Mobile unit attachment / update to cellular communication network

• US 20040203596A1
• Filed: 08/30/2002
• Published: 10/14/2004
• Est. Priority Date: 08/30/2002
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Purnadi, Rene, Sreemanthula, Srinivas
• Granted Patent: US 7,130,614 B2
• Time in Patent Office: Days
• US Class Current: 455/411
• CPC Class Codes: H04L 69/167 Adaptation for transition between two IP versions, e.g. between IPv4 and IPv6 translation of Internet protocol [IP] addresses H04L61/2503
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

As described above, for reducing IP level signaling and radio resource load during the attachment or update, e.g. L3 or IP attachment/update, of a mobile unit to a cellular wireless communication network, preferably an IPv6 based network, wherein access network elements and routing network elements are provided, an identification element is transmitted from the mobile unit to one of the access network elements. The identification element indicates a current attachment of the mobile unit to one of the routing network elements. The transmitted identification element is checked so as to determine whether the access network element is provided with a connection to the one routing network element. Furthermore, it is checked whether a network status still allows the usage of this routing network element by the mobile unit. If both of these criteria are fulfilled, the attachment or update procedure between the mobile unit and the access network element is completed while the attachment of the mobile unit to the routing network element is retained unaffected. This attachment is executable when the mobile unit moves from one cell area to another cell area, or when a network status concerning the attachment of the mobile unit has changed, or when a predetermined period of time is expired while the mobile unit remains in the same cell area.

Claims

1. Method of attaching/updating a mobile unit (MN1) to a cellular wireless communication network, said cellular wireless communication network comprising:

a plurality of access network elements (CAP1, CAP2, CAP3), each of which covering a respective cell area in said cellular wireless communication network, wherein said mobile unit is attached to one of said plurality of access network elements, and

a plurality of routing network elements (AR1, AR2) for forwarding data transmitted via said plurality of access network elements to and from said mobile unit, each of said routing network elements being connected with at least one of said plurality of access network elements, wherein said mobile unit is attached to one (AR1) of said plurality of routing network elements,

said method comprising the steps of

initializing (S20, S70, S30, S40) an attachment/update procedure of said mobile unit to one of said plurality of access network elements,

transmitting (S50, S80) from said mobile unit to said one of said plurality of access network elements an identification element indicating the current attachment of said mobile unit to said one of said plurality of routing network elements, and

checking (S50, S90, S100) said transmitted identification element so as to determine whether said one of said plurality of access network elements is provided with a connection to said one of said plurality of routing network elements.

2. Method according to claim 1, further comprising a step of measuring and determining (S55, S105) whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not.

3. Method according to claim 1, wherein said step of initializing said attachment/update procedure is performed when said mobile unit moves (S20) from one cell area (CAP1) to another cell area covered by said one of said plurality of access network elements (CAP2, CAP3).

4. Method according to claim 2, wherein said step of initializing said attachment/update procedure is performed when the network status for the connection of said mobile unit to said one of said plurality of routing network elements is not sufficient.

5. Method according to claim 1, wherein said step of checking said transmitted identification element comprises a step of comparing (S90, S100) said transmitted identification element with identification elements of the routing network elements to which said one of said plurality of access network elements is connected.

6. Method according to claim 5, wherein, when said comparing steps results that said transmitted identification element and said identification elements of the routing network elements to which said one of said plurality of access network elements is connected match, said method further comprises the step of

completing (S110) the attachment/update procedure between said mobile unit and said one of said plurality of access network elements (CAP2) while the attachment of said mobile unit to said one of said routing network elements is retained unaffected.

7. Method according to claim 5, wherein, when said comparing steps results that said transmitted identification element and said identification elements of the routing network elements to which said one of said plurality of access network elements is connected match, said method further comprises the steps of

measuring and determining (S105) whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when said network status is sufficient,

completing (S110) the attachment/update procedure between said mobile unit and said one of said plurality of access network elements (CAP2) while the attachment of said mobile unit to said one of said routing network elements is retained unaffected.

