System and method for echo assessment in a communication network

• US 6,952,473 B1
• Filed: 11/25/2002
• Issued: 10/04/2005
• Est. Priority Date: 11/25/2002
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Lee, Yueh-ju
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): SINGH, RAMNANDAN P
• Application Number:
  US10/304,147
• Time in Patent Office: 1,044 Days
• Field of Search: 37940601-40616
• US Class Current: 379/406.01
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Abstract

A method includes receiving a plurality of packets from at least two voice packet streams. The method also includes generating at least two voice signals using the plurality of packets. Each voice signal is associated with one of the voice packet streams. In addition, the method includes identifying an echo of one of the voice signals in at least one other of the voice signals.

Claims

1. A method for communicating voice data, comprising:

receiving a plurality of packets from at least two voice packet streams at a first location;

storing at least one packet from a first voice packet stream and at least one packet from a second voice packet stream at the first location;

compensating at least partially at least a portion of the packets of the first voice packet stream for a first jitter amount associated with a destination of the first voice packet stream;

compensating at least partially at least a portion of the packets of the second voice packet stream for a second jitter amount associated with a destination of the second voice packet stream;

extracting voice data from the first voice packet stream and the second voice packet stream after at least a portion of the packets of the first voice packet stream and at least a portion of the packets of the second voice packet stream have been compensated for jitter;

generating, at the first location, a first voice signal from voice data extracted from the first voice packet stream;

generating, at the first location, a second voice signal from voice data extracted from the second voice packet stream;

comparing the first voice signal to the second voice signal; and

identifying an echo of one of the voice signals in at least one other of the voice signals based on a comparison of the first voice signal and the second voice signal.

2. The method of claim 1, further comprising identifying an echo annoyance index associated with the identified echo.

3. The method of claim 2, further comprising identifying an amplitude and a delay associated with the identified echo;

and

wherein identifying the echo annoyance index comprises identifying the echo annoyance index using the amplitude and the delay.

4. The method of claim 3, wherein identifying the delay comprises:

generating a signal distribution using a cross-correlation function with the identified echo and one of the voice signals;

identifying a maximum amplitude in the signal distribution; and

identifying a time associated with the maximum amplitude, a magnitude of the time representing the delay.

5. The method of claim 2, wherein identifying the echo annoyance index comprises identifying the echo annoyance index using at least one International Telecommunication Union—

Telecommunications (ITU-T) G.131 amplitude-delay curve.

6. The method of claim 1, wherein receiving the plurality of packets comprises tapping a shared medium used by the at least two voice packet streams.

7. The method of claim 1, wherein receiving the plurality of packets comprises:

determining whether a packet is of interest; and

retaining the packet if it is of interest.

8. The method of claim 7, wherein determining whether a packet is of interest comprises examining a destination address of the packet.

9. The method of claim 1, wherein generating one of the voice signals comprises

decoding the extracted voice data.

10. The method of claim 1, wherein identifying the echo comprises supplying the at least two voice signals to an adaptive filter, the filter operable to generate a signal identifying the echo.

11. The method of claim 1, wherein the at least two voice packet streams comprise an upstream channel and a downstream channel for a telephone call.

12. The method of claim 1, further comprising tapping at least one of a network node, an endpoint, and a wireless link to receive the packets.

13. The method of claim 1, wherein the packets comprise at least one of Internet Protocol packets, frame relay frames, and Asynchronous Transfer Mode cells.

14. The method of claim 1, wherein one or more endpoints generate the at least two voice packet streams without using test equipment at the one or more endpoints.

15. Logic embodied on at least one computer readable medium and operable when executed to:

receive a plurality of packets from at least two voice packet streams at a first location;

store at least one packet from a first voice packet stream and at least one packet from a second voice packet stream at the first location;

compensate at least partially at least a portion of the packets of the first voice packet stream for a first jitter amount associated with a destination of the first voice packet stream;

compensate at least partially at least a portion of the packets of the second voice packet stream for a second jitter amount associated with a destination of the second voice packet stream;

extract voice data from the first voice packet stream and the second voice packet stream after at least a portion of the packets of the first voice packet stream and at least a portion of the packets of the second voice packet stream have been compensated for jitter;

generate, at the first location, a first voice signal from voice data extracted from the first voice packet stream;

generate, at the first location, a second voice signal from voice data extracted from the second voice packet stream;

compare the first voice signal to the second voice signal; and

identify an echo of one of the voice signals in at least one other of the voice signals based on a comparison of the first voice signal and the second voice signal.

16. The logic of claim 15, wherein the logic is further operable to identify an echo annoyance index associated with the identified echo.

17. The logic of claim 16, wherein:

the logic is further operable to identify an amplitude and a delay associated with the identified echo; and

the logic is operable to identify the echo annoyance index using the amplitude and the delay.

18. The logic of claim 17, wherein the logic is operable to identify the delay by:

generating a signal distribution using a cross-correlation function with the identified echo and one of the voice signals;

identifying a maximum amplitude in the signal distribution; and

identifying a time associated with the maximum amplitude, a magnitude of the time representing the delay.

19. The logic of claim 15, wherein the logic is operable to receive the plurality of packets by tapping a shared medium used by the at least two voice packet streams, the shared medium forming at least a part of a network node, an endpoint, or a wireless link.

