Radio transmitting system having back-up radio receiver operable in

Abstract

A radio calling system includes a central control station simultaneously broadcasting a calling signal of an arbitrary pager terminal, and a plurality of radio transmitting stations coupled to the central control station. The plurality of radio transmitting stations simultaneously transmit the calling signal received from the central control station at the same radio frequency. The calling signal transmitted from the radio transmitting stations reach the arbitrary pager terminal and at least a neighboring one of the radio transmitting stations. At least an arbitrary one of the radio transmitting stations includes a first relay for relaying the calling signal received from the central control station, a second relay which has a receiver part for receiving the calling signal transmitted from a radio transmitting station other than the arbitrary radio transmitting station, and a storage relay part for storing the calling signal received by the receiver part and for transmitting the stored calling signal during a time in which no transmission is made by the radio transmitting stations other than the arbitrary radio transmitting station. A switching circuit coupled to the first and second relays carries out switching to enable one of the first and second relays, depending on whether or not a communication failure exists between the central control station and the arbitrary radio transmitting station.