Methods and apparatus for suppressing signaling tones in telephony signal

• US 7,245,637 B2
• Filed: 09/11/2003
• Issued: 07/17/2007
• Est. Priority Date: 09/11/2003
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Miao, Kai X., Lam, Siu H.
• Primary Examiner(s): Jain; Raj K.
• Application Number:
  US10/660,180
• Publication Number:
  US 20050058120A1
• Time in Patent Office: 1,405 Days
• Field of Search: None
• US Class Current: 370/512
• CPC Class Codes: H04M 7/0069 comprising a residential gateway, e.g. those which provide an adapter for POTS or ISDN terminals
• CPC Class Codes: H04M 7/1295 Details of dual tone multiple frequency signalling

Abstract

In some embodiments, a method includes detecting a tone in each data frame of a sequence of telephony signal data frames. A first data frame of the sequence of telephony signal data frames may be transmitted immediately after detecting the tone therein. Transmission of a last one or last ones of the sequence of telephony signal data frames may be deferred. It may then be determined whether the tone is present in a next data frame that immediately follows the sequence of telephony signal data frames. If it is determined that the tone is not present in the next data frame, the last one or ones of the sequence of data frames and the next data frame may be transmitted. If it is determined that the tone is present in the next data frame, a respective replacement data frame may be transmitted in place of each one of the last one or last ones of the sequence of data frames and in place of the next data frame.

Claims

1. A method comprising:

detecting a tone in each data frame of a sequence of telephony signal data frames;

transmitting a first data frame of the sequence of telephony signal data frames immediately after detecting the tone therein;

deferring transmission of a last one or ones of the sequence of telephony signal data frames;

selectively transmitting the last one or ones of the sequence of data frames and a next data frame that immediately follows the sequence of telephony signal data frames in response to said next data frame not including the tone; and

selectively transmitting a respective replacement data frame in place of each one of the last one or ones of the sequence of data frames and in place of said next data frame in response to said next data frame including the tone.

2. The method of claim 1, wherein each of the replacement data frames represents a silence audio signal.

3. The method of claim 1, wherein the sequence of telephony signal data frames includes three telephony signal data frames.

4. The method of claim 3, further comprising:

transmitting a second data frame of the sequence of telephony signal data frames, said second data frame immediately following said first data frame, said transmitting of said second data frame occurring immediately after detecting the tone in said second data frame.

5. The method of claim 1, further comprising:

detecting that the tone is present in a subsequent data frame that immediately follows said next data frame; and

transmitting a replacement data frame that represents a silence audio signal in place of said subsequent data frame.

6. The method of claim 1, further comprising:

receiving a signal from a destination device, the signal indicative of a jitter condition detected by the destination device; and

determining, based at least in part on the received signal from the destination device, a number of data frames of which transmission is deferred.

7. A method comprising:

receiving a signal from a destination device, the signal indicative of a jitter condition detected by the destination device;

determining, based at least in part on the received signal, a number of outbound telephony signal data frames for which transmission is to be deferred in case of detecting a tone in the outbound telephony signal data frames;

selectively deferring transmission based on a determined number of frames from the received sequence of outbound telephony signal data frames in response to the detected tone;

transmitting said determined number of frames if the detected tone has a duration that is less than a predetermined duration; and

selectively replacing each of said determined number of frames with a respective replacement data frame and transmitting said replacement data frames in response to the duration of the detected tone at least equaling the predetermined duration, each said replacement data frame representing a silence audio signal.

8. A method comprising:

analyzing a first telephony signal data frame to determine whether a tone is present in the first telephony signal data frame;

selectively immediately transmitting the first telephony signal data frame in response to the first telephony signal data frame not including the tone;

selectively deferring transmission of the first telephony signal data frame in response to the first telephony signal data frame including the tone;

analyzing a second telephony signal data frame to determine whether the tone is present in the second telephony signal data frame, the second telephony signal data frame immediately following the first telephony signal data frame in a sequence of telephony signal data frames;

selectively transmitting the first and second telephony signal data frames immediately after said analyzing of the second telephony signal data frame in response to the second telephony signal data frame not including the tone; and

selectively transmitting a respective replacement data frame in place of each of the first and second telephony signal data frames in response to the second telephony signal data frame including the tone.

