Tài liệu Dịch vụ mạng thế hệ kế tiếp P4 pdf

4

Mobile Networks

4.1 INTRODUCTION

Mobile telephony networks have been a phenomenal success story since

their introduction in the mid- to late 1980s. This success is being built

upon, and a number of operators (old and new) around the world are

looking to provide the latest generation of mobile network technology

labelled 3G for third generation. The 3G label is based on the generally

accepted premise that the first-generation cellular networks are the analo￾gue-based ones first made popular in the late 1970s and early 1980s

(AMPS in the US, TACS in the UK, NMT450/900 in Scandinavian coun￾tries and an NTT standard in Japan, more on these later), and that the

second generation the digital cellular networks that arrived in the early

1990s (global system for mobile communications (GSM) in Europe, perso￾nal digital cellular in Japan, D-AMPS or IS-54, IS-136 and IS-95 in the US,

again more on these later in the chapter).

The 3G mobile networks are subject to a set of standards developed by

the International Telecommunications Union (ITU) (formally CCITT),

Europe Telecommunications Standards Institute (ETSI) and the European

RACE project. This work was started as long ago as 1986.

The ITU concept is based around handset mobility, and the early

programme was dubbed future public land mobile telephone system

(FPLMTS). The concepts were expanded to include the idea that a user

should be able to access any telecommunications service from any suita￾ble terminal connected at any point on any network. This became known

as personal mobility. The ITU went on to define the concept as Universal

Personal Telecommunications (UPT). The ITU was dragging its feet on

what the standard should finally look like and the choice of technology for

FPLMTS. FPLMTS was eventually renamed international mobile commu￾Next Generation Network Services

Neill Wilkinson

Copyright q 2002 John Wiley & Sons, Ltd

ISBNs: 0-471-48667-1 (Hardback); 0-470-84603-8 (Electronic)