Controller Providing Gradual Transition of Multiple Terminals from Unicast Transmission

• US 20110228769A1
• Filed: 03/22/2010
• Published: 09/22/2011
• Est. Priority Date: 03/22/2010
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Haimi-Cohen, Raziel, Hearn, John
• Granted Patent: US 9,374,231 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/612 for unicast

Abstract

A controller in a video headend or other transmission element of a signal distribution system is operative to detect a condition in which unicast transmissions of a given content stream to a plurality of terminals meet a specified threshold. The controller starts a multicast transmission of the given content stream in response to the detected condition, and transitions at least one of the terminals to the multicast transmission. In one embodiment, the controller identifies at least one of the terminals as a terminal that will receive the multicast transmission of the given content stream in place of its unicast transmission prior to one or more of the other terminals receiving the multicast transmission. The controller stops the unicast transmission to the identified terminal if that unicast transmission has already been started, starts the multicast transmission, switches the identified terminal to the multicast transmission, and subsequently transitions one or more of the other terminals to the multicast transmission. The identified terminal may be a leading terminal or a trailing terminal.

Claims

1. A method comprising:

detecting a condition in which unicast transmissions of a given content stream to a plurality of terminals meet a specified threshold;

starting a multicast transmission of said given content stream in response to said detected condition; and

transitioning at least one of the plurality of terminals to the multicast transmission.

2. The method of claim 1, further comprising:

identifying at least one of the plurality terminals as a terminal to receive the multicast transmission of the given content stream in place of its unicast transmission prior to one or more of the other terminals receiving said multicast transmission; and

stopping the unicast transmission to the identified terminal.

3. The method of claim 1 further comprising identifying at least one of a leading terminal and a trailing terminal.

4. The method of claim 1, wherein detecting is based on timing information or buffering information.

5. The method of claim 1 further comprising reducing a rate of the multicast transmission to synchronize delivery of the given content stream.

6. The method of claim 1 further comprising transmitting the given content stream to at least one of the plurality of terminals at a rate greater than a rate for another of the plurality of terminals.

7. The method of claim 6, wherein the rate is increased by at least one of denting and bursting.

8. An article of manufacture comprising a computer-readable storage medium having embodied therein executable program code that when executed by a processor causes an associated processing device to perform the steps of the method of claim 1.

9. An apparatus comprising:

a controller comprising a processor;

wherein the controller is configured to detect a state in which unicast transmissions of a given content stream to respective terminals meet a threshold condition; and

wherein the controller, responsive to said detected state, is configured to start a multicast transmission of said given content stream, and to transition the terminals to the multicast transmission.

10. The apparatus of claim 9, wherein said controller is configured to identify at least one of the terminals as a terminal to receive the multicast transmission of the given content stream in place of its unicast transmission prior to one or more of the other terminals receiving said multicast transmission, to stop the unicast transmission to the identified terminal, and to start the multicast transmission to the identified terminal.

11. The apparatus of claim 9, wherein said controller is implemented in a video headend.

12. An integrated circuit comprising the apparatus of claim 9.

13. The apparatus of claim 9, wherein the controller is electromagnetically coupled to a gateway router.

14. The apparatus of claim 9, wherein the controller is configured to receive a message indicative of a maximum buffering capacity of at least one of the terminals.

15. The apparatus of claim 14, wherein the controller is configured to transition said at least one terminal to the multicast transmission based at least in part on said maximum buffering capacity.

16. The apparatus of claim 9, wherein the controller is configured to identify at least one of a leading terminal and a trailing terminal.

17. The apparatus of claim 9, wherein the controller is configured to increase a transmission rate of the given content stream by at least one of denting and bursting.

18. The apparatus of claim 9, wherein the controller is configured to transition at least one of the terminals by reducing a transmission rate of the given content stream.

19. The apparatus of claim 9, wherein the controller is configured to compensate for a timing difference between at least two of the terminals.

20. The apparatus of claim 9 wherein the controller is configured to synchronize delivery of the given content stream to the terminals.