Abstract: A mobile station receives radio waves from all signposts through the positioning channels while making communications using the voice channels. The signal levels of the radio waves thus received are subjected to comparison, so that a zone switching request is made to a signpost with the highest signal level, whereby a mobile station can make communication through that signpost which covers the zone where the mobile station is located, even while traveling. The positioning channels are so set that the frequencies assigned to the signposts are switched every frame in a time series mode, and none of the signposts transmit one and the same frequency at the same time. Therefore, the mobile station can receive radio waves from all the signposts without signal interference (which may be caused when a plurality of stations transmit signals equal in frequency). In the system of the invention, the transmission zones of adjacent signposts overlap each other.

Abstract: A mobile communication system is provided wherein a plurality of signposts enable communications among mobile stations and a switching system in a predetermined communicating area, and are connected through a transmission network connected to a fixed network according to the invention, each of the signposts has dual zone communications ability including a communicating area which overlaps the communicating areas or adjacent signposts, and a zone switching signal area which does not overlap the zone switching signal areas of adjacent signposts. The signpost and mobile stations, jointly detect on-going signal levels of the mobile station, and communication area switching operation are carried out as needed. In the mobile communication system of the invention, a transmitting and receiving equipment can be a single transceiver which switches over the frequencies to communicating channel frequencies and to zone switching controlling frequencies.