Patent ID: 7512227

Claim:
A method for controlling an echo canceller controller which controls a separate local echo canceller in a communications channel during a communication, with the echo canceller controller: measuring the power level of a transmitted signal (TX); measuring the power level of a received signal (RX); detecting a presence of double talk if the ratio of said power level of the transmitted signal to the power level of the of the received signal is below a first predetermined ratio; detecting a substantial absence of echo in said received signal if the ratio of said power level of the transmitted signal to the power level of the received signal is above a second predetermined ratio; determining if said local echo canceller is required, wherein: responsive to (i) not detecting a presence of double talk and (ii) not detecting a substantial absence of echo, determining that said local echo canceller is required; responsive to (i) not detecting a presence of double talk and (ii) detecting a substantial absence of echo, determining that said local echo canceller is not required; or responsive to a presence of double talk, determining that a requirement for said local echo canceller is indeterminate; and disabling said local echo canceller for the duration of the communication, responsive to determining that said local echo canceller is not required, and enabling said local echo canceller for the duration of the communication, responsive to determining that said local echo canceller is required.