Toward the personal communication era—A proposal of the “radio access” concept from Japan

Abstract

This paper presents our insights into so-called “personal communication” and describes a conceptual proposal of “radio access,” which connects terminals with network services. Firstly, personal communication services are classified into basic (personal connection) services and advanced (personalized) services. Based on this categorization, features of the Japanese Personal Handy Phone (PHP) system, which offers services in homes, offices, and outdoor environments using a small cordless telephone terminal, are presented. The PHP system is defined here as a combination of three functional elements: a digital cordless terminal, radio access, and intelligent network. Secondly, the PHP system is described in detail including service definition, system design, network configuration, and evolutional scenario. Thirdly, we present standardization activities for the PHP-common air interface (CAI). The results of a three-month series of verification experiments, which have been successfully completed in 1992, are also explained. Based on the results, the specifications of PHP CAI were fixed at the end of 1992 through the cooperation of MPT, industries, and network operators. Technical items, mainly the 1.9-GHz 4-channel TDMA-TDD technology, are presented. Concerning R&D activities, the structure of frame synchronization for improving frequency utilization efficiency is described as one example of the many technical breakthroughs made in developing the PHP system. Finally, general considerations on service aspects of the PHP system are presented. This section includes comparisons between PHP and cellular systems from service viewpoints, such as charging, terminal performance, and service coverage area. The important results demonstrate the possibility of the coexistence of and the prosperity of both systems, due to the spread of the outdoor communication market caused by the introduction of the economical PHP system. In addition, our view on the phased approach for future service integration is given.