Method and apparatus for centralized multipoint conferencing in a packet network

• US 6,404,745 B1
• Filed: 08/12/1999
• Issued: 06/11/2002
• Est. Priority Date: 09/18/1996
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Ezenia! Inc.
• Inventors: Kajos, George W., OʼNeil, John E.
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US09/373,873
• Time in Patent Office: 1,034 Days
• Field of Search: 370/259, 370/260, 370/261, 370/263, 370/264, 370/265, 370/267, 370/389, 370/390, 370/432, 348/12, 348/13, 348/14, 348/15, 348/17, 348/14.08, 348/14.09, 379/93.06, 379/93.08, 379/93.21, 379/201, 379/202, 709/204, 709/205
• US Class Current: 370/260
• CPC Class Codes: H04L 12/1827 Network arrangements for conference optimisation or adaptation
• CPC Class Codes: H04L 65/4038 with floor control
• CPC Class Codes: H04M 3/567 Multimedia conference systems
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04N 7/148 Interfacing a video terminal to a particular transmission medium, e.g. ISDN
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

A centralized multipoint conferencing arrangement uses a combination of multicast and unicast transmissions that is bandwidth efficient. A method of conferencing includes transmitting multimedia streams from endpoint terminals to a central resource such as a multipoint control unit (MCU) using unicast transmission. The multimedia streams are processed in the MCU and transmitted back to the endpoint terminals using multicast transmission. In addition, the MCU transmits other multimedia streams to selected endpoint terminals using unicast transmission. At the selected endpoint terminals, processing of the multimedia streams is inhibited in favor of processing the other multimedia streams.

Claims

1. A method of conferencing in a packet network, the method comprising:

transmitting first multimedia streams from endpoint terminals to a central resource;

processing the first multimedia streams in the central resource to generate second and third multimedia streams; and

transmitting the second multimedia streams from the central resource to the endpoint terminals in a multicast packet transmission and transmitting the third multimedia streams to selected endpoint terminals, each third multimedia stream being transmitted in a unicast packet transmission.

2. The method of claim 1 further comprising inhibiting processing of the second multimedia streams at the selected endpoint terminals.

3. The method of claim 2 wherein inhibiting comprises transmitting a control message from the central resource to the selected endpoint terminals, the control message suspending a logical channel at the selected endpoint terminal associated with the second multimedia streams.

4. The method of claim 2 wherein inhibiting comprises ignoring the second multimedia streams at the selected endpoint terminals.

5. The method of claim 4 wherein a selected endpoint terminal ignores a second stream upon determining that the second stream includes information from the first multimedia stream of that selected endpoint terminal.

6. The method of claim 1 wherein transmitting the third multimedia streams includes transmitting a unicast video stream to a one of the selected endpoint terminals associated with a designated video broadcaster.

7. The method of claim 1 wherein transmitting the third multimedia streams includes transmitting a unicast audio stream to a one of the selected endpoint terminals associated with a designated audio broadcaster.

8. The method of claim 1 wherein the multimedia streams comprise video and audio streams.

9. A method of conferencing in a packet network, the method comprising:

transmitting first video streams from endpoint terminals to a central resource;

processing the first video streams in the central resource to generate second and third video streams; and

transmitting the second video streams from the central resource to the endpoint terminals in a multicast transmission and transmitting the third video streams to selected endpoint terminals, each third video stream being transmitted in a unicast packet transmission.

10. The method of claim 9 further comprising inhibiting processing of the second video streams at the selected endpoint terminals.

11. The method of claim 10 wherein inhibiting comprises transmitting a control message from the central resource to the selected endpoint terminals, the control message suspending a logical channel at the selected endpoint terminal associated with the second video streams.

12. The method of claim 10 wherein inhibiting comprises ignoring the second video streams at the selected endpoint terminals.

13. The method of claim 12 wherein a selected endpoint terminal ignores a second stream upon determining that the second stream includes information from the first multimedia stream of that selected endpoint terminal.

14. The method of claim 9 wherein the selected endpoint terminals are each associated with a designated video broadcaster.

15. A multipoint conferencing system for use in a packet network, the system comprising:

endpoint terminals for transmitting and receiving multimedia streams;

a central resource operative to receive first multimedia streams from the endpoint terminals, process the first multimedia streams to second and third multimedia streams, transmit the second streams to the endpoint terminals in multicast packet transmission and transmit the third streams to selected endpoint terminals in unicast packet transmission.

16. The system of claim 15 wherein the central resource further comprises inhibiting means for inhibiting processing of the second multimedia streams at the selected endpoint terminals.

17. The system of claim 16 wherein the inhibiting means transmits a control message from the central resource to the selected endpoint terminals, the control message suspending a logical channel at the selected endpoint terminal associated with the second multimedia streams.

18. The system of claim 15 wherein the selected endpoint terminals ignore the second multimedia streams.

19. The system of claim 18 wherein a selected endpoint terminal ignores a second stream upon determining that the second stream includes information from the first multimedia stream of that selected endpoint terminal.

20. The system of claim 15 wherein a one of the selected endpoint terminals associated with a designated video broadcaster receives a unicast video stream.

21. The system of claim 15 wherein a one of the selected endpoint terminals associated with a designated audio broadcaster receives a unicast audio stream.

22. The system of claim 15 wherein the multimedia streams comprise video and audio streams.

23. A method of communication in a packet network, the method comprising:

receiving at an endpoint terminal from a central resource a first multimedia stream in a multicast packet transmission and a second multimedia stream in a unicast packet transmission; and

selecting one of the first and second multimedia streams for processing at the endpoint terminal, wherein selecting includes suspending a logical channel at the endpoint terminal associated with the first multimedia stream in response to receiving a control message from the central resource.