9. The method of claim 8, further comprising:

analyzing a third telephony signal data frame to determine whether the tone is present in the third telephony signal data frame, the third telephony signal data frame immediately following the second telephony signal data frame in the sequence of telephony signal data frames;

transmitting the third telephony signal data frame if it is determined that the tone is not present in the third telephony signal data frame; and

transmitting a replacement data frame in place of the third telephony signal data frame immediately after said analyzing of the third telephony signal data frame if it is determined that the tone is present in the third telephony signal data frame and if it was determined that the tone was present in each of the first and second telephony signal data frames.

10. The method of claim 9, wherein each of the replacement data frames represents a silence audio signal.

11. The method of claim 8, further comprising:

determining that the tone is present in a telephony signal data frame that immediately precedes the first telephony signal data frame in the sequence of telephony signal data frames; and

deferring transmission of said telephony signal data frame that immediately precedes the first telephony signal data frame until said analyzing of said second telephony signal data frame.

12. An apparatus comprising:

a buffer; and

circuitry coupled to the buffer and configured to;

detecting a tone in each data frame of a sequence of telephony signal data frames;

transmitting a first data frame of the sequence of telephony signal data frames immediately after detecting the tone therein;

deferring transmission of a last one or ones of the sequence of telephony signal data frames;

selectively transmitting the last one or ones of the sequence of data frames and a next data frame that immediately follows the sequence of telephony signal data frames in response to said next data frame not including the tone; and

selectively transmitting a respective replacement data frame in place of each one of the last one or ones of the sequence of data frames and in place of said next data frame in response to said next data frame including the tone.

13. The apparatus of claim 12, wherein each of the replacement data frames represents a silence audio signal.

14. The apparatus of claim 12, wherein the sequence of telephony signal data frames includes three telephony signal data frames.

15. The apparatus of claim 14, wherein said circuitry is further configured to:

transmitting a second data frame of the sequence of telephony signal data frames, said second data frame immediately following said first data frame, said transmitting of said second data frame occurring immediately after detecting the tone in said second data frame.

16. The apparatus of claim 12, wherein said circuitry is further configured to:

detecting that the tone is present in a subsequent data frame that immediately follows said next data frame; and

transmitting a replacement data frame that represents a silence audio signal in place of said subsequent data frame.

17. The apparatus of claim 12, wherein said circuitry is further configured to:

receiving a signal from a destination device, the signal indicative of a jitter condition detected by the destination device; and

determineing based at least in part on the received signal from the destination device, a number of data frames of which transmission is deferred.

18. An apparatus comprising:

a buffer; and

circuitry coupled to the buffer and configured to;

receiving a signal from a destination device, the signal indicative of a jitter condition detected by the destination device;

determineing, based at least in part on the received signal, a number of outbound telephony signal data frames for which transmission is to be deferred in case of detecting a tone in the outbound telephony signal data frames;

selectively deferring transmission based on determined number of frames from the received sequence of outbound telephony signal data frames in response to the detected tone;

transmitting said determined number of frames if the detected tone has a duration that is less than a predetermined duration; and

selectively replacing each of said determined number of frames with a respective replacement data frame and transmit said replacement data frames in response to the duration of the detected tone at least equaling to the predetermined duration, each said replacement data frame representing a silence audio signal.

19. An apparatus comprising:

a buffer; and

circuitry coupled to the buffer and configured to;

analyzing a first telephony signal data frame to determine whether a tone is present in the first telephony signal data frame;

selectively immediately transmitting the first telephony signal data frame in response to the first telephony signal data frame not including the tone;

selectively deferring transmission of the first telephony signal data frame in response to the first telephony signal data frame including the tone;

analyzing a second telephony signal data frame to determine whether the tone is present in the second telephony signal data frame, the second telephony signal data frame immediately following the first telephony signal data frame in a sequence of telephony signal data frames;

selectively transmitting the first and second telephony signal data frames immediately after analysis of the second telephony signal data frame in response to the second telephony signal data frame not including the tone; and

selectively transmitting a respective replacement data frame in place of each of the first and second telephony signal data frames in response to the second telephony signal data frame including the tone.

