Systems and methods for using a satellite positioning system to detect moved WLAN access points

• US 8,284,103 B2
• Filed: 08/17/2011
• Issued: 10/09/2012
• Est. Priority Date: 07/16/2009
• Status: Active Grant

• Current Assignee: Skyhook Wireless Incorporated (Liberty Broadband Corp.)
• Original Assignee: Skyhook Wireless Incorporated (Liberty Broadband Corp.)
• Inventors: Alizadeh-Shabdiz, Farshid
• Primary Examiner(s): Liu, Harry
• Application Number:
  US13/211,711
• Publication Number:
  US 20110298660A1
• Time in Patent Office: 419 Days
• Field of Search: 342/458
• US Class Current: 342/458
• CPC Class Codes: G01S 19/00 Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: G01S 5/0242 Determining the position of transmitters to be subsequently used in positioning G01S5/0289 takes precedence
• CPC Class Codes: G01S 5/0263 by combining or switching between positions derived from two or more separate positioning systems
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services

Abstract

The disclosed subject matter generally relates to hybrid positioning systems and methods and, more specifically, systems and methods of detecting moved WLAN assess points using a wireless local area network based positioning system (WLAN-PS) and a satellite-based positioning system (SPS) with at least two satellites measurement.

Claims

1. A method of using a Wireless Local Area Network (WLAN) and satellite enabled device to infer that a reference location associated with a detected WLAN access point (AP) is not a present location of the WLAN AP, the method comprising:

identifying a plurality of WLAN APs detected by the WLAN and satellite enabled device;

accessing a reference database to obtain a reference location associated with each WLAN AP of the plurality;

receiving satellite measurements from at least two satellites;

receiving a hybrid position estimate for the device, the hybrid position estimate being based on the satellite measurements and at least one of the reference locations associated with at least one of the WLAN APs of the plurality;

estimating a distance between the reference location associated with at least one of the WLAN APs of the plurality and the hybrid position estimate of the device; and

inferring that the reference location associated with the WLAN AP for which the distance was estimated is not the present location of the WLAN AP based on the distance between the reference location associated with the WLAN AP for which the distance was estimated and the hybrid position estimate of the device.

2. The method of claim 1, further comprising indicating in the reference database that the reference location associated with the WLAN AP for which the distance was estimated is not the present location of the WLAN AP.

3. The method of claim 1, further comprising updating the reference location associated with the WLAN AP for which the distance was estimated in the reference database to reflect an estimated present location of the associated WLAN AP.

4. The method of claim 1, the inferring that the reference location associated with the WLAN AP for which the distance was estimated is not the present location of the WLAN AP being based on the distance between the reference location associated with the WLAN AP and the hybrid position estimate of the device exceeding a predetermined threshold.

5. The method of claim 4, wherein the predetermined threshold is based on an estimated coverage area of the WLAN AP.

6. A system for using a Wireless Local Area Network (WLAN) and satellite enabled device to infer that a reference location associated with a detected WLAN access point (AP) is not the present location of the AP, the system comprising:

logic for identifying a plurality of WLAN APs detected by the WLAN and satellite enabled device;

logic for accessing a reference database to obtain a reference location associated with each WLAN AP of the plurality;

logic for providing satellite measurements from at least two satellites;

logic for providing a hybrid position estimate for the device, the hybrid position estimate being based on the satellite measurements and at least one of the reference locations associated with at least one of the WLAN APs of the plurality;

logic for estimating a distance between the reference location associated with at least one of the WLAN APs of the plurality and the hybrid position estimate of the device; and

logic for inferring that the reference location associated with the WLAN AP for which the distance was estimated is not the present location of the WLAN AP based on the distance between the reference location associated with the WLAN AP for which the distance was estimated and the hybrid position estimate of the device.

7. The system of claim 6, further comprising logic for indicating in the reference database that the reference location associated with the WLAN AP for which the distance was estimated is not the present location of the WLAN AP.

8. The system of claim 6, further comprising logic for updating the reference location associated with the WLAN AP for which the distance was estimated in the reference database to reflect an estimated present location of the associated WLAN AP.

9. The system of claim 6, the inferring that the reference location associated with the WLAN AP for which the distance was estimated is not the present location of the WLAN AP being based on the distance between the reference location associated with the WLAN AP and the hybrid position estimate of the device exceeding a predetermined threshold.

10. The system of claim 9, wherein the predetermined threshold is based on an estimated coverage area of the WLAN AP.