Methods and apparatus for supporting session signaling and mobility management in a communications system

• US 20020191593A1
• Filed: 06/11/2002
• Published: 12/19/2002
• Est. Priority Date: 06/14/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm Flarion Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Park, Vincent, Corson, M. Scott, Tsirtsis, George, OʼNeill, Alan
• Granted Patent: US 6,970,445 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04W 12/062 Pre-authentication
• CPC Class Codes: H04W 12/069 using certificates or pre-shared keys
• CPC Class Codes: H04W 76/12 Setup of transport tunnels
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14
• CPC Class Codes: H04W 88/005 Data network PoA devices

Abstract

A mobile communications system that uses IP packets to transmit data between end nodes, such as mobile devices, is described. In order to facilitate session establishment, maintenance, security, and handoff operations, access nodes through which end nodes communicate with one another include a session signaling server module and a mobility agent module. The session signaling server module may be implemented as a SIP server while the mobility agent module may be implemented using Mobil IP signaling. The mobility agent and SIP server within an access node are identified using a single shared identifier, IP address. The same security method and common secret may be used to provide security with regard to both mobile IP messages and SIP messages. Sessions admission decisions and resource allocation for admitted sessions can also take place internally to the access node of this invention without need for signaling to external elements.

Claims

1. A communications method for use in a communications system including a plurality of nodes, said plurality of nodes including first and second end nodes, the method including the steps of:

providing an access node including a session signaling server module through which the first end node can establish a data communications session with the second end node; and

operating said access node to transmit data communications signals from said first end node to said second end node once a data communications session between said first and second end nodes is established.

2. The method of claim 1, further comprising:

operating said session signaling server module to perform a session initiation operation.

3. The method of claim 2,

wherein said step of operating said session signaling server module to perform a session initiation operation includes:

operating said session signaling server module to transmit session initiation signals using SIP signaling.

4. The method of claim 3,

wherein said access node is a first wireless access router;

wherein said session signaling server module is a SIP server; and

wherein the step of operating said session signal server module includes;

transmitting a SIP message from said SIP server included in said first wireless access router to another SIP server included in said communications system.

5. The method of claim 4, wherein said another SIP server is included in a second wireless access router used to couple said second end node to said first wireless access router.

6. The method of claim 4, further comprising:

operating said first wireless access router to interact with a first plurality of mobile nodes over a wireless communications channel, said first end node being one of said plurality of mobile nodes.

7. The method of claim 6, further comprising:

operating a second wireless router including a second SIP server to interact with a second plurality of mobile nodes, said second end node being one of said second plurality of nodes.

8. The method of claim 2, further comprising:

operating said session signaling server module to reserve network resources.

9. The method of claim 1, further comprising:

operating said session signaling server module to transmit SIP signals to perform a session initiation operation used to initiate a data communications session between the first end node and the second end node; and

operating said session signaling server to transmit RSVP signals to reserve network resources for said data communications session.

10. The method of claim 1, further comprising

operating said session signaling server module to transmit SIP signals to perform a session initiation operation used to initiate a data communications session between the first end node and the second end node;

and

operating said session signaling server to reserve network resources for said data communications session as a function of information included in received SIP signals.

11. The method of claim 2, further comprising:

operating said access node to perform at least one of a session authorization and a session admission operation as part of said step of performing a session initiation operation.

12. The method of claim 9, further comprising:

operating said access node to generate a unique identifier associated with a session admitted by said access node.

13. The method of claim 12, wherein said step of operating said access node to generate a unique identifier includes combining a value associated with an end node associated with said admitted session and a value associated with said access node.

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

operating said access node to communicate with a first set of end nodes using wireless links; and

operating said access node to communicate with a second set of end nodes using a combination of wireless and wired communications links.

15. The communications method of claim 1, wherein said access node further includes a mobility agent module, the method comprising:

using said mobility agent module to facilitate communication between said first and second end nodes when said first end node changes the access node through which it accesses said communications system.

16. The method of claim 15, further comprising:

prior to establishing a data communications session, communicating a single common identifier used to identify both said session signaling server module and the mobility agent module included in said access node to a plurality of end nodes included in said communications system.

17. The method of claim 16, wherein said single identifier is an Internet Protocol address.

18. The method of claim 17, further comprising:

operating said first end node to transmit data session initiation signals, including said single common identifier, to the session signaling server included in said first access node to establish a data communications session.

19. The method of claim 15, further comprising:

operating an authentication module included in said access node to perform authentication operations to authenticate messages from end nodes that attempt to communicate with either of said session signaling server module and said mobility agent module.

20. The method of claim 19, wherein said authentication module uses the same authentication method to authenticate messages from end nodes attempting to communicate with the session signaling server module that said authentication module uses to authenticate messages from end nodes to said mobility agent module.

21. The method of claim 19, wherein said authentication module uses a secret value shared with the first end node to authenticate messages from first end node to said session signaling server module and uses the same shared secret to authenticate messages from the first end node to said mobility agent module.

22. The method of claim 15, further comprising:

operating said mobility agent module to interact with the first end node using Mobile IP signaling.

23. The method of claim 23, wherein said mobility agent is an MIPv4 Foreign Agent, the method further comprising:

operating said mobility agent module to interact with another node in said communications system using MIPv4 signaling.

