Teleconferencing System with Multiple Channels at Each Location

• US 20080233934A1
• Filed: 04/30/2007
• Published: 09/25/2008
• Est. Priority Date: 03/19/2007
• Status: Active Grant

• Current Assignee: Avaya Incorporated
• Original Assignee: Avaya Incorporated
• Inventors: Diethorn, Eric John
• Granted Patent: US 7,848,738 B2
• Time in Patent Office: Days
• US Class Current: 455/416
• CPC Class Codes: H04M 2203/1091 Fixed mobile conversion
• CPC Class Codes: H04M 2203/2094 Proximity
• CPC Class Codes: H04M 2242/30 Determination of the location of a subscriber
• CPC Class Codes: H04M 3/42263 where the same subscriber uses different terminals, i.e. nomadism
• CPC Class Codes: H04M 3/56 Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities video conference systems H04N7/15
• CPC Class Codes: H04M 3/568 audio processing specific to telephonic conferencing, e.g. spatial distribution, mixing of participants echo suppression in two-way loud-speaking telephone systems H04M9/02; sound field processing per se H04S7/30

Abstract

A method is disclosed that breaks the “one line, one location” paradigm of teleconferencing in the prior art. The teleconference bridge in the illustrative embodiment is able to utilize more than one audio channel from each location, where there are multiple signal sources present in the room. As a result, the bridge is able to determine acoustically whether two are more endpoints are collocated with each another. During an initialization sequence, the bridge transmits special audio signals to one or more endpoints present in a particular sound field; those endpoints then play the signals out of their loudspeakers. Based on a characteristic (e.g., amount of correlation, signal strength, etc.) of the signals received at each microphone present in the same sound field, the bridge determines whether to include or exclude signals that are received from a first endpoint when preparing a signal for transmission to a second endpoint during a conference call.

Claims

1. A method comprising:

determining, at a teleconference bridge, that a first endpoint is acoustically collocated with a second endpoint;

receiving a first receive audio signal s₁ from said first endpoint via a first port and a second receive audio signal s₂ from said second endpoint via a second port at said teleconference bridge; and

transmitting a first transmit audio signal x₁ for said first endpoint and a second transmit audio signal x₂ for said second endpoint, wherein at least a component of said signal s₁ is excluded from said signal x₂ based on the determination that said first endpoint being acoustically collocated with said second endpoint.

2. The method of claim 1 wherein said signal s₁ is excluded entirely from said signal x₂, based on said first endpoint being acoustically collocated with said second endpoint.

3. The method of claim 1 wherein said signal s₂ is included in said signal x₁.

4. The method of claim 3 wherein said first endpoint comprises cellular telephone functionality and said second endpoint is a conference telephone.

5. The method of claim 1 wherein said signal x₁ and said signal x₂ further comprise a third receive audio signal s₃ that said teleconference bridge receives via a third port from a third endpoint.

6. The method of claim 5 wherein said teleconference bridge is capable of only unidirectional communication from said third endpoint and is capable of bidirectional communication with said second endpoint.

7. The method of claim 1 wherein the determination of said first endpoint being acoustically collocated with a second endpoint comprises:

transmitting, from said teleconference bridge, a third transmit audio signal x₃ to said second endpoint;

receiving a third receive audio signal s₃ from said first endpoint; and

determining that said signal s₃ is sufficiently correlated with said signal x₃.

8. The method of claim 7 wherein said signal x₃ is transmitted before the start of a conference call that involves said first endpoint and said second endpoint.

9. The method of claim 7 further comprising:

transmitting, from said teleconference bridge, a fourth transmit audio signal x₄ to said first endpoint;

receiving a fourth receive audio signal s₄ from said second endpoint; and

determining that said signal s₄ is uncorrelated with said signal x₄.

10. The method of claim 1 wherein the determination of said first endpoint being acoustically collocated with a second endpoint is based on the geo-locations of said first endpoint and said second endpoint.

11. The method of claim 10 wherein the determination of said first endpoint being acoustically collocated with a second endpoint is also based on the terminal types of said first endpoint and said second endpoint.

