Apparatus and method of handoff between wireless networks

• US 8,798,627 B2
• Filed: 03/08/2010
• Issued: 08/05/2014
• Est. Priority Date: 09/01/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rimoni, Yoram, Yacobi, Eitan, Keidar, Ron, Zreiq, Samer
• Primary Examiner(s): Patel, Nimesh
• Application Number:
  US12/719,718
• Publication Number:
  US 20110064058A1
• Time in Patent Office: 1,611 Days
• Field of Search: 455/436, 455/440, 455/441, 455/442, 455/443
• US Class Current: 455/436
• 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. A method of performing a handover in a communications network, comprising:

maintaining, by a network gateway component, call parameters of an active call of a user terminal communicating on a first communications network having a first access technology type;

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, comprising obtaining a resource allocation on the second communications network to continue the active call on the second communications network based at least partially on at least a portion of the call parameters, 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;

obtaining a mobile originated call status or a mobile terminated call status of the active call of the user terminal communicating on the first communications network; and

maintaining the mobile originated call status or the mobile terminated call status of the active call on the second communications network.

2. The method of claim 1, wherein the obtaining of the resource allocation on second communications network further comprises exchanging at least the portion of the call parameters of the active call with the second communications network.

3. The method of claim 1, 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 the second communications network.

4. The method of claim 1, 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.

5. The method of claim 1, 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.

6. The method of claim 1, 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.

7. The method of claim 1, wherein the first communications network comprises a Wireless Local Area Network technology and wherein the second communications network comprises a cellular technology.

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

a network gateway component configured to;

maintain call parameters of an active call of a user terminal communicating on a first communications network having a first access technology type,

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, comprising obtaining a resource allocation on the second communications network to continue the active call on the second communications network based at least partially on at least a portion of the call parameters, 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,

obtain a mobile originated call status or a mobile terminated call status of the active call of the user terminal communicating on the first communications network, and

maintain the mobile originated call status or the mobile terminated call status of the active call on the second communications network.

9. The apparatus of claim 8, wherein the network gateway component to obtain the resource allocation on the second communications network is further configured to exchange at least the portion of the call parameters of the active call with the second communications network.

10. The apparatus of claim 8, 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 the second communications network.

11. The apparatus of claim 8, 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.

12. The apparatus of claim 8, 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.

13. The apparatus of claim 8, 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.

14. The apparatus of claim 8, wherein the first communications network comprises a Wireless Local Area Network technology and wherein the second communications network comprises a cellular technology.

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

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

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, comprising means for obtaining a resource allocation on the second communications network to continue the active call on the second communications network based at least partially on at least a portion of the call parameters, 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;

means for obtaining a mobile originated call status or a mobile terminated call status of the active call of the user terminal communicating on the first communications network; and

means for maintaining the mobile originated call status or the mobile terminated call status of the active call on the second communications network.

16. The apparatus of claim 15, wherein the means for obtaining the resource allocation on the second communications network further comprises means for exchanging at least the portion of the call parameters of the active call with the second communications network.

17. The apparatus of claim 15, 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 the second communications network.

18. The apparatus of claim 15, 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.

19. The apparatus of claim 15, 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.

20. The apparatus of claim 15, 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.

21. The apparatus of claim 15, wherein the first communications network comprises a Wireless Local Area Network technology and wherein the second communications network comprises a cellular technology.

22. The apparatus of claim 15, wherein the means for initiating the handover of the active call further comprises means for initiating in response to receiving the call handoff from the user terminal, wherein the active call on the first communications network comprises a mobile terminated call with respect to the user terminal, and further comprising, in response to the handover, means for continuing the active call on the second communications network as the mobile terminated call from the user terminal.

23. The apparatus of claim 15, further comprising means for receiving, at the network gateway component, a call from the user terminal at a first telephone number corresponding to a mobile originated call or at a second telephone number corresponding to a mobile terminated call, wherein the means for obtaining the mobile originated call status or the mobile terminated call status of the active call further comprises means for obtaining based on whether the call from the user terminal is received at the first telephone number or at the second telephone number.

24. The apparatus of claim 15, wherein the means for obtaining the mobile originated call status or the mobile terminated call status of the active call further comprises means for obtaining based on control channel communications with either the user terminal or a device associated with the active call.

25. The apparatus of claim 15, further comprising:

means for receiving, at the network gateway component, a call from the user terminal at a predetermined handoff telephone number to initiate the handover of the active call to the second communications network; and

means for establishing, prior to the initiating of the handover by the network gateway component, a linkage between the predetermined handoff telephone number associated with the active call on the second communications network and the active call established on the first communications network;

wherein the means for obtaining of the mobile originated call status or the mobile terminated call status of the active call further comprises means for obtaining based on the linkage.

26. 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 at least a portion of the call parameters are maintained at a second communications network, 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;

performing a handover of the active call to the second communications network having a second access technology type different from the first access technology type, comprising sending a call handoff from the user terminal, wherein the call handoff is configured to cause a network gateway component to obtain a mobile originated call status or a mobile terminated call status of the active call of the user terminal communicating on the first communications network, and to maintain the mobile originated call status or the mobile terminated call status of the active call on the second communications network; and

obtaining a resource allocation on the second communications network to continue the active call on the second communications network via the handover based at least partially on at least the portion of the call parameters.

