Abstract: When a cell phone fails in location registry to a base station, it removes the base station from a candidate group. Then it searches for and captures, for the next location registry, a base station whose pilot signal has the highest electric field intensity among the updated candidate group. When the registry is yet to be successful, the cell phone prohibits the location registry with maintaining an idle (waiting) state. Here, the pilot signals are observed among the candidate group. When a certain base station whose pilot signal exceeds a preset level of electric field intensity is detected, the idle handoff to the certain base station is executed. This success of the idle handoff then resumes the location registry to the certain base station.

Abstract: A PDC/PHS phone has both PDC communication function and PHS communication function. The PDC/PHS phone receives a call from a PHS phone through a PHS communication network when it is in the communication with a PDC phone through a PDC communication network. The PDC/PHS phone changes its connection to the PHS communication network to transmit to the PHS phone a fixed answer message indicating that it is in the middle of communication with the PDC phone. The fixed answer message may be transmitted automatically or in response to a predetermined key operation of a user of the PDC/PHS phone. The communication with the PDC phone may be continued irrespective of the call from the PHS phone, or a new communication with the PHS phone may be enabled in response to another predetermined key operation of the user while holding the communication with the PDC phone to be resumed later.