Method and apparatus for inband signaling control of vocoder bypass

• US 6,091,969 A
• Filed: 08/21/1998
• Issued: 07/18/2000
• Est. Priority Date: 08/21/1998
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Brophy, John Douglas, Ashley, James Patrick, Proctor, Lee Michael
• Primary Examiner(s): TO, DORIS HA
• Application Number:
  US09/138,183
• Time in Patent Office: 697 Days
• Field of Search: 455/560, 455/403, 455/445, 455/422, 455/501, 455/507, 455/517, 455/524, 455/550, 379/219, 379/229, 379/350, 379/353, 379/407, 370/287, 370/374, 370/378, 370/384-385, 370/522, 375/219, 375/242-243, 375/254, 375/277, 704/221, 704/214, 704/233
• US Class Current: 455/560
• CPC Class Codes: H04W 88/181 Transcoding devices; Rate adaptation devices

Abstract

Vocoder bypass is provided using in-band signaling. In preferred embodiments of the present invention, three signaling channels are arranged for transmission within the compressed speech. Each of the signaling channels are communicated at a preferred rate to permit fast, reliable detection of conditions indicating vocoder bypass mode of operation, to negotiate suitable vocoder type if necessary, and to synchronize and communicate compressed speech in a vocoder bypass mode of operation.

Claims

1. In a wireless communication system providing communication services between a first mobile and a second mobile, the first mobile having a first mobile vocoder, the second mobile having a second mobile vocoder and the wireless communication system having a vocoder active mode of operation and a vocoder bypass mode of operation, a method of transitioning the wireless communication system from vocoder active mode of operation to the vocoder bypass mode of operation, the method comprising the steps of:

providing a first signal within a compressed speech signal, the first signal including a vocoder bypass capability information and a vocoder type information;

detecting the first signal the compressed speech signal;

determining a compatibility of the first mobile vocoder and the second mobile vocoder based at least upon the vocoder type information;

determining an incompatibility between the first mobile vocoder and the second mobile vocoder;

negotiating a compatible vocoder type; and

initiating the vocoder bypass mode of operation based upon the compatibility.

2. The method of claim 1, comprising the step of continuing to provide the first signal within the uplink compressed speech signal during the vocoder bypass mode of operation.

3. The method of claim 2, wherein the first signal is transmitted on a channel within the compressed speech that is also used for at least one other network communication.

4. The method of claim 1, the first signal containing synchronization information.

5. The method of claim 1, the vocoder bypass mode of operation further comprising providing encoded speech information within the compressed speech channel and at a subrate thereof.

6. The method of claim 1, wherein the vocoder type information comprises a second signal within the compressed speech signal, the second signal including the vocoder type information.

7. The method of claim 6, further comprising inverting at least a portion of the first signal to provide an inverted portion and synchronizing the second signal to the inverted portion.

8. The method of claim 7, the inverted portion being transmitted in synchronization with at least one decoded speech frame contained within the speech channel.

9. The method of claim 1, wherein the vocoder type information comprises a first mobile vocoder type and a second mobile vocoder type, and the step of determining a compatibility comprises comparing the first mobile vocoder type with the second mobile vocoder type.

10. The method of claim 1, wherein the step of negotiating comprises:

selecting one of the first mobile vocoder and the second mobile vocoder as a master; and

having the master initiate a change in vocoder type.

11. A method of controlling vocoder operation within a wireless communication system comprising:

providing a signaling channel within a speech channel synchronized too and at a subrate thereof, the signaling channel at least providing synchronization information;

providing vocoder information within the speech channel and at a subrate thereof, the vocoder information being synchronized to the signaling channel;

detecting a vocoder compatibility and incompatibility;

negotiating a compatible vocoder type; and

upon determining the vocoder compatibility, providing an encoded speech channel within the speech channel and at a subrate thereof.

12. The method of claim 11, the step of providing vocoder information within the speech channel comprising, configuring the signaling channel to send vocoder type information.

