apparatus and method of handoff between wireless networks

• US 20110064058A1
• Filed: 03/08/2010
• Published: 03/17/2011
• Est. Priority Date: 09/01/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rimoni, Yoram, Yacobi, Eitan
• Granted Patent: US 8,798,627 B2
• Time in Patent Office: Days
• US Class Current: 370/332
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/72 using reservation actions during connection setup
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04M 15/8016 based on quality of service [QoS]
• CPC Class Codes: H04M 2207/18 wireless networks
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/36 by user or terminal equipment
• CPC Class Codes: H04W 40/20 based on geographic position or location
• CPC Class Codes: H04W 48/06 based on traffic conditions
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A system and method are provided for supporting a multi-mode portable user terminal (UT) hard handoff procedure for a call from a wireless local area network (WLAN) to a cellular telephone network. The method includes: establishing a link between a UT and a serving WLAN; establishing a call via the established WLAN link; monitoring the WLAN link signal strength; simultaneously monitoring a serving cellular network; initiating a hard handoff to the cellular network, responsive to the monitored WLAN link signal strength falling below a minimum threshold; and, continuing the call via the cellular network. More specifically, the method initiates a call handoff to a Cellular Gateway (CGW) telephone number, responsive to the monitored WLAN link signal strength falling below the minimum threshold. Then, continuing the call via the cellular network includes continuing the call to the first telephone number via the CGW handoff telephone number.

Claims

1. (canceled)

2. A method of performing a handover in a communications network, comprising:

maintaining call parameters of an active call of a user terminal communicating on a first communications network having a first access technology type; and

initiating a handover of the active call to a second communications network having a second access technology type different from the first access technology type.

3. The method of claim 2, wherein the initiating of the handover of the active call further comprises obtaining a resource allocation on the second communications network to continue the active call on the second communications network.

4. The method of claim 3, wherein the obtaining of the resource allocation on second communications network further comprises exchanging at least a portion of the call parameters of the active call with the second communications network, wherein the resource allocation is at least partially based on at least the portion of the call parameters.

5. The method of claim 3, wherein the initiating of the handover of the active call further comprises transmitting a handover request via the first communications network to the user terminal in response to the obtaining of the resource allocation on second communications network.

6. The method of claim 2, further comprising:

receiving a measured reception quality corresponding to the first communications network from the user terminal; and

determining to perform the initiating of the handover in response to the measured reception quality.

7. The method of claim 2, further comprising:

receiving a measured reception quality corresponding to the second communications network from the user terminal; and

determining to perform the initiating of the handover in response to the measured reception quality.

8. The method of claim 2, further comprising:

receiving a first measured reception quality corresponding to the first communications network from the user terminal;

receiving a second measured reception quality corresponding to the second communications network from the user terminal; and

determining to perform the initiating of the handover in response to the first measured reception quality and the second measured reception quality.

9. The method of claim 2, wherein the maintaining of the call parameters further comprises maintaining a first identifier of the user terminal on the first communications network and a second identifier of the user terminal on the second communications network.

10. The method of claim 2, wherein the first communications network comprises a WLAN technology and wherein the second communications network comprises a cellular technology.

11. An apparatus for performing a handover in a communications network, comprising:

a network gateway component to maintain call parameters of an active call of a user terminal communicating on a first communications network having a first access technology type, and to initiate a handover of the active call to a second communications network having a second access technology type different from the first access technology type.

12. The apparatus of claim 11, wherein the network gateway component to initiate the handover of the active call is further configured to obtain a resource allocation on the second communications network to continue the active call on the second communications network.

13. The apparatus of claim 12, wherein the network gateway component to obtain the resource allocation on second communications network is further configured to exchange at least a portion of the call parameters of the active call with the second communications network, wherein the resource allocation is at least partially based on at least the portion of the call parameters.

14. The apparatus of claim 12, wherein the network gateway component to initiate the handover of the active call is further configured to transmit a handover request via the first communications network to the user terminal in response to the obtaining of the resource allocation on second communications network.

15. The apparatus of claim 11, wherein the network gateway component is further configured to receive a measured reception quality corresponding to the first communications network from the user terminal, and to determine to perform the initiating of the handover in response to the measured reception quality.

16. The apparatus of claim 11, wherein the network gateway component is further configured to receive a measured reception quality corresponding to the second communications network from the user terminal, and to determine to perform the initiating of the handover in response to the measured reception quality.

17. The apparatus of claim 11, wherein the network gateway component is further configured to receive a first measured reception quality corresponding to the first communications network from the user terminal, to receive a second measured reception quality corresponding to the second communications network from the user terminal, and to determine to perform the initiating of the handover in response to the first measured reception quality and the second measured reception quality.

