| 摘要 |
PROBLEM TO BE SOLVED: To prevent a contact even in radio communication between a portable telephone set and a hand-free set by transmitting an identifying code from a transmission side and also validating a receiving signal only when the identifying code has been matched at a reception side. SOLUTION: An originating signal is transmitted from the hand-free set 1 to a radio module 3 side in originating a call but, at the same time, an ID code is transmitted from the hand-free set 1 to a radio module 3. The radio module 3 recognizes the ID code which is received together with an originating signal at first and executes the originating signal so as to start a speech when the ID code has been matched with the one which is stored at a module 3 side. Thus, when an operation switch 16 is operated and the call is originated from the hand-free set 1, the ID code intrinsic to the hand-free set 1 is simultaneously transmitted and a call originating operation is executed after recognizing it at the radio module 3 side so that one's own portable telephone set is not used in the hand-free set of another person. |
