Multilocation video conference terminal including rapid video switching

• US 4,574,374 A
• Filed: 10/25/1983
• Issued: 03/04/1986
• Est. Priority Date: 10/25/1983
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: AT&T, Inc.
• Inventors: Scordo, Dominick
• Primary Examiner(s): Olms, Douglas W.
• Application Number:
  US06/545,363
• Time in Patent Office: 861 Days
• Field of Search: 370/85, 370/58, 370/62, 358/86, 455/5, 455/6
• US Class Current: 370/265
• CPC Class Codes: H04M 3/561 by multiplexing
• 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
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04N 7/152 Multipoint control units therefor
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence

Abstract

In a multilocation conference terminal for transmitting audio and video information to a plurality of remote locations, rapid video and non-disrupted audio switching are obtained by employing a plurality of single composite digital signals each including all the video information from an associated location and all of the audio mixes for all of the locations in a conference. Then, the composite signals are switched prior to conversion for transmission to one or more of the locations. Since each composite signal includes all the audio mixes for all of the locations, when video from anyone of the locations is selected for transmission to any of the locations, the audio mixes for those locations are also switched.

Claims

1. In apparatus for transmitting video and audio information to a plurality of remote locations:

means associated with each of the remote locations for receiving at least first and second digital signals from each remote location, one of said at least first and second received signals includes video control signals in first prescribed bit locations, audio information in second prescribed bit locations and video information in third prescribed bit locations and the other of said at least first and second received signals includes video information, and said receiving means includes first formatting means for inserting said control signals and said audio information into first predetermined time slots of a first corresponding digital signal, for inserting said video information from said one of said at least first and second received signals into second predetermined time slots of said first corresponding signal and for inserting said video information from said other of said at least first and second received signals into third predetermined time slots in an at least second corresponding digital signal for the location;

means for processing said audio information from each of said remote locations into audio information to be transmitted to each of said remote locations;

second means for formatting said processed audio information for each remote location into predetermined fixed time slots assigned to the corresponding location in a plurality of composite signals associated on a one-to-one basis with the remote locations;

means associated with said receiving means for generating said plurality of composite signals, said generating means including means for combining said formatted audio information with said formatted video information to generate said composite signal for each location including the video information from that location in first predetermined time slots and the processed audio information for each of the plurality of locations in second predetermined time slots corresponding to the locations, wherein each of said composite signals includes all the video information from an associated location and the processed audio information for all of the remote locations; and

means supplied with said plurality of composite signals for controllably selecting any of said composite signals for transmission to any of said remote locations.

2. The apparatus as defined in claim 1 wherein said combining means includes time multiplexed switching means for generating said composite signals.

3. The apparatus as defined in claim 2 wherein said selecting means includes a N by N switch, where N is the number of inputs to and the number of outputs from said switch.

4. The apparatus as defined in claim 1 wherein said formatting means includes a time slot interchanger.

5. The apparatus as defined in claim 1 wherein said processing means includes means for inserting said video control signals for the video information from a location into the processed audio information for all of the locations to be included in the composite signal including the video information from that location.

6. The apparatus as defined in claim 5 further including third means for formatting said composite signals for transmission to said remote locations.

7. The apparatus as defined in claim 3 wherein said time multiplex switching means and said N×

N switch comprise a digital cross connect switch.

8. In apparatus for transmitting video and audio signals to a plurality of remote locations:

a plurality of means for receiving digital signals including video information and audio information, each of said receiving means being associated with one of said remote locations and includes means for identifying locations of the video information and audio information in the received digital signals from said associated remote location and first means for formatting said identified video information into first predetermined time slots of corresponding digital signals and for formatting said identified audio information in second predetermined time slots assigned to said associated remote location in said corresponding digital signals;

means supplied with said identified audio information in said corresponding digital signals from all of said plurality of remote locations for generating a corresponding plurality of audio mixes to be supplied to the remote locations;

second means for formatting said plurality of audio mixes into predetermined fixed time slots of a corresponding plurality of composite signals assigned to the remote locations;

a plurality of means associated on a one-to-one basis with said plurality of receiving means for generating said corresponding plurality of composite signals, each of said generating means including means for combining said formatted video information from said associated remote location and said formatted plurality of audio mixes to generate a single composite signal including all the video information from the associated location and all of the audio mixes for all of the remote locations; and

means supplied with said plurality of composite signals for controllably selecting any of said composite signals for transmission to any of said remote locations.

9. The apparatus as defined in claim 8 wherein each of said combining means includes a time multiplexed switch.

10. The apparatus as defined in claim 9 wherein said selecting means includes a N×

N switch, where N is the number of inputs to and outputs from said switch.

11. The apparatus as defined in claim 10 wherein said time multiplex switches and said N×

N switch comprise a digital cross connect switch.

12. The apparatus as defined in claim 10 wherein said first means includes a time slot interchanger.

13. The apparatus as defined in claim 8 further including a plurality of third means for formatting said selected composite signals for transmission to said remote locations.

14. The apparatus as defined in claim 8 wherein said identifying means and said first means comprises a digroup circuit.