Methods and apparatus for the utilization of core based nodes for state transfer

• US 6,862,446 B2
• Filed: 02/18/2003
• Issued: 03/01/2005
• Est. Priority Date: 01/31/2003
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Flarion Technologies Inc (Qualcomm, Inc.)
• Inventors: Park, Vincent, Corson, M. Scott, O'Neill, Alan, Tsirtsis, George
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US10/369,998
• Publication Number:
  US 20040203711A1
• Time in Patent Office: 742 Days
• Field of Search: 455/432.1, 455/432.2, 455/432.3, 455/433, 455/435.1, 455436-444, 455/560, 455/423, 455/424, 455/422.1, 370/328, 370/332, 370/331, 370/338, 370/401, 379/333
• US Class Current: 455/422.1
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/0033 with transfer of context information
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 8/08 Mobility data transfer
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/005 Data network PoA devices
• CPC Class Codes: H04W 92/12 between access points and access point controllers
• CPC Class Codes: H04W 92/20 between access points

Abstract

Methods and apparatus for storing, manipulating, retrieving, and forwarding state, e.g., context and other information, used to support communications sessions with one or more end nodes, e.g., mobile devices, are described. Various features are directed to a mobile node controlling the transfer of state from a first access node to a second access node during a handoff operation thereby eliminating any need for state transfer messages to be transmitted between the second access node and the first access node during handoff. Other features of the invention are directed to the use of a core network node to store state information. State information stored in the core node can be accessed and used by access nodes in cases where a mobile node does not send a state transfer message during a handoff, e.g., because communication with the first access node is lost or because such messages are not supported.

Claims

1. A communications method for use in a communications system including a first access node, a second access node and a mobile node, the method comprising:

operating the mobile node to transmit a signal to the first access node to transfer state information;

communicating state information between the first access node and the second access node in response to said signal transmitted to the first access node, wherein said step of communicating state information between the first access node and the second access node includes;

operating the first access node to communicate said state information to a first network node coupled to said first access node and said second access node;

operating the first network node to store said state information; and

operating the first network node to communicate said state information to said second access node,

wherein the step of operating the first network node to communicate said state information to said second access node includes;

operating the first network node to communicate said state information to said second access node in response to a signal received by said first network node from said second access node.

2. The method of claim 1, further comprising:

operating said second access node to generate said signal received by said first network node in response to a signal received from said mobile node.

3. The method of claim 2, further comprising the step of:

operating the second access node to check to determine if it has received state information corresponding to said mobile node prior to generating said signal received by said first network node.

4. A method of implementing a communications system including an end node, a first access node, a second access node and a first network node coupled to said first and second access nodes, said end node being coupled to at least one access node through which said end node can communicate with elements of said communication system, the method comprising:

storing state information in said first network node which can be used by either of said first and second access nodes to support communications with said end node;

updating the state information stored in said first network node with state information supplied by the first access node in response to a trigger event, said trigger event being an event in a group of events consisting of;

receipt by said first access node of a signal and a detection of a loss of communication with said end node;

operating said second access node to receive a signal from said end node indicating that state information corresponding to said end node should be retrieved;

operating said second access node to transmit a message requesting state information corresponding to said end node, wherein operating said second access node to transmit a message requesting state information corresponding to said end node includes transmitting a message from said second access node to said first network node; and

operating the second access node to use at least some of said state information that was stored in said first network node to support a communications session involving said end node following a handoff of said end node from said first access node to said second access node.

5. A method of implementing a communications system including an end node, a first access node, a second access node and a first network node coupled to said first and second access nodes, said end node being coupled to at least one access node through which said end node can communicate with elements of said communication system;

said system further includes a second network node, said second network node being in said second network region and coupling said first network node to said second access node;

said communications system further including a third network node, said third network node coupling said first network node to said second network node and being accessible from both said first and second network regions;

the method comprising;

storing state information in said first network node which can be used by either of said first and second access nodes to support communications with said end node;

updating the state information stored in said first network node with state information supplied by the first access node in response to a trigger event, said trigger event being an event in a group of events consisting of;

receipt by said first access node of a signal from said end node, a request for a state information update from said first network node, and a detection of a loss of communication with said end node;

operating said second access node to receive a signal from said end node indicating that state information corresponding to said end node should be retrieved;

operating said second access node to transmit a message requesting state information corresponding to said end node;

operating the second access node to use at least some of said stored state information to support a communications session involving said end node following a handoff of said end node from said first access node to said second access node;

communicating state information corresponding to said end node, from said first network node to said second network node; and

providing said second access node with at least some of said communicated state information corresponding to said end node,

wherein said first access node and said first network node are in a first network region, said second access node being in a second network region;

wherein operating said second access node to transmit a message requesting state information corresponding to said end node includes transmitting a message from said second access node to said second network node; and

wherein communicating state information corresponding to said end node, from said first network node to said second network node includes transmitting the communicated state information through said third network node.

6. The method of claim 5, wherein each of said first, second and third network nodes are authorization servers.

7. The method of claim 5, wherein each of said first, second and third network nodes are accounting servers.

8. The method of claim 5, further comprising:

storing state information obtained from said first access node, corresponding to said end node, in each of said second and third network nodes.

