| 摘要 |
PROBLEM TO BE SOLVED: To attain direct communication between respective portable telephones without being through any base station. SOLUTION: When a user performs an emergency calling operation during an accident, for example, in a mountain with no existence of a base station, a control part 13 controls a communication circuit 2 so as to transmit a pilot signal on a prescribed emergency channel. The pilot signal on the emergency channel is broadcast and transmitted. A portable telephone belonging to a rescue team searches channels of a communication channel and the emergency channel, and catches the pilot signal to attain communication synchronization when the pilot signal is detected on the emergency channel. Thus, a direct communication line is established between the portable telephone of the user in the accident and the portable telephone of the rescue team without going through a base station so that speech communication or the like can be directly performed between the portable telephone of the user in the accident and the portable telephone of the rescue team. COPYRIGHT: (C)2007,JPO&INPIT
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