PURPOSE: To prevent radio wave interference by avoiding allocation of a communications channel causing radio wave interference between adjacent base stations forming an overlapped zone for the same time zone.
CONSTITUTION: Plural base stations C1-C3 arranged at a predetermined distance are wired-connected to an exchange X2. Furthermore, the exchange X2 is provided with an operating channel storage section 11, a base station location information storage section 12 and a connection section 13. Thus, the exchange X2 grasps the relation of position of the base stations C1-C3 and grasps the communications channel used at present by the base stations C1-C3. As a result, the adjacent base stations C1-C3 forming an overlapped zone are controlled so as not to allocate the communications channel causing interference to mobile station P1-P3 for a same time zone. Thus, production of radio wave interference is prevented.