A SWITCHING TECHNIQUE FOR VOICE COMMUNICATION OVER EXISTING COPPER INFRASTRUCTURE

Christos S. Koukourlis

   In this paper a technique for the switching of voice communication over existing cabling is described. For example, an existing physical layer like the power grid infrastructure of a building can be used for voice transmission. The hardware implementation and the associated protocol implemented on a microprocessor are described. For such a preinstalled physical medium, the use of a voice communication switch or exchange (PBX) is obviously not applicable. The paper deals with the development of a “distributed” exchange, capable of switching voice in as many as 30 subscribers. Each user is allocated a time slot, which acts as a private mailbox. The switching is based on the principle of Time Slot Interchanging (TSI). The necessary modifications to the basic idea of TSI are described and the whole design, including the required protocol, is given.

Keywords: time slot interchange, power line modems, voice exchange, HDLC protocol

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