20. The apparatus of claim 19, wherein the circuitry is further operative to:

analyzing a third telephony signal data frame to determine whether the tone is present in the third telephony signal data frame, the third telephony signal data frame immediately following the second telephony signal data frame in the sequence of telephony signal data frames;

transmitting the third telephony signal data frame if it is determined that the tone is not present in the third telephony signal data frame; and

transmitting a replacement data frame in place of the third telephony signal data frame immediately after said analyzing of the third telephony signal data frame if it is determined that the tone is present in the third telephony signal data frame and if it was determined that the tone was present in each of the first and second telephony signal data frames.

21. The apparatus of claim 20, wherein each of the replacement data frames represents a silence audio signal.

22. The apparatus of claim 19, wherein the circuitry is further configured to:

determineing that the tone is present in a telephony signal data frame that immediately precedes the first telephony signal data frame in the sequence of telephony signal data frames; and

deferring transmission of said telephony signal data frame that immediately precedes the first telephony signal data frame until analysis of said second telephony signal data frame.

23. A system comprising:

an analog-to-digital converter to supply telephony signal data frames;

a buffer coupled to the analog-to-digital converter to temporarily store said telephony signal data frames; and

circuitry coupled to the buffer and configured to;

detecting a tone in each data frame of a sequence of telephony signal data frames;

transmitting a first data frame of the sequence of telephony signal data frames immediately after detecting the tone therein;

differing transmission of a last one or ones of the sequence of telephony signal data frames;

selectively transmitting the last one or ones of the sequence of data frames and a next data frame that immediately follows the sequence of telephony signal data frames in response to said next data frame not including the tone; and

selectively transmitting a respective replacement data frame in place of each one of the last one or ones of the sequence of data frames and in place of said next data frame in response to said next data frame including the tone.

24. The system of claim 23, wherein each of the replacement data frames represents a silence audio signal.

25. The system of claim 23, wherein the sequence of telephony signal data frames includes three telephony signal data frames.

26. The system of claim 25, wherein said circuitry is further configured to:

transmitting a second data frame of the sequence of telephony signal data frames, said second data frame immediately following said first data frame, said transmitting of said second data frame occurring immediateiy after detecting the tone in said second data frame.

27. The system of claim 23, wherein said circuitry is further configured to:

detecting that the tone is present in a subsequent data frame that immediately follows said next data frame; and

transmitting a replacement data frame that represents a silence audio signal in place of said subsequent data frame.

28. The system of claim 23, wherein said circuitry is further configured to:

receiving a signal from a destination device, the signal indicative of a jitter condition detected by the destination device; and

determineing, based at least in part on the received signal from the destination device, a number of data frames of which transmission is deferred.

29. An apparatus comprising:

a computer readable medium having stored therein a plurality of computer executable instructions that when executed result in the following;

detecting a tone in each data frame of a sequence of telephony signal data frames;

transmitting a first data frame of the sequence of telephony signal data frames immediately after detecting the tone therein;

deferring transmission of a last one or ones of the sequence of telephony signal data frames;

selectively transmitting the last one or ones of the sequence of data frames and a next data frame that immediately follows the sequence of telephony signal data frames in response to said next data frame not including the tone; and

selectively transmitting a respective replacement data frame in place of each one of the last one or ones of the sequence of data frames and in place of said next data frame in response to said next data frame including the tone.

30. The apparatus of claim 29, wherein each of the replacement data frames represents a silence audio signal.

31. The apparatus of claim 29, wherein the sequence of telephony signal data frames includes three telephony signal data frames.

32. The apparatus of claim 31, wherein the instructions further result in:

transmitting a second data frame of the sequence of telephony signal data frames, said second data frame immediately following said first data frame, said transmitting of said second data frame occurring immediately after detecting the tone in said second data frame.

33. The apparatus of claim 29, wherein the instructions further result in:

detecting that the tone is present in a subsequent data frame that immediately follows said next data frame; and

transmitting a replacement data frame that represents a silence audio signal in place of said subsequent data frame.

34. The apparatus of claim 29, wherein the instructions further result in:

receiving a signal from a destination device, the signal indicative of a jitter condition detected by the destination device; and

determining, based at least in part on the received signal from the destination device, a number of data frames of which transmission is deferred.