System and method for delivering content in a unicast/multicast manner

• US 7,082,142 B1
• Filed: 12/21/2001
• Issued: 07/25/2006
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Begeja, Lee
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): ROSE, KERRI M
• Application Number:
  US10/026,227
• Time in Patent Office: 1,677 Days
• Field of Search: 725 93- 97, 725/88, 725/90, 370/432, 370/270, 370/312, 370389-391, 370/411, 370/503, 370/507, 370/509, 370516-521, 375/354, 375/356, 375/359
• US Class Current: 370/507
• CPC Class Codes: H04N 21/234381 by altering the temporal resolution, e.g. decreasing the frame rate by frame skipping
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/2625 for delaying content or additional data distribution, e.g. because of an extended sport event
• CPC Class Codes: H04N 21/26275 for distributing content or additional data in a staggered manner, e.g. repeating movies on different channels in a time-staggered manner in a near video on demand system
• CPC Class Codes: H04N 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/6125 involving transmission via Internet transmission by internet of broadcast information H04H60/82
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

The present invention is a system and method for enabling multicast synchronization of initially unicasted content. Multiple unicast streams are synchronized in order to convert the unicast streams into a multicast stream. Each unicast stream may be accelerated or slowed down in relation to a reference stream to a common point within each stream upon which the unicast streams are replaced by a multicast stream of the same content.

Claims

1. A method comprising:

receiving a plurality of requests for unicast transmission streams;

providing the plurality of unicast transmission streams;

synchronizing the plurality of unicast transmission streams, wherein synchronizing the plurality of unicast transmission streams is performed by slowing down one or more of the unicast streams at a rate that depends on when the request for the unicast transmission stream is received; and

replacing the synchronized plurality of unicast transmission streams with a multicast stream.

2. The method of claim 1, wherein a single movie provider and a single movie theater share a single encryption key not shared by any other movie provider and movie theater.

3. The method of claim 1, wherein the plurality of unicast transmission streams contain a single pre-recorded event.

4. The method of claim 1, wherein the plurality of unicast transmission streams are started at different times.

5. A method, comprising:

synchronizing a plurality of separate unicasts, wherein synchronizing the plurality of separate unicasts includes differentially adjusting a delivery rate of each unicasts so that the unicasts converge at similar point within a predetermined time frame; and

converging the plurality of synchronized unicasts into a simgle multicast, wherein the unicasts have been converged at the same point within each unicast by slowing down one or more of the unicast streams at a rate that depends on when the request for the unicast stream is received.

6. The method of claim 5, further comprising:

delivering the plurality of separate unicasts to a plurality of unicast recipients.

7. The method of claim 5, further comprising:

receiving a plurality of requests for the unicast from a plurality of unicast requesters.

8. The method of claim 5, wherein converging the plurality of synchronized unicasts into a single multicast comprises:

terminating each of the plurality of synchronized unicasts; and

replacing each of the terminated plurality of synchronized unicasts with a multicast.

9. The method of claim 5, wherein converging the plurality of synchronized unicasts into a single multicast, wherein the single multicast replaces the plurality of unicasts.

10. A method, comprising:

synchronizing a plurality of separate unicasts, wherein synchronizing the plurality of separate unicasts includes dynamically altering each unicast in an undetectable manner so that each of the plurality of unicasts converge at a similar point within each unicast; and

converging the plurality of synchronized unicasts into a simgle multicast, wherein the unicasts have been converged at the same point within each unicast by slowing down one or more of the unicast streams at a rate that depends on when the request for the unicast stream is received.

11. The method of claim 10, further comprising:

delivering a plurality of separate unicasts to a plurality of unicast recipients.

12. The method of claim 10, further comprising:

receiving a plurality of requests for the unicast from a plurality of unicast requestors.

13. The method of claim 10, wherein converging the plurality of synchronized unicasts into a single multicast comprises:

terminating each of the plurality of synchronized unicasts; and

replacing each of the terminated plurality of synchronized unicasts with a multicast.

14. The method of claim 10, wherein converging the plurality of synchronized unicasts into a single multicast, wherein the single multicast replaces the plurality of unicasts.

15. A method, comprising:

synchronizing a plurality of separate unicasts; and

converging the plurality of synchronized unicasts into a simgle multicast, wherein the unicasts have been converged at the same point within each unicast by slowing down one or more of the unicast streams at a rate that depends on when the request for the unicast stream is received and by determining when the plurality of unicasts have converged to the same point; and

converting each of the plurality of unicasts into a single multicast.

16. The method of claim 15, further comprising:

delivering the plurality of separate unicats to a plurality of unicast recipients.

17. The method of claim 15, further comprising:

receiving a plurality of requests for the unicast from a plurality of unicast requestors.