Methods and systems for estimating a user position in a WLAN positioning system based on user assigned access point locations

• US 7,471,954 B2
• Filed: 02/23/2007
• Issued: 12/30/2008
• Est. Priority Date: 02/24/2006
• Status: Active Grant

• Current Assignee: Skyhook Wireless Incorporated (Liberty Broadband Corp.)
• Original Assignee: Skyhook Wireless Incorporated (Liberty Broadband Corp.)
• Inventors: Alizadeh-Shabdiz, Farshid, Brachet, Nicolas
• Primary Examiner(s): Le; Danh C
• Application Number:
  US11/678,301
• Publication Number:
  US 20070202888A1
• Time in Patent Office: 676 Days
• Field of Search: 455/456.5, 455/456.6, 455/457, 342/450, 707/100
• US Class Current: 455/456.5
• CPC Class Codes: G01S 2205/09 for tracking people
• 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 5/0295 Proximity-based methods, e.g. position inferred from reception of particular signals
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method of estimating a location of a WLAN-enabled user-device in a WLAN-based positioning system is provided. The WLAN-enabled device receives signals transmitted by WLAN-enabled access points in range of the WLAN-enabled user-device so that observed WLAN-enabled access points identify themselves. The method includes accessing a master database that associates WLAN-enabled access points with corresponding audited locations as determined by an audit of a relatively large geographic area and obtaining location information for any identified WLAN-enabled access point. The method includes accessing a supplemental database to obtain inferred location information corresponding to any identified WLAN-enabled access point. The supplemental database has a relatively small set of WLAN-enabled access points and corresponding inferred locations. The inferred locations are inferred based on input by a user of the WLAN-based positioning system. The method includes estimating a location of the WLAN-enabled user-device based on the audited location information and the inferred location information.

Claims

1. A method of estimating a geographic location of a WLAN-enabled user-device in a WLAN-based positioning system having a plurality of WLAN-enabled access points, the method comprising:

the WLAN-enabled device receiving signals transmitted by WLAN-enabled access points in range of the WLAN-enabled user-device so that observed WLAN-enabled access points identify themselves;

accessing a master database that associates WLAN-enabled access points with corresponding geographic locations for the WLAN-enabled access points as determined by an audit of a relatively large geographic area and obtaining geographic location information for any identified WLAN-enabled access point in range of the WLAN-enabled user-device;

accessing a supplemental database to obtain inferred geographic location information corresponding to any identified WLAN-enabled access point in range of the WLAN-enabled user-device, the supplemental database having a relatively small set of WLAN-enabled access points and corresponding inferred geographic locations, the inferred geographic locations being inferred based on input by a user of the WLAN-based positioning system; and

estimating a geographic location of the WLAN-enabled user-device based on the geographic location information obtained from the master database and the inferred geographic location information obtained from the supplemental database.

2. The method of claim 1, wherein the supplemental database includes a subset of WLAN-enabled access points of the master database and corresponding inferred geographic locations based on inferring the geographic locations of the WLAN-enabled access points of the subset are incorrect in the master database.

3. The method of claim 1, wherein the supplemental database includes WLAN-enabled access points that were not discovered by the audit of the relatively large geographic area.

4. The method of claim 1, wherein at least one geographic location from the master database and at least one inferred geographic location are for the same WLAN-enabled access point and wherein the inferred geographic location is used in place of the geographic location from the master database when estimating the geographic location of the WLAN-enabled user-device.

5. The method of claim 1, wherein the inferred geographic location information used to estimate the geographic location of the WLAN-enabled user-device is inferred based on input by a single selected user of the WLAN-based positioning system.

6. The method of claim 1, wherein at least one of the master database and the supplemental database resides on the WLAN-enabled user-device.

7. The method of claim 1, wherein at least one of the master database and the supplemental database resides on a server remote from the WLAN-enabled user-device.

8. The method of claim 1, wherein the inferred geographic location is supplied by a user of the WLAN-based positioning system.

9. The method of claim 8, wherein the inferred geographic location is a current location of the WLAN-enabled user-device.

10. The method of claim 8, wherein a WLAN-enabled access point and its inferred geographic location are included in the supplemental database if the difference between the user-supplied geographic location and the geographic location in the master database associated with the WLAN-enabled access point is greater than a threshold distance.

