Method and apparatus for reconfigurable and adaptive stream multicast

• US 5,940,391 A
• Filed: 11/25/1997
• Issued: 08/17/1999
• Est. Priority Date: 11/25/1997
• Status: Expired due to Term

• Current Assignee: Comcast IP Holdings I LLC (Comcast Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Yu, Philip Shi-Lung, Malkin, Peter Kenneth, Willebeek-LeMair, Marc Hubert
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): VANDERPUYE, KENNETH N
• Application Number:
  US08/977,864
• Time in Patent Office: 630 Days
• Field of Search: 370/408, 370/390, 370/401, 370/421, 370/420, 370/486, 370/487, 370/400, 370/466, 348/7, 348/8
• US Class Current: 370/390
• CPC Class Codes: H04L 12/185 with management of multicast group membership

Abstract

A multimedia stream is multicasted. A request to perform the multicast is received. A plurality of distribution nodes are assigned to provide the multicast to a plurality of receivers. The assignment of a node is based on the transformation capabilities of that node. The multicast is then performed and the assigned node performs its transformation. The transformed multicast is distributed to a receiver which is suitable for receiving the transformed multicast.

Claims

1. A method of multicasting a multimedia stream, comprising the steps of:

receiving a request to perform a multicast;

assigning a plurality of distribution nodes to provide said multicast to a plurality of receivers, an assignment of at least one of said nodes based upon transformation capability of said node;

performing said multicast;

performing a transformation of said multicast at said node;

distributing said transformed multicast to at least one receiver which is suitable for receiving said transformed multicast.

2. A method of multicasting a multimedia stream according to claim 1, further comprising the step of receiving from a multimedia stream source a request for said transformation to be performed.

3. A method of multicasting a multimedia stream according to claim 1, wherein said multimedia stream includes multiple components, further comprising the step of providing each of said components to a respective type of receiver.

4. A method of multicasting a multimedia stream according to claim 1, wherein said multimedia stream includes at least one of an audio stream and a video stream.

5. A method of multicasting a multimedia stream according to claim 3, wherein each of said components is distributed to each respective type of receiver through a respective multicast path.

6. A method of multicasting a multimedia stream according to claim 1, further comprising the step of indicating by said at least one receiver its receiving capability.

7. A method of multicasting a multimedia stream according to claim 6, wherein said receiver is pointed to said node responsive to said receiver indicating its receiving capability.

8. A method of multicasting a multimedia stream according to claim 6, wherein said receiver indicates its receiving capability using PICS.

9. A method of multicasting a multimedia stream according to claim 6, wherein said node indicates its ability to perform said transformation.

10. A method of multicasting a multimedia stream according to claim 1, further comprising the step of receiving from said receiver a request to join said multicast after a plurality of additional receivers have already begun to receive said multicast.

11. An apparatus for multicasting a multimedia stream, comprising:

a source node for requesting a multicast;

a plurality of distribution nodes for distributing said multicast, at least one of said nodes capable of transforming said multicast;

a plurality of receivers; and

a control node for assigning said plurality of said distribution nodes to provide said multicast to said plurality of receivers based upon transformation capability of at least one of said nodes.

12. An apparatus for multicasting a multimedia stream according to claim 11, further comprising a source node for providing said multimedia stream and for requesting said transformation to be performed.

13. An apparatus for multicasting a multimedia stream according to claim 11, wherein said multimedia stream includes multiple components and each of said components are receivable by a respective type of said plurality of receivers.

14. An apparatus for multicasting a multimedia stream according to claim 11, wherein said multimedia stream includes at least one of an audio stream and a video stream.

15. An apparatus for multicasting a multimedia stream according to claim 13, wherein each of said components is distributed to each respective type of receiver through a respective multicast path.

16. An apparatus for multicasting a multimedia stream according to claim 11, wherein at least one of said receivers indicates its receiving capability.

17. An apparatus for multicasting a multimedia stream according to claim 16, wherein said receiver is pointable to said node responsive to said receiver indicating its receiving capability.

18. An apparatus for multicasting a multimedia stream according to claim 16, wherein said receiver indicates its receiving capability using PICS.

19. An apparatus for multicasting a multimedia stream according to claim 16, wherein at least one of said nodes indicates its ability to perform said transformation.

20. An apparatus for multicasting a multimedia stream according to claim 11, wherein said receiver is permitted to join said multicast after a plurality of additional receivers have already begun to receive said multicast.