Abstract: A second communication system using existing wires of a first alert system for other, additional communications purposes, comprising means for connecting to the wires in two or more locations, and means for connecting to external communication devices in each location. The alert system may include a fire alarm system. The system may also include a communication system controller for supporting the second communications system.

Abstract: A communication system comprising: a first multiplexing/demutliplexing stage positioned at a first locality and connected to a telephone interchange; a plurality of second multiplexing/demultiplexing stage positioned in a plurality of second localities apart from said first locality; a communication link, such as a transmission line or radio link which connects said first multiplexing/demultiplexing stage to each of said second multiplexing/demultipleg stages; and a plurality of subscribers lines connected to each of a plurality said second multiplexing/demultiplexing stages.