System and method for fast start-up of live multicast streams transmitted over a packet network

• US 7,870,590 B2
• Filed: 10/20/2004
• Issued: 01/11/2011
• Est. Priority Date: 10/20/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Robins, Kristen Marie, Nguyen, Bich Tu, Jagadeesan, Ramanathan T., Wu, Fang
• Primary Examiner(s): Pendleton; Brian T
• Assistant Examiner(s): Stronczer; Ryan
• Application Number:
  US10/969,113
• Publication Number:
  US 20060083263A1
• Time in Patent Office: 2,274 Days
• Field of Search: 725/86, 725/90
• US Class Current: 725/93
• CPC Class Codes: H04L 12/2854 Wide area networks, e.g. public data networks

Abstract

A system for multicast streaming of programs over a packet network includes a node having a processor that conditions a video bitstream such that packets containing an I-frame are located near program specific information (PSI) packets, the processor marking a random join point (RJP) in the video bitstream immediately preceding the I-frame and PSI packets, the node outputting the conditioned and marked video bitstream across the packet network. An edge device of the network includes a buffer that caches packets of the conditioned and marked video bitstream video starting at the RJP, and sends the cached packets to a client receiver.

Claims

1. A system for multicast streaming of programs over a packet network comprising:

a multicast server having a processor that conditions a multicast video bitstream such that packets containing an I-frame are located near program specific information (PSI) packets, the PSI packets include conditional access table (CAT), program association table (PAT), and program map table (PMT) data, the processor marking a random join point (RJP) in the multicast video bitstream immediately preceding the I-frame and the PSI packets, the node outputting the conditioned and marked video bitstream across the packet network; and

an edge router or switch device of the network that receives the conditioned and marked video bitstream, the edge device including a buffer that caches packets of the conditioned and marked multicast video bitstream starting at the RJP, the edge device sending the cached packets to a client receiver in a multicast group in response to a request received by the edge device from the client receiver.

2. The system of claim 1 wherein the PSI packets further include encryption data.

3. The system of claim 1 wherein the client receiver comprises a set-top box.

4. A method for multicast streaming of programs over a packet network comprising:

transposing, by a head-end unit, packets of a multicast digital video transport stream such that packets containing an I-frame are located near program specific information (PSI) packets, the PSI packets including conditional access table (CAT), program association table (PAT), and program map table (PMT) data;

marking, by the head-end unit, a random join point (RJP) in the multicast digital video transport stream immediately preceding the I-frame and PSI packets;

caching, by a downstream device, packets of the multicast digital video transport stream starting at the RJP; and

bursting the cached packets to a client device in a multicast group responsive to a request received by the downstream device from the client device.

5. The method of claim 4 wherein the downstream device comprises a router or switch.

6. The method of claim 4 wherein the PSI packets further include encryption data.

7. In a packet-based network for multicast streaming of digital video programs, a computer-implemented method of conditioning a multicast digital video transport stream comprising:

transposing packets of an elementary stream contained within the multicast digital video transport stream such that packets containing an I-frame are located near program specific information (PSI) packets, the PSI packets including conditional access table (CAT), program association table (PAT), and program map table (PMT) data;

marking a random join point (RJP) in the multicast digital video transport stream immediately preceding the I-frame and PSI packets; and

sending the conditioned multicast digital video transport stream across an Internet Protocol (IP) distribution network to a router that is operable to cache a set of current data packets that includes the I-frame and PSI packets for subsequent burst transmission to a client receiver of a multicast group.

8. The method of claim 7 wherein marking comprises inserting a Real-Time Transport Protocol (RTP) signaling event RTP packet in the multicast digital video transport stream.

9. The method of claim 7 wherein marking comprises changing an Internet Protocol (IP) header field to signal the presence of the RJP in the multicast digital video transport stream.

10. The method of claim 7 wherein marking comprises changing an Real-Time Transport Protocol (RTP) header field to signal the presence of the RJP in the multicast digital video transport stream.

11. The method of claim 7 wherein the transposing and marking functions are performed in a multicast server.

12. The method of claim 7 wherein the transposing and marking functions are performed in a Transmitting Interworking Unit (TIU).

13. The method of claim 7 wherein the transposing and marking functions are performed in an encoding device.