US 2008/0187129 A1 · Method and System for Echo Cancellation In A Network Switch

Abstract

A method and system in network switch for cancelling multiple sources of network echo, including echo that is combined with a persistent, non-echo signal. A first echo canceller cancels a first echo signal that arises from an echo path in the network switch, and second echo canceller cancels a second echo signal that arises from an echo path in an external network device. The first echo canceller operates by first removing any persistent, non-echo signal that may be combined with the first echo signal, then training on the remaining, pure echo signal. The second echo canceller includes two sub-component echo cancellers that are coordinated so as to provide a minimum error signal for cancellation applied to the second echo signal.

Claims21

Dependent claims

A method of cancelling echo in a network switch using two echo cancellers, the method comprising:

adjusting a first echo canceller according to a test echo signal, the test echo signal being generated by a first echo path, the first echo path being located in the network switch;
receiving a signal comprising a first echo signal and a second echo signal, the first echo signal being generated by the first echo path, and the second echo signal being generated by a second echo path, the second echo path being located externally to the network switch;
cancelling the first echo signal with the first echo canceller;
adjusting the second echo canceller according to the second echo signal;
and
cancelling the second echo signal with the second echo canceller.

3 more elements

A network switch comprising:

an internal network interface operable to communicatively couple the network switch with at least one communication device;
an external network interface operable to communicatively couple the network switch with an external device;
at least one digital signal processor (DSP);
DSP data storage;
a first DSP-based echo canceller operable to cancel echo from a first echo path, the first echo path being located in the network switch;
a second DSP-based echo canceller operable to cancel echo from a second echo path, the second echo path being located externally to the external interface of the network switch;
and
DSP-language instructions stored in DSP data storage executable by the at least one DSP to cancel echo from the first echo path using the first DSP-based echo canceller and to cancel echo from the second echo path using the second DSP-based echo canceller.

5 more elements

Dependencies are inferred from the claim text.

Method and System for Echo Cancellation In A Network Switch

Life of this patent

Method and System for Echo Cancellation In A Network Switch

Life of this patent

Abstract

Claims21