Extended signaling system and method

Abstract

Embodiments are described that include a “front end” device located remotely from a local telephone location. The front end filters DC and AC current on a telephone line to separate these signals and passes a DC current through a low resistance Low Pass Filter without traditional resistance or current limiting means. The front end also provides signaling capability isolated from the DC and audio channels by a High Pass Filter. Some embodiments also include a “back end” unit located near a local telephone location. The “back end” unit filters the DC and AC currents into at least two DC current streams. One of the DC current streams provides sufficient current to power a local telephone. The other stream(s) provides current sufficient to power an auxiliary device. The “back end” device may also provide signaling isolated from the DC and audio channels that is complementary to the “front end” signaling.

What is claimed is: 
     
         1 . A method of providing direct current (DC) through a telephone line, the method comprising:
 providing direct current (DC) in a power signal;   filtering the power signal with a first low pass filter that provides a low equivalence resistance toward the DC and attenuates alternating current (AC) signals;   after the filtering:
 transmitting the power signal through a telephone line; 
   filtering at least a first portion of the power signal with a second low pass filter that provides a low equivalence resistance toward the DC and attenuates AC signals; and   passing the output from the second low pass filter to an input of a power supply.