Enhanced techniques for using core based nodes for state transfer

• US 20050063324A1
• Filed: 08/04/2004
• Published: 03/24/2005
• Est. Priority Date: 01/31/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sigal, leonid, Park, Vincent, Mazik, David R., Corson, M. Scott, O'Neill, Alan, Tsirtsis, George, Dynarski, Richard J.
• Granted Patent: US 7,668,541 B2
• Time in Patent Office: Days
• US Class Current: 370/310
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/03 by updating link state protocols
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/0892 by using authentication-authorization-accounting [AAA] servers or protocols
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 36/0033 with transfer of context information
• CPC Class Codes: H04W 40/248 Connectivity information update
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 8/22 Processing or transfer of terminal data, e.g. status or physical capabilities
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• 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 network including a core state management node and a plurality of access nodes coupled to said core state management node through which mobile nodes can attach to a communications network via wireless communications links, the method comprising:

operating the core state management node to receive a state update signal from a first access node, the state update signal including an access node identifier, end node state corresponding to a first end node, and a first count value;

operating the core state management node to determine if the core state management node already has stored state corresponding to said first end node;

in response to determining that the core state management node already includes stored state corresponding to said first end node, determining if the first count value was updated after the count value included in said stored state corresponding to said first end node was generated; and

when it is determined that the first count value was updated after the count value included in said stored state corresponding to the first end node, updating the stored state information with state information included in the received state update signal.

2. The method of claim 1, wherein the method further comprises:

in response to determining the core state management node does not already have stored state corresponding to said first end node, storing state information, including said received first count value, corresponding to said first end node received in said state update signal, in a data storage device accessible by said core state management node.

3. The method of claim 1,

when it is determined that the first count value was not updated after the count value included in said stored state, rejecting the state update request by leaving the stored state corresponding to the end node unchanged.

4. The method of claim 2, wherein said first count value is one of an access node dependent count value generated by an access node and an access node independent count value.

5. The method of claim 4, wherein said access node independent count value is a time stamp generated from a signal produced by said end node.

6. The method of claim 2, wherein said received update signal further includes an access node identifier, the method further comprising:

prior to determining if the first count value exceeds a stored count value, determining if said received access node identifier matches a stored access node identifier included with the stored state corresponding to said end node.

7. The method of claim 6, wherein said received update signal includes a second count value in addition to said first count value, the first count value being an access node dependent count value, said second count value being an access node independent count value, the method further comprising:

when it is determined that said received access node identifier does not match the stored access node identifier determining if said second count value is was increment after a stored access node independent count value included with said stored state information corresponding to said end node; and

rejecting said state when said received second count value was not updated after said stored access node independent count.

8. The method of claim 7, further comprising:

updating said state when said received second count value was updated after said stored access node independent count.

9. The method of claim 7, wherein said access node independent count is a time stamp.

10. A communications method for use in a communications network including a core state management node and a plurality of access nodes coupled to said core state management node through which mobile nodes can attach to a communications network via wireless communications links, the method comprising:

operating the core state management node to receive a state update signal from a first access node, the state update signal including an access node identifier, end node state information corresponding to a first end node, a first access node dependent count value, and a second access node independent count value;

operating the core state management node to store at least some of said received end node state information if it is determined that state corresponding to said end node is not present in storage;

operating the core state management node to store at least some of said end node state information state information if it is determined that either i) stored state information corresponding to said end node is present in storage, the access node identifier included in said received state update request signal matches a stored access node identifier associated with said stored state information corresponding to said end node, and the received state update message was generated subsequent to a state update message from said access node from which the stored information was obtained and ii) stored state information corresponding to said end node is present in storage, the access node identifier included in said received state update request signal does not match a stored access node identifier associated with said stored state information corresponding to said end node, and the received state update message was generated subsequent to a state update message from which the stored information was obtained; and

operating the core state management node to reject said state update message by leaving the stored state information corresponding to said end node unchanged when said state information is not stored in one of said preceding steps.

11. The method of claim 10, wherein said core state management node determines if said state update message was generated subsequent to a state update message from said access node from which the stored information was obtained as a function of a comparison of an access node dependent count value included in said stored state information and an access node dependent value included in said received state update request message.

12. The method of claim 11, wherein said core state management node determines if said state update message was generated subsequent to a state update message from said access node from which the stored information was obtained as a function of a comparison of an access node independent value included in said stored state information and the access node independent value included in said received state update request message.

13. The method of claim 11, wherein an access node independent count value does not depend on which access node supplied the access node independent value and wherein an access node dependent count value depends on which access node generated the access node dependent count value, different access nodes having different access node dependent counters which operate asynchronously from one another.

