TANDEM-FREE INTERSYSTEM VOICE COMMUNICATION

• US 20080288245A1
• Filed: 07/29/2008
• Published: 11/20/2008
• Est. Priority Date: 12/06/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: El-Maleh, Khaled Helmi, Kandhadai, Ananthapadmanabhan Arasanipalai, Manjunath, Sharath
• Granted Patent: US 8,432,935 B2
• Time in Patent Office: Days
• US Class Current: 704/201
• CPC Class Codes: G10L 19/173 Transcoding, i.e. converting between two coded representations avoiding cascaded coding-decoding
• CPC Class Codes: H04W 88/181 Transcoding devices; Rate adaptation devices

Abstract

Techniques are presented herein to provide tandem-free operation between two wireless terminals through two otherwise incompatible wireless networks. Specifically, embodiments provide tandem-free operation between a wireless terminal communicating through a continuous transmission (CTX) wireless channel to a wireless terminal communicating through a discontinuous transmission (DTX) wireless channel. In a first aspect, inactive speech frames are translated between DTX and CTX formats. In a second aspect, each wireless terminal includes an active speech decoder that is compatible with the active speech encoder on the opposite end of the mobile-to-mobile connection.

Claims

1. A method of providing tandem-free operation (TFO) communication between a first wireless terminal and a second wireless terminal, wherein the first wireless terminal encodes active speech using a first wideband speech coder associated with a first type of wireless interface and generates active speech frames having a first format, wherein the second wireless terminal encodes active speech using a second wideband speech coder associated with a second type of wireless interface and generates active speech frames having a second format, wherein the first and second wideband speech coders each sample voice signals at a sampling rate greater than 8,000 samples per second, wherein the first format is different from the second format, and wherein the first type of wireless interface is different from the second type of wireless interface, the method comprising:

encoding, at the first wireless terminal, first active speech data to generate an active speech frame having the first format; and

decoding, at the first wireless terminal, an active speech frame having the second format to generate second active speech data.

2. The method of claim 1 further comprising:

encoding, at the first wireless terminal, inactive speech frames in accordance the first type of wireless interface; and

decoding, at the first wireless terminal, inactive speech frames in accordance with the first type of wireless interface.

3. An apparatus comprising:

a speech encoder configured to encode speech data in accordance with a first speech coding format; and

a speech decoder configured to decode speech data in accordance with a second speech coding format, wherein the first speech coding format is different from the second speech coding format.

4. The apparatus of claim 3 wherein the speech encoder is a comfort noise speech encoder and the speech decoder is a comfort noise speech decoder.

5. The apparatus of claim 3 wherein the speech encoder is an active speech encoder and the speech decoder is an active speech decoder.

6. The apparatus of claim 3 wherein the speech encoder is a wideband active speech encoder and the speech decoder is a wideband active speech decoder.

7. The apparatus of claim 3 wherein the first format is an adaptive multi-rate (AMR) format and the second format is a selectable mode vocoder (SMV) format.

8. The apparatus of claim 3 wherein the first format is a selectable mode vocoder (SMV) format and the second format is an adaptive multi-rate (AMR) format.

9. The apparatus of claim 3 wherein the first format is a discontinuous transmission (DTX) format and the second format is a continuous transmission (CTX) format.

10. The apparatus of claim 3 wherein the first format is a continuous transmission (CTX) format and the second format is a discontinuous transmission (DTX) format.

11. A method of providing tandem-free operation (TFO) communication between a first wireless terminal communicating through a first type of wireless interface and a second wireless terminal communicating through a second type of wireless interface, wherein the first type is different from the second type, the method comprising:

encoding, at the first wireless terminal, and in accordance with a first speech coding format, speech data to be transmitted through a wireless channel; and

decoding, at the first wireless terminal, and in accordance with a second speech coding format, speech data received through the wireless channel, wherein the first speech coding format is different from the second speech coding format.

12. The method of claim 11 wherein the encoding is comfort noise encoding and the decoding is comfort noise decoding.

13. The method of claim 11 wherein the speech encoding is active speech encoding and the speech decoding is active speech decoding.

14. The method of claim 11 wherein the speech encoding is wideband active speech encoding and the speech decoding is wideband active speech decoding.

15. The method of claim 11 wherein the first format is an adaptive multi-rate (AMR) format and the second format is a selectable mode vocoder (SMV) format.

16. The method of claim 11 wherein the first format is a selectable mode vocoder (SMV) format and the second format is an adaptive multi-rate (AMR) format.

17. The method of claim 11 wherein the first format is a discontinuous transmission (DTX) format and the second format is a continuous transmission (CTX) format.

18. The method of claim 11 wherein the first format is a continuous transmission (CTX) format and the second format is a discontinuous transmission (DTX) format.

