DIAL SELECTIVE WIDEBAND INTERCOMMUNICATION SYSTEM

摘要

A key telephone system is arranged with a selective intercommunication link to provide wideband service between any two stations served by the system. A station lockout circuit controls access to the link to insure that only two stations, calling station and a called station, may be connected to the link at one time. A selector circuit operates in conjunction with the lockout circuit to match the transmit-receive lead pairs of a called station with the proper lead pairs of the calling station. The system is arranged such that a three-party wideband conference may be established between a line, a first station and a second station connected to the first station via the link. All the parties to the conference are connected together for continuous audio transmission while wideband transmission is maintained only between two of the parties under selective control of the first station.