Generation Change in Cellular Systems In Japan, mobile communications systems based on cellular technology have evolved, as illustrated in Figure . The first-generation analog car phones were first introduced in 1979, followed by the commercialization of the second-generation digital phones in 1993. Mobile phone subscribers have rapidly increased in number since then, owing to the liberation of terminal sales and continuous price reductions. In March 2000, the number of mobile phone subscribers outnumbered those of fixed telephones. Meanwhile, the expansion of data communications on a global scale – spearheaded by the Internet – is promoting the introduction of Packet-Switched (PS). | W-CDMA Mobile Communications System. Edited by Keiji Tachikawa Copyright 2002 John Wiley Sons Ltd. ISBN 0-470-84761-1 1 Overview Keisuke Suwa Yoshiyuki Yasuda and Hitoshi Yoshino Generation Change in Cellular Systems In Japan mobile communications systems based on cellular technology have evolved as illustrated in Figure . The first-generation analog car phones were first introduced in 1979 followed by the commercialization of the second-generation digital phones in 1993. Mobile phone subscribers have rapidly increased in number since then owing to the liberation of terminal sales and continuous price reductions. In March 2000 the number of mobile phone subscribers outnumbered those of fixed telephones. Meanwhile the expansion of data communications on a global scale - spearheaded by the Internet - is promoting the introduction of Packet-Switched PS communication systems that are suitable for data communications in a mobile environment. The standardization and system development of the next-generation mobile communications system known as the Third-Generation 3G International Mobile Telecommuni-cations-2000 IMT-2000 began in response to the rising need in recent years to achieve high-speed data communications capable of supporting mobile multimedia services and developing a common platform that would enable mobile phone subscribers to use their mobile terminals in any country across the world. From 2001 onwards IMT-2000 systems using Wideband Code Division Multiple Access W-CDMA technology are due to be introduced. The following is a rundown of mobile phone and car phone systems that have been commercialized to date. Analog Cellular Systems Analog cellular systems were studied by Bell Laboratories in the United States and the Nippon Telegraph and Telephone Public Corporation predecessor of NTT in Japan. The American and Japanese systems are referred to as the Advanced Mobile Phone Service AMPS and the NTT system respectively. Both systems are called .
