Methods and Apparatus for Mobile Station Location Estimation

• US 20130095852A1
• Filed: 11/30/2012
• Published: 04/18/2013
• Est. Priority Date: 04/03/2001
• Status: Active Grant

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: MacDonald, Alan Denis, Sather, Marc W., Snapp, John Lawrence
• Granted Patent: US 8,676,231 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/0252 Radio frequency fingerprinting
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04W 4/026 using orientation information, e.g. compass
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/003 locating network equipment
• CPC Class Codes: H04W 88/14 Backbone network devices

Abstract

Methods and apparatus for estimating mobile station location include receiving reported signal strengths or other attachment indicator values from a mobile station. The reported signal strengths are compared with characteristic received signal strength values in a coverage area of a mobile network. A mobile switching center determines if a local function is requested and initiates a location estimation process by a mobile location module (MLM). The MLM receives the reported signal strength contours associated with the attachment points. Based on a comparison of the reported attachment indicator values with characteristic values, the MLM provides a mobile location estimate.

Claims

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

obtaining, by a system having a processor, instantaneous location coordinates, associated with the mobile communication device, corresponding to a sliding time window;

calculating, by the system, average coordinates based upon the instantaneous location coordinates corresponding to the sliding time window;

calculating, by the system, error values indicating deviations between the instantaneous location coordinates and the average coordinates;

determining, by the system, whether the error values are acceptable based upon a comparison of the error values to pre-defined threshold values; and

determining, by the system, in response to determining that the error values are acceptable, the location of the mobile communication device based at least in part on the instantaneous location coordinates.

2. The method of claim 1, further comprising determining, by the system, peak error values.

3. The method of claim 2, wherein determining the peak error values comprises:

comparing the instantaneous location coordinates for the sliding time window and the average coordinates corresponding to the sliding time window; and

determining largest deviation coordinates as the peak error values.

4. The method of claim 3, wherein determining whether the error values are acceptable further comprises:

comparing the peak error values and the pre-defined threshold values;

determining the error values as acceptable if the peak error values are within the pre-defined threshold values; and

determining the error values as not acceptable if the peak error values are not within the pre-defined threshold values.

5. The method of claim 4, further comprising updating, by the system, in response to determining that the error value are acceptable, recent reliable coordinates using the instantaneous location coordinates.

6. The method of claim 4, further comprising determining, by the system, in response to determining that the error values are not acceptable, the location of the mobile communication device using the recent reliable coordinates associated with the mobile communication device.

7. The method of claim 1, wherein a size of the sliding time window corresponds to a desired level of accuracy for determining the location of the mobile communication device.

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

a processor; and

a tangible computer-readable storage device having computer-executable instructions that, when executed by the processor, cause the processor to perform operations comprising;

obtaining instantaneous location coordinates, associated with the mobile communication device, corresponding to a sliding time window;

calculating average coordinates based upon the instantaneous location coordinates for the sliding time window;

calculating error values indicating deviations between the instantaneous location coordinates and the average coordinates;

determining whether the error values are acceptable based upon a comparison of the error values and pre-defined threshold values; and

determining, in response to determining that the error values are acceptable, the location of the mobile communication device based at least in part on the instantaneous location coordinates.

9. The location system of claim 8, wherein the operations further comprise determining, by the system, peak error values.

10. The location system of claim 9, wherein the operation of determining the set of peak error values comprises:

comparing the instantaneous location coordinates for the sliding time window and the average coordinates for the sliding time window; and

determining largest deviation coordinates as the peak error values.

11. The location system of claim 10, wherein the operation of determining whether the error values are acceptable further comprises:

comparing the peak error values and the pre-defined threshold values;

determining the error values as acceptable if the peak error values are within the pre-defined threshold values; and

determining the error values as not acceptable if the peak error values are not within the pre-defined threshold values.

12. The location system of claim 11, wherein the operations further comprises updating, by the system in response to determining that the error value are acceptable, recent reliable coordinates using the instantaneous location coordinates.

13. The location system of claim 11, wherein the operations further comprise determining, by the system, in response to determining that the error values are not acceptable, the location of the mobile communication device using the recent reliable coordinates associated with the mobile communication device.

14. The location system of claim 8, wherein a size of the sliding time window corresponds to a desired level of accuracy for determining the location of the mobile communication device.

15. A tangible computer-readable storage device comprising instructions that, when executed by a processor, cause the processor to perform operations, for determining a location of a mobile communication device, comprising:

obtaining instantaneous location coordinates, associated with the mobile communication device, for a sliding time window;

calculating average coordinates based upon the instantaneous location coordinates for a sliding time window corresponding to the sliding time window;

calculating error values indicating deviations between the instantaneous location coordinates and the average coordinates;

determining whether the error values are acceptable based upon a comparison of the error values and pre-defined threshold values; and

determining, in response to determining that the error values are acceptable, the location of the mobile communication device based at least in part on the instantaneous location coordinates.

16. The tangible computer-readable storage device of claim 15, wherein the operations further comprise determining peak error values.

17. The tangible computer-readable storage device of claim 16, wherein the operation of determining the peak error values comprises:

comparing the instantaneous location coordinates for the sliding time window and the average coordinates for the sliding time window; and

determining largest deviation coordinates as the peak error values.

18. The tangible computer-readable storage device of claim 17, wherein the operation of determining whether the error values are acceptable further comprises:

comparing the peak error values and the pre-defined threshold values;

determining the error values as acceptable if the peak error values are within the pre-defined threshold values; and

determining the error values as not acceptable if the peak error values are not within the pre-defined threshold values.

19. The tangible computer-readable storage device of claim 18, wherein the operations further comprise updating, in response to determining that the error value are acceptable, recent reliable coordinates using the instantaneous location coordinates.

20. The tangible computer-readable storage device of claim 18, wherein the operations further comprise determining in response to determining that the error values are not acceptable, the location of the mobile communication device using the recent reliable coordinates associated with the mobile communication device.