, Kyu-Chul

    2011-01-01

    As senior population increases, various healthcare devices and services are developed such as fall detection device, home hypertension management service, and etc. However, to vitalize healthcare devices and services market, standardization for interoperability between device and service must precede. To achieve the standardization goal, the IEEE 11073 Personal Health Device (PHD) group has been standardized many healthcare devices, but until now there are few devices compatible with the PHD standard. One of main reasons is that it isn't easy for device manufactures to implement standard communication module by analyzing standard documents of over 600 pages. In this paper, we propose a standard message generation toolkit to easily standardize existing non-standard healthcare devices. The proposed toolkit generates standard PHD messages using inputted device information, and the generated messages are adapted to the device with the standard state machine file. For the experiments, we develop a reference H/W, and test the proposed toolkit with three healthcare devices: blood pressure, weighting scale, and glucose meter. The proposed toolkit has an advantage that even if the user doesn't know the standard in detail, the user can easily standardize the non-standard healthcare devices.

  4. Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests.

    Science.gov (United States)

    Ding, Xingjian; Sun, Guodong; Yang, Gaoxiang; Shang, Xinna

    2016-06-27

    Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments.

  5. IEEE-802.15.4-based low-power body sensor node with RF energy harvester.

    Science.gov (United States)

    Tran, Thang Viet; Chung, Wan-Young

    2014-01-01

    This paper proposes the design and implementation of a low-voltage and low-power body sensor node based on the IEEE 802.15.4 standard to collect electrocardiography (ECG) and photoplethysmography (PPG) signals. To achieve compact size, low supply voltage, and low power consumption, the proposed platform is integrated into a ZigBee mote, which contains a DC-DC booster, a PPG sensor interface module, and an ECG front-end circuit that has ultra-low current consumption. The input voltage of the proposed node is very low and has a wide range, from 0.65 V to 3.3 V. An RF energy harvester is also designed to charge the battery during the working mode or standby mode of the node. The power consumption of the proposed node reaches 14 mW in working mode to prolong the battery lifetime. The software is supported by the nesC language under the TinyOS environment, which enables the proposed node to be easily configured to function as an individual health monitoring node or a node in a wireless body sensor network (BSN). The proposed node is used to set up a wireless BSN that can simultaneously collect ECG and PPG signals and monitor the results on the personal computer.

  6. A Bi-Scheduler Algorithm for Frame Aggregation In IEEE 802.11N

    Directory of Open Access Journals (Sweden)

    Vanaja Ramaswamy

    2013-12-01

    Full Text Available IEEE 802.11n mainly aims to provide high throughput , reliability and good security over its other prev ious standards. The performance of 802.11n is very effec tive on the saturated traffic through the use of fr ame aggregation. But this frame aggregation will not ef fectively function in all scenarios. The main objec tive of this paper is to improve the throughput of the wire less LAN through effective frame aggregation using scheduler mechanism. The Bi-Scheduler algorithm pro posed in this article aims to segregate frames base d on their access categories. The outer scheduler sep arates delay sensitive applications from the incomi ng burst of multi-part data and also decides whether t o apply Aggregated - MAC Service Data Unit (A- MSDU aggregation technique or to send the data wit hout any aggregation. The inner scheduler schedules the remaining (delay-insensitive, background and be st-effort packets using Aggregated-MAC Protocol Data unit (A-MPDU aggregation technique.

  7. Low-power secure body area network for vital sensors toward IEEE802.15.6.

    Science.gov (United States)

    Kuroda, Masahiro; Qiu, Shuye; Tochikubo, Osamu

    2009-01-01

    Many healthcare/medical services have started using personal area networks, such as Bluetooth and ZigBee; these networks consist of various types of vital sensors. These works focus on generalized functions for sensor networks that expect enough battery capacity and low-power CPU/RF (Radio Frequency) modules, but less attention to easy-to-use privacy protection. In this paper, we propose a commercially-deployable secure body area network (S-BAN) with reduced computational burden on a real sensor that has limited RAM/ROM sizes and CPU/RF power consumption under a light-weight battery. Our proposed S-BAN provides vital data ordering among sensors that are involved in an S-BAN and also provides low-power networking with zero-administration security by automatic private key generation. We design and implement the power-efficient media access control (MAC) with resource-constraint security in sensors. Then, we evaluate the power efficiency of the S-BAN consisting of small sensors, such as an accessory type ECG and ring-type SpO2. The evaluation of power efficiency of the S-BAN using real sensors convinces us in deploying S-BAN and will also help us in providing feedbacks to the IEEE802.15.6 MAC, which will be the standard for BANs.

  8. On the non-existence for quantum LDPC codes of type IEEE802.16e with rates 1/2 and 2/3B

    OpenAIRE

    2008-01-01

    In this paper, we discuss a construction of CSS codes derived from pairs of practical irregular LDPC codes. Our design of irregular LDPC codes is based the design written in the standardization of IEEE802.16e. Our research has tried to make a CSS code with a pair of LDPC codes of type IEEE802.16e. To our regret, we proved that it was impossible to construct a CSS code if one of classical codes was of type IEEE802.16e with rate 1/2 and 2/3B. We would like to report the discussion on its imposs...

  9. Design and Implementation of IEEE 802.1Q VLAN Principle Experiments%IEEE802.1Q VLAN 原理实验的设计与实现

    Institute of Scientific and Technical Information of China (English)

    刘向东; 李志洁; 焉德军; 王德高

    2011-01-01

    VLAN is one important networking technology. An IEEE 802.1Q VLAN principle experiment designed is based on protocol analysis. The experimental test verifies the functions of VLAN, as well as the regulation of different attribute ports of switches of receiving and transmitting common frames and tagged frames. From the experiment,students can observe when and how support VLAN Ethernet switches add or remove 802.1Q tag to or from frames. Furthermore.students can experience network trouble due to switches add or remove lag to or from frames by inaccurate configuring switch ports attributes. The experiment can facilitate students better understanding frame structures and switching principles of IEEE802.1Q VLAN.%VLAN 原理实验利用协议分析方法,测试验证 VLAN 实现的功能,以及交换机不同属性端口接收、转发普通帧和标记帧的特性,观察支持 VLAN 的交换机对以太帧插入、删除802.1Q 标记的过程.并通过错误配置交换机端口属性,演示交换机加、去标记失配导致的网络故障,以加深学生对 IEEE 802.1Q VLAN 原理的理解.

  10. 基于IEEE 802.11p车联网安全应用消息传输性能分析%Internet of Vehicles Security Messages Transmission Based on IEEE 802.11p

    Institute of Scientific and Technical Information of China (English)

    段林侠

    2016-01-01

    从车联网安全消息传输性能的角度出发,针对车联网仿真需求,搭建了基于交通仿真软件SUMO和网络仿真软件OMNeT++的车联网仿真平台。在此基础上,对基于IEEE 802.11p协议的车联网中安全应用消息的传输性能进行了仿真与分析。仿真结果表明,IEEE 802.11p协议不能满足车联网中低时延高可靠的服务质量需求。%From the perspective of car security application message transmission performance,this paper aimes at the u-nique requirements of the Internet of Vehicles (IoV) simulation,set the IoV simulation platform based on traffic simulation soft-ware SUMO and network simulation software OMNeT++.Based on that,and analyzes the IoV network system performance based on the IEEE 802.11p protocol.