8. Method according to claim 5, wherein, when said comparing steps results that said transmitted identification element and said identification elements of the routing network elements to which said one of said plurality of access network elements is connected match, said method further comprises the steps of

measuring and determining (S105) whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when said network status is not sufficient,

establishing (S120) a radio bearer between said one of said plurality of access network elements and said mobile unit,

providing (S130) said mobile unit with the identification element of another routing network element to which said one of said plurality of access network elements is connected,

reconfiguring (S140) the attachment of said mobile unit to the new routing network element indicated by said provided identification element and performing a binding update procedure in said cellular wireless communication network,

completing (S150) the attachment/update procedure between said mobile unit and said one of said plurality of access network elements and

tearing down the radio bearer upon completion of the attachment/update procedure.

9. Method according to any of the claims 1 to 8, wherein said identification element is transmitted from said mobile unit to said one of said plurality of access network elements by a location update procedure signaling.

10. Method according to any of the claims 1 to 8, wherein said identification element is transmitted from said mobile unit to said one of said plurality of access network elements by a separate message when moving into the cell area of said one of said plurality of access network elements.

11. Method according to claim 1, wherein said step of initializing said attachment/update procedure is performed (S30) when a predetermined period of time is expired while said mobile unit remains in the same cell area (CAP1).

12. Method according to claim 11, wherein said step of checking said transmitted identification element comprises the steps of

recognizing (S50) said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said one of said plurality of access network elements is connected, and

completing (S60) the attachment/update procedure between said mobile unit and said one of said plurality of access network elements while the attachment of said mobile unit to said one of said routing network elements is retained unaffected.

13. Method according to claim 11, wherein said step of checking said transmitted identification element comprises the steps of

recognizing (S50) said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said one of said plurality of access network elements is connected,

measuring and determining (S55) whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when said network status is sufficient,

completing (S60) the attachment/update procedure between said mobile unit and said one of said plurality of access network elements while the attachment of said mobile unit to said one of said routing network elements is retained unaffected.

14. Method according to claim 11, wherein said step of checking said transmitted identification element comprises the steps of

recognizing (S50) said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said one of said plurality of access network elements is connected,

measuring and determining (S55) whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when said network status is not sufficient, establishing (S120) a radio bearer between said one of said plurality of access network elements and said mobile unit,

providing (S130) said mobile unit with the identification element of another routing network element to which said one of said plurality of access network elements is connected,

reconfiguring (S140) the attachment of said mobile unit to the new routing network element indicated by said provided identification element and performing a binding update procedure in said cellular wireless communication network,

completing (S150) the attachment/update procedure between said mobile unit and said one of said plurality-of access network elements and

tearing down the radio bearer upon completion of the attachment/update procedure.

15. Method according to claim 11, wherein said transmitted identification element is a flag indicating that the attachment of said mobile unit to said one of said plurality of routing network elements (AR1) is to be retained.

16. Method according to claim 1, wherein said cellular wireless communication network is an IP based network, preferably an IPv6 based network, wherein said mobile unit is a mobile node, said access network elements are cellular access points, and said routing network elements are access routers.

58. Computer program product usable for data processing devices, comprising software code portions for performing the steps of claim 1 when said product is run on said data processing devices.

59. A computer program product according to claim 58, wherein said computer program product comprises a medium readable by said data processing device, on which said software code portions are stored.

60. A computer program product according to claim 58, wherein said computer program product is directly loadable into an internal memory of said data processing devices.

61. A computer program product according to claim 58, wherein said computer program product is executed in a data processing device of a mobile unit and a data processing device of an access network element.

62. Method according to claim 1, wherein said method is usable for a L3 or IP attachment/updating.

63. System according to claim 13, wherein said system is usable for a L3 or IP attachment/updating.

17. System for attaching/updating a mobile unit (MN1) to a cellular wireless communication network, said cellular wireless communication network comprising:

a plurality of access network elements (CAP1, CAP2, CAP3), each of which covering a respective cell area in said cellular wireless communication network, wherein said mobile unit is attached to one of said plurality of access network elements, and

a plurality of routing network elements (AR1, AR2) for forwarding data transmitted via said plurality of access network elements to and from said mobile unit, each of said routing network elements being connected with at least one of said plurality of access network elements, wherein said mobile unit is attached to one (AR1) of said plurality of routing network elements,

said system comprising

means adapted to transmit, when an attachment/update procedure of said mobile unit to one of said plurality of access network elements is initialized, an identification element to said one of said plurality of access network elements, which identification element indicating the current attachment of said mobile unit to said one of said plurality of routing network elements, and

means adapted to check said transmitted identification element so as to determine whether said one of said plurality of access network elements is provided with a connection to said one of said plurality of routing network elements.

