Line communication systems incorporating mains electricity conductors

Abstract

A line communication system for linking a plurality of telephone subscribers to a public telephone exchange, wherein the subscribers are each located within the same general area, and wherein each subscriber is fed from the same mains electricity sub-station with mains electricity is provided. The line communication system provides subscriber apparatus which includes a cordless telephone (CT) handset and a frequency convertor for each subscriber. The handset is hard-wired to the mains electricity supply conductors via the frequency convertor so that CT signals at UHF are down-converted to HF for transmission through the mains electricity conductors. A CT base station is connected to the public telephone exchange. The CT base station is connected to the mains electricity supply conductors via a further frequency convertor for HF line communication purposes. A control matrix is provided in operative association with the base station, which serves to associate an address (corresponding to a telephone number) for each subscriber as recognized by the public telephone exchange with corresponding channels assigned by the CT protocol to each subscriber. Thus, the public telephone exchange and the subscribers are placed in mutual two-way communication and that calls are correctly routed and billed.