  11. IEEE P2030储能系统接入电网的互操作架构标准研究%Research on IEEE P2030 Interoperability Framework Standard About Energy Storage System Connected to Grid

    Institute of Scientific and Technical Information of China (English)

    侯义明; 于辉

    2014-01-01

    IEEE P2030系列标准中储能系统接入电网的互操作架构进行了介绍。阐述了IEEE P2030系列标准中储能系统与电力系统互操作(PS-IAP)、通信技术互操作(CT-IAP)和信息技术互操作(IT-IAP)的相关模型和信息,为国内储能系统与智能电网的建设提供参考和借鉴。%The interoperability framework of energy storage system connected to the grid in IEEE P2030 standard was introduced.The related modes and information of interoperability of power system,communication system,information system with energy storage system were elaborated.It can provide reference for the construction of energy storage system and smart grid.

  12. Design and implementation of an IEEE 802.11 baseband OFDM transceiver in 0.18 μm CMOS

    Science.gov (United States)

    Bin, Wu; Yumei, Zhou; Yongxu, Zhu; Zhengdong, Zhang; Jingjing, Cai

    2011-05-01

    An SISO IEEE 802.11 baseband OFDM transceiver ASIC is implemented. The chip can support all of the SISO IEEE 802.11 work modes by optimizing the key module and sharing the module between the transmitter and receiver. The area and power are decreased greatly compared with other designs. The baseband prototype has been verified under the WLAN baseband test equipment and through transferring the video. The 0.18 μm 1P/6M CMOS technology layout is finished and the chip is fabricated in SMIC, which occupies a 2.6 × 2.6 mm2 area and consumes 83 mW under typical work modes.

  13. Adaptive high definition MPEG-2 streaming using frame-based prioritization over IEEE 802.11a WLAN

    Science.gov (United States)

    Park, SangHoon; Lee, Seungjoo; Kim, JongWon

    2005-07-01

    In this paper, we propose a practical implementation of network-adaptive high definition (HD) MPEG-2 streaming using frame-based prioritized packetization over the IEEE 802.11a WLAN. The proposed adaptive streaming system nicely combines frame-based prioritized packetization and priority-based dropping based on the end-toend network monitoring. With the popular VideoLAN open software, we develop a real-time MPEG-2 TS (transport stream) parsing tool to provide the guide for required frame-based prioritization. The implemented system is evaluated over an IEEE 802.11a WLAN testbed and the experiment results verifies the intended the end-to-end QoS adaptation capability.

  14. The Performance Evaluation of an IEEE 802.11 Network Containing Misbehavior Nodes under Different Backoff Algorithms

    Directory of Open Access Journals (Sweden)

    Trong-Minh Hoang

    2017-01-01

    Full Text Available Security of any wireless network is always an important issue due to its serious impacts on network performance. Practically, the IEEE 802.11 medium access control can be violated by several native or smart attacks that result in downgrading network performance. In recent years, there are several studies using analytical model to analyze medium access control (MAC layer misbehavior issue to explore this problem but they have focused on binary exponential backoff only. Moreover, a practical condition such as the freezing backoff issue is not included in the previous models. Hence, this paper presents a novel analytical model of the IEEE 802.11 MAC to thoroughly understand impacts of misbehaving node on network throughput and delay parameters. Particularly, the model can express detailed backoff algorithms so that the evaluation of the network performance under some typical attacks through numerical simulation results would be easy.

  15. THE DESIGN AND IMPLEMENTATION OF THE IEEE 802.11 MAC BASED ON SOFT-CORE PROCESSOR AND RTOS

    Institute of Scientific and Technical Information of China (English)

    Xiao Wan'ang; Fang Zhi; Shi Yin

    2007-01-01

    The implementation method of the IEEE 802.11 Medium Access Control (MAC) protocol is mainly based on DSP (Digital Signal Processor)/ARM (Advanced Reduced instruction set computer Machine) processor or DSP/ARM IP (Intellectual Property) core. This paper presents a method based on Nios Ⅱ soft-core processor embedded in Altera's Cyclone FPGA (Field Programmable Gate Array)and MicroC/OS-Ⅱ RTOS (Real-Time Operation System). The benefits and drawbacks of above methods are compared, and then the method presented in this paper is described. The hardware and software partitioning are discussed; the hardware architecture is also illustrated and the MAC software programming is described in detail. The presented method has some advantages, such as low cost,easy-implementation and very suitable for the implementation of IEEE 802.11 MAC in research stage.

  16. Traffic Adaptive Distributed Backoff Control Mechanism for Cluster-Based IEEE802.15.4 WSNs with Traffic Fluctuations

    Science.gov (United States)

    Mori, Kazuo; Naito, Katsuhiro; Kobayashi, Hideo

    The traffic adaptive 2-level active period control has been proposed as a traffic adaptation mechanism to handle temporal and spatial (geographical) traffic fluctuations in cluster-based wireless sensor networks (WSNs) employing IEEE802.15.4 medium access control (MAC). This paper proposes a traffic adaptive distributed backoff control mechanism for cluster-based WSNs with the traffic adaptive 2-level active period control to enhance the system performance, especially transmission performance. The proposed mechanism autonomously adjusts the starting time of the backoff procedure for channel accesses in the contention access period (CAP) specified by the IEEE802.15.4 MAC, and then distributes the channel access timing over a wide range within the CAP, which can mitigate channel access congestion. The results of computer simulations show that the proposed mechanism can improve the transmission delay performance while keeping the enhancement in throughput and energy consumption at the cluster-based WSNs under non-uniform traffic environments.

  17. Design and implementation of an IEEE 802.11 baseband OFDM transceiver in 0.18 {mu}m CMOS

    Energy Technology Data Exchange (ETDEWEB)

    Wu Bin; Zhou Yumei; Zhu Yongxu; Zhang Zhengdong; Cai Jingjing, E-mail: wubin@ime.ac.cn [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

    2011-05-15

    An SISO IEEE 802.11 baseband OFDM transceiver ASIC is implemented. The chip can support all of the SISO IEEE 802.11 work modes by optimizing the key module and sharing the module between the transmitter and receiver. The area and power are decreased greatly compared with other designs. The baseband prototype has been verified under the WLAN baseband test equipment and through transferring the video. The 0.18 {mu}m 1P/6M CMOS technology layout is finished and the chip is fabricated in SMIC, which occupies a 2.6 x 2.6 mm{sup 2} area and consumes 83 mW under typical work modes. (semiconductor integrated circuits)

  18. IMPROVING PERFORMANCE OF IEEE 802.11 BY A DYNAMIC CONTROL BACKOFF ALGORITHM UNDER UNSATURATED TRAFFIC LOADS

    Directory of Open Access Journals (Sweden)

    Hatm Alkadeki

    2015-12-01

    Full Text Available The IEEE 802.11 backoff algorithm is very important for controlling system throughput over contentionbased wireless networks. For this reason, there are many studies on wireless network performance focus on developing backoff algorithms. However, most existing models are based on saturated traffic loads, which are not a real representation of actual network conditions. In this paper, a dynamic control backoff time algorithm is proposed to enhance both delay and throughput performance of the IEEE 802.11 distributed coordination function. This algorithm considers the distinction between high and low traffic loads in order to deal with unsaturated traffic load conditions. In particular, the equilibrium point analysis model is used to represent the algorithm under various traffic load conditions. Results of extensive simulation experiments illustrate that the proposed algorithm yields better performance throughput and a better average transmission packet delay than related algorithms.

  19. Proposal of an ISO/IEEE11073 platform for healthcare telemonitoring: plug-and-play solution with new use cases

    OpenAIRE

    M. Galarraga; Martínez, I; Serrano, L.; Toledo,Paula; Escayola, J.; Fernández, Julián; Jiménez-Fernández, S.; Led, S.; Martínez-Espronceda, M.; Viruete, E.; García, José

    2007-01-01

    Proceeding of: 29th Annual International Conference of IEEE Engineering in Medicine and Biology Society, (EMBS 2007), Lyon, France, 23-26th august 2007. Remote patient monitoring in e-Health is everyday closer to be a mature technology / service. However, there is still a lack of development in areas such as standardization of the sensor’s communication interface, integration into Electronic Healthcare Record systems or incorporation in ambient-intelligent scenarios. This work identifies a...

