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无线局域网（WLAN）技术的发展带来的多媒体业务流量的剧增,是无线网络的资源管理、服务质量（QoS）保障等问题日益突出,传统的媒体访问控制（MAC）协议需要重新设计才能对无线网络的QoS问题进行有效的解决。本文介绍了无限局域网QoS技术的发展,包括针对IEEE802．11MAC层协议进行的各种QoS增强技术。通过与传统的802．11标准的MAC层进行对比分析,讨论了IEEE802．11e的两个新的策略：增强的分布式协调功能和混合协调功能。通过对受控竞争机制的分析,指出了IEEE802．11e仍存在的不足及未来的发展方向。 相似文献
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无线局域网QoS机制解析 总被引：1，自引：0，他引：1
无线局域网（WLAN）技术的发展带来的多媒体业务流量的剧增,使无线网络的资源管理、服务质量（QoS）保障等问题日益突出,传统的媒体访问控制（MAC）协议需要重新设计才能有效地解决无线网络的QoS问题。本文介绍了无限局域网QoS技术的发展,包括针对IEEE802．11 MAC层协议进行的各种QoS增强技术。通过与传统的802．11标准的MAC层进行对比分析．讨论了IEEE802．11e的2个新策略：增强的分布式协调功能和混合协调功能。通过对受控竞争机制的分析,指出了IEEE802．11e仍存在的不足及未来的发展方向。 相似文献
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文章介绍了无线局域网和无线个域网所涉及的主要标准的应用场合、技术特点及协议构成，比较了它们存在的差异及各自的特点，并根据市场发展给出了它们可能的发展趋势。 相似文献
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本文介绍了超宽带技术和无线个域网的概念和基于超宽带技术的高速无线个域网的性能特点及应用，并与其他短距离无线通信方式进行了比较和技术评价，最后对它的局限性、问题和未来发展方向做了仔细分析。 相似文献
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近年来,超宽带(UWB)无线通信成为短距离、高速无线网络最热门的物理层技术之一。介绍了超宽带无线通信技术的概念及其信号传输过程中使用的关键技术,包括脉冲成形技术、调制技术以及接收技术,给出了超宽带无线传输系统的基本模型,最后分析了该技术在无线多媒体个域网中的应用。 相似文献
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无线个域网(WPAN)是一种与无线广域网(WWAN)、无线城域网(WMAN)、无线局域网(WLAN)并列但覆盖范围相对较小的无线网络.WPAN所覆盖的范围一般在10m半径以内,必须运行于许可的无线频段.WPAN能够有效地解决"最后的几米电缆"的问题,进而将无线联网进行到底.阐述了无线个域网基本概念、网络分类及特点,并将其与无线局域网进行简单比较,同时对相关技术进行了分析. 相似文献
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近年来,超宽带(UWB)无线通信成为短距离、高速无线网络最热门的物理层技术之一。本文介绍了UWB的发展历史并详细归纳了技术特性,最后分析了该技术在无线多媒体个域网中的应用。 相似文献
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针对太赫兹无线个域网双信道媒体访问控制(Medium Access Control, MAC)协议中存在的信道资源分配公平性差、数据帧重传效率低和控制开销较高的问题,提出了一种公平高效的MAC层优化机制。新机制采用基于历史时隙申请信息的信道资源分配策略优化时隙分配公平性,根据信道质量自适应选择数据帧重传机制,控制节点从申请时隙的节点发送的控制帧中的“duration”字段提取时隙申请信息,省略时隙申请帧的发送,从而降低数据帧排队时延和控制开销,提高吞吐量。仿真结果表明,与TAB-MAC和MDP-MAC协议的机制相比,所提机制的数据帧平均排队时延降低了15%,吞吐量提高了5%。 相似文献
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Hännikäinen Marko Lavikko Tommi Kukkala Petri Hämäläinen Timo D. 《Telecommunication Systems》2003,23(3-4):297-333
Quality of Service (QoS) support has generally been lacking from WPAN and WLAN technologies, which has motivated the research
of TUTWLAN. Design objectives have been relatively simple network architecture and capability to support real time services
ranging from sensor data to multimedia streaming. The main TUTWLAN entities for QoS support are the Medium Access Control
(MAC) protocol called TUTMAC and TUTWLAN Access Point (AP). The channel access is based on dynamic reservation Time Division
Multiple Access (TDMA). TUTWLAN is shown to be suitable for wireless home and office applications. It provides flexibility,
interoperability and availability of services exceeding the recent QoS proposals that has been accounted at the standardisation
bodies for standard wireless technologies.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
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Zhao Liqiang Zhang Jie Zhang Hailin 《Wireless Communications and Mobile Computing》2009,9(9):1220-1230
IEEE 802.11 is one of the most influential wireless LAN (WLAN) standards. Point coordination function (PCF) is its medium access control (MAC) protocol with real‐time traffic (rt‐traffic) quality‐of‐service (QoS) guarantees. In PCF, it is very likely that non‐real‐time traffic (nrt‐traffic) will use the contention free period (CFP) that should be dedicated to traffic having higher priority such as rt‐traffic. Therefore, a modified PCF protocol called MPCF, which is based on hub polling and an integrated QoS differentiation, is presented in this paper. With the integrated QoS differentiation, MPCF can prioritize bandwidth requests according to service classes and QoS requirements. With hub polling, MPCF can reduce the bandwidth for control frames and improve the network throughput. A simple and accurate analytical model is derived and presented in this paper to calculate the system throughput of MPCF. Simulation results show that MPCF protocol is much better than PCF in terms of system capacity and rt‐traffic QoS guarantees. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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提出了一种在分布式UWB网络结构中提供QoS服务的MAC协议.该MAC协议能够自适应地协调功耗与速率,设计过程分为资源分配和多路接入两方面.仿真结果表明,通过与功率控制机制及速率控制机制的比较.提出的协议在功率消耗,网络吞吐量及延时方面都有较好的改善. 相似文献
