Echo cancellation is a method used in data transmission for error detection. The procedure consists of replicating the expected echoes from the transmitted signal as accurately as possible and subtracting them from the received signal.
For echo cancellation, an adaptive echo canceller is implemented on both sides of the transmission device. Its task is to exactly reproduce the incoming echoes in their entire time course. Because the echoes depend on line characteristics, the echo canceller must adapt to the instantaneous line characteristics. Echo cancellers are implemented with integrated circuits.