  20. Introduction to the special issue on the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum.

    Science.gov (United States)

    Burt, Eric; Gill, Patrick

    2012-03-01

    The 8 invited and 17 contributed papers in this special issue focus on the following topical areas covered at the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum, held in San Francisco, California: 1) Materials and Resonators; 2) Oscillators, Synthesizers, and Noise; 3) Microwave Frequency Standards; 4) Sensors and Transducers; 5) Timekeeping and Time and Frequency Transfer; and 6) Optical Frequency Standards.

  1. Dynamic subframe allocation for mobile broadband m-health using IEEE 802.16j mobile multihop relay networks.

    Science.gov (United States)

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

    2012-01-01

    The concept of 4G health will be one of the key focus areas of future m-health research and enterprise activities in the coming years. WiMAX technology is one of the constituent 4G wireless technologies that provides broadband wireless access (BWA). Despite the fact that WiMAX is able to provide a high data rate in a relatively large coverage; this technology has specific limitations such as: coverage, signal attenuation problems due to shadowing or path loss, and limited available spectrum. The IEEE 802.16j mobile multihop relay (MMR) technology is a pragmatic solution designed to overcome these limitations. The aim of IEEE 802.16j MMR is to expand the IEEE 802.16e's capabilities with multihop features. In particular, the uplink (UL) and downlink (DL) subframe allocation in WiMAX network is usually fixed. However, dynamic frame allocation is a useful mechanism to optimize uplink and downlink subframe size dynamically based on the traffic conditions through real-time traffic monitoring. This particular mechanism is important for future WiMAX based m-health applications as it allows the tradeoff in both UL and DL channels. In this paper, we address the dynamic frame allocation issue in IEEE 802.16j MMR network for m-health applications. A comparative performance analysis of the proposed approach is validated using the OPNET Modeler(®). The simulation results have shown an improved performance of resource allocation and end-to-end delay performance for typical medical video streaming application.

  2. Mathematical Analysis of EDCA's Performance on the Control Channel of an IEEE 802.11p WAVE Vehicular Network

    Directory of Open Access Journals (Sweden)

    Hussein T. Mouftah

    2010-01-01

    Full Text Available Wireless networks for vehicular environments are gaining increasing importance due to their ability to provide a means for stations on the roadside and radio units on board of vehicles to communicate and share safety-related information, thus reducing the probability of accidents and increasing the efficiency of the transportation system. With this goal in mind, the IEEE is currently developing the Wireless Access in Vehicular Environments (WAVE IEEE 802.11p standard. WAVE devices use the IEEE 802.11's Enhanced Distributed Channel Access (EDCA MAC protocol to compete for the transmission medium. This work proposes an analytical tool to evaluate the performance of EDCA under the specific conditions of the so-called control channel (CCH of a WAVE environment, including the particular EDCA parameter values and the fact that all safety-critical data frames are broadcasted. The protocol is modeled using Markov chains and results related to throughput, frame-error rate, buffer occupancy and delay are obtained under different traffic-load conditions. The main analysis is performed assuming that the CCH works continuously, and then an explanation is given as to the considerations that are needed to account for the fact that activity on the CCH is intermittent.

  3. Priority-Based Inter-Vehicle Communication for Highway Safety Messaging Using IEEE 802.11e

    Directory of Open Access Journals (Sweden)

    Chakkaphong Suthaputchakun

    2009-01-01

    Full Text Available We propose to use IEEE 802.11e in conjunction with retransmission mechanisms for priority-based Intervehicle Communication (IVC for highway safety messaging in both vehicular infrastructure and ad hoc networks. Each IVC message, which is assigned a priority based on the safety event urgency, requires different quality of service in terms of communication reliability and average delay. To increase the communication reliability in a broadcast-based IVC, we apply retransmission mechanisms that can provide proportional reliability differentiation for each prioritized message. We evaluate the performance of our proposed protocol using OPNET Modeler, in terms of percentage of successful transmissions and average delay. The protocol performance is evaluated for (1 different system parameters such as the packet size, number of vehicles, and percentage of priority 1 vehicles, and (2 priority-based protocol parameters, such as contention window, interframe spacing and retransmission parameters. The results show that proper protocol parameter settings per priority message result in an efficient solution for priority based broadcast IVC. Moreover, the proposed protocol is fully compatible with both IEEE 802.11 and IEEE 802.11e standards.

  4. Experimental Performance Evaluation of Multihop IEEE 802.15.4/4g/4e Smart Utility Networks in Outdoor Environment

    Directory of Open Access Journals (Sweden)

    Chin-Sean Sum

    2017-01-01

    Full Text Available This paper presents the experimental performance evaluation results of the IEEE 802.15.4/4g/4e Smart Utility Networks (SUN in applications suited for outdoor environment. SUN is an advanced wireless communications network designed for reliable, low data rate, and low energy consumption networks for command-and-control applications like utility service, sensor network, and so on. IEEE 802.15.4g/4e is the international standard for SUN supported by multiple utility providers and product vendors. In this paper, a comprehensive field test was conducted by employing the implementation we have developed to evaluate the performance of the SUN devices based on IEEE 802.15.4/4g/4e standard. The output power of the implementation is 250 mW for extended range, reducible to 20 mW for short-range scalability and battery preservation. Results showed that in an outdoor line-of-sight environment, the achievable one-hop range of a 50 kbps SUN device was 450 m. Next, in a non-line-of-sight environment involving typical residential concrete building, the communications could be established penetrating obstructions to reach above the 11th storey, reaching the performance degradation limits at the 20th storey. Next, the network of the SUN system was proven to be capable of supporting a typical multihop tree network in a dense populated building, meeting the required performance by the standard.

  5. Performance Analysis of IEEE 802.15.6 CSMA/CA Protocol for WBAN Medical Scenario through DTMC Model.

    Science.gov (United States)

    Kumar, Vivek; Gupta, Bharat

    2016-12-01

    The newly drafted IEEE 802.15.6 standard for Wireless Body Area Networks (WBAN) has been concentrating on a numerous medical and non-medical applications. Such short range wireless communication standard offers ultra-low power consumption with variable data rates from few Kbps to Mbps in, on or around the proximity of the human body. In this paper, the performance analysis of carrier sense multiple access with collision avoidance (CSMA/CA) scheme based on IEEE 802.15.6 standard in terms of throughput, reliability, clear channel assessment (CCA) failure probability, packet drop probability, and end-to-end delay has been presented. We have developed a discrete-time Markov chain (DTMC) to significantly evaluate the performances of IEEE 802.15.6 CSMA/CA under non-ideal channel condition having saturated traffic condition including node wait time and service time. We also visualize that, as soon as the payload length increases the CCA failure probability increases, which results in lower node's reliability. Also, we have calculated the end-to-end delay in order to prioritize the node wait time cause by backoff and retransmission. The user priority (UP) wise DTMC analysis has been performed to show the importance of the standard especially for medical scenario.

  6. Service differentiated and adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems.

    Science.gov (United States)

    Xia, Feng; Li, Jie; Hao, Ruonan; Kong, Xiangjie; Gao, Ruixia

    2013-01-01

    Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay.

  7. Service Differentiated and Adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems

    Directory of Open Access Journals (Sweden)

    Feng Xia

    2013-01-01

    Full Text Available Cyber-Physical Systems (CPS that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay.