14. A communications method for use in a communications system including a first access node, a second access node and a core state management node, said core state management system including stored state, said stored state including a first access node identifier corresponding to the first access node, a first access specific count corresponding to the first access node, and state information received from the first access node, the method comprising:

operating the second access node to send a first state update signal to said core state management node, the first state update signal including a second access node identifier corresponding to said second access node, the first access node identifier, a second first access node specific count, and state information obtained from said second access node;

operating the core state management node to receive said first update signal;

operating the core state management node to compare the first first access node specific count to the second first access node specific count included in the received first update message to determine if the second first access node count was generated before the first first access node specific count; and

upon determining that the second first access node specific count was generated before said first first access node specific count, responding to said update signal by transmitting a response signal including at least some of said stored state information to said second access node.

15. The method of claim 14, further comprising:

operating the second access node to receive and combine at least some state information included in said response signal with state information that was included in said first state information update signal.

16. The method of claim 15, wherein said response signal further includes said first first access node specific count, the method further comprising:

transmitting at least some of said combined state information to said core state management node in a second state update signal, said second state update signal also including said first first access node specific count.

17. The method of claim 16,

wherein said second state update signal further includes a second access node specific count.

18. The method of claim 17, further comprising:

operating the core state management node to store at least some of the state information included in said second state update signal with said second access node specific count.

19. The method of claim 18, wherein said state information included in said first and second state update signals corresponds to a mobile node.

20. The method of claim 19, wherein said mobile node maintains communications connectivity with said first and second access nodes at the same time.

21. The method of claim 18, further comprising, prior to generation of said first state update signal, performing the steps of:

operating the core state management node to store state information received from said first access node;

operating the cores state management node to communicate at least some of said state information received from said first access node to said second access node along with said second first access node specific count; and

operating the cores state management node to subsequently store additional state information received from said first access node along with said first first access node specific count.

22. The method of claim 21, wherein said first and second first access node specific counts are time stamps generated by said first access node.

23. The method of claim 22, wherein said first second access node specific count is a time stamp generated by said second access node.

24. The method of claim 21, wherein said state information included in said first and additional state updates corresponds to a mobile node.

25. The method of claim 19, wherein said mobile node maintains communications connectivity with said first and second access nodes at the same time.

26. The method of claim 14, where said first first access node count is generated after said second first access node count by said first access node incrementing said second first access node specific count.

27. A communications method for use in a communications system including a mobile node, a first access node, a second access node, and a core state management node, said core state management node including stored state corresponding to said mobile node, the method comprising:

operating the second access node to receive a request to access said second access node transmitted by said end node to said second access node via said first access node;

operating the second access node to transmit to said core state management node a signal requesting state corresponding to said mobile node; and

operating the second access node to receive from said core state management node state information corresponding to said mobile node.

28. The communications method of claim 27, further comprising:

establishing wireless communications between said end node and said second access node following receipt of state information corresponding to said mobile node by said second access node.

29. The communications method of claim 27, further comprising:

operating the second access node to transmit a handshake signal through said first access node to said end node following receipt of said state information from said core state management node; and

operating the second access node to receive a handshake signal response from said end node which is communicated through said first access node.

30. The communications method of claim 29, further comprising:

establishing wireless communications between said end node and said second access node following receipt of said handshake signal form said end node.

31. The communications method of claim 29, wherein said handshake signal is a challenge request generated from security information included in the state information received from said core state management node.

32. The communications method of claim 31, wherein said handshake response signal is a challenge response including a value generated from information stored in said mobile node and information included in said received challenge request.

33. The communications method of claim 29, wherein said request to access said second access node is a handoff initiation signal.

34. The communications method of claim 29, further comprising:

operating the second access node to communicate access link configuration information to said end node via said first access node to be used by said mobile node to configure at least one

35. The communications method of claim 29, further comprising:

establishing wireless communications between said end node and said second access node following transmission of said configuration information to said end node.

36. The communication method of claim 35, wherein said configuration information includes information about signals transmitted by said second access node.

37. The communication method of claim 35, wherein said configuration information includes information about the operation of the wireless link between the first end node and the second access node.

38. A communications method for use in a communications system including a first access node, a second access node, a core state management node and an end node which communicates via a wireless communications connection with at least one of said first and second access nodes, the method comprising:

operating the first access node to generate a state update message in response to one of;

receiving a signal producing a state change in state corresponding to said end node which is stored in said first access node and detecting a change in state corresponding to said end node which occurs inside said access node;

transmitting the state update message to said core state management node;

operating the core state management node to store state included in said state update message; and

operating the core state management node to transmit said stored state to said second access node in response to a state request message received by said core state management node that was transmitted by said second access node and which includes an end node identifier corresponding to said end node.

39. A communications system, comprising:

a core state management node;

a plurality of access nodes coupled to said core state management node through which mobile nodes can attach to a communications network via wireless communications links,

wherein said core state management node includes;

means for receiving a state update signal from a first access node in said plurality of access nodes, the state update signal including an access node identifier, end node state corresponding to a first end node, and a first count value;

means for determining if the core state management node already has stored state corresponding to said first end node;

means for determining if the first count value was updated after the count value included in said stored state corresponding to said first end node was generated; and

means for updating the stored state information with state information included in the received state update signal when it is determined that the first count value was updated after the count value included in said stored state corresponding to the first end node.