Call hand-over in a wireless local area network

• US 7,400,886 B2
• Filed: 01/09/2004
• Issued: 07/15/2008
• Est. Priority Date: 01/09/2004
• Status: Active Grant

• Current Assignee: Unify Patente GmbH & Co. KG (Atos Se)
• Original Assignee: Siemens Communications Incorporated (Siemens AG)
• Inventors: Sahim, Faramarz, Ozery, Nissim J., Samayamantry, Mallikarjuna, Trueman, Nigel
• Primary Examiner(s): Gary, Erika A.
• Application Number:
  US10/755,065
• Publication Number:
  US 20050153698A1
• Time in Patent Office: 1,649 Days
• Field of Search: 455/444, 455/436, 455/442, 455/432.1
• US Class Current: 455/444
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1083 In-session procedures
• CPC Class Codes: H04L 65/1094 Inter-user-equipment sessions transfer or sharing
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/1446 wherein at least one of the networks is unlicensed
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method and apparatus for automatically handing over calls between a wireless LAN and a non-WLAN, with minimum or no disruption of active calls. The invention gives users flexibility in customizing hand-over preferences and allows telephony features to be transferred during the hand-over.

Claims

1. A method for handing over an active call between a first call device and a second call device comprising the steps of:

defining a set of target hand-over devices with a mobility server;

automatically detecting call hand-over threshold for said first call device, automatically initiating hand-overs responsive to detecting said threshold and monitoring said first call device for on-demand hand-over overrides, wherein at least one of said first call device and said set of target hand-over devices supports wireless local area network (WLAN) communications and said on-demand hand-over overrides include halting automatic hand-overs and forcing hand-overs;

selecting said second call device from the previously defined said set of target hand-over devices responsive to automatic detection of said call hand-over threshold, wherein selection of said second call device is manually selectable from said first device; and

establishing a connection to said second call device upon acceptance of said call by said second call device.

2. The method of claim 1 wherein said first call device is a non-WLAN device.

3. The method of claim 2 wherein said non-WLAN device is a cellular telephone and said method further comprises maintaining connection to hand-over calls after handing over.

4. The method of claim 3, wherein said non-WLAN cellular telephone device uses 3G air interface technology.

5. The method of claim 3, wherein said non-WLAN cellular telephone device uses TDMA air interface technology.

6. The method of claim 3, wherein said non-WLAN cellular telephone device uses GSM air interface technology.

7. The method of claim 3, wherein said non-WLAN cellular telephone device uses COMA air interface technology.

8. The method of claim 3, wherein said non-WLAN cellular telephone device uses UMTS technology.

9. The method of claim 2 wherein said non-WLAN device is an office wireline telephone.

10. The method of claim 1 wherein said first call device is a WLAN device connected to a first WLAN and before initiating a call hand-over to said second device, said method further comprises:

attempting a handoff of said first call device to a second WLAN; and

whenever an attempted said handoff is successful,

returning to automatically detecting said call hand-over threshold.

11. The method of claim 10 wherein said WLAN device is a Personal Digital Assistance (PDA).

12. The method of claim 1 wherein said first call device supports both WLAN and non-WLAN communications.

13. The method of claim 1 wherein said second call device supports both WLAN and non-WLAN communications.

14. The method of claim 1 wherein said first call device and said second call device are the same.

15. The method of claim 1 wherein said first call device and said second call device are integrated as a single call device.

16. The method of claim 1, wherein said method further comprises the step of dialing the telephone number of said second call device after selecting said second call device.

17. The method of claim 1 further comprising the step of disconnecting said call from first call device after establishing said connection to said second call device.

18. The method of claim 1, wherein said hand-over threshold is reached when said call loses Internet Protocol connectivity.

19. The method of claim 1 wherein said hand-over threshold is determined based on Radio Frequency signal strength of the active call.

20. The method of claim 1, wherein said hand-over is performed on-demand prior to reaching said hand-over threshold responsive to an on-demand hand-over override from said first call device.

21. The method of claim 20, wherein a user access code is used to perform said on-demand hand-over override.

22. The method of claim 20, wherein a user access code is used to select telephony features for transfer from said first call device to said second call device.

23. The method of claim 1 wherein said call remains active after the hand-over is complete.

24. The method of claim 1 wherein one or more hand-overs are performed per call.

25. The method of claim 1, wherein user associated personalized settings and telephony features are handed over with each said hand-over.

26. The method of claim 1, wherein said call hand-over threshold is determined based on available resources in network of said target device.

27. The method of claim 1 wherein said call hand-over threshold is determined based on at least one of call priority or desired call Quality of Service of said call.

28. An apparatus for handing over an active call between a first call device and second call device, said apparatus comprising:

a user interface for pre-selecting a set of target hand-over devices, at least one of said first call device and said set of target hand-over devices supporting wireless local area network (WLAN) communications;

a detector circuit that detects hand-over threshold for said call;

a selector indicator that automatically selects said second call device from said set of target hand-over devices and automatically initiates hand-overs to selected second call devices;

an on-demand hand-over override selectively overriding said detector circuit responsive to manual input on said first device, said selector indicator further determining whether to halt an automatic hand-over or to select said second call device and hand-over responsive to said on-demand hand-over override; and

a mobility server that provides said set of target hand-over devices for pre-selection to said user interface and establishes a connection to said target device upon acceptance of said call by said target device.

29. The apparatus of claim 28 wherein said first call device is a non-WLAN device and said mobility server maintaining connection to hand-over calls after handing over.

30. The apparatus of claim 28 wherein said first call device is a WLAN device and said selector indicator selects when said WLAN device hands over to a non-WLAN device responsive to wireless local area network information and call priorities.

31. The apparatus of claim 28, wherein said user interface sets hand-over targets and preferences.

32. The apparatus of claim 31, wherein said user interface is provided via a dial up connection.

33. The apparatus of claim 31, wherein said user interface is provided via a personal computer.

34. The apparatus of claim 28 further comprising a voice prompt generator for notifying other call party when said hand-over is in progress.

35. The apparatus of claim 28 wherein said first call device and said second call device are the same.