19. A computer-readable medium comprising instructions which, when executed by a processor, cause said processor to configure a speech coder to perform steps of a method of providing tandem-free operation (TFO) communication between a first wireless terminal communicating through a first type of wireless interface and a second wireless terminal communicating through a second type of wireless interface, wherein the first type is different from the second type, the method comprising:

encoding, at the first wireless terminal, and in accordance with a first speech coding format, speech data received through a wireless channel; and

decoding, at the first wireless terminal, and in accordance with a second speech coding format, speech data received through the wireless channel, wherein the first speech coding format is different from the second speech coding format.

20. An apparatus for providing tandem-free operation (TFO) communication between a first wireless terminal communicating through a first type of wireless interface and a second wireless terminal communicating through a second type of wireless interface, wherein the first type is different from the second type, the apparatus comprising:

means for encoding, at the first wireless terminal, speech data through a wireless channel in accordance with a first speech coding format; and

means for decoding, at the first wireless terminal, speech data received through the wireless channel in accordance with a second speech coding format, wherein the first speech coding format is different from the second speech coding format.

21. A speech coder comprising:

an active speech encoder configured to encode active speech data in accordance with a first speech coding format;

an active speech decoder configured to decode active speech data in accordance with a second speech coding format, wherein the first speech coding format is different from the second speech coding format;

an inactive speech encoder configured to encode inactive speech data in accordance with the first speech coding format; and

an inactive speech decoder configured to decode inactive speech data in accordance with the first speech coding format.

22. The speech coder of claim 21 wherein the first format is an adaptive multi-rate (AMR) format and the second format is a selectable mode vocoder (SMV) format.

23. The speech coder of claim 21 wherein the first format is a selectable mode vocoder (SMV) format and the second format is an adaptive multi-rate (AMR) format.

24. The speech coder of claim 21 wherein the active speech encoder is a wideband active speech encoder, and wherein the active speech decoder is a wideband active speech decoder.

25. The speech coder of claim 21 wherein the first format is a discontinuous transmission (DTX) format and the second format is a continuous transmission (CTX) format.

26. The speech coder of claim 21 wherein the first format is a continuous transmission (CTX) format and the second format is a discontinuous transmission (DTX) format.

27. A speech coder comprising:

an active speech encoder configured to encode active speech data in accordance with a speech coding format;

an active speech decoder configured to decode active speech data in accordance with the speech coding format;

a first inactive speech encoder configured to encode inactive speech data in accordance with a continuous transmission (CTX) format;

a first inactive speech decoder configured to decode inactive speech data in accordance with the CTX format;

a second inactive speech encoder configured to encode inactive speech data in accordance with a discontinuous transmission (DTX) format; and

a second inactive speech decoder configured to decode inactive speech data in accordance with the DTX format.

28. A wireless network apparatus comprising a discontinuous transmission (DTX)/continuous transmission (CTX) converter configured to convert comfort noise frames from a DTX format to a CTX format in a first direction and from a CTX format to a DTX format in a second direction, wherein the first direction is opposite to the second direction.

29. A method for providing tandem-free operation between a first wireless terminal communicating over a discontinuous transmission (DTX) wireless interface and a second wireless terminal communicating over a continuous transmission (CTX) wireless interface, the method comprising:

converting inactive speech frames received over the DTX wireless interface from the first wireless terminal from a DTX inactive speech frame format to a CTX inactive speech frame format; and

converting inactive speech frames received over the CTX wireless interface from the second wireless terminal from a CTX inactive speech frame format to a DTX inactive speech frame format.

30. A wireless network apparatus comprising a base station controller (BSC) configured to insert a continuous transmission (CTX) speech frame into a payload portion of a discontinuous transmission (DTX) speech frame, to adjust a mode of the DTX speech frame based on the size of the CTX speech frame.

31. A method for providing tandem-free operation between a first wireless terminal communicating over a discontinuous transmission (DTX) wireless interface and a second wireless terminal communicating over a continuous transmission (CTX) wireless interface, the method comprising:

inserting a CTX speech frame into a payload portion of a DTX speech frame; and

adjusting a mode of the DTX speech frame based on the size of the CTX speech frame.

32. A wireless network apparatus comprising a base station controller (BSC) configured to receive a silence indicator (SID) frame, to insert the SID frame into a payload portion of a continuous transmission (CTX) speech frame corresponding to a first speech frame period, and to generate a dummy continuous transmission (CTX) inactive speech frame corresponding to a second speech frame period, wherein the second speech frame period immediately follows the first speech frame period, and wherein the dummy CTX inactive speech frame contains no inactive speech data.

33. A method for providing tandem-free operation between a first wireless terminal communicating over a discontinuous transmission (DTX) wireless interface and a second wireless terminal communicating over a continuous transmission (CTX) wireless interface, the method comprising:

inserting a SID frame into a payload portion of a CTX speech frame corresponding to a first speech frame period; and

generating a dummy CTX inactive speech frame corresponding to a second speech frame period, wherein the second speech frame period immediately follows the first speech frame period, and wherein the dummy CTX inactive speech frame contains no inactive speech data.