PURPOSE: To simplify the position registration of a terminal station by dividing a speech channel into plural small zones in a wide zone and using them.

CONSTITUTION: Plural base stations 11-13 are installed almost at an equal interval in an area 1a where a call channel reaches from a center 1, and a signal transmitted through a speech channel from the base stations 11-13 is sent with a comparatively small power. Then areas 11a-13a where the transmission signal of the speech cannel reaches from the base stations 11-13 are selected to be comparatively small ranges. Furthermore, transmission frequencies are different from each other in a call channel and a speech channel. Thus, the large area (large zone) 1a where the transmission signal of a call channel reaches from the center 1 is divided into plural small areas (small zones) 11a-13a whose communication is available through a speech channel from the base stations 11-13.