18. The apparatus of claim 11, wherein the call parameters further comprise a first identifier of the user terminal on the first communications network and a second identifier of the user terminal on the second communications network.

19. The apparatus of claim 11, wherein the first communications network comprises a WLAN technology and wherein the second communications network comprises a cellular technology.

20. An apparatus for performing a handover in a communications network, comprising:

means for maintaining call parameters of an active call of a user terminal communicating on a first communications network having a first access technology type; and

means for initiating a handover of the active call to a second communications network having a second access technology type different from the first access technology type.

21. The apparatus of claim 20, wherein the means for initiating the handover of the active call further comprises means for obtaining a resource allocation on the second communications network to continue the active call on the second communications network.

22. The apparatus of claim 21, wherein the means for obtaining the resource allocation on second communications network further comprises means for exchanging at least a portion of the call parameters of the active call with the second communications network, wherein the resource allocation is at least partially based on at least the portion of the call parameters.

23. The apparatus of claim 21, wherein the means for initiating the handover of the active call further comprises means for transmitting a handover request via the first communications network to the user terminal in response to the obtaining of the resource allocation on second communications network.

24. The apparatus of claim 20, further comprising:

means for receiving a measured reception quality corresponding to the first communications network from the user terminal; and

means for determining to perform the initiating of the handover in response to the measured reception quality.

25. The apparatus of claim 20, further comprising:

means for receiving a measured reception quality corresponding to the second communications network from the user terminal; and

means for determining to perform the initiating of the handover in response to the measured reception quality.

26. The apparatus of claim 20, further comprising:

means for receiving a first measured reception quality corresponding to the first communications network from the user terminal;

means for receiving a second measured reception quality corresponding to the second communications network from the user terminal; and

means for determining to perform the initiating of the handover in response to the first measured reception quality and the second measured reception quality.

27. The apparatus of claim 20, wherein the means for maintaining of the call parameters further comprises means for maintaining a first identifier of the user terminal on the first communications network and a second identifier of the user terminal on the second communications network.

28. The apparatus of claim 20, wherein the first communications network comprises a WLAN technology and wherein the second communications network comprises a cellular technology.

29. A method at a user terminal for performing a handover in a communications network, comprising:

engaging in an active call by the user terminal communicating on a first communications network having a first access technology type, wherein the active call includes corresponding call parameters maintained at the first communications network; and

performing a handover of the active call to a second communications network having a second access technology type different from the first access technology type.

30. The method of claim 29, further comprising obtaining a resource allocation on the second communications network to continue the active call on the second communications network via the handover.

31. The method of claim 30, wherein the obtaining of the resource allocation on second communications network is based on an exchanging of at least a portion of the call parameters of the active call between the first communications network and the second communications network, wherein the resource allocation is at least partially based on at least the portion of the call parameters.

32. The method of claim 30, wherein the performing of the handover of the active call further comprises receiving a handover request via the first communications network at the user terminal in response to the obtaining of the resource allocation on second communications network.

33. The method of claim 29, further comprising:

transmitting a measured reception quality corresponding to the first communications network; and

wherein the handover is in response to the measured reception quality.

34. The method of claim 29, further comprising:

transmitting a measured reception quality corresponding to the second communications network; and

wherein the handover is in response to the measured reception quality.

35. The method of claim 29, further comprising:

transmitting a first measured reception quality corresponding to the first communications network;

transmitting a second measured reception quality corresponding to the second communications network; and

wherein the handover is in response to the first measured reception quality and the second measured reception quality.

36. The method of claim 29, wherein the call parameters further comprise a first identifier of the user terminal on the first communications network and a second identifier of the user terminal on the second communications network.

37. The method of claim 29, wherein the first communications network comprises a WLAN technology and wherein the second communications network comprises a cellular technology.

38. A computer program product operable on a user terminal for performing a handover in a communications network, comprising:

a memory comprising;

at least one instruction for causing the user terminal to engage in an active call by the user terminal communicating on a first communications network having a first access technology type, wherein the active call includes corresponding call parameters maintained at the first communications network; and

at least one instruction for causing the user terminal to perform a handover of the active call to a second communications network having a second access technology type different from the first access technology type.

39. The computer program product of claim 38, further comprising at least one instruction for the user terminal to obtain a resource allocation on the second communications network to continue the active call on the second communications network.

40. The computer program product of claim 39, wherein the at least one instruction for the user terminal to obtain the resource allocation on second communications network is based on an exchanging of at least a portion of the call parameters of the active call between the first communications network and the second communications network, wherein the resource allocation is at least partially based on at least the portion of the call parameters.

