PURPOSE: To announce whether a moving body communication device is in a service area or not to a user by generating an audible tone on the discrimination to whether the moving body communication device is in or out of the service area.
CONSTITUTION: In a portable radio 100, when a CPU161 receives a synchronization dislocating signal, which is outputted when the respective synchronization of D, P and A channels can not be obtained in a prescribed control signal to be outputted from a base station, from a control signal processing part 168, an audible tone generating signal is outputted to an audio part control part 169 in order to announce that the radio is out of the service area. Thus, an, audible tone signal is outputted from an audible tone generating part 121 and the audible tone is outputted from a speaker 113 through an output amplifier 115 in order to announce that the radio is out of the service area. The synchronization dislocating signal is outputted when the prescribed synchronization can not be obtained in the D, P and A channels of the prescribed control signal from the base station in case that such a radio telephone set is out of the prescribed service area.
ISHII TAKAAKI
KITA KATSUHIKO
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