12. A method comprising:

transmitting, from a teleconference bridge, a first transmit audio signal x₁ to a first endpoint via a first port and a second transmit audio signal x₂ to a second endpoint via a second port at said teleconference bridge;

receiving a first receive audio signal s₁ from said first endpoint and a second receive audio signal s₂ from said second endpoint;

determining whether said signal s₁ is sufficiently correlated with said signal x₂; and

when said signal s₁ is sufficiently correlated with said signal x₂, adjusting a first transfer function to exclude, during a conference call, at least a component of a third receive audio signal s₃ received from said first endpoint from a third transmit audio signal x₃ transmitted to said second endpoint.

13. The method of claim 12 wherein said signal x₁ and said signal x₂ are transmitted at different times.

14. The method of claim 12 wherein said signal x₁ and said signal x₂ are transmitted concurrently and are substantially acoustically orthogonal with respect to each other.

15. The method of claim 12 further comprising:

determining whether said signal s₂ is sufficiently correlated with said signal x₁; and

when said signal s₂ is sufficiently correlated with said signal x₁, adjusting a second transfer function to exclude, during said conference call, at least a component of a fourth receive audio signal s₄ received from said second endpoint from a fourth transmit audio signal x₄ that is transmitted to said first endpoint.

16. The method of claim 15 wherein the determination of whether said signal s₁ is sufficiently correlated with said signal x₂ and whether said signal S2 is sufficiently correlated with said signal x₁ occurs before said conference call ends.

17. The method of claim 16 wherein the determination of whether said signal s₁ is sufficiently correlated with said signal x₂ and whether said signal s₂ is sufficiently correlated with said signal x₁ occurs before said conference call starts.

18. The method of claim 15 wherein said first endpoint comprises cellular telephone functionality and said second endpoint is a conference telephone.

19. The method of claim 12 wherein said teleconference bridge is capable of only unidirectional communication from said first endpoint and is capable of bidirectional communication with said second endpoint.

20. A method comprising:

selecting, at a teleconference bridge, a plurality of endpoints that comprises a first endpoint and a second endpoint, wherein said teleconference bridge is able to receive signals from each endpoint of said plurality via a different port dedicated to each endpoint;

transmitting a predetermined audio signal x₀ to said second endpoint;

receiving at least a first receive audio signal s₁ from at least said first endpoint of said plurality after the transmission of said signal x₀ to said second endpoint has started;

determining whether said signal s₁ is sufficiently correlated with said signal x₀; and

when said signal s₁ is sufficiently correlated with said signal x₀, adjusting a first transfer function to exclude, during a conference call, at least a component of a second receive audio signal s₂ that is received from said first endpoint, from a first transmit audio signal x₁ that is transmitted to said second endpoint.

21. The method of claim 20 further comprising

transmitting said predetermined audio signal x₀ to said second endpoint;

receiving at least a third receive audio signal s₃ from at least a third endpoint of said plurality after the transmission of said signal x₀ to said second endpoint has started;

determining whether said signal s₃ is sufficiently correlated with said signal x₀; and

when said signal s₃ is sufficiently correlated with said signal x₀, adjusting said first transfer function to exclude, during said conference call, at least a component of a fourth receive audio signal s₄ received from said third endpoint from said first transmit audio signal x₁ that is transmitted to said second endpoint.

22. The method of claim 20 wherein the selection of said plurality of endpoints is based on the endpoints that are participating in said conference call.

23. The method of claim 22 wherein the determination of whether said signal s₁ is sufficiently correlated with said signal x₀ occurs before said conference call starts.

24. The method of claim 20 wherein said first endpoint is a conference telephone and said second endpoint comprises cellular telephone functionality.

25. The method of claim 20 wherein said plurality comprises at least one endpoint which said teleconference bridge is capable of only receiving signals from.

26. The method of claim 25 wherein said plurality comprises at least one endpoint which said teleconference bridge is capable of only transmitting signals to.