WIRELESS HANDOFFS BETWEEN MULTIPLE NETWORKS

• US 20070249291A1
• Filed: 10/05/2006
• Published: 10/25/2007
• Est. Priority Date: 04/20/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Jayaram, Ranjith, Deshpande, Manoj M., Nanda, Sanjiv, Meylan, Arnaud
• Granted Patent: US 8,275,377 B2
• Time in Patent Office: Days
• US Class Current: 455/73
• CPC Class Codes: H04W 36/0022 for transferring data sessions between adjacent core network technologies
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 48/20 Selecting an access point

Abstract

The disclosure is directed to an access terminal, and method for selecting an access point for handing off the access terminal. The access terminal may include a processor. The processor may be configured to access a list access points and select one of the access points on the list based on the current traffic state of the access terminal.

Claims

1. An access terminal, comprising:

a processor configured to access a list of access points and select one of the access points on the list based on the current traffic state of the access terminal.

2. The access terminal of claim 1, wherein the processor is further configured to maintain a database in the access terminal, the database comprising the list of access terminals.

3. The access terminal of claim 1, wherein the processor is further configured to access a second list containing information regarding access points that have previously served the access terminal, the processor being further configured to update the information related to the selected one of the access points.

4. The access terminal of claim 3, wherein the updated information relates to whether the access terminal is able to associate with the selected one of the access points.

5. The access terminal of claim 3, wherein the information relates to the quality of service provided by the selected one of the access points to the access terminal.

6. The access terminal of claim 5, wherein the quality of service includes delay, jitter, packet loss rate, or time taken to associate with the selected one of the access points.

7. The access terminal of claim 5, wherein the quality of service includes dropped frames.

8. The access terminal of claim 7, wherein the quality of service includes dropped frames between the access terminal and the far end connection.

9. The access terminal of claim 1, wherein the processor is further configured to access a second list containing information regarding access points that have previously served the access terminal, the processor being further configured to maintain indicators for one or more of the access points on the list from the information on the second list, the selection of said one of the access points also being based on the indicators.

10. The access terminal of claim 9, wherein the indicators for each of one or more access points indicates whether the access point is a handoff candidate for each traffic state, and wherein the processor is further configured to control the state of the indicators based on the information on the second list.

11. The access terminal of claim 9, wherein the information on the second list includes historical information relating to the quality of service provided to the access terminal by one or more access points that have previously served the access terminal.

12. The access terminal of claim 9, wherein the information on the second list identifies the access points that belong to the same subnet served by the same dynamic host configuration protocol (DHCP).

13. The access terminal of claim 9, wherein the information on the second list identifies access points that belong to the same authentication domain.

14. The access terminal of claim 1, wherein the processor is further configured to handoff the access terminal from a serving access point in a first network to the selected one of the access points, the selected one of the access points being in a second network.

15. The access terminal of claim 1, wherein the processor is further configured to handoff the access terminal from a serving access point in a network to the selected one of the access points, the selected one of the access points being in the same network as the serving access point.

16. The access terminal of claim 1, wherein the processor is further configured to select one of the access points on the list by performing a periodic scan having an interval that depends on the current traffic state of the access terminal.

17. The access terminal of claim 1, wherein the selection of said one of the selected access points by processor is also based on real time measurements of the access points on the list.

18. The access terminal of claim 17, wherein the real time measurements include received power from the access points, loading on the access points, and interference on the channel of each of the access points.

19. The access terminal of claim 1, wherein the processor is further configured to access a second list of access points that the access terminal is prohibited from associating with, the selection of said one of the access points also being based on the second list.

20. The access terminal of claim 1, wherein the processor is further configured to access a list of preferred access points, the selection of said one of the access points also being based on the list of preferred access points.

21. The access terminal of claim 1, wherein the access points on the list are from a wireless local area network (WLAN) and a cellular network, and wherein the processor is further configured to select said one of the access points by searching for access points in the WLAN before searching for access points in the cellular network when the access terminal is in a data session.

22. The access terminal of claim 1, wherein the access points on the list are from a wireless local area network (WLAN) and a cellular network, and wherein the processor is further configured to select said one of the access points by searching for access points in the cellular network before searching for access points in the WLAN when the access terminal is in a voice call.

23. A method of communications on an access terminal, comprising:

accessing a list access points; and

selecting one of the access points on the list based on the current traffic state of the access terminal.

24. The method of claim 23, further comprising maintaining a database in the access terminal, the database comprising the list of access terminals.

25. The method of claim 23, further comprising accessing a second list containing information regarding access points that have previously served the access terminal, and updating the information related to the selected one of the access points.

26. The method of claim 25, wherein the updated information relates to whether the access terminal is able to associate with the selected one of the access points.

27. The method of claim 25, wherein the information relates to the quality of service provided by the selected one of the access points to the access terminal.