20. The logic of claim 15, wherein the logic is operable to receive the plurality of packets by:

determining whether a packet is of interest; and

retaining the packet if it is of interest.

21. The logic of claim 15, wherein the logic is operable to generate one of the voice signals by

decoding the extracted voice data.

22. The logic of claim 15, wherein the logic is operable to identify the echo by supplying the at least two voice signals to a finite impulse response filter, the filter operable to generate a signal identifying the echo.

23. A system for communicating voice data, comprising:

a voice packet capture module operable to receive packets in at least two voice packet streams;

at least one processing module operable to;

receive the packets;

store at least one packet from a first voice packet stream and at least one packet from a second voice packet stream in a memory associated with the processing module;

compensate at least partially at least a portion of the packets of the first voice packet stream for a first jitter amount associated with a destination of the first voice packet stream;

compensate at least partially at least a portion of the packets of the second voice packet stream for a second jitter amount associated with a destination of the second voice packet stream;

extract voice data from the first voice packet stream and the second voice packet stream after at least a portion of the packets of the first voice packet stream and at least a portion of the packets of the second voice packet stream have been compensated for jitter;

generate, at the first location, a first voice signal from voice data extracted from the first voice packet stream; and

generate, at the first location, a second voice signal from voice data extracted from the second voice packet stream; and

a filter operable to compare the first voice signal to the second voice signal and to identify an echo of one of the voice signals in at least one other of the voice signals based on a comparison of the first voice signal and the second voice signal.

24. The system of claim 23, further comprising an echo assessor module operable to identify an echo annoyance index associated with the identified echo.

25. The system of claim 24, wherein the echo assessor module is operable to identify the echo annoyance index using an amplitude and a delay associated with the identified echo.

26. The system of claim 25, further comprising a delay module operable to identify the delay associated with the identified echo.

27. The system of claim 23, wherein the voice packet capture module is operable to receive the plurality of packets by tapping a shared medium used by the at least two voice packet streams, the shared medium forming at least a part of a network node, an endpoint, or a wireless link.

28. The system of claim 23, wherein the at least one processing module is operable to generate one of the voice signals by

decoding the extracted voice data.

29. A system for communicating voice data, comprising:

a memory operable to store a plurality of packets from at least two voice packet streams; and

one or more processors collectively operable to;

compensate at least partially at least a portion of the packets of a first voice packet stream for a first jitter amount associated with a destination of the first voice packet stream;

compensate at least partially at least a portion of the packets of a second voice packet stream for a second jitter amount associated with a destination of the second voice packet stream;

extract voice data from the first voice packet stream and the second voice packet stream after at least a portion of the packets of the first voice packet stream and at least a portion of the packets of the second voice packet stream have been compensated for jitter;

generate, at the first location, a first voice signal from voice data extracted from the first voice packet stream;

generate, at the first location, a second voice signal from voice data extracted from the second voice packet stream;

compare the first voice signal to the second voice signal; and

identify an echo of one of the voice signals in at least one other of the voice signals based on a comparison of the first voice signal and the second voice signal.

30. The system of claim 29, wherein the one or more processors are further collectively operable to identify an echo annoyance index associated with the identified echo.

31. The system of claim 30, wherein the one or more processors are collectively operable to identify the echo annoyance index using an amplitude and a delay associated with the identified echo.

32. The system of claim 31, wherein the one or more processors are further collectively operable to identify the amplitude and the delay associated with the identified echo.

33. The system of claim 32, wherein the one or more processors are collectively operable to identify the delay by:

generating a signal distribution using a cross-correlation function with the identified echo and one of the voice signals;

identifying a maximum amplitude in the signal distribution; and

identifying a time associated with the maximum amplitude, a magnitude of the time representing the delay.

34. The system of claim 29, wherein the one or more processors are collectively operable to receive the plurality of packets by tapping a shared medium used by the at least two voice packet streams, the shared medium forming at least a part of a network node, an endpoint, or a wireless link.

35. The system of claim 29, wherein the one or more processors are collectively operable to generate one of the voice signals by

decoding the extracted voice data.

36. A system for communicating voice data, comprising:

means for receiving a plurality of packets from at least two voice packet streams at a first location;

means for storing at least one packet from a first voice packet stream and at least one packet from a second voice packet stream at the first location;

means for compensating at least partially at least a portion of the packets of the first voice packet stream for a first litter amount associated with a destination of the first voice packet stream;

means for compensating at least partially at least a portion of the packets of the second voice packet stream for a second jitter amount associated with a destination of the second voice packet stream;

means for extracting voice data from the first voice packet stream and the second voice packet stream after at least a portion of the packets of the first voice packet stream and at least a portion of the packets of the second voice packet stream have been compensated for litter;

means for generating, at the first location, a first voice signal from voice data extracted from the first voice packet stream;

means for generating, at the first location, a second voice signal from voice data extracted from the second voice packet stream,

means for comparing the first voice signal to the second voice signal;

means for identifying an echo of one of the voice signals in at least one other of the voice signals based on a comparison of the first voice signal and the second voice signal; and

means for identifying an echo annoyance index associated with the identified echo.