System and method to improve WLAN handover behavior at entry/exit points

• US 7,769,378 B2
• Filed: 08/26/2003
• Issued: 08/03/2010
• Est. Priority Date: 08/26/2003
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hirsbrunner, Alex P., Belkin, Anatoly S., Gipson, Jack Anthony, Hufferd, Lowell C. III, Alen, Anand Bernard, Dorenbosch, Jheroen P., Storm, Brian D.
• Primary Examiner(s): PHAN, HUY Q
• Application Number:
  US10/649,756
• Publication Number:
  US 20050048972A1
• Time in Patent Office: 2,534 Days
• Field of Search: 455436-453, 455/435.2, 455/435.1, 455/403, 455/422.1, 370/331, 370/337, 370/338, 370/328, 370/344
• US Class Current: 455/435.1
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• 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 84/12 WLAN [Wireless Local Area Networks]

Abstract

A system, wireless device (306) and method determine that a wireless device (306) is detecting a triggering event. The triggering event includes detecting a WLAN border cell (210), detecting a first signal from an egress portal (302), or detecting a degradation in signal quality. The wireless device (306) then detects at least one signal from an egress portal (302), determines that the wireless device (306) is moving from the coverage area of a first communications system to the coverage area of a second communications system according to the order of signals received from the egress portal (302), initiates a registration sequence with the second wireless communication system in response to determining that the wireless device (306) is moving from the coverage area of the first communications system to the coverage area of the second communications system, and conducts present and subsequent calls via the second wireless communication system.

Claims

1. A method comprising:

detecting a first signal from an egress portal, the first signal associated with indicating passage through the egress portal, wherein the egress portal resides within a cell of a wireless local area network and occupies a region that is smaller than the cell;

initiating, in response to detecting the first signal from the egress portal, a registration sequence with a second wireless communication system; and

conducting a present or a subsequent call via the second wireless communication system.

2. The method of claim 1, further comprising:

detecting a second signal from the egress portal; and

determining, based upon an order of receiving the first signal and the second signal, that a wireless device is moving from the coverage area of the wireless local area network to a coverage area of the second wireless communication system, wherein the step of initiating is performed in response to determining that the wireless device is moving from the coverage area of the wireless local area network to the coverage area of the second wireless communication system.

3. The method according to claim 2, wherein the first signal comprises a wireless local area network signal substantially transmitted to an interior side of the egress portal and wherein the second signal comprises a wireless local area network signal substantially transmitted to an exterior side of the egress portal, the second signal being different from the first signal.

4. The method of claim 1, wherein the second wireless communication system is a wide area network (WAN).

5. The method of claim 4, wherein the wide area network (WAN) uses code division multiple access (CDMA), wideband code division multiple access (WCDMA), time division multiple access (TDMA), global system for mobile communications (GSM) or integrated digital enhanced network (iDEN).

6. The method of claim 1, wherein the wireless local area network (WLAN) uses at least one protocol of IEEE Standard 802.11 and Bluetooth.

7. The method of claim 1, wherein the egress portal comprises a Bluetooth access point, an infrared transmitter, or an electronic security detection device.

8. The method of claim 1, wherein the detecting a first signal step is performed in response to detecting a triggering event.

9. The method of claim 8, wherein the triggering event comprises detecting a wireless local area network border cell, detecting a degradation in signal quality, or detecting a start of a call.

10. The method according to claim 1, wherein the first signal is only for indicating passage through the egress portal.

11. The method according to claim 1, further comprising conducting a present or prior call via the wireless local area network.

12. A method comprising:

determining that a wireless device, operating in a first communication system is detecting a wireless local area network inner border cell of the first communication system, wherein the inner border cell broadcasts an inner border cell indicator;

initiating a registration sequence with a second wireless communication system in response to determining that the wireless device is detecting the wireless local area network inner border cell;

detecting a second wireless local area network outer border cell, wherein the outer border cell broadcasts an outer border cell indicator;

determining that the wireless device is moving from a coverage area of the first communications system to a coverage area of the second communications system in response to detecting the second wireless local area network outer border cell; and

conducting a present or a subsequent call via the second wireless communication system.

13. The method according to claim 12, wherein detecting the second wireless local area network border cell is done within a predetermined amount of time.

14. The method according to claim 12, wherein conducting the present or the subsequent call via the second wireless communication system is performed in response to determining that the wireless device is moving from the coverage area of the first communications system to the coverage area of the second communications system.

15. The method according to claim 12, wherein the inner border cell is substantially present within the interior of a structure and the outer border cell is substantially present outside the structure.

16. A method comprising:

detecting a triggering event;

detecting a signal from an egress portal in response to detecting a triggering event, the signal associated with indicating passage through the egress portal, wherein the egress portal resides within a cell of a wireless local area network and occupies a region that is smaller than the cell;

obtaining available wide area network information from a wireless local area network access point; and

scanning, in response to the detecting, for at least one wide area network listed in the available wide area network information.

17. The method of claim 16, wherein the triggering event comprises detecting a wireless local area network border cell, detecting a degradation in signal quality, or detecting a start of a call.

