Method and apparatus for voice latency reduction in a voice-over-data wireless communication system

• US 6,785,262 B1
• Filed: 09/28/1999
• Issued: 08/31/2004
• Est. Priority Date: 09/28/1999
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Brown, James M., Yao, Yu-Dong, Tomcik, James, von Damm, Matthew B.
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): Hyun, Soon-Dong
• Application Number:
  US09/406,945
• Time in Patent Office: 1,799 Days
• Field of Search: 370/229, 370/230-235, 370/252, 370/349, 370/412-417, 370/493, 370/516, 370/352, 370/356, 370/395.64, 370/506
• US Class Current: 370/352
• CPC Class Codes: G10L 19/002 Dynamic bit allocation for perceptual audio coders G10L19/032

Abstract

A method and apparatus for reducing voice latency in a voice-over-data wireless communication system. In a transmitter, data frames are created from audio information by a vocoder and stored in a queue. Prior to storage, some of the data frames are eliminated, or dropped, and are not stored in the queue. In a receiver, data frames are generated from received signals and stored in a queue. Prior to storage in the receiver queue, some of the data frames are dropped. Data frames are dropped either at a single fixed rate, a dual fixed rate, or a variable rate, generally depending on a communication channel latency. By dropping data frames at the transmitter, the receiver, or both, voice latency due to data frame retransmissions is reduced.

Claims

1. A method for reducing voice latency in a voice-over-data wireless communication system, comprising the steps of:

generating a plurality of data frames;

dropping one or more of said plurality of data frame to keep a plurality of remaining data frames, wherein said step of dropping further comprises;

determining a voice frame integrity;

comparing said voice frame integrity with a predetermined value, said predetermined value representing a minimum desired voice quality;

increasing a variable queue threshold if said voice frame integrity is less than said predetermined value;

decreasing said variable queue threshold if said voice frame integrity is greater than said predetermined value;

dropping times at a first rate if a length of said queue is less than said variable queue threshold;

dropping frames at a second rate if said length is greater than said variable queue; and

storing said plurality of remaining data frames in a queue.

2. The method of claim 1 wherein the step of dropping one or more of said plurality of data frames comprises the step of dropping said plurality of data frames at a fixed, predetermined rate.

3. A method for reducing voice latency in a voice-over-data wireless communication system, comprising the steps of:

generating a plurality of data frames;

dropping an entire one or more of said plurality of data frames to keep a plurality of remaining data frames, wherein said step of dropping further comprises;

determining a communication channel latency; and

dropping entire ones of each of said plurality of data frames having an encoded rate equal to a first encoding rate out of a number of possible encoder rates if said communication channel latency exceeds a predetermined threshold; and

storing said plurality of remaining data frames in a queue.

4. The method of claim 3, further comprising the step of dropping each of said plurality of data frames having an encoded rate equal to said first encoding rate and a second encoding rate if said communication channel latency exceeds a second predetermined threshold.

5. An apparatus for reducing voice latency in a voice-over-data wireless communication system, comprising:

means for generating data flames;

a processor connected to said data frame generating means for determining a communication channel latency and for dropping an entire one or more of said data frames to keep remaining data frames; and

a queue for storing said remaining data frames, wherein;

entire ones of said data frames having an encoded rate equal to a first encoding rate out of a number of possible encoder rates are dropped if said communication channel latency exceeds a predetermined threshold.

6. The apparatus of claim 5, wherein said processor is further for dropping each of said data frames having an encoded rate equal to said first encoding rate and a second encoding rate if said communication channel latency exceeds a second predetermined threshold.

7. An apparatus for reducing voice latency in a voice-over-data wireless communication system, comprising:

a receiver for receiving a wireless communication signal;

a demodulator for demodulating said wireless communication signal and for producing data frames;

means for determining a voice frame integrity;

a processor connected to said demodulator for dropping one or more of said data frames to keep remaining data frames, said processor further for comparing said voice frame integrity with a predetermined value, said predetermined value representing a minimum desired voice quality, for increasing a variable queue threshold if said voice frame integrity is less than said predetermined value, for decreasing said variable queue threshold if said voice frame integrity is greater than said predetermined value, for dropping frames at a first rate if a length of said queue is less than said variable queue threshold, and for dropping frames at a second rate if said length is greater than said variable queue threshold; and

a queue for storing said remaining data frames.