41. The computer program product of claim 39, wherein the at least one instruction for the user terminal to perform the handover of the active call further comprises at least one instruction for the user terminal to receive a handover request via the first communications network based on the obtaining of the resource allocation on second communications network.

42. The computer program product of claim 38, further comprising:

at least one instruction for transmitting a measured reception quality corresponding to the first communications network; and

wherein the handover is in response to the measured reception quality.

43. The computer program product of claim 38, further comprising:

at least one instruction for transmitting a measured reception quality corresponding to the second communications network; and

wherein the handover is in response to the measured reception quality.

44. The computer program product of claim 38, further comprising:

at least one instruction for transmitting a first measured reception quality corresponding to the first communications network;

at least one instruction for transmitting a second measured reception quality corresponding to the second communications network; and

wherein the handover is in response to the first measured reception quality and the second measured reception quality.

45. The computer program product of claim 38, wherein the call parameters further comprise a first identifier of the user terminal on the first communications network and a second identifier of the user terminal on the second communications network.

46. The computer program product of claim 38, wherein the first communications network comprises a WLAN technology and wherein the second communications network comprises a cellular technology.

47. A user terminal for performing a handover in a communications network, comprising:

means for engaging in an active call by the user terminal communicating on a first communications network having a first access technology type, wherein the active call includes corresponding call parameters maintained at the first communications network; and

means for performing a handover of the active call to a second communications network having a second access technology type different from the first access technology type.

48. The user terminal of claim 47, further comprising means for obtaining a resource allocation on the second communications network to continue the active call on the second communications network.

49. The user terminal of claim 48, wherein the means for obtaining the resource allocation on second communications network is based on an exchanging of at least a portion of the call parameters of the active call between the first communications network and the second communications network, wherein the resource allocation is at least partially based on at least the portion of the call parameters.

50. The user terminal of claim 48, wherein the means for performing the handover of the active call further comprises means for receiving a handover request via the first communications network at the user terminal based on the obtaining of the resource allocation on second communications network.

51. The user terminal of claim 47, further comprising:

means for transmitting a measured reception quality corresponding to the first communications network; and

wherein the handover is in response to the measured reception quality.

52. The user terminal of claim 47, further comprising:

means for transmitting a measured reception quality corresponding to the second communications network; and

wherein the handover is in response to the measured reception quality.

53. The user terminal of claim 47, further comprising:

means for transmitting a first measured reception quality corresponding to the first communications network

means for transmitting a second measured reception quality corresponding to the second communications network; and

wherein the handover is in response to the first measured reception quality and the second measured reception quality.

54. The user terminal of claim 47, wherein the call parameters further comprise a first identifier of the user terminal on the first communications network and a second identifier of the user terminal on the second communications network.

55. The user terminal of claim 47, wherein the first communications network comprises a WLAN technology and wherein the second communications network comprises a cellular technology.

56. A user terminal for performing a handover in a communications network, comprising:

a first subsystem engaging in an active call by the user terminal communicating on a first communications network having a first access technology type, wherein the active call includes corresponding, call parameters maintained at the first communications network;

circuitry to perform a handover of the active call to a second communications network having a second access technology type different from the first access technology type; and

a second subsystem to continue the active call with the second communications network.

57. The user terminal of claim 56, wherein the second subsystem obtains a resource allocation on the second communications network to continue the active call on the second communications network.

58. The user terminal of claim 57, wherein the resource allocation on second communications network is based on an exchanging of at least a portion of the call parameters of the active call between the first communications network and the second communications network, wherein the resource allocation is at least partially based on at least the portion of the call parameters.

59. The user terminal of claim 57, wherein the circuitry to perform the handover of the active call is triggered by receiving a handover request via the first communications network at the user terminal based on the obtaining of the resource allocation on second communications network.

60. The user terminal of claim 56, further comprising:

circuitry to transmit a measured reception quality corresponding to the first communications network; and

wherein the handover is in response to the measured reception quality.

61. The user terminal of claim 56, further comprising:

circuitry to transmit a measured reception quality corresponding to the second communications network; and

wherein the handover is in response to the measured reception quality.

62. The user terminal of claim 56, further comprising:

circuitry to transmit a first measured reception quality corresponding to the first communications network;

circuitry to transmit a second measured reception quality corresponding to the second communications network; and

wherein the handover is in response to the first measured reception quality and the second measured reception quality.

63. The user terminal of claim 56, wherein the call parameters further comprise a first identifier of the user terminal on the first communications network and a second identifier of the user terminal on the second communications network.

64. The user terminal of claim 56, wherein the first subsystem comprises a WLAN subsystem and wherein the second subsystem comprises a cellular subsystem.