MOBILE RADIO TELEPHONE SET

摘要

PROBLEM TO BE SOLVED: To enable voice communication to be performed by using a public telephone set without using the handset of the public telephone set by utilizing a portable telephone set. SOLUTION: The portable telephone set 1 is connected to the data port of an ISDN 4 complying public telephone 3 through an adapter 2. In the case of performing communication by using the ISDN 4, the telephone set 1 sets a communication channel between the opposite communication telephone set 5 and a portable telephone 1 by making a call-out to the ISDN 4 through the adapter 2 and the telephone 3 not through a radio base station. The speech communication is performed between the portable telephone 1 and the telephone set 5 by transmitting/receiving voice data on the communication channel.