Đang chuẩn bị liên kết để tải về tài liệu:
Wireless địa phương vòng - lý thuyết và ứng dụng P10

Wireless local loop (WLL) or fixed wireless access systems are attractive solutions to the so-called last mile problem because of their low capital cost, fast network deployment capability and low maintenance cost [1]. They would, therefore, be effective during the transition period from fibre to the curb (FTTC) to fibre to the home (FTTH). WLL has the potential of becoming a major competitor of local exchange networks, cable television (CATV) networks | Wireless Local Loops Theory and Applications Peter Stavroulakis Copyright 2001 John Wiley Sons Ltd ISBNs 0 471 49X46 7 Hardback 0-470-84187-7 Electronic Part II Applications Wireless Local Loops Theory and Applications Peter Stavroulakis Copyright 2001 John Wiley Sons Ltd ISBNs L71 PLS 7 Hardback 70-84187-7 Electronic 10 Development of a Prototype of the Broadband Radio Access Integrated Network Masugi Inoue Gang Wu and Yoshihiro Hase 10.1 Introduction Wireless local loop WLL or fixed wireless access systems are attractive solutions to the so-called last mile problem because of their low capital cost fast network deployment capability and low maintenance cost 1 . They would therefore be effective during the transition period from fibre to the curb FTTC to fibre to the home FTTH . WLL has the potential of becoming a major competitor of local exchange networks cable television CATV networks digital subscriber line family xDSL and FTTH. Actually the federal communications commission FCC in the U.S.A licensed 1 GHz of spectrum at 28 GHz and an additional 300 MHz of spectrum at 31 GHz for local multipoint distribution service LMDS systems. LMDS systems use mm-wave signals in those bands to transmit voice video and data signals within cells 3-10 miles in diameter. In Europe the European Telecommunications Standards Institute ETSI has started a project for standardization of LMDS-like system called HIPERACCESS for physical and data link control DLC layers. In Japan the Ministry of Posts and Telecommunications has announced that in the first stages of spectrum allocation in total 2040 MHz of spectrum at 22 26 and 38 GHz bands will be allocated to service providers offering point-to-point and point-to-multipoint wireless access services. In addition to these broadband systems attention is being paid to narrowband WLL systems that are based on the Japanese digital cordless phone system called personal handy-phone system PHS . WLL technology is also gaining popularity in the