11. The method of claim 10, wherein the threshold distance is based on the average signal propagation distance of more than one WLAN-enabled access points of the WLAN-based positioning system.

12. The method of claim 11, wherein the threshold distance is about 300 meters.

13. The method of claim 1, wherein the input by the user of the WLAN-based positioning system is a street address.

14. The method of claim 1, wherein the input by the user of the WLAN-based positioning system is a latitude and longitude.

15. The method of claim 1, wherein the inferred geographic location is based on input by more than one user of the WLAN-based positioning system.

16. The method of claim 1, further comprising estimating a street address corresponding to the estimated geographic location of the WLAN-enabled user-device.

17. The method of claim 16, wherein estimating the street address is based on a user-supplied street address having a distance from the estimated geographic location of the WLAN-enabled user-device that is less than a threshold distance.

18. The method of claim 17, wherein the threshold distance is about 30 meters.

19. A system for estimating a geographic location of a WLAN-enabled user-device in a WLAN-based positioning system having a plurality of WLAN-enabled access points, the system comprising:

a WLAN-enabled device for receiving signals transmitted by WLAN-enabled access points in range of the WLAN-enabled user-device so that observed WLAN-enabled access points identify themselves;

a first logic for accessing a master database that associates WLAN-enabled access points with corresponding geographic locations for the WLAN-enabled access points as determined by an audit of a relatively large geographic area and obtaining geographic location information for any identified WLAN-enabled access point in range of the WLAN-enabled user-device;

a second logic for accessing a supplemental database to obtain inferred geographic location information corresponding to any identified WLAN-enabled access point in range of the WLAN-enabled user-device, the supplemental database having a relatively small set of WLAN-enabled access points and corresponding inferred geographic locations, the inferred geographic locations being inferred based on input by a user of the WLAN-based positioning system; and

a third logic for estimating a geographic location of the WLAN-enabled user-device based on the geographic location information obtained from the master database and the inferred geographic location information obtained from the supplemental database.

20. The system of claim 19, wherein the supplemental database includes a subset of WLAN-enabled access points of the master database and corresponding inferred geographic locations based on inferring the geographic locations of the WLAN-enabled access points of the subset are incorrect in the master database.

21. The system of claim 19, wherein the supplemental database includes WLAN-enabled access points that were not discovered by the audit of the relatively large geographic area.

22. The system of claim 19, wherein at least one geographic location from the master database and at least one inferred geographic location are for the same WLAN-enabled access point and wherein the inferred geographic location is used in place of the geographic location from the master database when estimating the geographic location of the WLAN-enabled user-device.

23. The system of claim 19, wherein the inferred geographic location information used to estimate the geographic location of the WLAN-enabled user-device is inferred based on input by a single selected user of the WLAN-based positioning system.

24. The system of claim 19, wherein at least one of the master database and the supplemental database resides on the WLAN-enabled user-device.

25. The system of claim 19, wherein at least one of the master database and the supplemental database resides on a server remote from the WLAN-enabled user-device.

26. The system of claim 19, wherein the inferred geographic location is supplied by a user of the WLAN-based positioning system.

27. The system of claim 26, wherein the inferred geographic location is a current location of the WLAN-enabled user-device.

28. The system of claim 26, wherein a WLAN-enabled access point and its inferred geographic location are included in the supplemental database if the difference between the user-supplied geographic location and the geographic location in the master database associated with the WLAN-enabled access point is greater than a threshold distance.

29. The system of claim 28, wherein the threshold distance is based on the average signal propagation distance of more than one WLAN-enabled access points of the WLAN-based positioning system.

30. The system of claim 29, wherein the threshold distance is about 300 meters.

31. The system of claim 19, wherein the input by the user of the WLAN-based positioning system is a street address.

32. The system of claim 19, wherein the input by the user of the WLAN-based positioning system is a latitude and longitude.

33. The system of claim 19, wherein the inferred geographic location is based on input by more than one user of the WLAN-based positioning system.

34. The system of claim 19, further comprising a fourth logic for estimating a street address corresponding to the estimated geographic location of the WLAN-enabled user-device.

35. The system of claim 34, wherein estimating the street address is based on a user-supplied street address having a distance from the estimated geographic location of the WLAN-enabled user-device that is less than a threshold distance.

36. The system of claim 35, wherein the threshold distance is about 30 meters.