TAILIEUCHUNG - Điện thoại di động mạng lưới Radio P11

Development of the Personal Handyphone System in Japan At the end of the 1980s, two cordless telephone systems, CT2 and DECT, had entered the second step of their development process. At that time, Japan had not yet developed any comparable technology; therefore work began in 1989 on a Japanese cordless standard, which has become known as the Personal Handyphone System (PHS). Disadvantages of conventional cellular telephone systems, such as high costs of infrastructure and cell-planning resulting in high communication fees, had motivated the development of a less expensive system. . | Mobile Radio Networks Networking and Protocols. Bernhard H. Walke Copyright 1999 John Wiley Sons Ltd ISBNs 0-471-97595-8 Hardback 0-470-84193-1 Electronic 11 Personal Handyphone System PHS Development of the Personal Handyphone System in Japan At the end of the 1980s two cordless telephone systems CT2 and DECT had entered the second step of their development process. At that time Japan had not yet developed any comparable technology therefore work began in 1989 on a Japanese cordless standard which has become known as the Personal Handyphone System PHS . Disadvantages of conventional cellular telephone systems such as high costs of infrastructure and cell-planning resulting in high communication fees had motivated the development of a less expensive system. The review by the Telecommunications Technology Council a consulting organization for the Japanese Ministry of Posts and Telecommunications MPT and the technical study by the Research and Development Centre for Radio Systems RCR of PHS started at the beginning of 1991 in Japan. The PHS air interface was then standardized through the publication of the RCR STD-28 1 Version 1 in December 1993. Various held trials in the Sapporo area in October 1993 and in the Tokyo area in April 1994 were then conducted to prove the feasibility of PHS for various demands and services respectively. The PHS service was commercially launched in Japan by three operator groups NTT Nippon Telegraph and Telephone Personal Group DDI Daini Denden Inc. Pocket Telephone Group and the Astel Group in July 1995. The technology gained unprecedent popularity with the number of subscribers reaching the six million mark by the beginning of 1997 just two years after its introduction. As of August 1998 the number of subscribers was about million 4 . Attracted by the success in Japan other Asian countries including Thailand and Hong Kong and some South American countries announced plans to establish PHS networks. With the collaboration of .

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