DETERMINING PHYSICAL LOCATION BASED UPON RECEIVED SIGNALS

• US 20070202887A1
• Filed: 06/30/2006
• Published: 08/30/2007
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Glenner, Steve, Krumm, John, Counts, Scott, Schwartz, Jordan
• Granted Patent: US 7,933,612 B2
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: G01S 5/0244 Accuracy or reliability of position solution or of measurements contributing thereto
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/0295 Proximity-based methods, e.g. position inferred from reception of particular signals
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

The subject disclosure pertains to systems and methods for determining locations of mobile devices. In particular, a set of regions is defined based upon the relative strength of signals received from one or more base stations within the region. Each region has associated location information (e.g., latitude and longitude). The location of a mobile device can be determined by analyzing the strength of received signals, identifying base stations and generating an ordered list of base stations based upon signal strength. The ordered list can be compared to the set of regions to determine the region in which the mobile device is located. The location information for the retrieved region can be used to estimate the location of the mobile device.

Claims

1. A system for determining location of a mobile device, comprising:

a receiver component for the mobile device that receives a signal from at least one base station;

a ranking component generates a ranking of the at least one base station based upon the received signal strength; and

a location component that obtains location information for the mobile device based upon the ranking of the at least one base station.

2. The system of claim 1, the location information includes a confidence indicator that indicates the accuracy of the location information.

3. The system of claim 1, further comprising:

a rank region data store that maintains a plurality of rank regions with associated location information, each of the plurality of rank regions is defined by a base station ranking; and

a search component that obtains a rank region and associated location information from the rank region data store based upon the ranking of the at least one based station.

4. The system of claim 3, further comprising:

an output component that returns the location information associated with the obtained rank region.

5. The system of claim 4, the location information associated with the rank region is represented as a single geographic point.

6. The system of claim 4, the location information associated with the rank region is based at least in part upon an average of a plurality of data points within the rank region.

7. The system of claim 1, further comprising:

a confidence component that generates a confidence indicator for the location information.

8. The system of claim 7, the confidence indicator is based at least in part upon the ranking.

9. A method for determining location of a mobile device, comprising:

obtaining at least one signal from at least one base station;

generating an ordered list of the at least one base station; and

obtaining a location estimate based at least in part upon the ordered list.

10. The method of claim 9, obtaining the location estimate further comprising:

obtaining a region from a collection of regions based at least in part upon the ordered list; and

retrieving the location estimate associated with the region.

11. The method of claim 10, the location estimate is a single geographic point.

12. The method of claim 10, further comprising:

generating the collection of regions based at least in part upon a plurality of input data points for a geographic area.

13. The method of claim 12, generating the collection of regions further comprises:

grouping the plurality of input data points into regions based upon received signal strengths for the input data points; and

generating a summary representation for each region in the collection of regions.

14. The method of claim 13, generating the summary representation includes averaging the input data points.

15. The method of claim 9, further comprising generating a confidence level for the location estimate.

16. A system for determining location of a mobile device, comprising:

means for receiving at least one signal from at least one base station;

means for generating an ordered list of the at least one base station based at least in part upon signal strength; and

means for obtaining location information for the mobile device based at least in part upon the ordered list.

17. The system of claim 16, further comprising:

means for searching a set of rank regions based at least in part upon the ordered list to obtain a rank region that includes the location information.

18. The system of claim 17, further comprising:

means for obtaining a confidence indicator associated with the search of the set of rank regions.

19. The system of claim 18, the confidence indicator is based at least in part upon number of base stations in the ordered list.

20. The system of claim 16, the location information is obtained based upon a subset of the ordered list.