Fixed Wireless Access Systems The goal of this chapter is to review the main techniques used for Wireless Local Loop (WLL) including the Multichannel Multipoint Distribution Service (MMDS), and the Local Multipoint Distribution Service (LMDS). We also present the main aspects, advantages and disadvantages, and applications of these techniques. The chapter also deals with the wireless local loop subscriber terminals, Wireless Local Loop Interfaces to the Public Switched Telephone Network (PSTN), and the IEEE standards on Broadband Wireless Access. Then a final section is given to summarize the main points presented in this chapter. . | Wireless Networks. P. Nicopolitidis M. S. Obaidat G. I. Papadimitriou and A. S. Pomportsis Copyright 2003 John Wiley Sons Ltd. ISBN 0-470-84529-5 8 Fixed Wireless Access Systems The goal of this chapter is to review the main techniques used for Wireless Local Loop WLL including the Multichannel Multipoint Distribution Service MMDS and the Local Multipoint Distribution Service LMDS . We also present the main aspects advantages and disadvantages and applications of these techniques. The chapter also deals with the wireless local loop subscriber terminals Wireless Local Loop Interfaces to the Public Switched Telephone Network PSTN and the IEEE standards on Broadband Wireless Access. Then a final section is given to summarize the main points presented in this chapter. Wireless Local Loop versus Wired Access Fixed Wireless Access FWA systems which can also be called Wireless Local Loop WLL systems are intended to provide primary access to the telephone network that is wireless services supporting subscribers in fixed and known locations. In general WLL is a system that connects subscribers to the public switched telephone network PSTN using radio signals as a substitute for copper transmission media for all or part of the connection between the subscriber and the switch. This may include cordless access systems proprietary fixed radio access and fixed cellular systems. There are two alternatives to WLL narrowband and broadband schemes. Narrowband WLL offers a replacement for existing telephone system while broadband WLL can provide high speed voice and data service. Some authors call WLL Radio In The Loop RITL Fixed-Radio Access FRA or Fixed Wireless Access FWA 1 2 . It is expected that the global WLL market will exceed 202 million subscribers by the year 2005. Much of this growth will be in the developing countries where over half the world s population lacks Plain Old Telephone Service POTS . This approach is cost effective and can save burying tons of .
