Method for testing echo cancellers

摘要

The performance of an echo canceller is assessed using a) a test signal launched from originating test equipment and b) a simulated echo of the test signal launched from terminating test equipment. The launch of the simulated echo signal is timed in such a way that it arrives at the tandem echo canceller(s) at a particular point in time relative to the arrival of the test signal, at the tandem echo canceller(s), when the tandem echo canceller(s) is (are) not able to cancel the simulated echo signal. The latter thus arrives uncanceled at the target echo canceller. The launch of the simulated echo signal is further timed in such a way that it arrives at the target echo canceller at a point in time relative to the arrival of the test signal, at the target echo canceller, when the target echo canceller is able to cancel the simulated echo signal. As a result, any residual echo received at the originating test equipment is a measure of the performance of the target echo canceller exclusive of the performance of the tandem echo canceller(s).

主权项

1. Processor-based equipment adapted to operate under the control of programming to test a target echo canceller connected between origination and termination points of a communications path, the processor-based equipment comprising
at least one processor, and at least one medium on which is stored programming that, when executed by the at least one processor, causes the processor-based equipment to launch a test signal over the path from the origination point, and launch a simulated echo signal over the path from the termination point, the simulated echo signal containing a simulated echo of the test signal, and the simulated echo signal being launched at such a time relative to the launching of the test signal that only the target echo canceller cancels any significant portion of the simulated echo, even if there is a tandem echo canceller connected in the path.