Efficient multicast call setup method and system

• US 20070168555A1
• Filed: 01/18/2006
• Published: 07/19/2007
• Est. Priority Date: 01/18/2006
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Dorenbosch, Jheroen
• Application Number:
  US11/333,977
• Publication Number:
  US 20070168555A1
• Time in Patent Office: Days
• US Class Current: 709/245
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 65/1101 Session protocols
• 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

Abstract

A system (100) and method (200) of setting up a multicast session in a wireless system having at least one access point serving a plurality of wireless terminals that are members of a multicast group can include collecting (202) a member set representing members of the multicast group and receiving (206) a multicast packet by the access point. The method further determines (208) a target set of terminals receiving the multicast packet. If a number of terminals in the target set is greater or equal to a threshold, then the multicast packet is multicast (214) to a multicast address. If the number of terminals in the target set is less than the threshold and greater than zero, then a copy of the multicast packet is unicast (216) to the unicast address of each terminal. The method can also suppress (218) the multicast packet if the number of terminals is zero.

Claims

1. A method of sending a multicast packet in a wireless system having at least one access point serving a plurality of wireless terminals that are members of a multicast group, comprising the steps of:

collecting at the access point, a member set representing members of the multicast group that are being served, the member set including a unicast address for each wireless terminal in the set among the plurality of wireless terminals;

receiving a multicast packet by the access point;

determining a target set of served wireless terminals that are members of the multicast group that will receive the multicast packet;

multicasting the multicast packet on a downlink from the access point to a multicast address if a number of wireless terminals in the target set is greater or equal to a threshold; and

unicasting a copy of the multicast packet on the downlink to the unicast address of each of the wireless terminals in the target set, if the number of wireless terminals in the target set is below the threshold.

2. The method of claim 1, wherein the method further comprises the step of suppressing the multicast packet on the downlink if the number of wireless terminals in the target set is zero.

3. The method of claim 1, wherein the step of collecting comprises detecting by the access point a session setup request for a multicast session directed to a member of the multicast group.

4. The method of claim 3, further comprising the step of joining a multicast distribution tree for the multicast group by the access point in response to the detecting of the session setup request for the multicast session.

5. The method of claim 4, wherein the access point generates a protocol independent-sparse mode message for joining a multicast group in response to the detecting of the session setup request for the multicast session.

6. The method of claim 1, wherein the method further comprises the step of determining membership in the multicast group by modifying an Internet Group Management Protocol signal or by modifying a Multicast Listener Discovery protocol signal.

7. The method of claim 1, wherein the method further comprises the step of forwarding the multicast group member sets representing members of the multicast group that are being served to an adjacent access point to enable a proactive joining by the adjacent access point to a multicast distribution tree for the multicast group.

8. The method of claim 7, wherein the proactive joining occurs in response to a receipt by the access point of a location update from a wireless terminal in the target set.

9. The method of claim 1, wherein the step of determining the target set depends on whether the multicast packet is received from a member in the member set.

10. An access point serving a plurality of wireless terminals that are members of a multicast group, comprising:

a wireless transceiver;

a processor coupled to the wireless transceiver, wherein the processor is programmed to;

collect at the access point, a member set representing members of the multicast group that are being served, the member set including a unicast address for each wireless terminal in the set among the plurality of wireless terminals;

receive a multicast packet by the access point;

determine a target set of served wireless terminals that are members of the multicast group that will receive the multicast packet;

multicast the multicast packet on a downlink from the access point to a multicast address if a number of wireless terminals in the target set is greater or equal to a threshold; and

unicast a copy of the multicast packet on the downlink to the unicast address of each of the wireless terminals in the target set, if the number of wireless terminals in the target set is below the threshold.

11. The access point of claim 10, wherein the processor is further programmed to suppress the multicast packet on the downlink if the number of wireless terminals in the target set is zero.

12. The access point of claim 10, wherein the processor is programmed to collect by detecting a session setup request for a multicast session directed to a member of the multicast group.

13. The access point of claim 12, wherein the processor is further programmed to join a multicast distribution tree for the multicast group by the access point in response to the detecting of the session setup request for the multicast session.

14. The access point of claim 13, wherein the access point generates a protocol independent-sparse mode message for joining a multicast group in response to the detecting of the session setup request for the multicast session.

15. The access point of claim 10, wherein the processor is further programmed to determine membership in the multicast group by modifying an Internet Group Management Protocol signal or by modifying a Multicast Listener Discovery protocol signal

16. The access point of claim 10, wherein the processor is further programmed to forward the multicast group member set representing members of the multicast group that are being served to an adjacent access point to enable a proactive joining by the adjacent access point to a multicast distribution tree for the multicast group in response to a receipt by the access point of a location update from a wireless terminal in the target set.

17. The access point of claim 10, wherein the processor is further programmed to determine the target set of served wireless terminals that are members of the multicast group that will receive the multicast packet based on whether the multicast packet is received from a wireless terminal source or a network source.

18. A machine-readable storage, having stored thereon a computer program having a plurality of code sections executable by a machine for causing the machine to perform the steps of.

collecting a member set representing members of a multicast group that are being served by an access point, the member set including a unicast address for each wireless terminal in the set among a plurality of wireless terminals;

receiving a multicast packet by the access point;

determining a target set of served wireless terminals that are members of the multicast group that will receive the multicast packet;

multicasting the multicast packet on a downlink from the access point to a multicast address if a number of wireless terminals in the target set is greater or equal to a threshold; and

unicasting a copy of the multicast packet on the downlink to the unicast address of each of the wireless terminals in the target set, if the number of wireless terminals in the target set is above zero and below the threshold.

19. The machine-readable storage of claim 18, wherein the machine-readable storage is further programmed to collect the member set by detecting a session setup request for a multicast session directed to a member of the multicast group and to join a multicast distribution tree for the multicast group by the access point in response to the detecting of the session setup request for the multicast session.

20. The machine-readable storage of claim 19, wherein the machine-readable storage is further programmed to suppress the multicast packet on a downlink from the access point to a wireless terminal if the number of wireless terminals in the target set is zero.