27. The method of claim 26, wherein the obtaining of the resource allocation on second communications network is based on an exchanging of at least the portion of the call parameters of the active call between the first communications network and the second communications network.

28. The method of claim 26, 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.

29. The method of claim 26, 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.

30. The method of claim 26, 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.

31. The method of claim 26, further comprising:

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

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

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

32. The method of claim 26, wherein the first communications network comprises a Wireless Local Area Network technology and wherein the second communications network comprises a cellular technology.

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

a non-transitory 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 a portion of the call parameters are maintained at a second communications network, 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;

perform a handover of the active call to the second communications network having a second access technology type different from the first access technology type, comprising sending a call handoff from the user terminal, wherein the call handoff is configured to cause a network gateway component to obtain a mobile originated call status or a mobile terminated call status of the active call of the user terminal communicating on the first communications network, and to maintain the mobile originated call status or the mobile terminated call status of the active call on the second communications network; and

obtain a resource allocation on the second communications network to continue the active call on the second communications network based at least partially on at least the portion of the call parameters.

34. The computer program product of claim 33, wherein the at least one instruction for the user terminal to obtain the resource allocation on the second communications network is based on an exchanging of at least the portion of the call parameters of the active call between the first communications network and the second communications network.

35. The computer program product of claim 33, 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 the second communications network.

36. The computer program product of claim 33, 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.

37. The computer program product of claim 33, 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.

38. The computer program product of claim 33, further comprising:

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

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

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

39. The computer program product of claim 33, wherein the first communications network comprises a Wireless Local Area Network technology and wherein the second communications network comprises a cellular technology.

40. 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 at least a portion of the call parameters are maintained at a second communications network, 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;

means for performing a handover of the active call to the second communications network having a second access technology type different from the first access technology type, comprising means for sending a call handoff from the user terminal, wherein the call handoff is configured to cause a network gateway component to obtain a mobile originated call status or a mobile terminated call status of the active call of the user terminal communicating on the first communications network, and to maintain the mobile originated call status or the mobile terminated call status of the active call on the second communications network; and

means for obtaining a resource allocation on the second communications network to continue the active call on the second communications network based at least partially on at least the portion of the call parameters.

41. The user terminal of claim 40, wherein the means for obtaining the resource allocation on second communications network is based on an exchanging of at least the portion of the call parameters of the active call between the first communications network and the second communications network.

42. The user terminal of claim 40, 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 the second communications network.

43. The user terminal of claim 40, 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.

44. The user terminal of claim 40, 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.

45. The user terminal of claim 40, 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.

46. The user terminal of claim 40, wherein the first communications network comprises a Wireless Local Area Network technology and wherein the second communications network comprises a cellular technology.

47. The apparatus of claim 40, wherein the means for performing of the handover of the active call further comprises means for sending a call handoff from the user terminal, wherein the active call on the first communications network comprises a mobile terminated call with respect to the user terminal, and further comprising, in response to the handover, means for continuing the active call on the second communications network as the mobile terminated call from the user terminal.

48. The apparatus of claim 40, wherein the means for sending the call handoff from the user terminal further comprises means for making a call from the user terminal to a first telephone number corresponding to a mobile originated call or at a second telephone number corresponding to a mobile terminated call.

49. The apparatus of claim 40, further comprising means for transmitting a control channel communication to provide the mobile originated call status or the mobile terminated call status of the active call.

50. The apparatus of claim 40, wherein the means for sending the call handoff from the user terminal further comprises means for making a call from the user terminal to a predetermined handoff telephone number to initiate the handover of the active call to the second communications network, wherein the call to the predetermined handoff telephone number is configured to enable a linkage between the predetermined handoff telephone number associated with the active call on the second communications network and the active call established on the first communications network to maintain the mobile originated call status or the mobile terminated call status of the active call based on the linkage.

51. 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, and at least a portion of the call parameters are maintained at a second communications network, 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;

circuitry to perform a handover of the active call to the second communications network having a second access technology type different from the first access technology type, comprising sending a call handoff from the user terminal, wherein the call handoff is configured to cause a network gateway component to obtain a mobile originated call status or a mobile terminated call status of the active call of the user terminal communicating on the first communications network, and to maintain the mobile originated call status or the mobile terminated call status of the active call on the second communications network; and

a second subsystem to obtain a resource allocation on the second communications network, based at least partially on at least the portion of the call parameters, to continue the active call with the second communications network.

52. The user terminal of claim 51, wherein the resource allocation on second communications network is based on an exchanging of at least the portion of the call parameters of the active call between the first communications network and the second communications network.

53. The user terminal of claim 51, 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 the second communications network.

54. The user terminal of claim 51, 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.

55. The user terminal of claim 51, 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.

56. The user terminal of claim 51, 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.

57. The user terminal of claim 51, wherein the first subsystem comprises a WLAN subsystem and wherein the second subsystem comprises a cellular subsystem.

58. A computer program product operable on a network gateway component in a communications network, comprising:

a non-transitory memory, comprising at least one instruction for causing the 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;

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, comprising obtaining a resource allocation on the second communications network to continue the active call on the second communications network based at least partially on at least a portion of the call parameters, 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;

obtain a mobile originated call status or a mobile terminated call status of the active call of the user terminal communicating on the first communications network; and

maintain the mobile originated call status or the mobile terminated call status of the active call on the second communications network.