Abstract: A mobile radio extension unit for converting a conventional mobile transceiver having a transmitter and a receiver to use as a repeater or transponder for establishing a bidirectional communications link between a transceiver of limited range and a base station or other mobile transceivers in the network. In a mobile communications system network having a plurality of extension units, associated mobile radios, and limited range transceivers, each extension unit includes means for automatically inhibiting multiple transmissions by units within range of one another and for providing punch through priority communications from a limited range transceiver to the base station or other mobile transceivers via one selected extension unit when the receiver associated therewith is repeating a communication to the transceiver.