Abstract: An extension telephone is coupled to a telephone line through a control unit which receives and forwards by radio incoming calls and is fully controlled from the extension unit for outgoing calls. Incoming calls ring the remote mobile unit which is then coupled for conversation to the line through a control unit actuated from the extension unit. The mobile unit transmits actuation and dialing signals to the control unit for outgoing calls from the mobile unit in response to successively transmitted tone modulations to dial any party on the telephone line and thereupon connects the mobile microphone and receiver directly to the line.