13. The method of claim 11, the step of providing vocoder information within the speech channel comprising, providing a message channel within the speech channel and at a subrate thereof.

14. The method of claim 13, the step of providing vocoder information comprising inverting a portion of the synchronization information to provide an inverted portion, and synchronizing the vocoder type information to the inverted portion.

15. The method of claim 14, inverted portion being transmitted in synchronization with at least one decoded speech frame contained within the speech channel.

16. In a wireless communication system, the wireless communication system having a vocoder mode of operation and a vocoder bypass mode of operation, a method for inband signaling control of the vocoder bypass mode of operation, the method comprising the steps of:

in the vocoder active mode of operation;

receiving a coded first signal from a mobile, decoding the coded first signal to create a decoded first signal and coupling the decoded first signal into a speech channel in a first direction;

receiving a decoded second signal in the speech channel in a second direction, coding the decoded second signal and transmitting the coded second signal to the mobile;

generating a first bypass signal and embedding the first bypass signal into the speech channel in the first direction and generating a second bypass signal and embedding the second bypass signal into the speech channel in the second direction;

upon detecting both the first bypass signal and the second bypass signal in the speech channel, determining a vocoder compatibility; and

upon determining the vocoder compatibility entering the second mode of operation;

in the second mode of operation;

receiving the coded first signal from the mobile and coupling the coded first signal into the speech channel in the first direction; and

receiving a coded second signal in the speech channel in the second direction and transmitting the coded second signal to the mobile;

wherein each of the first bypass signal and the second bypass signal contain synchronization information;

further comprising in the second mode of operation the steps of providing a first vocoder type information signal in the speech channel in the first direction and providing a second vocoder type information signal in the speech channel in the second direction, the first vocoder type information and the second vocoder type information being synchronized to the synchronization information.

17. The method of claim 16, the first bypass signal containing first vocoder type information, the second bypass signal containing second vocoder type information, and the step of determining a vocoder compatibility comprising comparing the first vocoder type information and the second vocoder type information.

18. The method of claim 16, further comprising in the second mode of operation the steps of providing a first vocoder type information signal in the speech channel in the first direction and providing a second vocoder type information signal in the speech channel in the second direction, and the step of determining a vocoder compatibility comprising comparing the first vocoder type information and the second vocoder type information.

19. The method of claim 18, wherein the step of providing a first vocoder type information in the speech channel comprises inserting a burst signal in the speech channel.

20. The method of claim 19, wherein each of the first bypass signal and the second bypass signal contain synchronization information and the step of inserting a burst signal comprises detecting an inversion of at least a portion of the synchronization information.

21. The method of claim 20, wherein the inversion is synchronized to decode speech information within the speech channel.

22. The method of claim 16, the synchronization information comprising an inverted portion of at least one of the first bypass signal and the second bypass signal.

23. The method of claim 16, wherein in the second mode of operation:

the method further comprising;

generating the first bypass signal and embedding the first bypass signal into the speech channel in the first direction and generating the second bypass signal and embedding the second bypass signal into the speech channel in the second direction.

24. The method of claim 16, comprising concomitantly generating the first bypass signal and embedding the first bypass signal into the speech channel in the first direction and generating the second bypass signal and embedding the second bypass signal into the speech channel in the second direction.

25. In a communication system, a method for providing in-band signaling comprising the steps of:

inserting a first signal in a communication channel;

inverting a portion of the first signal to signal a presence of a second signal within the communication channel; and

detecting the second signal.

26. The method of claim 25, inverted portion and the second signal being substantially simultaneous.

27. The method of claim 25, the inverted portion and the second signal being substantially simultaneous with decoded information contained within the communication channel.

28. The method of claim 25, further comprising prior to inverting the portion of the first signal, determining a need to send the second signal.

29. The method of claim 25, the first signal comprising vocoder bypass capability information and the second signal comprising vocoder type information.

30. The method of claim 29, the second signal further comprising alternate vocoder type information.