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US 2001/0043701 A1Published application
Method and apparatus for echo control in a communication system
AssigneeNortel Networks Limited
InventorDAVID DAL FARRA
Life of this patent
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AssigneeNortel Networks Limited
InventorDAVID DAL FARRA
Estimating the term…
The invention relates to an acoustic echo canceller particularly well suited for use in a hands-free terminal or teleconference system. The echo canceller is designed to assess the inherent signal attenuation occurring in the analog loop that connects the terminal to the switch mechanism of the PSTN domain or the PBX domain. The echo canceller is then adjusted in accordance with the degree of signal attenuation manifested by the loop. For high signal attenuation levels, the degree of echo control at the terminal is reduced since the signal attenuation occurring in the loop itself will compensate for the reduction, allowing to reach the echo control target at the far end of the loop (switch side). This feature avoids overly attenuating the echo at the terminal by taking advantage of the inherent echo control provided by the local loop conductors.
An echo canceller for reducing the magnitude of an echo occurring in a return channel of a communication device, said communication device being coupled to a switch mechanism through a local loop, said echo canceller including:
A method for reducing a magnitude of an echo occurring in a return channel of a communication device, the communication device being coupled to a switch mechanism through a local loop, said method including the steps of:
A CPE for coupling to a switch mechanism through a local analog loop, said CPE comprising:
An echo attenuation device for reducing a magnitude of an echo occurring in a communication device, said echo attenuation device being responsive to a signal indicative of an inherent loss characteristics of a pathway transporting a signal precursor of the echo signal and the echo signal to vary a level of echo attenuation in dependence of the signal.
Dependencies are inferred from the claim text.