Broadband Wireless Access: 578 (The Springer International Series in Engineering and Computer Science) - Tapa blanda

This chapter has discussed how a commonbroadcast medium can be shared among many contending users. Multiple access protocols differ primarily by the amount of coordination needed to control potentially conflicting packet transmissions. Ato neextreme is random access where no coordinationis provideda ndp acket collisions arep ossible. Atthe other endo fthe spectrum, the class of fixed assignment access protocols eliminates collisions entirely butpay the price ofadditional overhead required forscheduling user access. Hybrid access protocolsb etweenthese two extremes exist While these protocols attempt to combine the advantages ofrandom andfixed access, they also suffer the c ombined drawbacks and overhead ofboth classes of access schemes. Amongt he many factors that determine the performance ofa n access protocol include the propagation delay/packet transmission timeratio, the message arrival process, the types of feedback information available, the user population, and the ability of the user to sense the activities in the network. BIBLIOGRAPHY [ABRA93] Abramson, N. , Multiple Access Communications , IEEE Press, 1993. [BERT92] Bertsekas, D. and Gallager, R. , Data Networks , Prentice Hall, 1992. [CHOU83]Chou,W, ComputerCommunications Volume1:Principles , Prentice Hall, 1983. [CIDO87] Cidon, I. andSidi, M. , "Erasures and Noise in Splitting Multiple Access Algorithms", IEEE Transactions on Information Theory, Vol. 33, No. 1, January 1987, pp. 132 - 140. [CIDO88] Cidon, I, Kodesh, H. and Sidi, M. , "Erasure, Capture and Random Power Level Selectionin Multiple Access Systems", IEEE Transactions on Communications , Vol. 3 6,N o. 3,March 1988, pp. 263 - 271.

This book discusses the design, performance and implementation of access protocols with emphasis on how such protocols can efficiently support disparate classes of multimedia traffic. These protocols are deployed or experimented in various broadband wireless environments such as wireless ATM, satellite networks, mobile cellular and personal communication systems, wireless local loops, wireless local area networks, and others. Besides a comprehensive introduction and survey to the evolution of access protocols, some of the hottest topics of current interest are covered. These include: * Connection control and QoS provisioning. * Traffic load balancing techniques. * Developments in advanced CDMA/TDMA/OFDM systems. * International standardization efforts (e.g., 3G, IMT 2000). * Emerging broadband wireless access (e.g., wireless ATM, satellite ATM, high-speed wireless LANs). * The complete design, performance analysis, simulation and protocol verification of a generalized broadband multiple access protocol. While engineering aspects are discussed, the emphasis is on the physical understanding of access protocols, from basic proposals to the latest innovations. Mathematical treatment is kept to a minimum, and most of the fundamental concepts are explained based on intuition and insights, supplemented by numerous illustrative figures. In addition, these concepts are expressed succinctly and concisely. Wherever possible, important references that make major contributions to the field are included for interested readers to investigate further. Latest updates and useful Web resources are posted at the book's Web site.