JP2927055B

In order to effectively determine an assigned control channel in a cellular mobile communications system wherein there are no dedicated control channels, a mobile unit, before entering into a standby mode, scans a plurality of channels for determining an assigned control channel which is specified by the presence of a frequency shift keying subcarrier component therein. The mobile unit selects one of the plurality of channels assigned to the system, and detects a signal strength of the selected channel and also detects the frequency shift keying subcarrier. Subsequently, the mobile unit compares the signal strength of the selected channel with a reference level. If the signal strength is below said reference level the absence of an assigned control channel is indicated. In this case, the mobile unit scans another channel. On the other hand, if the signal strength exceeds said reference level and simultaneously the frequency shift keying component is detected, the presence of an assigned control channel is indicated and the mobile unit terminates the channel scanning.