Method and apparatus for group leader selection in wireless multicast service

• US 20070091889A1
• Filed: 10/25/2005
• Published: 04/26/2007
• Est. Priority Date: 10/25/2005
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Xiao, Xin, Cushing, Christopher, Capurka, Tomas
• Granted Patent: US 7,688,755 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/46 Cluster building
• CPC Class Codes: H04L 51/58 Message adaptation for wireless communication
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements

Abstract

In a telecommunication system comprising a multicast group (110) and a base station (200), a signal performance value (304) is received from at least two members of the multicast group (110) to generate a set of signal performance values (306). A group leader (310) of the multicast group (110) is selected as a function of the set of signal performance values (306) to acknowledge multicast transmissions from the base station (200) to the multicast group (110).

Claims

1. A method of selecting a group leader for a multicast group comprising steps of:

(a) receiving a signal performance value from at least two members of the multicast group to generate a set of signal performance values; and

(b) selecting the group leader as a function of the set of signal performance values to acknowledge subsequent multicast messages or datagrams successfully received from a base station and to request re-transmission of messages or datagrams that are not successfully received from the base station.

2. The method of claim 1 wherein the signal performance value comprises at least one of a signal quality estimate, outbound received power, a received signal strength indicator, a missed packet percentage, and a successfully received packet percentage.

3. The method of claim 1 wherein step (a) comprises polling at least one member of the multicast group for the signal performance value.

4. The method of claim 1 wherein step (a) comprises including the signal performance value in a multicast channel access/group signup message.

5. The method of claim 1 wherein step (a) comprises including the signal performance value in an Internet Group Management Protocol membership report.

6. The method of claim 1 wherein step (a) comprises including the signal performance value in a Receive Ready message.

7. The method of claim 1 further comprising repeating step (b) when the group leader leaves the multicast group.

8. The method of claim 1 further comprising repeating step (b) when the signal performance value of a member of the multicast group other than the group leader worsens by more than a selected threshold.

9. The method of claim 1 further comprising repeating step (b) when the signal performance value of the group leader of the multicast group improves by more than a selected threshold.

10. The method of claim 1 wherein step (a) comprises including the signal performance value in an Is Receive Ready message.

11. The method of claim 1 wherein step (b) comprises selecting the group leader as a function of the set of signal performance values to request re-transmission of messages or datagrams that are not successfully received from the base station.

12. A base station for a telecommunication system comprising:

a set of signal performance values generated from a signal performance value received from each of at least two members of a multicast group; and

a group leader selection management module for selecting a group leader for the multicast group as a function of the set of signal performance values to acknowledge subsequent multicast messages or datagrams successfully received from a base station.

13. The base station of claim 12 wherein the signal performance value comprises at least one of a signal quality estimate, outbound received power, a received signal strength indicator, a missed packet percentage, and a successfully received packet percentage.

14. The base station of claim 13 wherein the group leader selection management module polls at least one member of the multicast group for the signal performance value.

15. The base station of claim 13 wherein the group leader selection management module receives the signal performance value in a multicast channel access/group signup message.

16. The base station of claim 13 wherein the signal performance value is included in an Internet Group Management Protocol membership report.

17. The base station of claim 13 wherein the signal performance value is included in one of a Receive Ready message and an Is Receive Ready message.

18. The base station of claim 12 further comprising a new set of signal performance values for replacing the group leader of the multicast group as a function of the new set of signal performance values when the group leader leaves the multicast group.

19. The base station of claim 12 further comprising a new set of signal performance values for replacing the group leader of the multicast group as a function of the new set of signal performance values when the signal performance value of a member of the multicast group other than the group leader worsens by more than a selected threshold.

20. The base station of claim 12 further comprising a new set of signal performance values for replacing the group leader of the multicast group as a function of the new set of signal performance values when the signal performance value of the group leader of the multicast group improves by more than a selected threshold.

21. The base station of claim 12 further comprising a unicast message sent from the base station to each member of the multicast group except the group leader to suspend acknowledgment of multicast transmissions from the base station to the multicast group.

22. The base station of claim 12 further comprising a group leader selection timer to initiate a group leader selection procedure.

23. The base station of claim 12 further comprising a group leader re-selection timer to initiate a group leader selection procedure when the group leader fails to acknowledge a multicast message.

24. The base station of claim 12 wherein the group leader selection management module selects a group leader for the multicast group as a function of the set of signal performance values to request re-transmission of messages or datagrams that are not successfully received from the base station.