De-registering a multicast group member from a multicast group within a wireless communications network

1. A method of multicasting within a wireless communication system, comprising:

receiving a first multicast registration message from an access terminal, the first multicast registration message identifying a first set of multicast groups;

registering the access terminal for each of the first set of multicast groups;

receiving a second multicast registration message from the access terminal, the second multicast registration message omitting at least one multicast group from among the first set of multicast groups;

interpreting the second multicast registration message as a request to de-register the access terminal from the omitted at least one multicast group;

updating a group member list of access terminals currently registered to each of the multicast groups; and

updating a set of sectors for multicast based on the updated group member list.

2. The method of claim 1 , wherein the first set of multicast groups includes one multicast group.

3. The method of claim 1 , wherein the first set of multicast groups includes more than one multicast group.

4. the method of claim 1 , wherein the first and second multicast registration messages are BCMSFlowRegistration messages.

5. The method of claim 1 , wherein the first multicast registration message identifies the first set of multicast groups based on the BCMCSFlowID for each of the first set of multicast groups.

6. The method of claim 1 , wherein the second multicast registration message identifies a second set of multicast groups, the second set of multicast groups being different from the first set of multicast groups.

7. The method of claim 6 , wherein the second set of multicast groups includes at least one multicast group not present within the first set of multicast groups.

8. The method of claim 6 , wherein the second set of multicast groups omits at least one multicast group present within the first set of multicast groups.

9. The method of claim 7 , wherein the second set of multicast groups omits at least one multicast group present within the first set of multicast groups.

10. The method of claim 1 , wherein the second multicast registration message does not identify any multicast groups.

11. The method of claim 10 , further comprising:

de-registering the access terminal from all multicast groups to which the access terminal is currently registered.

12. The method of claim 11 , further comprising:

ceasing to transmit multicast messages associated with the omitted at least one multicast group at the access terminal's sector if the de-registering step results in zero access terminals within the access terminal's sector being registered for the omitted at least one multicast group.

13. The method of claim 1 , wherein the second multicast registration message identifies only one special multicast group that is designated to imply an empty group.

14. The method of claim 13 , further comprising: de-registering the access terminal from all multicast groups to which the access terminal is currently registered.

15. The method of claim 14 , further comprising:

ceasing to transmit multicast messages associated with the omitted at least one multicast group at the access terminal's sector if the de-registering step results in zero access terminals within the access terminal's sector being registered for the omitted at least one multicast group.

16. The method of claim 1 , further comprising:

de-registering the access terminal from the omitted at least one multicast group.

17. The method of claim 16 , further comprising:

ceasing to transmit multicast messages associated with the omitted at least one multicast group at the access terminal's sector if the de-registering step results in zero access terminals within the access terminal's sector being registered for the omitted at least one multicast group.

18. An access network, comprising:

means for receiving a first multicast registration message from an access terminal, the first multicast registration message identifying a first set of multicast groups;

means for registering the access terminal for each of the first set of multicast groups;

means for receiving a second multicast registration message from the access terminal, the second multicast registration message omitting at least one multicast group from among the first set of multicast groups;

means for interpreting the second multicast registration message as a request to de-register the access terminal from the omitted at least one multicast group;

means for updating a group member list of access terminals currently registered to each of the multicast groups; and

means for updating a set of sectors for multicast based on the updated group member list.

19. The access network of claim 18 , further comprising:

means for de-registering the access terminal from the omitted at least one multicast group.

20. The access network of claim 19 , further comprising:

means for ceasing to transmit multicast messages associated with the omitted at least one multicast group at the access terminal's sector if the de-registration results in zero access terminals within the access terminal's sector being registered for the omitted at least one multicast group.

