| 摘要 |
PROBLEM TO BE SOLVED: To improve battery saving efficiency and to extend the battery life by detecting the 2nd network information during an external operation to lock the channel frequency based on the detected network information and discontinuing all channel frequency scans until the step-out occurs. SOLUTION: A channel is scanned in the battery saving timing set in an asynchronous state. When a synchronizing signal is detected in the scanned channel and the synchronization is established, the channel is scanned in the battery saving timing. A CPU 402 is uniquely locked at the frequency of an external area to omit the scanning of all frequency bands if the external area information is included in the batch where the CPU 402 itself belongs and the network information on an associate area having the service contract settled in the said batch is available. As a result, the battery saving efficiency is improved. |