  8. Low-cost platform for the evaluation of single phase electromagnetic phenomena of power quality according to the IEEE 1159 standard

    Directory of Open Access Journals (Sweden)

    Jorge Luis Díaz-Rodríguez

    2015-01-01

    Full Text Available Este artículo presenta la implementación de un sistema de adquisición y evaluación de fenómenos electromagnéticos asociados con la calidad de la energía según el Estándar IEEE 1159-1992 y aplicado al caso particular de sistemas eléctricos monofásicos. El software de evaluación se implementa en el software profesional Labview®, utilizando como dispositivo de adquisición una tarjeta NI USB 6009 de la National Instrument®. Se muestra la implementación del hardware de la sensórica, también el desarrollo del algoritmo y el diseño de una interfaz gráfica de usuario que permiten visualizar las formas de onda de tensión y de corriente, espectros, frecuencia, potencia y los disturbios de calidad de la energía tales como sag, swell, undervoltage, overvoltage, etc. De igual forma al final se realiza un conciso análisis de costos para demostrar que el sistema desarrollado presenta un precio inferior a las soluciones actuales que se consiguen en el mercado, por último se muestra un estudio de caso.

  9. Performance evaluation of reactive and proactive routing protocol in IEEE 802.11 ad hoc network

    Science.gov (United States)

    Hamma, Salima; Cizeron, Eddy; Issaka, Hafiz; Guédon, Jean-Pierre

    2006-10-01

    Wireless technology based on the IEEE 802.11 standard is widely deployed. This technology is used to support multiple types of communication services (data, voice, image) with different QoS requirements. MANET (Mobile Adhoc NETwork) does not require a fixed infrastructure. Mobile nodes communicate through multihop paths. The wireless communication medium has variable and unpredictable characteristics. Furthermore, node mobility creates a continuously changing communication topology in which paths break and new one form dynamically. The routing table of each router in an adhoc network must be kept up-to-date. MANET uses Distance Vector or Link State algorithms which insure that the route to every host is always known. However, this approach must take into account the adhoc networks specific characteristics: dynamic topologies, limited bandwidth, energy constraints, limited physical security, ... Two main routing protocols categories are studied in this paper: proactive protocols (e.g. Optimised Link State Routing - OLSR) and reactive protocols (e.g. Ad hoc On Demand Distance Vector - AODV, Dynamic Source Routing - DSR). The proactive protocols are based on periodic exchanges that update the routing tables to all possible destinations, even if no traffic goes through. The reactive protocols are based on on-demand route discoveries that update routing tables only for the destination that has traffic going through. The present paper focuses on study and performance evaluation of these categories using NS2 simulations. We have considered qualitative and quantitative criteria. The first one concerns distributed operation, loop-freedom, security, sleep period operation. The second are used to assess performance of different routing protocols presented in this paper. We can list end-to-end data delay, jitter, packet delivery ratio, routing load, activity distribution. Comparative study will be presented with number of networking context consideration and the results show

  10. Optimizing the MAC Protocol in Localization Systems Based on IEEE 802.15.4 Networks

    Directory of Open Access Journals (Sweden)

    Juan J. Pérez-Solano

    2017-07-01

    Full Text Available Radio frequency signals are commonly used in the development of indoor localization systems. The infrastructure of these systems includes some beacons placed at known positions that exchange radio packets with users to be located. When the system is implemented using wireless sensor networks, the wireless transceivers integrated in the network motes are usually based on the IEEE 802.15.4 standard. But, the CSMA-CA, which is the basis for the medium access protocols in this category of communication systems, is not suitable when several users want to exchange bursts of radio packets with the same beacon to acquire the radio signal strength indicator (RSSI values needed in the location process. Therefore, new protocols are necessary to avoid the packet collisions that appear when multiple users try to communicate with the same beacons. On the other hand, the RSSI sampling process should be carried out very quickly because some systems cannot tolerate a large delay in the location process. This is even more important when the RSSI sampling process includes measures with different signal power levels or frequency channels. The principal objective of this work is to speed up the RSSI sampling process in indoor localization systems. To achieve this objective, the main contribution is the proposal of a new MAC protocol that eliminates the medium access contention periods and decreases the number of packet collisions to accelerate the RSSI collection process. Moreover, the protocol increases the overall network throughput taking advantage of the frequency channel diversity. The presented results show the suitability of this protocol for reducing the RSSI gathering delay and increasing the network throughput in simulated and real environments.

  11. Optimizing the MAC Protocol in Localization Systems Based on IEEE 802.15.4 Networks.

    Science.gov (United States)

    Pérez-Solano, Juan J; Claver, Jose M; Ezpeleta, Santiago

    2017-07-06

    Radio frequency signals are commonly used in the development of indoor localization systems. The infrastructure of these systems includes some beacons placed at known positions that exchange radio packets with users to be located. When the system is implemented using wireless sensor networks, the wireless transceivers integrated in the network motes are usually based on the IEEE 802.15.4 standard. But, the CSMA-CA, which is the basis for the medium access protocols in this category of communication systems, is not suitable when several users want to exchange bursts of radio packets with the same beacon to acquire the radio signal strength indicator (RSSI) values needed in the location process. Therefore, new protocols are necessary to avoid the packet collisions that appear when multiple users try to communicate with the same beacons. On the other hand, the RSSI sampling process should be carried out very quickly because some systems cannot tolerate a large delay in the location process. This is even more important when the RSSI sampling process includes measures with different signal power levels or frequency channels. The principal objective of this work is to speed up the RSSI sampling process in indoor localization systems. To achieve this objective, the main contribution is the proposal of a new MAC protocol that eliminates the medium access contention periods and decreases the number of packet collisions to accelerate the RSSI collection process. Moreover, the protocol increases the overall network throughput taking advantage of the frequency channel diversity. The presented results show the suitability of this protocol for reducing the RSSI gathering delay and increasing the network throughput in simulated and real environments.

  12. An Authentication and Key Management Mechanism for Resource Constrained Devices in IEEE 802.11-based IoT Access Networks

    Directory of Open Access Journals (Sweden)

    Ki-Wook Kim

    2017-09-01

    Full Text Available Many Internet of Things (IoT services utilize an IoT access network to connect small devices with remote servers. They can share an access network with standard communication technology, such as IEEE 802.11ah. However, an authentication and key management (AKM mechanism for resource constrained IoT devices using IEEE 802.11ah has not been proposed as yet. We therefore propose a new AKM mechanism for an IoT access network, which is based on IEEE 802.11 key management with the IEEE 802.1X authentication mechanism. The proposed AKM mechanism does not require any pre-configured security information between the access network domain and the IoT service domain. It considers the resource constraints of IoT devices, allowing IoT devices to delegate the burden of AKM processes to a powerful agent. The agent has sufficient power to support various authentication methods for the access point, and it performs cryptographic functions for the IoT devices. Performance analysis shows that the proposed mechanism greatly reduces computation costs, network costs, and memory usage of the resource-constrained IoT device as compared to the existing IEEE 802.11 Key Management with the IEEE 802.1X authentication mechanism.

  13. An Authentication and Key Management Mechanism for Resource Constrained Devices in IEEE 802.11-based IoT Access Networks.

