SYSTEMS AND METHODS FOR USING A SATELLITE POSITIONING SYSTEM TO DETECT MOVED WLAN ACCESS POINTS

• US 20110298660A1
• Filed: 08/17/2011
• Published: 12/08/2011
• 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
• Granted Patent: US 8,284,103 B2
• Time in Patent Office: Days
• US Class Current: 342/357.31
• 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 the present location of the AP, the method comprising:

identifying at least one WLAN AP detected by the WLAN and satellite enabled device;

accessing a reference database to obtain a reference location associated with the at least one WLAN AP and a quality measurement associated with the reference location;

receiving a position estimate for the device from a Satellite Positioning System (SPS);

estimating a distance between the reference location associated with the WLAN AP and the position estimate of the device from the SPS; and

inferring that the reference location associated with the WLAN AP is not the present location of the WLAN AP based on (i) the distance between the reference location associated with the WLAN AP and the position estimate of the device from the SPS and (ii) the quality measurement associated with the reference location.

2. The method of claim 1, further comprising indicating in the reference database that the reference location associated with the WLAN AP 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 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 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 position estimate of the device from the SPS 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 at least one WLAN AP detected by the WLAN and satellite enabled device;

logic for accessing a reference database to obtain a reference location associated with the at least one WLAN AP and a quality measurement associated with the reference location;

logic for providing a position estimate for the device from a Satellite Positioning System (SPS);

logic for estimating a distance between the reference location associated with the WLAN AP and the position estimate of the device from the SPS; and

logic for inferring that the reference location associated with the WLAN AP is not the present location of the WLAN AP based on (i) the distance between the reference location associated with the WLAN AP and the position estimate of the device from the SPS and (ii) the quality measurement associated with the reference location.

7. The system of claim 6, further comprising logic for indicating in the reference database that the reference location associated with the WLAN AP 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 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 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 position estimate of the device from the SPS 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.