21. An access network, comprising:

logic configured to receive a first multicast registration message from an access terminal, the first multicast registration message identifying a first set of multicast groups;

logic configured to register the access terminal for each of the first set of multicast groups;

logic configured to receive a second multicast registration message from the access terminal, the second multicast registration message omitting at least one multicast group from among the first set of multicast groups;

logic configured to interpret the second multicast registration message as a request to de-register the access terminal from the omitted at least one multicast group;

logic configured to update a group member list of access terminals currently registered to each of the multicast groups; and

logic configured to update a set of sectors for multicast based on the updated group member list.

22. The access network of claim 21 , further comprising:

logic configured to de-register the access terminal from the omitted at least one multicast group.

23. The access network of claim 22 , further comprising:

logic configured to cease to transmit multicast messages associated with the omitted at least one multicast group at the access terminal's sector if the de-registration results in zero access terminals within the access terminal's sector being registered for the omitted at least one multicast group.

24. A non-transitory computer-readable storage medium having stored thereon computer-executable software instructions configured to cause a processor of an access network of a wireless communications system to perform operations comprising:

receiving a first multicast registration message from an access terminal, the first multicast registration message identifying a first set of multicast groups;

registering the access terminal for each of the first set of multicast groups; program code to receive a second multicast registration message from the access terminal, the second multicast registration message omitting at least one multicast group from among the first set of multicast groups;

interpreting the second multicast registration message as a request to de-register the access terminal from the omitted at least one multicast;

updating a group member list of access terminals currently registered to each of the multicast groups; and

updating a set of sectors for multicast based on the updated group member list.

25. The non-transitory computer-readable storage medium of claim 24 , wherein the stored computer-executable software instructions are configured to cause the processor of the access network of a wireless communications system to perform operations further comprising:

de-registering the access terminal from the omitted at least one multicast group.

26. The non-transitory computer-readable storage medium of claim 25 , wherein the stored computer-executable software instructions are configured to cause the processor of the access network of a wireless communications system to perform operations further comprising:

ceasing to transmit multicast messages associated with the omitted at least one multicast group at the access terminal's sector if the de-registration results in zero access terminals within the access terminal's sector being registered for the omitted at least one multicast group.

27. The method of claim 1 , wherein updating the set of sectors comprises:

determining target sectors in which access terminals currently registered to each of the multicast groups are located or are potentially located;

determining support sectors for each of the determined target sectors; and

updating target sector and support sector assignments,

the method further comprising:

updating movement of each of the access terminals in the updated group member list and

transmitting multicast messages associated with each of the multicast groups to the determined target sectors and support sectors of each respective multicast group.

28. The access network of claim 18 , wherein means for updating the set of sectors comprises:

means for determining target sectors in which access terminals currently registered to each of the multicast groups are located or are potentially located;

means for determining support sectors for each of the determined target sectors; and

means for updating target sector and support sector assignments,

the access network further comprising:

means for updating movement of each of the access terminals in the updated group member list; and

means for transmitting multicast messages associated with each of the multicast groups to the determined target sectors and support sectors of each respective multicast group.

29. The access network of claim 21 , wherein logic configured to update the set of sectors comprises:

logic configured to determine target sectors in which access terminals currently registered to each of the multicast groups are located or are potentially located;

logic configured to determine support sectors for each of the determined target sectors; and

logic configured to update target sector and support sector assignments,

the access network further comprising:

logic configured to update movement of each of the access terminals in the updated group member list; and

logic configured to transmit multicast messages associated with each of the multicast groups to the determined target sectors and support sectors of each respective multicast group.

30. The non-transitory computer-readable storage medium of claim 24 , wherein the stored computer-executable software instructions are configured to cause the processor of the access network of a wireless communications system to perform operations such that updating a set of sectors for multicast based on the updated group member list comprises:

determining target sectors in which access terminals currently registered to each of the multicast groups are located or are potentially located;

determining support sectors for each of the determined target sectors; and

updating target sector and support sector assignments, and

wherein the stored computer-executable software instructions are configured to cause the processor of the access network of a wireless communications system to perform operations further comprising:

updating movement of each of the access terminals in the updated group member list; and

transmitting multicast messages associated with each of the multicast groups to the determined target sectors and support sectors of each respective multicast group.