Abstract:
A telephony system includes a plurality of local network terminations connected to a street cabinet in turn connected to an exchange. The street cabinet has a power supply for supplying voltage, a clock for generating a master ringer signal, and a modulator for modulating the voltage with the ringer signal. The filters extract the DC voltage and the ringer signal. The extracted DC voltage and the extracted ringer signal obviate the prior art requirements to provide a separate DC power supply and a separate clock within each local network termination, thereby avoiding duplication of components within each local network termination.