18. System according to claim 17, further comprising means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not.

19. System according to claim 17, wherein said attachment/update procedure is initialized when said mobile unit moves from one cell area (CAP1) to another cell area covered by said one of said plurality of access network elements (CAP2, CAP3).

20. System according to claim 18, wherein said attachment/update procedure is initialized when a network status for the connection of the mobile unit to said one of said plurality of routing network elements is determined to be not sufficient.

21. System according to claim 17, wherein said means adapted to check said transmitted identification element compares said transmitted identification element with identification elements of the routing network elements to which said one of said plurality of access network elements is connected.

22. System according to claim 21, further comprising means adapted to complete the attachment/update procedure between said mobile unit and said one of said plurality of access network elements (CAP2) and to retain the attachment of said mobile unit to said one of said routing network elements unaffected, when the comparison results that said transmitted identification element and said identification elements to which said one of said plurality of access network elements is connected match.

23. System according to claim 21, further comprising

means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and

means adapted to complete the attachment/update procedure between said mobile unit and said one of said plurality of access network elements (CAP2) and to retain the attachment of said mobile unit to said one of said routing network elements unaffected, when the comparison results that said transmitted identification element and said identification elements to which said one of said plurality of access network elements is connected match and the determination results that said network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient.

24. System according to claim 21, further comprising, when said comparison results that said transmitted identification element and said identification elements of the routing network elements to which said one of said plurality of access network elements is connected match,

means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when the determination results that said network status for the connection of the mobile unit to said one of said plurality of routing network elements is not sufficient

means adapted to establish a radio bearer between said one of said plurality of access network elements and said mobile unit,

means adapted to provide said mobile unit with the identification element of another routing network element to which said one of said plurality of access network elements is connected,

means adapted to reconfigure the attachment of said mobile unit to the new routing network element indicated by said provided identification element and to perform a binding update procedure in said cellular wireless communication network, and

means adapted to complete the attachment/update procedure between said mobile unit and said one of said plurality of access network elements and to tear down the radio bearer upon completion of the attachment/update procedure.

25. System according to any of the claims 19 to 24, wherein said identification element is transmitted from said mobile unit to said one of said plurality of access network elements by a location update procedure signaling.

26. System according to any of the claims 19 to 24, wherein said identification element is transmitted from said mobile unit to said one of said plurality of access network elements by a separate message when moving into the cell area of said one of said plurality of access network elements.

27. System according to claim 17, wherein said attachment/update procedure is initialized when a predetermined period of time is expired while said mobile unit remains in the same cell area (CAP1).

28. System according to claim 27, wherein said means adapted to check said transmitted identification element is adapted to recognize said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said one of said plurality of access network elements is connected, said system further comprising

means adapted to complete the attachment/update procedure between said mobile unit and said one of said plurality of access network elements and to retain the attachment of said mobile unit to said one of said routing network elements unaffected.

29. System according to claim 27, wherein said means adapted to check said transmitted identification element is adapted to recognize said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said one of said plurality of access network elements is connected, said '"'"'system further comprising

means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when the determination results that said network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient

means adapted to complete the attachment/update procedure between said mobile unit and said one of said plurality of access network elements and to retain the attachment of said mobile unit to said one of said routing network elements unaffected.

