Call eavesdropping arrangement
Call processing using previously obtained line characteristics
Call related information reception using sigma/delta modulation
Caller ID circuit powered through hookswitch devices
Caller identification transmit path limiter
Canceller trained echo suppressor
Capacitor cancellation method and apparatus
Central office interface techniques for digital subscriber...
Central office interface techniques for digital subscriber...
Central office interface techniques for digital subscriber...
Central office line interface circuit for an analog network priv
Channel interface unit
Channel unit interface circuit
Channel unit interface circuit
Circuit and method for detecting AC voltage pulses
Circuit and method for stimulation of a telephone apparatus
Circuit arrangement for a module in the exchange of a digital TD
Circuit arrangement for generating charge pulses
Circuit arrangement for protecting electronic interface circuit
Circuit arrangement for providing power for an IC chip in a tele