9. A method of implementing a communications system including an end node, a first access node, a second access node and a first network node coupled to said first and second access nodes, said end node being coupled to at least one access node through which said end node can communicate with elements of said communication system, the method comprising:

storing state information in said first network node which can be used by either of said first and second access nodes to support communications with said end node;

updating the state information stored in said first network node with state information supplied by the first access node in response to a trigger event, said trigger event being an event in a group of events consisting of;

receipt by said first access node of a signal from said end node, a request for a state information update from said first network node, and a detection of a loss of communication with said end node; and

operating the second access node to use at least some of said stored state information to support a communications session involving said end node following a handoff of said end node from said first access node to said second access node,

wherein said first network node includes a database which is accessible by said first and second access nodes, and wherein said first and second access nodes access said database through first and second authorization servers, respectively.

10. The method of claim 9, wherein said database is incorporated into a third authorization server.

11. The method of claim 9, wherein said first network node and said first authorization server are located in a first network region, said first authorization server providing authorization information only to nodes included in said first network region;

said second authorization server and said second network node being in a second network region, said second authorization server providing authorization information only to nodes included in said second network region; and

said database providing state information to said first and second authorization servers.

12. A method of implementing a communications system including an end node, a first access node, a second access node and a first network node coupled to said first and second access nodes, said end node being coupled to at least one access node through which said end node can communicate with elements of said communication system, the method comprising:

storing state information in said first network node which can be used by either of said first and second access nodes to support communications with said end node;

updating the state information stored in said first network node with state information supplied by the first access node in response to a trigger event, said trigger event being an event in a group of events consisting of;

receipt by said first access node of a signal from said end node, a request for a state information update from said first network node, and a detection of a loss of communication with said end node;

operating the second access node to use at least some of said stored state information to support a communications session involving said end node following a handoff of said end node from said first access node to said second access node, wherein said first network node includes a database which is accessible by said first and second access nodes, and wherein said first and second access nodes access said database through first and second accounting servers, respectively.

13. A method of implementing a communications system including an end node, a first access node, a second access node and a first network node coupled to said first and second access nodes, said end node being coupled to at least one access node through which said end node can communicate with elements of said communication system, the method comprising:

storing state information in said first network node which can be used by either of said first and second access nodes to support communications with said end node;

updating the state information stored in said first network node with state information supplied by the first access node in response to a trigger event, said trigger event being an event in a group of events consisting of;

receipt by said first access node of a signal from said end node, a request for a state information update from said first network node, and a detection of a loss of communication with said end node;

operating the second access node to use at least some of said stored state information to support a communications session involving said end node following a handoff of said end node from said first access node to said second access node; and

operating said first access node to detect the cessation of communications with said end node received via a wireless link, said detection of the cessation of communication triggering the first access node to transmit state update information to be stored in said first network node.

14. A method of implementing a communications system including an end node, a first access node, a second access node and a first network node coupled to said first and second access nodes, said end node being coupled to at least one access node through which said end node can communicate with elements of said communication system, the method comprising:

storing state information in said first network node which can be used by either of said first and second access nodes to support communications with said end node;

updating the state information stored in said first network node with state information supplied by the first access node in response to a trigger event, said trigger event being an event in a group of events consisting of;

receipt by said first access node of a signal from said end node, a request for a state information update from said first network node, and a detection of a loss of communication with said end node;

operating the second access node to use at least some of said stored state information to support a communications session involving said end node following a handoff of said end node from said first access node to said second access node; and

operating said first access node to receive a request for a state information update from said first network node, said received request triggering the first access node to transmit state update information to be stored in said first network node.

15. The method of claim 14, wherein said transmitted state update information includes state information corresponding to a plurality of end nodes coupled to said first access node.

16. The method of claim 14, further comprising:

operating said first network node to periodically transmit said request for a state information update to said first access node.

17. A communications system used to provide communications services to a plurality of end nodes, said communication system comprising:

a plurality of access nodes, each one of the access nodes storing state information used to provide communications services to end nodes coupled to said one of the access nodes;

a first core node coupled to said plurality of access nodes, said core node including;

i. state information received from a first one of said access nodes; and

ii. means for communicating said state information to a second one of said access nodes following a handoff from said first one of said access nodes to a second one of said access nodes,

wherein said first core node is in a first region of said communication system, the system further comprising;

a second core node located in a second communications region; and

a third core node coupled to said first and second core nodes, said third core node being used to transfer state information from said first core node to said second core node when a mobile node passes from said first region to said second region.

18. The communication system of claim 17, wherein said first, second and third core nodes are part of an accounting and authorization system.

19. The communication system of claim 17, wherein said first, second and third core nodes each store at least some state information, obtained from the first access node, corresponding to said mobile node.

20. A method of supporting handoffs from a first access node to a second access node in a communications network including said first and second access nodes, a mobile node, a first network node coupled to said first and second access nodes, a second network node, and a third network node, said first, second, and third network nodes being arranged in a hierarchical relationship with said third network node coupling said first network node to said second network node, the method comprising:

storing state information corresponding to said mobile node in both said first access node and said first network node;

updating the state information corresponding to said mobile node stored in said first network node with state information obtained from said first access node;

supplying said updated state information stored in said first network node to said second access node as part of a handoff of said mobile node from said first access node to said second access node;

storing said updated state information corresponding to said mobile node in said third network node in addition to said first network node; and

operating said second network node to retrieve said updated state information from said third network node in response to a state transfer request message corresponding to said mobile node.