    Science.gov (United States)

    Kim, Ki-Wook; Han, Youn-Hee; Min, Sung-Gi

    2017-09-21

    Many Internet of Things (IoT) services utilize an IoT access network to connect small devices with remote servers. They can share an access network with standard communication technology, such as IEEE 802.11ah. However, an authentication and key management (AKM) mechanism for resource constrained IoT devices using IEEE 802.11ah has not been proposed as yet. We therefore propose a new AKM mechanism for an IoT access network, which is based on IEEE 802.11 key management with the IEEE 802.1X authentication mechanism. The proposed AKM mechanism does not require any pre-configured security information between the access network domain and the IoT service domain. It considers the resource constraints of IoT devices, allowing IoT devices to delegate the burden of AKM processes to a powerful agent. The agent has sufficient power to support various authentication methods for the access point, and it performs cryptographic functions for the IoT devices. Performance analysis shows that the proposed mechanism greatly reduces computation costs, network costs, and memory usage of the resource-constrained IoT device as compared to the existing IEEE 802.11 Key Management with the IEEE 802.1X authentication mechanism.

  14. IPv6 and IEEE 1888: Fundamental Infrastructure and Protocol for Smart Grid%IPv6和IEEE1888:国际智能电网的基础架构和协议

    Institute of Scientific and Technical Information of China (English)

    谷展

    2012-01-01

    With rapid development of Intemet, information technologies have deployed widely into many application fields. For example, IP,Internet of Things and cloud computing have been widely used in green industry and smart energy. Recently IP for Smart Object Alliance (IPSO Alliance ) published lPv6 and IEEE 1888 based white paper for Smart Grid infrastructure and protocol, joint with many leading enterprises in international industry chain, including Cisco, Itron, Duke Energy, as well as domestic China Telecom and BII Group. As a core protocol for next generation Internet, IPv6 provides broad develop space for smart grid. IEEE 1888 protocol constructs a uniform control and management platform for smart terminals to access Internet. This paper mainly introduced this white paper, beginning from network requirements, analysed necessity for smart grid to adopting IPv6 and IEEE 1888 as fimdamental infrastructure and protocol. Finally this paper discussed key technologies and related technical standards in detail. This paper provided a comprehensive overview for the last kilometer to smart grid.%随着互联网的发展,信息技术深入到各行各业,如IP,物联网,云计算等技术被广泛地应用于绿色节能、智慧能源中。最近国际物联网联盟IPSO集合国内外产业领头公司.国外的如Cisco,Itron,Duke Energy,国内的如中国电信,天地互连公司,联合发布了以IPv6和IEEE1888为国际智能电网基础架构和协议的白皮书。其中,IPv6协议作为下一代互联网的基础协议为智能电网信息化提供了更广阔的空间。而IEEE1888开放标准为末端智能终端接入互联网提供了统一的管控平台。本文主要介绍该白皮书的内容,从智能电网最后一公里的网络需求入手,讲述智能电网为什么需要IPv6和IEEE1888作为基础通信架构和协议.详细解析白皮书中关于IPv6通信基础架构的关键技术模块和相关技术标准。为国际智

  15. Bandwidth scheduling scheme based on IEEE 802.16j network%一种基于IEEE802.16j网络的带宽调度方案

    Institute of Scientific and Technical Information of China (English)

    胡致远; 常颖华

    2012-01-01

    针对IEEE 802.16j网络,提出了一种上行业务的动态联合带宽资源调度方案.根据该网络系统树状拓扑结构,在基站BS和中继站RS间采用分级分布式资源调度体制,从而既保障了业务的带宽需求,又提升了上行带宽利用率,同时还提出了针对不同类型业务采用不同的调度算法,改善了调度的公平合理性.仿真结果表明,提出的动态联合调度方案相比严格优先级调度更具灵活性,能够在兼顾用户速率公平的条件下有效地保证各种服务的QoS要求,同时也可获得较高的带宽资源利用率.%For the IEEE 802. 16j network .(his paper proposed a dynamic join! Bandwidth resource scheduling strategy for (he services in uplink. According to the irec-lopology of IEEE 802. 16j system, used a hierarchical distributed resource scheduling scheme between the base station ( BS) and the relay station ( RS) , which enhanced the bandwidth utilization and provider! Various multimedia communications with QoS guarantee effectively. At the same time, this paper proposed different scheduling algorithm for different types of services to improve the fairness. Simulation results show that the proposed Bcheme is more flexible than strict priority scheduling. It can meet various QoS requirements of multimedia services well without sacrificing services' rate fairness, and gel the preferable utilization of bandwidth in WiMAX system.

  16. Convert of floating-point data in IEEE754 based on C++ Builder6.0%基于C++ Builder 6.0的IEEE 754中单精度浮点数转换实现

    Institute of Scientific and Technical Information of China (English)

    翟振辉; 欧世峰; 刘继长; 钟全雄; 高颖

    2014-01-01

    IEEE 754标准规定了可以精确表示某一浮点型数据的单精度(常用)和双精度表示方法,这在许多对数据精度要求较高的场合得到广泛应用,而在数据通信过程中所有数据都是以十六进制打包和解析、二进制形式传输的,所以研究如何根据该标准把所要传输的浮点型数据编程转换成8位十六进制数据具有重要的实用意义。这里在分析和研究IEEE 754标准中浮点型数据单精度表示方式的基础上,结合Borland C++Builder 6.0可视化编程工具,阐述了如何把单精度浮点型数据转换成所需要的8位十六进制数,以及如何把8位十六进制数转换成单精度浮点类型数据,并实现显示。%The single precision and double precision expressive methods which can accurately express a float-point data are stipulated in IEEE754 standard. They are widely in the field,in which the accuracy requirement is high. On the base of studying and analyzing the expression of the 32 bits floating-point,how to translate the floating-point data to the needed hexadecimal da-ta,and how to translate the hexadecimal data to the floating-point data are elaborated in combination with the visual program-ming tools Borland C++ Builder 6.0,and the expression of the 32 bits floating-point data in the IEEE 754 standard. The data display was realized.

  17. OPTIMISATION OF IEEE 802.15.4-BASED AVIATION GROUND UNITS MONITORING NETWORK DELAY%基于IEEE 802.15.4民航地面设备监控网络时延优化

    Institute of Scientific and Technical Information of China (English)

    陈维兴; 钱杰; 孙毅刚

    2014-01-01

    Airport metering system for ground units (including ground power unit and ground air conditioning ) uses wireless sensor network (WSN)with IEEE 802.15.1 protocol to monitor a large number of parameters of the ground units.The importance of these data varies with the different collection locations,and the data also have diverse grade requirements on real-time transmission and mass data block transmission.Using IEEE 802.15.4 GTS mechanism,and on the basis of original first-come,first-served (FCFS)algorithm,the GTS request queue is maintained at PAN node,for GTS allocation,the preemptive priority allocation of GTS according to the importance of data at terminal node is adopted.Meanwhile in light of the characteristics of GTS requests and GTS responses,the way of reservation on GTS Allocate requests are used until GTS Deallocate occur,so as to guarantee the priority transmission of important data.Simulation results show that using GTS priority scheduling and GTS requests reservation,the performance of fast data transmission improves significantly with respect to the FCFS algorithm.%机场地面设备(包括地面电源和地面空调)计量系统利用IEEE 802.15.4协议无线传感器网络WSN对地面设备的许多参数进行监测,这些数据因采集的位置不同,其重要性也不同,对实时传输和大量数据快速传输上有不同的等级要求。利用IEEE 802.15.4 GTS机制,在原有的先来先服务FCFS算法的基础上,在PAN节点维护GTS请求队列,对GTS分配采取按终端节点数据重要性进行优先级抢占分配GTS,同时针对GTS请求和GTS响应的特点,对GTS Allocate请求采取保留的方式,直至GTS Deallocate到来,以保证重要数据的优先传输。仿真结果表明,采用GTS优先级调节和GTS请求保留相对于FCFS算法在数据传输快速性能上有明显的提升。

  18. 15th IEEE/ACIS International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing

    CERN Document Server

    2015-01-01

    This edited book presents scientific results of 15th IEEE/ACIS International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing (SNPD 2014) held on June 30 – July 2, 2014 in Las Vegas Nevada, USA. The aim of this conference was to bring together scientists, engineers, computer users, and students to share their experiences and exchange new ideas, research results about all aspects (theory, applications and tools) of computer and information science, and to discuss the practical challenges encountered along the way and the solutions adopted to solve them. The conference organizers selected the 13 outstanding papers from those papers accepted for presentation at the conference.

