MULTICASTING WITHIN A WIRELESS COMMUNICATIONS SYSTEM

• US 20100322131A1
• Filed: 06/23/2009
• Published: 12/23/2010
• Est. Priority Date: 06/23/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gurelli, Mehmet, Attar, Rashid Ahmed, Song, Bongyong, Gill, Harleen
• Granted Patent: US 8,787,234 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 72/121 for groups of terminals or users
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

An access network determines to transmit multicast messages on a downlink shared channel. The access network receives a multicast registration message and a traffic channel request from at least one access terminal. The access network assigns a traffic channel to the at least one access terminal, and transmits the multicast messages on the downlink shared channel. In another example, the access network can determine a channel type upon which the support a multicast session, can indicate the channel type selection to the at least one access terminal in an announce message and can then transmit the multicast messages for the multicast session on the selected channel type. The at least one access terminal receives the announce message, requests a traffic channel and receives a traffic channel assignment, registers to the multicast session and monitors the downlink shared channel for multicast messages.

Claims

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

determining to transmit multicast messages associated with an announced multicast session on a downlink shared channel;

receiving, from one or more access terminals, a multicast session registration message to request registration to an announced multicast session and a traffic channel request to request a traffic channel;

assigning a traffic channel to each of the one or more access terminals; and

transmitting the multicast messages to the one or more access terminals on the downlink shared channel.

2. The method of claim 1, wherein the downlink shared channel corresponds to a downlink control channel.

3. The method of claim 2, wherein transmitting step transmits the multicast messages within one or more asynchronous control capsules in one or more control channel cycles of the downlink control cycle.

4. The method of claim 1, wherein the transmitting step only transmits the multicast messages within sectors that are expected to include one or more of the plurality of multicast group members, such that sectors that do not include one or more of the plurality of multicast group members do not transmit the multicast messages.

5. The method of claim 1, wherein the determining, assigning and transmitting steps are performed on a per-subnet basis.

6. The method of claim 5,

wherein, for a first subnet, the transmitting step only transmits the multicast messages within sectors that are expected to include one or more of the plurality of multicast group members, such that sectors that do not include one or more of the plurality of multicast group members do not transmit the multicast messages, and

wherein a second subnet transmits the multicast messages on a downlink broadcast channel within sectors that are expected to include one or more of the plurality of multicast group members and also within at least one sector that does not include one or more of the plurality of multicast group members.

7. The method of claim 1, wherein the determining, assigning and transmitting steps are performed for a first group of sectors within a given subnet, further comprising:

transmitting the multicast messages within a second group of sectors within the given subnet on a downlink broadcast channel.

8. The method of claim 1, wherein each assigned traffic channel includes a forward link traffic channel and a reverse link traffic channel.

9. The method of claim 8, further comprising:

tracking locations of each of the one or more access terminals based on the assigned reverse link traffic channels.

10. The method of claim 9, further comprising:

ceasing transmission of the multicast messages on the downlink shared channel in a first sector if the tracking step determines that at least one of the one or more access terminals hands off from the first sector to a second sector and zero of the one or more access terminals remain in the first sector after the handoff.

11. The method of claim 9, further comprising:

beginning transmission of the multicast messages on the downlink shared channel in a second sector if the tracking step determines that at least one of the one or more access terminals hands off from a first sector to the second sector and zero of the one or more access terminals were present in the second sector before the handoff.

12. The method of claim 8, further comprising:

associating the traffic channel request from a given access terminal with the multicast registration message from the given access terminal

13. A method of multicasting within a wireless communications system, comprising:

receiving an announce message for announcing a multicast session to a plurality of multicast group members;

determining a channel type upon which to support the multicast session;

configuring the announce message to indicate the determined channel type;

transmitting the configured announce message to the plurality of multicast group members within at least one of a plurality of sectors; and

transmitting multicast messages associated with the announced multicast session on the determined channel type only within sectors that are expected to include one or more of the plurality of multicast group members.

14. The method of claim 13, wherein the determining step selects a downlink shared channel as the channel type upon which to support the multicast session.

15. The method of claim 14, wherein the downlink shared channel is a downlink control channel or a downlink broadcast channel.

16. The method of claim 13, wherein the configuring step generates a supplemental message for indicating the determined channel type, and the transmission of the configured announce message corresponds to a transmission of the supplemental message along with the announce message.

17. The method of claim 13, wherein the determining step is performed on a per-subnet basis, such that different subnets are capable of selecting different channel types upon which to support the multicast session.

18. The method of claim 17, wherein a first subnet performing the determining step determines to support the multicast session on a downlink shared channel and a second subnet determines to support the multicast session on a downlink broadcast channel.

19. The method of claim 13,

wherein the determining step is performed independently for each of a plurality of groups of sectors within a given subnet,

wherein a first instance of the determining step determines to support the multicast session on a downlink shared channel for a first group of sectors within the given subnet, and

wherein a second instance of the determining step determines to support the multicast session on a downlink broadcast channel for a second group of sectors within the given subnet,

20. The method of claim 13, further comprising:

receiving a multicast session registration from each of the one or more multicast group members to request registration to the announced multicast session; and

if the determining step determines to support the multicast session on a downlink shared channel, receiving a traffic channel request from each of the one or more multicast group members, and assigning a downlink traffic channel to each of the one or more multicast group members,

wherein the multicast messages are transmitted, on the downlink shared channel, only in sectors including the one or more multicast group members from which the multicast session registrations are received.