28. The method of claim 27, wherein the quality of service includes delay, jitter, packet loss rate, or time taken to associate with the selected one of the access points.

29. The method of claim 27, wherein the quality of service includes dropped frames.

30. The method of claim 29, wherein the quality of service includes dropped frames between the access terminal and the far end connection.

31. The method of claim 23, further comprising accessing a second list containing information regarding access points that have previously served the access terminal, and maintaining indicators for one or more of the access points on the list from the information on the second list, the selection of said one of the access points also being based on the indicators.

32. The method of claim 31, wherein the indicators for each of one or more access points indicates whether the access point is a handoff candidate for each traffic state, the method further comprising controlling the state of the indicators based on the information on the second list.

33. The method of claim 31, wherein the information on the second list includes historical information relating to the quality of service provided to the access terminal by one or more access points that have previously served the access terminal.

34. The method of claim 31, wherein the information on the second list identifies the access points that belong to the same subnet served by the same dynamic host configuration protocol (DHCP).

35. The method of claim 31, wherein the information on the second list identifies access points that belong to the same authentication domain.

36. The method of claim 23, further comprising handing off the access terminal from a serving access point in a first network to the selected one of the access points, the selected one of the access points being in a second network.

37. The method of claim 23, further comprising handing off the access terminal from a serving access point in a network to the selected one of the access points, the selected one of the access points being in the same network as the serving access point.

38. The method of claim 23, wherein the selection of said one of the access points comprising performing a periodic scan having an interval that depends on the current traffic state of the access terminal.

39. The method of claim 23, wherein the selection of said one of the selected access points is also based on real time measurements of the access points on the list.

40. The method of claim 39, wherein the real time measurements include received power from the access points, loading on the access points, and interference on the channel of each of the access points.

41. The method of claim 23, further comprising accessing a second list of access points that the access terminal is prohibited from associating with, the selection of said one of the access points also being based on the second list.

42. The method of claim 23, further comprising accessing a list of preferred access points, the selection of said one of the access points also being based on the list of preferred access points.

43. The method of claim 23, wherein the access points on the list are from a wireless local area network (WLAN) and a cellular network, and wherein the selection of said one of the access points comprises searching for access points in the WLAN before searching for access points in the cellular network when the access terminal is in a data session.

44. The method of claim 23, wherein the access points on the list are from a wireless local area network (WLAN) and a cellular network, and wherein the selection of said one of the access points comprises searching for access points in the cellular network before searching for access points in the WLAN when the access terminal is in a voice call.

45. An access terminal, comprising:

means for accessing a list access points; and

means for selecting one of the access points on the list based on the current traffic state of the access terminal.

46. The access terminal of claim 45, further comprising means for maintaining a database in the access terminal, the database comprising the list of access terminals.

47. The access terminal of claim 45, further comprising means for accessing a second list containing information regarding access points that have previously served the access terminal, and means for updating the information related to the selected one of the access points.

48. The access terminal of claim 47, wherein the updated information relates to whether the access terminal is able to associate with the selected one of the access points.

49. The access terminal of claim 47, wherein the information relates to the quality of service provided by the selected one of the access points to the access terminal.

50. The access terminal of claim 49, wherein the quality of service includes delay, jitter, packet loss rate, or time taken to associate with the selected one of the access points.

51. The access terminal of claim 49, wherein the quality of service includes dropped frames.

52. The access terminal of claim 51, wherein the quality of service includes dropped frames between the access terminal and the far end connection.

53. The access terminal of claim 45, further comprising means for accessing a second list containing information regarding access points that have previously served the access terminal, and means for maintaining indicators for one or more of the access points on the list from the information on the second list, and wherein the means for selecting one of the access points on the list is configured to use the indicators to select said one of the access points.

54. The access terminal of claim 53, wherein the indicators for each of one or more access points indicates whether the access point is a handoff candidate for each traffic state, the access terminal further comprising means for controlling the state of the indicators based on the information on the second list.

55. The access terminal of claim 53, wherein the information on the second list includes historical information relating to the quality of service provided to the access terminal by one or more access points that have previously served the access terminal.

56. The access terminal of claim 53, wherein the information on the second list identifies the access points that belong to the same subnet served by the same dynamic host configuration protocol (DHCP).

57. The access terminal of claim 53, wherein the information on the second list identifies access points that belong to the same authentication domain.

58. The access terminal of claim 45, further comprising means for handing off the access terminal from a serving access point in a first network to the selected one of the access points, the selected one of the access points being in a second network.

59. The access terminal of claim 45, further comprising handing off the access terminal from a serving access point in a network to the selected one of the access points, the selected one of the access points being in the same network as the serving access point.

60. The access terminal of claim 45, wherein the means for selecting one of the access points further comprises means for performing a periodic scan having an interval that depends on the current traffic state of the access terminal.

