Method and system for audio compression negotiation for multiple channels

• US 5,742,773 A
• Filed: 04/18/1996
• Issued: 04/21/1998
• Est. Priority Date: 04/18/1996
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Taylor, Jeffrey Eames, Blomfield-Brown, Christopher, Donner, Robert David
• Primary Examiner(s): Kim, Kenneth S.
• Application Number:
  US08/634,243
• Time in Patent Office: 733 Days
• Field of Search: 341/50, 341/61, 358/426, 370/263, 370/342, 370/345, 370/441, 370/442, 370/479, 370/498, 704/500, 395/200.77, 395/200.58
• US Class Current: 709/228
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04M 7/0072 Speech codec negotiation H04L65/1069 takes precedence

Abstract

Modem-equipped computers which can initiate an audio channel using the modem data connection. The connection is initiated with a new protocol called the voice-over-data protocol. The new protocol does not require any additional modem hardware or telephone line features, and is not tied to any proprietary hardware/software compression or transmission schemes. The voice-over-data protocol negotiates an audio compression/decompression scheme and then sets up an audio channel over an existing data connection using a socket. Compressed audio data is then delivered to the remote computer where it is decompressed and output. The voice-over-data protocol significantly reduces the latency which disrupts normal speech patterns when voice data is sent over a data connection. This protocol also reduces the bandwidth required to send voice over a data connection.

Claims

1. In a computer system having a first computer in communications with a remote second computer over a data link, a method of creating a virtual two channel audio connection over the data link, the two channel connection including a higher quality audio channel, and a lower quality audio channel, the method comprising the following steps:

maintaining on the first computer a first list of available audio data compression and decompression processes, the first list including higher quality, and lower quality audio data compression and decompression processes;

maintaining on the remote second computer a second list of available audio data compression and decompression processes, the second list including higher quality, and lower quality audio data compression and decompression processes;

negotiating between the remote second computer and the first computer a high quality audio compression and decompression process to be used for the higher quality audio channel and a low quality audio compression and decompression process to be used for the lower quality audio channel;

sending higher quality audio data from the first computer to the remote second computer over the data link using the negotiated high quality audio compression process, the data link thereby serving as a high quality, virtual audio channel; and

sending lower quality audio data from the remote second computer to the first computer over the data link using the negotiated low quality audio compression process, the data link thereby also serving as a low quality virtual audio channel.

2. A computer readable medium having stored therein instructions for causing the first computer to perform the method of claim 1.

3. The method of claim 1 wherein the lower quality audio channel is used to send voice data.

4. The method of claim 1 where the first list of available audio data compression and decompression processes on the first computer is identical to the second list of available audio data compression and decompression processes on the remote second computer.

5. The method of claim 1 where the first list of available audio data compression and decompression processes on the first computer is not identical to the second list of available audio data compression and decompression processes on the remote second computer.

6. The method of claim 1 in which said data link serves concurrently to provide both said higher quality and lower quality virtual audio channels.

7. The method of claim 1 which includes employing a socket to establish the data link.

8. The method of claim 7 wherein the step of establishing an audio connection using a socket includes using a datagram socket.

9. The method of claim 1 wherein the high quality audio data is sampled at a rate greater than 11 KHz.

10. The method of claim 1 wherein the low quality audio data is sampled at a rate less than or equal to 11 KHz.

11. The method of claim 1 further comprising:

maintaining on the remote second computer a second list of available audio data compression and decompression processes, the second list including at least one but less than all of the high quality, and low quality audio data compression and decompression processes contained in the first list.

12. In a system having a first computer in communications with a second remote computer over a data link, a method of establishing a virtual plural channel audio connection therebetween, where each of said audio channels is capable of sending two or more streams of compressed audio data, the method comprising the following steps:

negotiating between the first computer and the remote second computer a number of audio channels to establish, wherein said number of audio channels is two or more;

negotiating between the first computer and the remote second computer an audio data compression and decompression process for each of said number of audio channels;

transmitting audio data from the first computer to the remote second computer in two or more compressed audio data streams over each of said virtual audio channels using the audio compression process negotiated therefor.

13. The method of claim 12 which includes employing a socket to establish the data link.

14. The method of claim 13 wherein said socket is a datagram socket.

15. The method of claim 12 wherein the virtual audio channels are used to provide audio location cues for teleconferencing.

16. The method of claim 12 wherein the virtual audio channels are used to provide full spatial imaging cues for teleconferencing.

17. A computer readable medium having stored therein instructions for causing a first computer to perform the method of claim 12.