ENABLING FOREIGN NETWORK MULTICASTING FOR A ROAMING MOBILE NODE, IN A FOREIGN NETWORK, USING A PERSISTENT ADDRESS

• US 20080151808A1
• Filed: 03/03/2008
• Published: 06/26/2008
• Est. Priority Date: 06/14/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: O'Neill, Alan
• Granted Patent: US 8,102,792 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• 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 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 45/16 Multipoint routing
• CPC Class Codes: H04W 8/10 between location register and external networks
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

Permitting a mobile host to roam in a foreign network, with multiple access node handoffs, while permitting foreign network multicasting by (i) having the mobile node (MN) use a persistent address, for purposes of multicasting, and (ii) relaxing or modifying reverse path forwarding checks, and (iii) modifying the forwarding of multicast packets sent from a non-local source address. The persistent address, used in mobile networks as the source address in the IGMP Membership reports and the multicast packets, may be the permanent and hence stable host home address (HoA). This enables the HoA to be supported as a source address by foreign agents (FAs) and multicast routing protocols in foreign networks.

Claims

1. A processor for use in a mobile node of a communications system including:

a first network system serving as a home network for a mobile node and including a first mobility agent which is coupled to a home network multicast system, and

a second network system, said second network system including said access node and a foreign network multicast system, the access node including;

a second mobility agent, and

a multicast facility;

the processor being configured to control the mobile node to implement a communications method, the method comprising;

a) submitting a signaling message, from the mobile node, to the multicast facility of the access node for joining a multicast data communications group in the foreign network multicast system; and

b) sending, from the mobile node, unencapsulated multicast data to the multicast data communications group, via the access node, using a source address that is not local to the second, visited, network system.

2. The method of claim 1, wherein the source address is a persistent address.

3. The method of claim 1, wherein the source address is a host home address.

4. A computer readable medium including machine executable instructions for controlling a mobile node to implement a communications method while in a communications system, the communications system including:

a first network system serving as a home network for a mobile node and including a first mobility agent which is coupled to a home network multicast system, and

a second network system, said second network system including said access node and a foreign network multicast system, the access node including;

a second mobility agent, and

a multicast facility;

the communications method comprising;

a) submitting a signaling message, from the mobile node, to the multicast facility of the access node for joining a multicast data communications group in the foreign network multicast system; and

b) sending, from the mobile node, unencapsulated multicast data to the multicast data communications group, via the access node, using a source address that is not local to the second, visited, network system.

5. The computer readable medium of claim 4, wherein the source address is a persistent address.

6. The computer readable medium of claim 4, wherein the source address is a host home address.

7. A processor for use in an access node, the access node being for use with a communications system including

a mobile node,

a first network system serving as a home for the mobile node and including a first mobility agent and a home network multicast system, and

a second, visited, network system including said access node and a foreign network multicast system,

the processor being configured to control the access node to implement a method comprising:

a) accepting multicast group information, including a non-local address, from the mobile node; and

b) storing the multicast group information to be used for the reception of multicast data from the foreign network multicast system.

8. The processor of claim 7, wherein the access node has an address, the processor being further configured to:

c) distribute, from the access node, the address of the access node as a source-specific reverse path forwarding address.

9. The processor of claim 7, wherein the processor is further configured to control the access node to perform the steps of:

c) accept a multicast packet from the mobile node; and

d) determine whether or not to forward the multicast packet based on mobility information, related to the mobile node, and used by the access node.

10. A computer readable medium including machine executable instructions for controlling an access node in a communications system to implement a communications method, the communications system including:

a mobile node,

a first network system serving as a home for the mobile node and including a first mobility agent, and

a second, visited, network system including an access node,

the communications method comprising;

a) accepting multicast group information, including a non-local address, from the mobile node;

b) storing the multicast group information

c) accepting a multicast packet from the mobile node;

d) determining whether or not to forward the multicast packet based on mobility information, related to the mobile node, and used by the access node,

wherein the step of determining whether or not to forward the multicast packet includes;

i) determining whether a source address of the multicast packet is on a visitor list; and

ii) if it is determined that the source address of the multicast packet is on the visitor list, considering the multicast packet to have passed a reverse path forwarding check, despite the fact that the source address is a non-local address.

11. The computer readable media of claim 10, wherein the communications method further comprises:

e) if the access node is a multicast router running a shared tree protocol specifying a shared tree having a root, then tunneling the accepted multicast packet to the root of the tree.

12. An access node for use in a multicast communications system, the access node comprising:

a) multicast facility support means for supporting multicast operations including multicast establishment and forwarding operations; and

b) mobility facility support means for supporting the roaming to, and multicast connectivity at said access node, of a mobile end node, wherein the mobile end node uses a non-local address for the reception of local multicast data from other nodes in a foreign network multicast system, said non-local address corresponding to a home network.

13. The access node of claim 12, wherein the non-local address used by the mobile node is a Mobile Internet Protocol home address.

14. The access node of claim 12 further comprising:

c) wireless interface means for effecting a wireless link with the mobile node.

15. The access node of claim 12 further comprising:

c) interface means for coupling the access node to another node, the another node including a multicast routing and forwarding process.

16. An access node for use in a multicast communications system, the access node comprising:

a) multicast facility support means for supporting multicast operations including multicast establishment and forwarding operations;

b) mobility facility support means for supporting the roaming to, and multicast connectivity at said access node, of a mobile end node, wherein the mobile end node uses a non-local address for local multicast services;

c) memory means including a stored set of available mobility state information and a stored set of available multicast state information; and

d) means for correctly forwarding multicast data from the mobile node into a multicast system, despite the fact that the source address of the multicast packets are not local to the access node, using the set of available mobility state information.

17. The access node of claim 16, wherein said mobility facility support means supports Mobile Internet Protocol signaling.

18. A mobile node belonging to a first network system and having a home agent in the first network system, for use in a multicast communications system of a second, visited, network system including a foreign network multicast system and an access node, said access node including:

a foreign mobility agent, and

a multicast facility,

the mobile node comprising;

a) a signaling generation module for generating a signaling message to the multicast facility of the access node for joining a multicast data communications group at the foreign network multicast system;

b) a multicast data generation module for generating multicast data to the multicast data communications group, using a multicast source address that is not local to the second, visited, network system; and

c) a transmitter for transmitting the signaling message and multicast data to the access node.

19. The mobile node of claim 18, wherein the source address is a persistent address.

20. The mobile node of claim 18, wherein the source address is a host home address.