21. A method of multicasting within a wireless communications system, comprising:

receiving an announce message announcing a multicast session;

sending a traffic channel request to request a traffic channel in response to the received announce message;

receiving a traffic channel assignment in response to the traffic channel request;

sending a registration request to register to the announced multicast session; and

monitoring a downlink shared channel for multicast messages associated with the announced multicast session.

22. The method of claim 21, wherein the downlink shared channel corresponds to a downlink control channel.

23. The method of claim 21, wherein the announce message is configured to indicate that the announced multicast session is supported on the downlink shared channel.

24. The method of claim 23, wherein the announce message is configured to indicate that the announced multicast session is supported on the downlink shared channel based on the announce message being sent along with a supplemental message indicating the downlink shared channel.

25. The method of claim 21, further comprising:

handing off from a first sector to a second sector; and

continuing to monitor the downlink shared channel, after the handoff in the second sector, for multicast messages associated with the announced multicast session.

26. The method of claim 21,

wherein the traffic channel assignment assigns a forward link traffic channel and a reverse link traffic channel to an access terminal,

wherein the forward link traffic channel is silent if the announced multicast session is active and a separate unicast session with the access terminal is not established, and

wherein the access terminal transmits, on the reverse link traffic channel, messaging sufficient to maintain the assigned forward and reverse link traffic channels and to permit an access network to track the access terminal'"'"'s location.

27. An access network within a wireless communications system, comprising:

means for determining to transmit multicast messages associated with an announced multicast session on a downlink shared channel;

means for receiving, from one or more access terminals, a multicast session registration message to request registration to an announced multicast session and a traffic channel request to request a traffic channel;

means for assigning a traffic channel to each of the one or more access terminals; and

means for transmitting the multicast messages to the one or more access terminals on the downlink shared channel.

28. An access network within a wireless communications system, comprising:

means for receiving an announce message for announcing a multicast session to a plurality of multicast group members;

means for determining a channel type upon which to support the multicast session;

means for configuring the announce message to indicate the determined channel type;

means for transmitting the configured announce message to the plurality of multicast group members within at least one of a plurality of sectors; and

means for transmitting multicast messages associated with the announced multicast session on the determined channel type only within sectors that are expected to include one or more of the plurality of multicast group members.

29. An access terminal within a wireless communications system, comprising:

means for receiving an announce message announcing a multicast session;

means for sending a traffic channel request to request a traffic channel in response to the received announce message;

means for receiving a traffic channel assignment in response to the traffic channel request;

means for sending a registration request to register to the announced multicast session; and

means for monitoring a downlink shared channel for multicast messages associated with the announced multicast session.

30. An access network within a wireless communications system, comprising:

logic configured to determine to transmit multicast messages associated with an announced multicast session on a downlink shared channel;

logic configured to receive, from one or more access terminals, a multicast session registration message to request registration to an announced multicast session and a traffic channel request to request a traffic channel;

logic configured to assign a traffic channel to each of the one or more access terminals; and

logic configured to transmit the multicast messages to the one or more access terminals on the downlink shared channel.

31. An access network within a wireless communications system, comprising:

logic configured to receive an announce message for announcing a multicast session to a plurality of multicast group members;

logic configured to determine a channel type upon which to support the multicast session;

logic configured to configure the announce message to indicate the determined channel type;

logic configured to transmit the configured announce message to the plurality of multicast group members within at least one of a plurality of sectors; and

logic configured to transmit multicast messages associated with the announced multicast session on the determined channel type only within sectors that are expected to include one or more of the plurality of multicast group members.

32. An access terminal within a wireless communications system, comprising:

logic configured to receive an announce message announcing a multicast session;

logic configured to send a traffic channel request to request a traffic channel in response to the received announce message;

logic configured to receive a traffic channel assignment in response to the traffic channel request;

logic configured to send a registration request to register to the announced multicast session; and

logic configured to monitor a downlink shared channel for multicast messages associated with the announced multicast session.

33. A computer-readable storage medium comprising instructions encoded thereon, which, when executed by an access network within a wireless communications system, cause the access network to perform operations, the instructions comprising:

program code to determine to transmit multicast messages associated with an announced multicast session on a downlink shared channel;

program code to receive, from one or more access terminals, a multicast session registration message to request registration to an announced multicast session and a traffic channel request to request a traffic channel;

program code to assign a traffic channel to each of the one or more access terminals; and

program code to transmit the multicast messages to the one or more access terminals on the downlink shared channel.

34. A computer-readable storage medium comprising instructions encoded thereon, which, when executed by an access network within a wireless communications system, cause the access network to perform operations, the instructions comprising:

program code to receive an announce message for announcing a multicast session to a plurality of multicast group members;

program code to determine a channel type upon which to support the multicast session;

program code to configure the announce message to indicate the determined channel type;

program code to transmit the configured announce message to the plurality of multicast group members within at least one of a plurality of sectors; and

program code to transmit multicast messages associated with the announced multicast session on the determined channel type only within sectors that are expected to include one or more of the plurality of multicast group members.

35. A computer-readable storage medium comprising instructions encoded thereon, which, when executed by an access terminal within a wireless communications system, cause the access terminal to perform operations, the instructions comprising:

program code to receive an announce message announcing a multicast session;

program code to send a traffic channel request to request a traffic channel in response to the received announce message;

program code to receive a traffic channel assignment in response to the traffic channel request;

program code to send a registration request to register to the announced multicast session; and

program code to monitor a downlink shared channel for multicast messages associated with the announced multicast session.