論文

The authors present their insights into the so-called 'personal communication' and describe 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, the features of the JapanesePersonal Handy Phone (PHP) system, which offers services in homes, offices, and outdoor environments using a small cordless telephoneterminal, 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, they present standardization activities for the PHP-common air interface (CAI).The results of a three-month series of verification experiments arealso!explained. Technical items, mainly the 1.9-GHz 4-channel TDMA-TDD technology, are presented. The structure of frame synchronization for improving frequency utilization efficiency is described as one example of the many technical breakthroughsmade in developing the PHP system. Finally, general considerations on service aspects of the PHP system are presented.