| 摘要 |
PROBLEM TO BE SOLVED: To accurately grasp the state of the opposite party of calling by preparing such a constitution where a portable telephone set notifies a base station of the on/off state of a power supply, the base station manages the on/off state of the telephone set based on the notification received from the telephone set and then the base station transmits a message showing the off- state of the power supply or an out-of-area state to the calling side if no answer is received from the telephone set after receiving an incoming call and calling the telephone set. SOLUTION: When the power supply of a portable telephone set 1 is turned off by a user, the power off control is started at a PS control part 10 and an off-signal is transmitted to a base station 2. The power OFF reception processing is started at the station 2 via a CS control part 20. Then the identifier of the set 1 is stored in a storage part 23, and an off-confirmation signal is transmitted to the set 1. If the calling is confirmed under such conditions, the set 1 is called and no answer is received from the set 1 since its power supply is kept in an off-state. Thus, a message is sent to the calling side to show the power-off state after confirming that the identifier of the set 1 is stored in the part 23. |