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In this paper we introduce a novel MAC protocol that provides Quality of Service (QoS) support for multimedia traffic in UWB-based
wireless local area networks. The proposed protocol allocates transmission opportunities to QoS and best effort traffic using
a set of scheduling and resource control algorithms. The algorithms account for the UWB characteristics such as the co-existence
of multiple simultaneous transmissions as well as the possibility of dynamically assigning the nodes' transmission rate and
power. The simulation results show that the proposed protocol can provide QoS support while optimizing resource utilization.
Yuechun Chu received her B.Sc. degree in electrical engineering from Shanghai University, China, in 1996 and M.Sc. degree in electrical
engineering from University of Science and Technology of China in 1999. She is currently pursuing the Ph.D. degree in the
department of electrical and computer engineering at the University of Massachusetts Amherst. Her research interests include
MAC protocol design for UWB-based networks, wireless multimedia applications, and architectures and protocols for wireless
networks with QoS guarantees.
Aura Ganz is currently an Associate Professor and Director of the Multimedia Networks Laboratory at the ECE Department, University
of Massachusetts at Amherst. She has experience in topics related to multimedia wireless networks, optical networks and ubiquitous
computing. The research results are validated by a combination of analytical, simulation and prototyping tools. She has published
a book “Multimedia Wireless Networks: Technologies, Standards and QoS” (Prentice Hall) and authored over one hundred and fifty
peer reviewed publications. Dr. Ganz received her BSc, MSc and Ph.D degrees in Computer Science from the Technion in Israel. 相似文献
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Giuseppe Razzano Francesco Delli Priscoli Roberto Cusani 《Wireless Personal Communications》2006,39(1):25-40
The paper describes the design and simulation of a radio modem architecture, which provides wireless access to Internet in a single-hop, ad hoc network.The main emphasis is on the Medium Access Control (MAC) and Dynamic Link Control (DLC) layer’s design, and in particular on the adopted innovative scheduling algorithm, which has been developed to satisfy the system requirements of the WIND-FLEX radio modem. The algorithm is presented and compared to the Earliest Deadline First (EDF) solution.Several software simulation tests have been executed on the network, to test the performance of the system, in order to verify the capability of the scheduler algorithm to satisfy the expected requirements and the efficiency of the implemented solutions. Giuseppe Razzano was born in Roma, Italy, in 1974. He has graduated in Electronic Engineering “summa cum laude” and has received PhD in Communication Systems and Computer Science, in 2004 from University of Rome “La Sapienza”. From 2000 to 2001 he worked as research assistant at VTT electronics, in Finland. From 2004 to 2005 he worked as senior researcher at Forschungzentrum Telekommunikation Wien (Telecommunication Research Centre Vienna) in Austria. Currently, he works as System Engineer for Vitrociset S.p.A., working in a project funded by European Space Agency (ESA), for the development of a new generation space launcher vehicle (VEGA). In the past years, he worked in several projects funded by EC within the IST (Information Societies Technology) program, being also involved in projects in collaboration