To remove a drawback in which deterioration occurs in an S/N ratio of data to be received by a center apparatus in a base station transmission system which consists of a plurality of base stations and a plurality of mobile stations, the base stations being connected in series, and transmits the data from a mobile station to the center apparatus via a predetermined base station when transmitting the data from the mobile station to the center apparatus.

Signals of not all base stations which have received signals are composed and transmitted to the center station, but only the data received from one base station are transmitted to the center station by controlling signal receiving lines so as to be connected or disconnected depending on whether or not having received a signal from a lower-order base station.