Techniques for selecting SPS measurements to use in determining a final location estimate based on a WLAN-based location estimate

• US 10,031,237 B2
• Filed: 03/24/2015
• Issued: 07/24/2018
• 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 K
• Application Number:
  US14/666,886
• Publication Number:
  US 20150198720A1
• Time in Patent Office: 1,218 Days
• Field of Search: 34235729
• 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

In one embodiment, a mobile device detects one or more wireless local area network (WLAN) access points (APs) and a WLAN-based location estimate is determined for the mobile device using a wireless local area network based positioning system (WLAN-PS). The WLAN-based location estimate is based on the one or more detected WLAN APs and information maintained in a reference database associated with the one or more detected WLAN APs. The mobile device also obtains a plurality of satellite-based positioning system (SPS) measurements. A selection of a set of SPS measurements is made from the plurality of SPS measurements based on consistency of the set of SPS measurements with the WLAN based location estimate. The selected set of SPS measurements is used in determining a final location estimate of the mobile device.

Claims

1. A method comprising:

detecting, by a mobile device, one or more wireless local area network (WLAN) access points (APs);

determining a WLAN-based location estimate for the mobile device using a wireless local area network based positioning system (WLAN-PS), the WLAN-based location estimate based on the one or more detected WLAN APs and information maintained in a reference database associated with the one or more detected WLAN APs;

obtaining, by the mobile device, a plurality of satellite-based positioning system (SPS) measurements;

selecting a set of SPS measurements from the plurality of SPS measurements that are consistent with the WLAN based location estimate based on a distance between the WLAN based location estimate and a location estimate determined from the set of SPS measurements, wherein the set of SPS measurements is considered consistent with the WLAN based location estimate if the distance is less than a threshold; and

using the selected set of SPS measurements in determining a final location estimate of the mobile device.

2. The method of claim 1, wherein the plurality of SPS measurements are raw SPS measurements.

3. The method of claim 1, wherein the threshold is based on an expected error of the WLAN-PS or the SPS.

4. The method of claim 1, wherein the using the selected set of SPS measurements further comprises:

using a location estimate determined from the selected set of SPS measurements as the final location estimate of the mobile device.

5. The method of claim 1, wherein the using the selected set of SPS measurements further comprises:

combining a location estimate determined from the selected set of SPS measurements with information from the WLAN PS to determine the final location estimate of the mobile device.

6. The method of claim 1, wherein the using the selected set of SPS measurements further comprises:

eliminating one or more SPS measurements that are not part of the selected set of SPS measurements from consideration in determining the final location estimate of the mobile device.

7. The method of claim 1, wherein the selected set of SPS measurements are a cluster of SPS measurements that point to a geographical area as a potential location of the mobile device.

8. The method of claim 1, wherein the WLAN APs are WiFi APs.

9. An apparatus comprising:

a processor;

positioning system software configured to be executed on the processor, the software including;

wireless local area network based positioning system (WLAN-PS) software configured to determine a WLAN-based location estimate for a mobile device, the WLAN-based location estimate based on one or more WLAN APs detected by the mobile device and information maintained in a reference database associated with the one or more detected WLAN APs; and

satellite-based positioning system (SPS) software configured to select a set of SPS measurements from a plurality of SPS measurements that are consistent with the WLAN based location estimate based on a distance between the WLAN based location estimate and a location estimate determined from the set of SPS measurements, wherein the set of SPS measurements is considered consistent with the WLAN based location estimate if the distance is less than a threshold,

wherein the selected set of SPS measurements is used by the positioning system software to determine a final location estimate of the mobile device.

10. The apparatus of claim 9, wherein the plurality of SPS measurements are raw SPS measurements.

11. The apparatus of claim 9, wherein the selected set of SPS measurements are a cluster of SPS measurements that point to a geographical area as a potential location of the mobile device.

12. The apparatus of claim 9, wherein one or more SPS measurements that are not part of the selected set of SPS measurements are eliminated from consideration in determining the final location estimate of the mobile device.

13. The apparatus of claim 9, wherein the WLAN APs are WiFi APs.

14. Software encoded in a non-transitory computer readable medium, the software when executed on one or more processors operable to:

determine one or more wireless local area network (WLAN) access points (APs) that are in range of a mobile device;

obtain a plurality of satellite-based positioning system (SPS) measurements;

determine two or more sets of SPS measurements from the plurality of SPS measurements;

select a set of SPS measurements from the plurality of SPS measurements that are consistent with the WLAN based location estimate based on a distance between the WLAN based location estimate and a location estimate determined from the set of SPS measurements, wherein the set of SPS measurements is considered consistent with the WLAN based location estimate if the distance is less than a threshold; and

use SPS measurements of the selected set of SPS measurements in determining a final location estimate of the mobile device, while excluding SPS measurements from use that are only members of a non-selected set of SPS measurements.

15. The software of claim 14, wherein the plurality of SPS measurements are raw SPS measurements.

16. The software of claim 14, wherein the instructions that use the selected set of SPS measurements comprise instructions operable to:

use a location estimate determined from the selected set of SPS measurements as the final location estimate of the mobile device.

17. The software of claim 14, wherein the instructions that use the selected set of SPS measurements comprise instructions operable to:

combine a location estimate determined from the selected set of SPS measurements with information from the WLAN PS to determine the final location estimate of the mobile device.