with Italian companies. His research is focused on resource management algorithms for wireless LANs and cellular networks. He is also interested in object-oriented programming and development methodologies. In these fields, he is author of several papers published in international journals and conferences. Francesco Delli Priscoli was born in Rome in 1962. He graduated in Electronic Engineering “summa cum laude” from the University of Rome “La Sapienza” in 1986. He received the Ph.D. in system engineering from the University of Rome “La Sapienza” in 1991. From 1986 to 1991 he worked in the “Studies and Experimentation” Department of Telespazio (Rome). Since 1991 he is working for the University of Rome “La Sapienza” where, at present, he is “Full Professor” and holds the courses “Automatic Controls”, “System Theory” and “Network Control and Management I and II”. In the framework of his activity, he researches in the nonlinear control theory and in the area of control-based resource management procedures for the third and forth generation of mobile systems. He is the author of about 150 technical papers on the above topics appeared on major international reviews (about 50) and conferences (about 100). In 2000 he has been scientific consultant for the Italian Council of Ministers in the framework of the auction for the assignment of the Italian Universal Mobile Telecommunication System (UMTS) licensees. He is an associate editor of Control Engineering Practice and a member of the IFAC Technical Committee on “Networked Systems”. He is/has been scientific responsible, for the University of Rome “La Sapienza”, of 17 projects financed by the European Union (fourth, fifth and sixth framework programmes) or by the European Space Agency (ESA), dealing with resource management for UMTS and broadband terrestrial and satellite wireless systems. He is also a project evaluator for the European Commission. Roberto Cusani received the “laurea” degree in Electronic Engineering (cum laude) and the Ph.D. in Communication Systems and Computer Science from the University of Rome “La Sapienza”. From 1986 to 1990 he was research engineer at the University of Rome “Tor Vergata”, teaching Digital Signal Processing. In 1991 he joined the University of Rome “La Sapienza” as Associate Professor of Signal Theory. In 2000 he becomes Full Professor and teaches Information Theory and Coding, and Mobile Communications. His former research activities concern transmission and coding of signals and images, with emphasis on random processes, spectral estimation and image coding. Since 1992 he focused his activities in the field of the digital communication systems, with emphasis on channel equalisation and coding for HF and radio-mobile (GSM) links, on the design of CDMA receivers for UMTS and, in general, on the use of digital techniques within telecommunication equipments. More recently his interests also includes the study of MAC (Multiple Access Control) protocols with application to wireless area networks (WLANs), reconfigurable ad-hoc networks and satellite links. He is author of more than 100 publications in international journals and conferences, of the text-book “Teoria dei Segnali” and of five patents regarding telecommunication applications. He was involved in many research programs, both national and international, and in projects with the industrie. 相似文献
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介绍了IEEE802.15.3 MAC协议及其QoS机制,分析了超帧中的CAP,针对实时VBR业务流,提出了一种动态资源分配算法,在性能上与平均资源分配算法进行了比较和分析,通过仿真验证了此动态资源分配算法能有效降低实时VBR码流的丢帧率,提高系统传输的QoS. 相似文献
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近年来,超宽带（UWB）无线通信成为短距离、高速度无线网络最热门的物理层技术之一。本文介绍了UWB的发展历史,详细归纳了其技术特性,总结了该技术在无线个域网中的最新应用,并对前景作出了展望。 相似文献
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超宽带（UWB）无线通信技术分析 总被引：1，自引：0，他引：1
超宽带（UWB：ultra—wideband）技术是近几年发展起来的一项十分有潜力的无线通信技术,其高性能、低成本的无线数据通信能力,已成为实现无线个人局域网的富有竞争力的技术之一。文章主要介绍了超宽带技术的特点、基本方案和信道模型,并对比了该技术与其他短距离无线通信技术的优缺点。 相似文献