24. The method of claim 15, further comprising:

operating said mobility agent to perform a routing update operation to update routing information in other network nodes used to route information to said first end node through said access node.

25. The method of claim 15, further comprising:

operating said access node to use information included in a set of mobility agent state information maintained by said mobility agent module to control processing of session control signals.

26. The method of claim 25, wherein the step of operating said access node to control processing of session control signals includes the step of:

performing a signal reformatting operation on said session control signals as a function of said mobility agent state information.

27. The method of claim 15, further comprising:

operating said access node to use mobility agent state information obtained from said mobility agent module to control forwarding of session control signals to an accessing system.

28. The method of claim 15, further comprising:

operating said mobility agent module to maintain a set of state information corresponding to said first end node; and

using information included in said set of mobility agent state information to implement a handoff of said first end node from said access node to another node included in said system.

29. The method of claim 28, wherein said access node is part of a first cell;

and

wherein said additional access node is part of a second cell.

30. The method of claim 28, further comprising:

operating said access node to use information included in said set of mobility agent state information to control forwarding of session control signals to said additional access node.

31. The method of claim 30, wherein said access node and said additional access node are routers and wherein the information included in said set of mobility agent state information used to control forwarding of session control signals to said additional node identifies the additional access node.

32. An access node for use in a communications system which includes a plurality of end nodes, said access node comprising:

an interface for coupling said access node to another node and to a first end node in said plurality of end nodes; and

a session signaling module for supporting session signaling operations including communications session establishment operations.

33. The access node of claim 32, wherein said first end node is a mobile node and wherein the access node further includes:

a mobility agent module for supporting mobile node handoff operations.

34. The access node of claim 33, wherein said session signaling module includes a Session Initiation Protocol server.

35. The access node of claim 34, wherein said access node is a wireless router, said interface including:

transmitter circuitry for transmitting to said first end node over the air.

36. The access node of claim 35, wherein said interface further includes:

circuitry for coupling said access node to said another node, said another node including a Session Initiation Protocol server.

37. The access node of claim 33, wherein said session signaling module includes:

means for generating SIP signals as part of a session initiation operation used to initiate a data communications session between said first mobile node and a second mobile node.

38. The access node of claim 37, wherein said session signaling module includes:

means for generating RSVP signals to reserve network resources for said data communications session.

39. The access node of claim 37, further including:

a set of available network resource information; and

wherein said session signaling module includes means for reserving network resources indicated to be available by said set of available network resource information.

40. The access node of claim 37,

a set of available network resource information;

and

wherein said session signaling module includes means for reserving network resources indicated to be available by said set of available network resource information for said data communication session as a function of information included in received SIP signals.

41. The access node of claim 37, wherein said session signaling module includes:

means for performing at least one of a session authorization and a session admission operation as part a session initiation operation.

42. The access node of claim 41, wherein said session signaling module includes:

means for generating a unique identifier associated with a session admitted by said access node.

43. The access node of claim 33, further comprising:

an authentication module for performing authentication operations used to authenticate messages from end nodes that attempt to communicate with either of said session signaling server module and said mobility agent module.

44. The access node of claim 43, where said authentication module uses the same authentication method to authenticate messages from end nodes attempting to communicate with the session signaling server module that said authentication module uses to authenticate messages from end nodes to said mobility agent module.

45. The access node of claim 43, further comprising:

a shared secret used to authenticate messages directed to either of the session signaling module and the mobility agent module.

46. The access node of claim 37, where said mobility agent module supports Mobile IP signaling.

47. The access node of claim 37, where said mobility agent module includes an MIPv4 foreign agent.

48. The access node of claim 37, where said mobility agent module includes an MIPv6 attendant.

49. The access node of claim 37, where said mobility agent module includes a routing daemon.

50. The access node of claim 33, where said session signaling module includes:

means for processing session control signals, to be sent to another node as part of a mobile node handoff operation, as a function of information maintained by said mobility agent module.

51. The access node of claim 50, wherein said means for processing session control signals to be sent to another node as part of a mobile node handoff operation reformats session control signals as a function of mobility agent state information.

52. The access node of claim 50, further comprising:

a set of state information; and

wherein said mobility agent module further comprises means for using information included in said set of state information to control the forwarding of session control signals to said another node.

53. A communications system, the system comprising:

a first access node including a first session initiation signaling module coupled to a first mobile node;

a second access node including a second session initiation signaling module coupled to a second mobile node; and

an intermediate node coupling said first access node to said second access node.

54. The communications system of claim 53, wherein said first and second access nodes each further include a mobility management module which performs signaling relating to mobile node handoff operations.

55. The communications system of claim 54, wherein said mobility management module included in said first access node includes:

means for controlling the forwarding Session Initiation Protocol signals from said first access node to another access node as part of a handoff of the first mobile node to said another access node.

56. The communications system of claim 54, wherein said mobility management module included in said first access node includes:

means for controlling the forwarding of state information from said first access node to another access node as part of a handoff of the first mobile node to said another access node.

57. The communications system of claim 56, wherein the session initiation signaling module and mobility management module included in the first access node share the same IP address.

58. The communications system of claim 57, wherein the session initiation signaling module is a Session Initiation Protocol server.

59. The communication system of claim 58, wherein the first access node further includes:

a housing, said Session Initiation Protocol server and said mobility management module being located inside said housing.