摘要:
A testing and performance analysis methodology applies a series of test vector pairs to the input ports of an echo canceller under test. The test vector signal pair may represent a particular speech activity state transition, e.g., a Brady Model transition. A scoring compression function such as a sigmoid squashing function is used to evaluate quantized performance parameters. The sub-scores may be weighted and averaged to provide an overall performance score.
摘要:
A method, or corresponding apparatus, assumes a call is a Voice Band Data (VBD) call. The method disables a local echo canceller and transmits a tone that disables distal echo canceller(s) along a communications path across which the call is communicated. After disabling the echo cancellers, the echo cancellers are allowed to operate in a typical manner, such as according to ITU standards, after the call is established, including remaining disabled if the call is a Voice Band Data call and being automatically enabled if the call is or becomes a voice call. The method or apparatus is particularly useful in networks having Point of Service (POS) devices that have modems that do not send out a 2100 Hz tone to disable echo cancelling in the communications path. In one embodiment, the method or corresponding apparatus is deployed in a gateway.