  19. 14th ACIS/IEEE International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing

    CERN Document Server

    Studies in Computational Intelligence : Volume 492

    2013-01-01

    This edited book presents scientific results of the 14th ACIS/IEEE International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing (SNPD 2013), held in Honolulu, Hawaii, USA on July 1-3, 2013. The aim of this conference was to bring together scientists, engineers, computer users, and students to share their experiences and exchange new ideas, research results about all aspects (theory, applications and tools) of computer and information science, and to discuss the practical challenges encountered along the way and the solutions adopted to solve them. The conference organizers selected the 17 outstanding papers from those papers accepted for presentation at the conference.  

  20. IEEE Conference Record of 1978 Thirteenth Pulse Power Modulator Symposium, Buffalo, New York, 20-22 June 1978.

    Science.gov (United States)

    1978-01-01

    Kracht " HVDC Vacuum Circuit Breakers ," IEEE Trans. PAS Vol. 91, pp. 1575-1588 (1972). 2. R. W. Warren, ’"Vacuum Interrupters Used for the Interruption... breaker . zontal time scale is different in Figures 4 and 5; in each case, about 1-1/2 cycles of operation are shown. Control Circuit (5) Figure 2 is a...mitters lacking fast trip circuit breakers when a positive voltage appears on the for interrupting the supply of H.T. current thyratron grid

  1. ELBA: A New Efficient Load-Balancing Association in IEEE 802.15.4-Based Wireless Sensor Networks

    Science.gov (United States)

    Lee, Jae-Hyung; Kim, Dong-Sung; Shin, Soo-Young

    In this letter, a novel association method called ELBA (efficient load balancing association) is proposed for improved load balancing in IEEE 802.15.4-based WSNs (wireless sensor networks). ELBA adds new nodes to the network in an efficient load-balancing manner by exploiting not only RSSI (received signal strength indicator), which is used in the standard, but also traffic-load, the number of allocated GTSs (guaranteed time slots), and the number of parent nodes and child nodes. Simulation results show that ELBA offers better performance in load balancing and preventing congestion.

  2. 基于IEEE 802.1 x/EAP-TLS认证协议安全性的改进%The Improvement of Security based on IEEE 802 . 1 x/EAP-TLS Protocol

    Institute of Scientific and Technical Information of China (English)

    孟迪

    2014-01-01

    Nowadays, the Internet Technology develops rapidly, the application of WLAN has become more and more widespread. Because the wireless network has the nature of opening,at the same time of applying rap-idly,the security problem is constraining the wireless network. By studying the security of IEEE 802. 1x/EAP-TLS protocol,this thesis provides an improvement scheme to make the information which are transmitted be-tween client and AP more secure,promote the security of wireless network in some degree.%在网络技术飞速发展的今天,无线网的应用范围越来越广泛.由于无线网具有开放性,在广泛应用的同时,其安全问题也成为了制约网络发展的关键问题.本文详细研究了IEEE 802.1x/EAP-TLS认证协议的安全问题,针对安全漏洞提出了改进方案,通过对客户端与认证系统之间传递信息的改进,在一定程度上提升了无线网的安全性.

  3. Research channel estimation for IEEE 802.16d in mobile environment%移动环境中IEEE 802.16d系统的信道估计研究

    Institute of Scientific and Technical Information of China (English)

    何招旺; 陈辉; 易淼

    2009-01-01

    This paper analyzed the channel estimation algortihms in the IEEE802.16d mobile system.In order to enhance the mobility of the system , porposed an linear model to approximate the time-varying characteristic of channel impulse response in the frequency domain during each frame.The simulation results show that the proposed methods can still provide accurate channel information even in large Doppler frequency shift as well as poor channel environment,it can be good support the access of mobile terminal in the system.%对在移动环境中的IEEE 802.16d系统中的信道估计进行了分析.为了增强系统对移动性的支持,提出了一种利用线性模型预测的方法来跟踪每帧中时变信道的频域信息.仿真结果表明,采用该方法可以在有较大多普勒频移以及恶劣的信道环境下仍能精确地得到信道信息,能很好地支持系统中移动终端的接入.

  4. Research on puncturing convolutional code for IEEE 802.11p%IEEE 802.11p下删余卷积编码译码方法的研究

    Institute of Scientific and Technical Information of China (English)

    阮峥; 景为平

    2012-01-01

    应用于智能交通系统的无线接入协议IEEE802.11p,其物理层卷积编码的码率可通过对(2,1,7)卷积编码器的删余来实现.讨论了删余位置的图案和算法,分析了在删余位置插入不同哑元时维特比译码后误码率的统计特性.仿真的同时比较了固定哑元下不同码率所引入的误比特率.%IEEE802.11p, acts as wireless access protocol in the vehicular environment applied in the intelligent transportation systems, its convolutional code with three different code rate in the physical layer is achieved through (2,1,7) encoder. This paper proposed puncturing method that is omitting some encoded bits at specific position and inserting dummy metric in these places when utilize Viterbi decoder, discussed the selection on dummy metric, and finally compared BER results in inserting different dummy metrics and given code rate respectively.

  5. 基于 IEEE 1500标准的嵌入式 ROM及SRAM内建自测试设计%Built-in Self-test Design of the Embedded ROM and SRAM Based on the IEEE 1500 Standard

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      嵌入式存储器在SOC中所占的面积比越来越大,同时也对嵌入式存储器测试技术提出了新的挑战.IEEE 1500标准为IP核设计商与集成商制订了标准的测试接口.基于此标准,本文完成了针对嵌入式存储器的测试外壳与具有兼容性的控制器的设计,以SRAM和ROM为测试对象进行验证,测试结果表明,该系统能准确地检测存储器存在的故障.%Embedded memory in SOC occupied area ratio increasing ,also presented new challenges for embedded memory test technology .IEEE 1500 standard for IP core providers and integrators to develop a standard test interface .This paper designs a test wrapper and compatibility controller for embedded memory .This paper validates the SRAM and ROM as test object .And the test results show that the system can accurately detect the existence of the fault of the embedded memory .

  6. 基于IEEE 802.11ac的动态频率选择算法研究%Research on DFS Algorithm based on IEEE 802.11ac

    Institute of Scientific and Technical Information of China (English)

    杨顺; 田文龙

    2014-01-01

    本文提出了一种新的动态频率选择算法,该算法基于IEEE 802.11ac的信道绑定机制,相对于原来的算法,能显著改善信道和AP之间相互干扰的状况,并大幅度提高系统吞吐量,文章描述了该算法的处理过程,并给出了相应的仿真结果。%This paper proposes a new dynamic frequency selection algorithm,the algorithm is based on the IEEE 802.11ac channel binding mechanism,with respect to the original algorithm, Can significantly improve the situation of mutual interference between the channel and the AP,and greatly improve the system throughput,the article de-scribes the process of the algorithm,and the corresponding simulation results.