30. System according to claim 27, wherein said means adapted to check said transmitted identification element is adapted to recognize said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said one of said plurality of access network elements is connected, said system further comprising

means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when the determination results that said network status for the connection of the mobile unit to said one of said plurality of routing network elements is not sufficient,

means adapted to establish a radio bearer between said one of said plurality of access network elements and said mobile unit,

means adapted to provide said mobile unit with the identification element of another routing network element to which said one of said plurality of access network elements is connected,

means adapted to reconfigure the attachment of said mobile unit to the new routing network element indicated by said provided identification element and to perform a binding update procedure in said cellular wireless communication network, and

means adapted to complete the attachment/update procedure between said mobile unit and said one of said plurality of access network elements and to tear down the radio bearer upon completion of the attachment/update procedure.

31. System according to claim 27, wherein said transmitted identification element is a flag indicating that the attachment of said mobile unit to said one of said plurality of routing network elements (AR1) is to be retained.

32. System according to claim 17, wherein said cellular wireless communication network is an IP based network, preferably an IPv6 based network, wherein said mobile unit is a mobile node, said access network elements are cellular access points, and said routing network elements are access routers.

33. Mobile unit (MN1) being attachable to a cellular wireless communication network, said cellular wireless communication network comprising:

a plurality of access network elements (CAP1, CAP2, CAP3), each of which covering a respective cell area in said cellular wireless communication network, wherein said mobile unit is attached to one of said plurality of access network elements, and

a plurality of routing network elements (AR1, AR2) for forwarding data transmitted via said plurality of access network elements to and from said mobile unit, each of said routing network elements being connected with at least one of said plurality of access network elements, wherein said mobile unit is attached to one (AR1) of said plurality of routing network elements,

said mobile unit comprising

means adapted to transmit, when an attachment/update procedure of said mobile unit to one of said plurality of access network elements is initialized, an identification element to said one of said plurality of access network elements, which identification element indicating the current attachment of said mobile unit to said one of said plurality of routing network elements.

34. Mobile unit according to claim 33, wherein said attachment/update procedure is initialized when said mobile unit moves from one cell area (CAP1) to another cell area covered by said one of said plurality of access network elements (CAP2, CAP3).

35. Mobile unit according to claim 33, wherein said attachment/update procedure is initialized when it is determined that a network status for the connection of the mobile unit to said one of said plurality of routing network elements is not sufficient.

36. Mobile unit according to claim 33, said mobile unit being adapted to reconfigure the attachment of said mobile unit to a new routing network element to which said one of said plurality of access network elements is connected, indicated by a provided identification element, and to perform a binding update procedure in said cellular wireless communication network.

37. Mobile unit according to any of the claims 33 to 36, wherein said identification element is transmitted from said mobile unit to said one of said plurality of access network elements by a location update procedure signaling.

38. Mobile unit according to any of the claims 33 to 36, wherein said identification element is transmitted from said mobile unit to said one of said plurality of access network elements by a separate message when moving into the cell area of said one of said plurality of access network elements.

39. Mobile unit according to claim 33, wherein said attachment/update procedure is initialized when a predetermined period of time is expired while said mobile unit remains in the same cell area (CAP1).

40. Mobile unit according to claim 39, wherein said transmitted identification element is a flag indicating that the attachment of said mobile unit to said one of said plurality of routing network elements (AR1) is to be retained.

41. Mobile unit according to claim 33, wherein said cellular wireless communication network is an IP based network, preferably an IPv6 based network, wherein said mobile unit is a mobile node, said access network elements are cellular access points, and said routing network elements are access routers.

42. Access network element (CAP1, CAP2, CAP3) of a cellular wireless communication network to which a mobile unit (MN1) is attachable, said cellular wireless communication network comprising:

a plurality of access network elements (CAP1, CAP2, CAP3), each of which covering a respective cell area in said cellular wireless communication network, wherein said mobile unit is attached to one of said plurality of access network elements, and

a plurality of routing network elements (AR1, AR2) for forwarding data transmitted via said plurality of access network elements to and from said mobile unit, each of said routing network elements being connected with at least one of said plurality of access network elements, wherein said mobile unit (AR1) is attached to one of said plurality of routing network elements,

said access network element comprising

means adapted to means adapted to check, when an attachment/update procedure of said mobile unit to said network element is initialized, an identification element transmitted from said mobile unit to said access network element, which identification element indicating the current attachment of said mobile unit to said one of said plurality of routing network elements, wherein it is determined whether said access network element is provided with a connection to said one of said plurality of routing network elements.

