Location tracking

• US 8,965,403 B2
• Filed: 08/14/2013
• Issued: 02/24/2015
• Est. Priority Date: 04/14/2011
• Status: Active Grant

• Current Assignee: HERE Global B.V. (Nokia Corporation)
• Original Assignee: HERE Global B.V. (Nokia Corporation)
• Inventors: Rieger, Charles J. III
• Primary Examiner(s): PHUONG, DAI
• Application Number:
  US13/966,661
• Publication Number:
  US 20130331124A1
• Time in Patent Office: 559 Days
• Field of Search: 455/404.1, 455/404.2, 455/432.1, 455/434, 455/436, 455/440, 4554561-4563, 455/457
• US Class Current: 455/456.1
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 4/025 using location based information parameters

Abstract

One or more systems, devices, and/or methods for tracking a wireless device are disclosed. For example, a method includes receiving signal strength data for each of a plurality of access points. The signal strength data from the plurality of access points is compared to identify an anchor access point having a highest signal strength. Remaining signal strength data from the plurality of access points are compared to a threshold signal strength to identify at least one attractor access point. A memory is accessed for locations of the anchor access point and the at least one attractor access point. A pull point is calculated along a line from the anchor access point to the at least one attractor access point. A location of the wireless device is estimated as an average of the pull point and the location of the anchor access point.

Claims

1. A method comprising:

receiving signal strength data for a plurality of communication beacons;

comparing the signal strength data to identify an anchor having a highest signal strength of the plurality of communication beacons;

receiving data indicative of a location of the anchor;

comparing the signal strength data of the plurality of communication beacons to a threshold signal strength; and

when none of the signal strength data of the plurality of communication beacons except the anchor is greater than the threshold signal strength, estimate a location of a wireless device as the location of the anchor,

wherein the plurality of communication beacons are indoor communication beacons.

2. The method of claim 1, further comprising:

calculating the threshold signal strength as a function of the highest signal strength belonging to the anchor.

3. The method of claim 2, wherein the threshold signal strength is a predetermined power value less than the highest signal strength belonging to the anchor.

4. The method of claim 1, wherein the location of the wireless device is estimated without any calibration phase or pre-recorded signal strength information.

5. The method of claim 1, wherein the communication beacons are access points connected to a network.

6. The method of claim 1, wherein the signal strength data is collected by at least one radio frequency identification tag or at least one wi-fi tag.

7. The method of claim 1, further comprising:

identifying at least one communication beacon besides the anchor with signal strength data greater than the threshold signal strength as at least one attractor communication beacon;

receiving data indicative of a location of the at least one attractor communication beacon; and

estimating the location of the wireless device based on the location of the at least one attractor communication beacon and the location of the anchor.

20. The method of claim 1 wherein the highest signal strength is different than the threshold signal strength.

8. A method comprising:

receiving signal strength data for a plurality of communication beacons;

comparing the signal strength data to identify an anchor having a highest signal strength of the plurality of communication beacons;

receiving data indicative of a location of the anchor;

comparing the signal strength data of the plurality of communication beacons to a threshold signal strength;

when none of the signal strength data of the plurality of communication beacons except the anchor is greater than the threshold signal strength, estimate a location of a wireless device as the location of the anchor;

designating at least one of the plurality of communication beacons, except the anchor, having signal strength data greater than the threshold signal strength as an attractor;

calculating location data for a pull point along a line from the anchor to the attractor; and

estimating a location of the wireless device as an average of the location data of the pull point and the location data of the anchor.

9. A method comprising:

receiving signal strengths for a plurality of access points;

identifying an anchor access point having a highest signal strength of the plurality of access points;

identifying an attractor access point from the plurality of access points;

calculating a pull point along a line from the anchor access point to the attractor access point, wherein the pull point is calculated using a pull factor is calculated based on a ratio of a signal strength of the anchor access point and a signal strength of the attractor access point or calculated based on a difference between the signal strength of the anchor access point and the signal strength of the attractor access point; and

calculating a location of a wireless device as based on the pull point and a location of the anchor access point.

10. The method of claim 9, wherein identifying the attractor access point from the plurality of access points comprises:

comparing the signal strengths for the plurality of access points to a threshold value.

11. The method of claim 10, further comprising:

calculating the threshold value as a function of the highest signal strength of the anchor access point.

12. The method of claim 9, wherein the pull point is calculated as a function of an inverse of the signal strength of the attractor access point.

13. The method of claim 9, wherein the pull point is a first pull point, the method further comprising:

identifying a second attractor access point from the plurality of access points; and

calculating a second pull point along a line from the anchor access point to the second attractor access point, wherein the second pull point is calculated using a second pull factor.

14. The method of claim 13, wherein the location of the wireless device is calculated based on the first pull point, the second pull point, and the location of the anchor access point.

15. An apparatus comprising:

at least one processor; and

at least one memory including computer program code for one or more programs,

the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following,

receive signal strengths for a plurality of access points;

compare the signal strengths to a threshold;

identify an anchor access point having a highest signal strength of the plurality of access points; and

calculate a location of a wireless device based on a location of the anchor access point when no other signal strengths exceed the threshold and based on an average of the location of the anchor access point and at least one additional access point when the at least one additional access point has signal strengths that exceed the threshold.

16. The apparatus of claim 15, the computer program code further configured to:

calculate one or more pull points along one or more lines from the anchor access point to the at least one additional access point.

17. The apparatus of claim 16, wherein the one or more pull points are calculated based on a ratio between the signal strength of the at least one additional access point and the signal strength the anchor access point.

18. The apparatus of claim 16, wherein the location of the wireless device is calculated based on an average of the one or more pull points.

19. The apparatus of claim 15, wherein the threshold is calculated as a function of the highest signal strength of the anchor access point.