  7. IEEE802.11无线网络中DCF模式媒介服务状态分析%Service Status of DCF Model in IEEE 802.11 Wireless Network

    Institute of Scientific and Technical Information of China (English)

    吴大鹏; 王汝言; 武穆清; 甄岩

    2011-01-01

    For the distributed coordination function (DCF) defined in the IEEE 802. 11 standard, the nodes is obtained an access rights to the wireless medium by contention method. As a result, the service time of the data frame becomes larger than the transmission time. Based on analysis of the transition be tween the status of frame transmitting, frame collision and idle, the medium status can be described by the binomial distribution; moreover, the service time for the given network status can be estimated. Sim ulations show that the estimated results are accurate.%IEEE 802.11标准的分布式协调功能(DCF)模式下,节点通过竞争获得无线媒介的访问权,导致媒介服务时间远大于数据帧传输时间.通过深入分析数据帧传输、数据帧碰撞以及媒介空闲3种媒介状态的转换情况,采用近似二项分布建立媒介状态描述模型,获得了媒介服务时间估计值.仿真结果表明,所建立的模型能够准确地衡量给定网络状态下的媒介服务时间.

  8. IEEE802.15.4的CC2530无线数据收发设计%Point-to-point Communication Based on CC2530 and IEEE 802.15.4

    Institute of Scientific and Technical Information of China (English)

    李志方; 钟洪声

    2011-01-01

    Wireless sensor network(WSN) protocol of IEEE802. 15. 4(ZigBee) is implemented based on TI CC2530. The working mechanism of Command Strobe/CSMA-CA Processor is discussed after analysis of CSMA-CA arithmetic. Meanwhile, a small star topology network is structured. Experimental results illustrate that nodes can communicate with each others successfully and accurately within their communicaton ranges.%基于TI公司的CC2530实现了IEEE 802.15.4(ZigBee)的无线传感器网络(Wireless Sensor Network,WSN)协议;在分析CSMA-CA算法的基础上,重点讨论了片内集成的命令选通/CSMA-CA处理器的工作机制,同时组建了一个小型星状网络.测试结果表明,在节点通信范围内,节点收发的成功率和正确率均达到了100%.

  9. IEEE802.15.4中的安全研究及缺陷分析%Study of the Security and Analysis of the Vulnerability in the IEEE 802.15.4

    Institute of Scientific and Technical Information of China (English)

    马亲民; 戴光智

    2013-01-01

    IEEE 802.15.4是无线传感器网络物理层和MAC层的工业标准,介绍了该协议中的安全体系:安全服务、安全模式、安全组件,并对CTR、CBC-MAC、CCM三种操作模式进行了详细的剖析,最后对该协议本身的缺陷造成容易受到的同nonce攻击、重发防止攻击、ACK攻击进行了分析,还提出了相应的对策。%The IEEE 802.15.4 specification is matter-of-fact standard of physical layer and MAC layer for WSN. The security mechanisms in the specification are analyzed ,including security services, security modes and security suites. There are some vul-nerabilities in the specification, which leading the WSN suffering many attacks.The security enhancements are provided to pre-vent from attacking.

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

    Directory of Open Access Journals (Sweden)

    Amry Daulat Gultom

    2014-06-01

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

  11. Evaluation of IEEE 802.11g and 802.16 for Lunar Surface Exploration Missions Using MACHETE Simulations

    Science.gov (United States)

    Segui, John; Jennings, Esther; Vyas, Hemali

    2009-01-01

    In this paper, we investigated the suitability of terrestrial wireless networking technologies for lunar surface exploration missions. Specifically, the scenario we considered consisted of two teams of collaborating astronauts, one base station and one rover, where the base station and the rover have the capability of acting as relays. We focused on the evaluation of IEEE 802.11g and IEEE 802.16 protocols, simulating homogeneous 802.11g network, homogeneous 802.16 network, and heterogeneous network using both 802.11g and 802.16. A mix of traffic flows were simulated, including telemetry, caution and warning, voice, command and file transfer. Each traffic type had its own distribution profile, data volume, and priority. We analyzed the loss and delay trade-offs of these wireless protocols with various link-layer options. We observed that 802.16 network managed the channel better than an 802.11g network due to controlled infrastructure and centralized scheduling. However, due to the centralized scheduling, 802.16 also had a longer delay. The heterogeneous (hybrid) of 802.11/802.16 achieved a better balance of performance in terms of data loss and delay compared to using 802.11 or 802.16 alone.

  12. Analysis of Power Saving Class II Traffic in IEEE 802.16E with Multiple Sleep State and Balking

    Directory of Open Access Journals (Sweden)

    Misra Chinmaya

    2015-03-01

    Full Text Available The battery life of Mobile Stations in IEEE 802.16e can be extended substantially by applying the sleep mode mechanism. This paper studies an effcient method to analyze the performance of the power saving class type II for delay sensitive traffc in multiple sleep state. The incoming data frames may join or balk the buffer due to impatience with some probability. We present an M/M/1/N queueing model with balking and multiple vacations in order to exhibit the self-similar property of IEEE 802.16e. We develop a cost function to determine the optimal service rate that minimizes the total expected cost. Various performance indices such as the average number of data frames in the system, the mean waiting time of the data frame in the system, the the average balking rate due to impatience, etc. have been presented. Numerical results are provided to show the inuence of various parameters on the behavior of the system. The proposed model provides a tradeoff between the average abandon rate and the power consumption.

  13. Performance evaluation of complete data transfer of physical layer according to IEEE 802.15.4 standard

    Science.gov (United States)

    Raju, Kota Solomon; Merugu, Naresh Babu; Neetu, Babu, E. Ram

    2016-03-01

    ZigBee is well-accepted industrial standard for wireless sensor networks based on IEEE 802.15.4 standard. Wireless Sensor Networks is the major concern of communication these days. These Wireless Sensor Networks investigate the properties of networks of small battery-powered sensors with wireless communication. The communication between any two wireless nodes of wireless sensor networks is carried out through a protocol stack. This protocol stack has been designed by different vendors in various ways. Every custom vendor possesses his own protocol stack and algorithms especially at the MAC layer. But, many applications require modifications in their algorithms at various layers as per their requirements, especially energy efficient protocols at MAC layer that are simulated in Wireless sensor Network Simulators which are not being tested in real time systems because vendors do not allow the programmability of each layer in their protocol stack. This problem can be quoted as Vendor-Interoperability. The solution is to develop the programmable protocol stack where we can design our own application as required. As a part of the task first we tried implementing physical layer and transmission of data using physical layer. This paper describes about the transmission of the total number of bytes of Frame according to the IEEE 802.15.4 standard using Physical Layer.

  14. Empirical investigation on the dependence of TCP downstream throughput on SNR in an IEEE802.11b WLAN system

    Directory of Open Access Journals (Sweden)

    Ikponmwosa Oghogho

    2017-04-01

    Full Text Available The dependence of TCP downstream throughput (TCPdownT on signal to noise ratio (SNR in an IEEE802.11b WLAN system was investigated in various environments and varieties of QoS traffic. TCPdownT was measured for various SNR observed. An Infrastructure based IEEE802.11b WLAN system having networked computers on which measurement software were installed, was set up consecutively in various environments (open corridor, small offices with block walls and plaster boards and free space. Empirical models describing TCPdownT against SNR for different signal ranges (all ranges of signals, strong signals only, grey signals only and weak signals only were statistically generated and validated. As the SNR values changed from high (strong signals through low (grey signals to very low (weak signals, our results show a strong dependence of TCPdownT on the received SNR. Our models showed lower RMS errors when compared with other similar models. We observed RMS errors of 0.6734791 Mbps, 0.472209 Mbps, 0.9111563 Mbps and 0.5764460 Mbps for general (all SNR model, strong signals model, grey signals model and Weak signals model respectively. Our models will provide researchers and WLAN systems users with a tool to estimate the TCP downstream throughput in a real network in various environments by monitoring the received SNR.

