To surely synchronize plural base stations and to improve reusability of frequency in time-division transmission without increasing interference by arranging an absolute synchronizing station for providing a synchronizing refer ence to each of plural 2nd base stations.

An absolute synchronizing station 3 is a reference for the synchronization of respective synchronizing areas 4-1, 4-2, 4-3,.... Each of these synchronizing area 4-1, 4-2, 4-3,... includes a master base station 1 and plural slave base stations 2. The master base station 1 is used not for a call processing service but for synchronization establishment of respective slave base stations 2. On the other hands, respective slave base stations 2 are used for the practical service. The absolute synchronizing station 3 is prepared for synchronization and does not communicate with mobile stations. Each of 2nd base stations 1 controls the timing of a control channel signal to be transmitted to other 2nd base stations 1 based on the timing of a control channel signal transmitted from the station 3.