18. A mobile communication device comprising:

at least two transceivers, each transceiver designed to operate on a separate wireless communications system, for transmitting and receiving wireless information;

a controller, communicatively coupled to each transceiver, for managing the operation of the mobile communication device;

a first wireless communications system stack, communicatively coupled to the controller, having instructions for communicating according to its respective protocol;

a second wireless communications system stack, communicatively coupled to the controller, having instructions for communicating according to its respective protocol;

a means for receiving signals from an egress portal, the signals associated with indicating passage through the egress portal; and

a handover manager, communicatively coupled to the controller, the first wireless communications system stack, the second wireless communications system stack, and the means for receiving signals from an egress portal, the handover manager for determining, in response to determining that the means for receiving signals from an egress portal has received at least one signal from the egress portal indicating passage therethrough, when to handover from a first wireless communication system to a second wireless communication system, wherein the egress portal resides within a cell of a wireless local area network and occupies a region that is smaller than the cell.

19. The mobile communication device of claim 18, wherein the at least two transceivers share common hardware and software.

20. The mobile communication device of claim 18, wherein the means for receiving signals from an egress portal comprises a Bluetooth transceiver, an infrared sensor, or an electronic security detection device.

21. A mobile communication system comprising:

a structure having at least one entry/exit point;

at least one egress portal located at the at least one entry/exit point, the egress portal for transmitting signals to a mobile communications device, wherein the signals are associated with indicating passage through the at least one egress portal;

at least one cell of a wireless local area network communications system, the cell providing communication coverage within the structure, wherein the egress portal resides within the cell of the wireless local area network communications system and occupies a region that is smaller than the cell; and

at least one coverage cell of a second communications system, overlapping the at least one cell of the wireless local area network, for providing communication coverage outside the structure;

wherein at least one mobile subscriber device can be communicatively coupled with the at least one cell of the wireless local area network communications system and the at least one cell of the second communications system, the device for determining, in response to determining that the device has received the signals from the at least one egress portal indicating passage therethrough, when to handover from one wireless communication system to the second wireless communication system.

22. A mobile communication system of claim 21 further comprising:

at least one border cell of the wireless local area network communications system, the border cell located at the entry/exit point of the structure, providing a transition region between the wireless local area network communications system and the second communications system.

23. A memory comprising computer instructions for performing the steps of:

detecting a first signal from an egress portal, the first signal associated with indicating passage through the egress portal, wherein the egress portal resides within a cell of a wireless local area network and occupies a region that is smaller than the cell;

initiating, in response to detecting the first signal from the egress portal, a registration sequence with a second wireless communication system; and

conducting a present or a subsequent call via the second wireless communication system.

24. The memory of claim 23, further comprising computer instructions for:

detecting a second signal from the egress portal; and

determining, based upon an order of receiving the first signal and the second signal, that a wireless device is moving from the coverage area of the wireless local area network to a coverage area of the second wireless communication system, wherein the step of initiating is performed in response to determining that the wireless device is moving from the coverage area of the wireless local area network to the coverage area of the second communication system.

25. The memory of claim 23, wherein the egress portal comprises a Bluetooth access point, an infrared transmitter or an electronic security detection device.

26. The memory of claim 23, wherein the step of detecting a first signal is performed in response to detecting a triggering event.

27. The memory of claim 26, wherein the triggering event comprises detecting a wireless local area network border cell, detecting a degradation in signal quality, or detecting a start of a call.

28. A memory comprising computer instructions for performing the steps of:

determining that a wireless device, operating in a first communication system is detecting a wireless local area network inner border cell of the first communication system, wherein the inner border cell broadcasts an inner border cell indicator;

initiating a registration sequence with a second wireless communication system in response to determining that the wireless device is detecting a wireless local area network inner border cell;

detecting a second wireless local area network outer border cell, wherein the outer border cell broadcasts an outer border cell indicator;

determining that the wireless device is moving from a coverage area of the first communications system to a coverage area of the second communications system in response to detecting the second wireless local area network outer border cell; and

conducting a present or a subsequent call via the second wireless communication system.

29. The method according to claim 28, wherein detecting the second wireless local area network border cell is done within a predetermined amount of time.

30. The method according to claim 28, wherein conducting the present or the subsequent call via the second wireless communication system is performed in response to determining that the wireless device is moving from the coverage area of the first communications system to the coverage area of the second communications system.

31. At an egress portal, a method to improve handover behavior of a mobile device between a wireless local area network (WLAN) containing a plurality of WLAN access points and a wireless wide area network (WAN) containing a plurality of WAN cells, the egress portal being located at an entry/exit point of the WLAN and not including a WLAN access point or a cell for a WAN, the method comprising:

conducting a call via a first network, the first network being either the WLAN or the WAN;

detecting by the egress portal a movement of the mobile device from a coverage area of the first network to a coverage area of a second network, the second network being the other one of the WLAN or the WAN;

in response to detecting the movement of the mobile device, advising the mobile device to switch to the second network; and

conducting, in response to advising the mobile device to switch to the second network, the call via the second network.