Double talk occurs when both sides of a conversation attempt to speak simultaneously. The near end speaker, phone B in Figure 1, confuses the echo identification process, thus limiting the effectiveness of the echo canceller. Also, The echo canceller must not clip the beginning of the double talk session. The echo canceller also needs to identify and remove background noise. Once an echo is identified, the echo canceller subtracts the echo from the returning signal.
Echo cancellation can be very resource intensive.
The amount of processing power necessary to accurately compare and filter out echo can be high. This need for high processing power can be detrimental to the vendor s overall solution. Since processing power is a finite resource, as more resources are diverted to echo cancellation, fewer resources are available for processing additional voice channels. In summary, high processing power requirements for echo cancellation mean more power consumption, higher cost, and lower port density. The Mapletree Difference Mapletree s echo cancellation technique is able to determine when echo is likely to occur, ignoring the first portion of delay, and concentrating on when echo is likely.