61. The access terminal of claim 45, wherein the means for selecting one of the access points is configured to use real time measurements to select said on of the access points.

62. The access terminal of claim 61, wherein the real time measurements include received power from the access points, loading on the access points, and interference on the channel of each of the access points.

63. The access terminal of claim 45, further comprising means for accessing a second list of access points that the access terminal is prohibited from associating with, wherein the means for selecting one of the access points is configured to use the second list to select said one of the access points.

64. The access terminal of claim 45, further comprising means for accessing a list of preferred access points, wherein the means for selecting one of the access points is configured to use the list of preferred access points to select said one of the access points.

65. The access terminal of claim 45, wherein the access points on the list are from a wireless local area network (WLAN) and a cellular network, and wherein the means for selecting one of the access points is configured to search for access points in the WLAN before searching for access points in the cellular network when the access terminal is in a data session.

66. The access terminal of claim 45, wherein the access points on the list are from a wireless local area network (WLAN) and a cellular network, and wherein the means for selecting one of the access points is configured to search for access points in the cellular network before searching for access points in the WLAN when the access terminal is in a voice call.

67. A computer-readable medium including instructions stored thereon, comprising:

a first instruction set for accessing a list access points; and

a second instruction set for selecting one of the access points on the list based on the current traffic state of the access terminal.

68. The computer-readable medium of claim 67, further comprising a third instruction set for maintaining a database in the access terminal, the database comprising the list of access terminals.

69. The computer-readable medium of claim 67, further comprising a third instruction set for accessing a second list containing information regarding access points that have previously served the access terminal, and a fourth instruction set for updating the information related to the selected one of the access points.

70. The computer-readable medium of claim 69, wherein the updated information relates to whether the access terminal is able to associate with the selected one of the access points.

71. The computer-readable medium of claim 69, wherein the information relates to the quality of service provided by the selected one of the access points to the access terminal.

72. The computer-readable medium of claim 71, wherein the quality of service includes delay, jitter, packet loss rate, or time taken to associate with the selected one of the access points.

73. The computer-readable medium of claim 71, wherein the quality of service includes dropped frames.

74. The computer-readable medium of claim 73, wherein the quality of service includes dropped frames between the access terminal and the far end connection.

75. The computer-readable medium of claim 67, further comprising a third instruction set for accessing a second list containing information regarding access points that have previously served the access terminal, and a fourth instruction set for maintaining indicators for one or more of the access points on the list from the information on the second list, and wherein the second instruction set is configured to use the indicators to select said one of the access points.

76. The computer-readable medium of claim 75, wherein the indicators for each of one or more access points indicates whether the access point is a handoff candidate for each traffic state, the computer-readable medium further comprising a fifth instruction set for controlling the state of the indicators based on the information on the second list.

77. The computer-readable medium of claim 75, wherein the information on the second list includes historical information relating to the quality of service provided to the access terminal by one or more access points that have previously served the access terminal.

78. The computer-readable medium of claim 75, wherein the information on the second list identifies the access points that belong to the same subnet served by the same dynamic host configuration protocol (DHCP).

79. The computer-readable medium of claim 75, wherein the information on the second list identifies access points that belong to the same authentication domain.

80. The computer-readable medium of claim 67, further comprising a third instruction set for handing off the access terminal from a serving access point in a first network to the selected one of the access points, the selected one of the access points being in a second network.

81. The computer-readable medium of claim 67, further comprising a third instruction set for handing off the access terminal from a serving access point in a network to the selected one of the access points, the selected one of the access points being in the same network as the serving access point.

82. The computer-readable medium of claim 67, wherein the second instruction set is configured to perform a periodic scan having an interval that depends on the current traffic state of the access terminal.

83. The computer-readable medium of claim 67, wherein the second instruction set is configured to use real time measurements to select said on of the access points.

84. The access terminal of claim 83, wherein the real time measurements include received power from the access points, loading on the access points, and interference on the channel of each of the access points.

85. The computer-readable medium of claim 67, further comprising a third instruction set for accessing a second list of access points that the access terminal is prohibited from associating with, wherein the second instruction set is configured to use the second list to select said one of the access points.

86. The computer-readable medium of claim 67, further comprising a third instruction set for accessing a list of preferred access points, wherein the second instruction set is configured to use the list of preferred access points to select said one of the access points.

87. The computer-readable medium of claim 67, wherein the access points on the list are from a wireless local area network (WLAN) and a cellular network, and wherein the second instruction set is configured to search for access points in the WLAN before searching for access points in the cellular network when the access terminal is in a data session.

88. The computer-readable medium of claim 67, wherein the access points on the list are from a wireless local area network (WLAN) and a cellular network, and wherein the second instruction set is configured to search for access points in the cellular network before searching for access points in the WLAN when the access terminal is in a voice call.