Estimating the location of a wireless terminal based on non-uniform locations

• US 7,753,278 B2
• Filed: 05/22/2006
• Issued: 07/13/2010
• Est. Priority Date: 05/22/2006
• Status: Active Grant

• Current Assignee: Polaris Wireless Incorporated
• Original Assignee: Polaris Wireless Incorporated
• Inventors: Spain, David Stevenson Jr., Feuerstein, Martin, Dressler, Robert Morris
• Primary Examiner(s): Frech; Karl D.
• Application Number:
  US11/419,649
• Publication Number:
  US 20060240843A1
• Time in Patent Office: 1,513 Days
• Field of Search: 455/456.1, 455/404.1, 455/404, 235/472.01, 235/472.02, 235/472.03
• US Class Current: 235/472.01
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A technique for estimating the location of a wireless terminal at an unknown location in a geographic region is disclosed. The technique is based on the recognition that there are traits of electromagnetic signals that are dependent on topography, the receiver, the location of the transmitter, and other factors. For example, if a particular radio station is known to be received strongly at a first location and weakly at a second location, and a given wireless terminal at an unknown location is receiving the radio station weakly, it is more likely that the wireless terminal is at the second location than at the first location.

Claims

1. A method comprising estimating the location of a wireless terminal in an environment based on comparing a measurement of a trait of a signal processed by said wireless terminal to an expected value of said trait for one or more of a plurality of locations;

wherein the boundaries of one or more of said plurality of locations are based, at least in part, on empirical data regarding the location of individuals in said environment.

2. The method of claim 1 further comprising generating an adjacency graph of said locations.

3. The method of claim 1 wherein said plurality of locations represent an overpass and an underpass.

4. The method of claim 1 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on legal laws governing the environment.

5. The method of claim 1 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on the calendrical time T.

6. The method of claim 1 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on the environmental conditions N.

7. A method comprising:

modeling an environment as a plurality of locations, wherein the boundaries of one or more of said plurality of locations are based, at least in part, on the calendrical time T; and

estimating the location of a wireless terminal in said environment based on comparing a measurement of a trait of a signal processed by said wireless terminal to an expected value of said trait for one or more of a plurality of locations.

8. The method of claim 7 further comprising generating an adjacency graph of said locations.

9. The method of claim 7 wherein said plurality of locations represent an overpass and an underpass.

10. The method of claim 7 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on legal laws governing the environment.

11. The method of claim 7 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on empirical data regarding the location of individuals in said environment.

12. The method of claim 7 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on the environmental conditions N.

13. A method comprising estimating the location of a wireless terminal in an environment based on comparing a measurement of a trait of a signal processed by said wireless terminal to an expected value of said trait for one or more of a plurality of locations;

wherein the boundaries of one or more of said plurality of locations are based, at least in part, on theoretical predictions regarding the movement of individuals.

14. The method of claim 13 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on legal laws governing the environment.

15. The method of claim 13 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on the calendrical time T.

16. The method of claim 13 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on the environmental conditions N.

17. A method comprising:

modeling an environment as a plurality of locations, wherein the boundaries of one or more of said plurality of locations are based, at least in part, on the environmental conditions N; and

estimating the location of a wireless terminal in said environment based on comparing a measurement of a trait of a signal processed by said wireless terminal to an expected value of said trait for one or more of a plurality of locations.

18. The method of claim 17 further comprising generating an adjacency graph of said locations.

19. The method of claim 17 wherein said plurality of locations represent an overpass and an underpass.

20. The method of claim 17 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on legal laws governing the environment.

21. The method of claim 17 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on empirical data regarding the location of individuals in said environment.

22. The method of claim 17 wherein the boundaries of one or more of said plurality of locations are based, at least in part, on the calendrical time T.