| 摘要 |
PURPOSE:To obtain the same functions as those of the so-called ideal portable telephone set using a radio channel for a duplex channel, by giving effect to digital IC-implementation on the whole except talking-concerned circuits by using a conventional switching network nearly as it is. CONSTITUTION:Fixed telephone subscriber 1 calls a traveling subscriber with portable telephone set 9 via radio calling transmission station 4 and the traveling subscriber having received this call connects the portable telephone set 9 to a regular telephone network via connector 16 to have a talk. Following the call from radio calling transmission station 4 to portable telephone set 9, a calling-subscriber's number is sent and the portable telephone set receives the call on judging that this call is directed to its own station, and has the function of displaying the calling- subscriber's number. Further, when a talk is taken by connecting the portable telephone set to the regular telephone network via the connector, an exchange sends out a message-rate signal, which is counted by telephose set 9, and when this message rate reaches a certain limit, replaceable built-in memory 19 is broken to disable the call. |