43. Access network element according to claim 42, further comprising means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not.

44. Access network element according to claim 42, wherein said attachment/update procedure is initialized when said mobile unit moves from one cell area (CAP1) to another cell area covered by said access network element (CAP2, CAP3).

45. Access network element according to claim 43, wherein said attachment/update procedure is initialized when the network status for the connection of the mobile unit to said one of said plurality of routing network elements is determined to be not sufficient.

46. Access network element according to claim 42, wherein said means adapted to check said transmitted identification element compare said transmitted identification element with identification elements of the routing network elements to which said access network element is connected.

47. Access network element according to claim 46, further comprising means adapted to complete the attachment/update procedure between said mobile unit and said one of said access network elements (CAP2) and to retain the attachment of said mobile unit to said one of said routing network elements unaffected, when the comparison results that said transmitted identification element and said identification elements to which said access network element is connected match.

48. Access network element according to claim 46, further comprising

means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and

means adapted to complete the attachment/update procedure between said mobile unit and said one of said plurality of access network elements (CAP2) and to retain the attachment of said mobile unit to said one of said routing network elements unaffected, when the comparison results that said transmitted identification element and said identification elements to which said one of said plurality of access network elements is connected match and the determination results that said network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient.

49. Access network element according to 46, further comprising, when said comparison results that said transmitted identification element and said registered identification element match,

means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when the determination results that said network status for the connection of the mobile unit to said one of said plurality of routing network elements is not sufficient,

means adapted to establish a radio bearer between said access network element and said mobile unit, and

means adapted to provide said mobile unit with the identification element of another routing network element to which said access network element is connected, and

means adapted to tear down the radio bearer upon completion of the attachment/update procedure.

50. Access network element according to any of the claims 42 to 49, wherein said identification element is transmitted from said mobile unit to said access network element by a location update procedure signaling.

51. Access network element according to any of the claims 42 to 49, wherein said identification element is transmitted from said mobile unit to said access network element by a separate message when moving into the cell area of said access network element.

52. Access network element according to claim 42, wherein said attachment/update procedure is initialized when a predetermined period of time is expired while said mobile unit remains in the same cell area (CAP1).

53. Access network element according to claim 52, wherein said means adapted to check said transmitted identification element is adapted to recognize said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said access network element is connected, said access network element further comprising

means adapted to complete the attachment/update procedure between said mobile unit and said access network element and to retain the attachment of said mobile unit to said one of said routing network elements unaffected.

54. Access network element according to claim 52, wherein said means adapted to check said transmitted identification element is adapted to recognize said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said access network element is connected, said access network element further comprising

means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when the determination results that said network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient,

means adapted to complete the attachment/update procedure between said mobile unit and said access network element and to retain the attachment of said mobile unit to said one of said routing network elements unaffected.

55. Access network element according to claim 52, wherein said means adapted to check said transmitted identification element is adapted to recognize said transmitted identification element as an indication that said mobile unit is attached to one of said plurality of routing network elements to which said access network element is connected, said access network element further comprising

means adapted to measure and determine whether a network status for the connection of the mobile unit to said one of said plurality of routing network elements is sufficient or not, and when the determination results that said network status for the connection of the mobile unit to said one of said plurality of routing network elements is not sufficient,

means adapted to establish a radio bearer between said access network element and said mobile unit, and

means adapted to provide said mobile unit with the identification element of another routing network element to which said access network element is connected, and

means adapted to tear down the radio bearer upon completion of the attachment/update procedure.

56. Access network element according to claim 52, wherein said transmitted identification element is a flag indicating that the attachment of said mobile unit to said one of said plurality of routing network elements (AR1) is to be retained.

57. Access network element according to claim 42, wherein said cellular wireless communication network is an IP based network, preferably an IPv6 network, wherein said mobile unit is a mobile node, said access network element is a cellular access point, and said routing network elements are access routers.

64. Access network element according to claim 42, wherein said access network element is used in a L3 or IP attachment/updating.