| 摘要 |
PROBLEM TO BE SOLVED: To avoid in advance the continuation of a silent state over a long time. SOLUTION: When the silent state is detected to continue for a predetermined time or more, a radio status report 2 is transmitted to a portable telephone network 10. The portable telephone network 10 transmits the designation of a radio channel for changeover destination, when the radio status report 2 is received from the portable telephone terminal 1. When the portable telephone terminal 1 receives the designation of the radio channel for changeover destination from the portable telephone network 10, it can perform switching of the communication channel. Thereafter, the continuation of the silent state is avoided previously to continue over a long time by performing switching to other communication channels from a communication channel responsible for the silent state when the communication channel of the changeover destination is normal. |