  15. A Power-Efficient Access Point Operation for Infrastructure Basic Service Set in IEEE 802.11 MAC Protocol

    Directory of Open Access Journals (Sweden)

    Hua Ye Ming

    2006-01-01

    Full Text Available Infrastructure-based wireless LAN technology has been widely used in today's personal communication environment. Power efficiency and battery management have been the center of attention in the design of handheld devices with wireless LAN capability. In this paper, a hybrid protocol named improved PCF operation is proposed, which intelligently chooses the access point- (AP- assisted DCF (distributed coordinator function and enhanced PCF (point coordinator function transmission mechanism of IEEE 802.11 protocol in an infrastructure-based wireless LAN environment. Received signal strength indicator (RSSI is used to determine the tradeoff between direct mobile-to-mobile transmission and transmission routed by AP. Based on the estimation, mobile stations can efficiently communicate directly instead of being routed through AP if they are in the vicinity of each other. Furthermore, a smart AP protocol is proposed as extension to the improved PCF operation by utilizing the historical end-to-end delay information to decide the waking up time of mobile stations. Simulation results show that using the proposed protocol, energy consumption of mobile devices can be reduced at the cost of slightly longer end-to-end packet delay compared to traditional IEEE 802.11 PCF protocol. However, in a non-time-critical environment, this option can significantly prolong the operation time of mobile devices.

  16. Performance Analyses and Improvements for the IEEE 802.15.4 CSMA/CA Scheme with Heterogeneous Buffered Conditions

    Directory of Open Access Journals (Sweden)

    Chunfeng Lv

    2012-04-01

    Full Text Available Studies of the IEEE 802.15.4 Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA scheme have been received considerable attention recently, with most of these studies focusing on homogeneous or saturated traffic. Two novel transmission schemes—OSTS/BSTS (One Service a Time Scheme/Bulk Service a Time Scheme—are proposed in this paper to improve the behaviors of time-critical buffered networks with heterogeneous unsaturated traffic. First, we propose a model which contains two modified semi-Markov chains and a macro-Markov chain combined with the theory of M/G/1/K queues to evaluate the characteristics of these two improved CSMA/CA schemes, in which traffic arrivals and accessing packets are bestowed with non-preemptive priority over each other, instead of prioritization. Then, throughput, packet delay and energy consumption of unsaturated, unacknowledged IEEE 802.15.4 beacon-enabled networks are predicted based on the overall point of view which takes the dependent interactions of different types of nodes into account. Moreover, performance comparisons of these two schemes with other non-priority schemes are also proposed. Analysis and simulation results show that delay and fairness of our schemes are superior to those of other schemes, while throughput and energy efficiency are superior to others in more heterogeneous situations. Comprehensive simulations demonstrate that the analysis results of these models match well with the simulation results.

  17. Efficient Distributed Authentication Key Scheme for Multi-hop Relay In IEEE 802.16j Network

    Directory of Open Access Journals (Sweden)

    ADNAN SHAHID KHAN,

    2010-06-01

    Full Text Available Relaying and cooperation have re-emerged as important research topic in the wireless communication over the past decade. IEEE 802.16j Multihop relay network is assiduously developing to accomplish high capacity services with large cell coverage. Considerable interest currently exists in the exploitation of Relay based Wimax. This is mainly the result of lower infrastructure cost and high data transfer rates compared to existing 3G. However due to lack of physical boundaries and injection of distributed relays, it is known to be morevulnerable to security holes as a trade off. In this paper we propose a new distributed authentication key scheme for Multihop Relays IEEE 802.16j network service. The propose scheme uses decode and forward relays with localized authentication. The scheme works in distributed authentication to authenticate Subscriber station (SS and Relay stations (RS at initial network entry. Our new efficient distributed scheme utilizes healthy security issues and the Multihop Relay network application features. Both analysis and performance evaluation shows that our scheme can significantly reduce the security holes as well as communication overheads.

  18. Performance Analyses and Improvements for the IEEE 802.15.4 CSMA/CA Scheme with Heterogeneous Buffered Conditions

    Science.gov (United States)

    Zhu, Jianping; Tao, Zhengsu; Lv, Chunfeng

    2012-01-01

    Studies of the IEEE 802.15.4 Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) scheme have been received considerable attention recently, with most of these studies focusing on homogeneous or saturated traffic. Two novel transmission schemes—OSTS/BSTS (One Service a Time Scheme/Bulk Service a Time Scheme)—are proposed in this paper to improve the behaviors of time-critical buffered networks with heterogeneous unsaturated traffic. First, we propose a model which contains two modified semi-Markov chains and a macro-Markov chain combined with the theory of M/G/1/K queues to evaluate the characteristics of these two improved CSMA/CA schemes, in which traffic arrivals and accessing packets are bestowed with non-preemptive priority over each other, instead of prioritization. Then, throughput, packet delay and energy consumption of unsaturated, unacknowledged IEEE 802.15.4 beacon-enabled networks are predicted based on the overall point of view which takes the dependent interactions of different types of nodes into account. Moreover, performance comparisons of these two schemes with other non-priority schemes are also proposed. Analysis and simulation results show that delay and fairness of our schemes are superior to those of other schemes, while throughput and energy efficiency are superior to others in more heterogeneous situations. Comprehensive simulations demonstrate that the analysis results of these models match well with the simulation results. PMID:22666076

  19. Performance modeling of a two-tier primary-secondary network with IEEE 802.11 broadcast scheme

    KAUST Repository

    Khabazian, Mehdi

    2011-03-01

    In this paper, we study the performance of a two-tier primary-secondary network based on IEEE 802.11 broadcast scheme. We assume that a number of primary and secondary users coexist in the radio environment and share a single band. To protect the primary users\\' priority, the secondary users are allowed to contend for the channel only if they sense it idle for a certain sensing time. Considering an exponential packet inter-arrival time for the primary network, we model each primary user as an independent M/G/1 queue. Subsequently, we determine the primary users\\' average medium access delay in the presence of secondary users as well as the hybrid network\\'s throughput. Numerical results and discussions show the effects of parameters pertaining to the secondary users, such as as sensing time, packet payload size and population size, on the performance of the primary network. Furthermore, we provide simulation results which confirm the accuracy of the proposed analysis. © 2011 IEEE.

  20. Improving the communication reliability of body sensor networks based on the IEEE 802.15.4 protocol.

    Science.gov (United States)

    Gomes, Diogo; Afonso, José A

    2014-03-01

    Body sensor networks (BSNs) enable continuous monitoring of patients anywhere, with minimum constraints to daily life activities. Although the IEEE 802.15.4 and ZigBee(®) (ZigBee Alliance, San Ramon, CA) standards were mainly developed for use in wireless sensors network (WSN) applications, they are also widely used in BSN applications because of device characteristics such as low power, low cost, and small form factor. However, compared with WSNs, BSNs present some very distinctive characteristics in terms of traffic and mobility patterns, heterogeneity of the nodes, and quality of service requirements. This article evaluates the suitability of the carrier sense multiple access-collision avoidance protocol, used by the IEEE 802.15.4 and ZigBee standards, for data-intensive BSN applications, through the execution of experimental tests in different evaluation scenarios, in order to take into account the effects of contention, clock drift, and hidden nodes on the communication reliability. Results show that the delivery ratio may decrease substantially during transitory periods, which can last for several minutes, to a minimum of 90% with retransmissions and 13% without retransmissions. This article also proposes and evaluates the performance of the BSN contention avoidance mechanism, which was designed to solve the identified reliability problems. This mechanism was able to restore the delivery ratio to 100% even in the scenario without retransmissions.