METHOD AND SYSTEM FOR CONTROLLING ECHO CANCELLATION USING ZERO ECHO PATH, RINGING, AND OFF-HOOK DETECTION

摘要

A system and method for controlling echo using zero echo path detector (90), ringing detector (100), and off-hook detector (110). When conditions for zero echo path are detected, the present embodiment bypasses echo cancellation by replacing the output signal with the input to the echo canceller. In addition, the present embodiment also provides ringing and off-hook detections which additionally evaluate when the output should be replaced by the input to the echo canceller. The system and method provides additional detection and control benefits to echo canceller (60) and can be implemented in echo cancellation systems without substantial change to the existing echo canceller.