Methods and apparatus for mobile station location estimation

• US 8,676,231 B2
• Filed: 11/30/2012
• Issued: 03/18/2014
• Est. Priority Date: 04/03/2001
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Agosta, Steve D
• Application Number:
  US13/691,031
• Publication Number:
  US 20130095852A1
• Time in Patent Office: 473 Days
• Field of Search: 455/404.2, 4554561-457, 455/550.1, 370/310.2, 370/328
• 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, in connection with a sliding time window, instantaneous location coordinates associated with the mobile communication device;

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

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

comparing the instantaneous location coordinates and the average coordinates;

identifying largest deviation coordinates as peak error values;

comparing the peak error values and pre-defined thresholds;

determining, if the peak error values are within the pre-defined thresholds, that the error values as acceptable;

determining, if the peak error values are not within the pre-defined thresholds, that the error values as not acceptable;

updating, by the system, in response to determining that the error values are acceptable, recent reliable coordinates using the instantaneous location coordinates; 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, 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.

3. 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.

4. 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, in connection with a sliding time window, associated with the mobile communication device;

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

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

comparing the instantaneous location coordinates and the average coordinates;

identifying largest deviation coordinates as peak error values;

comparing the peak error values and pre-defined thresholds;

determining, if the peak error values are within the pre-defined thresholds, that the error values as acceptable;

determining, if the peak error values are not within the pre-defined thresholds, that the error values as not acceptable;

updating, in response to determining that the error values are acceptable, recent reliable coordinates using the instantaneous location coordinates;

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.

5. The location system of claim 4, 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.

6. The location system of claim 4, wherein a size of the sliding time window corresponds to a desired level of accuracy for determining the location of the mobile communication device.

7. 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, in connection with a sliding time window, associated with the mobile communication device;

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

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

comparing the instantaneous location coordinates and the average coordinates;

identifying largest deviation coordinates as peak error values;

comparing the peak error values and pre-defined thresholds;

determining, if the peak error values are within the pre-defined thresholds, that the error values as acceptable;

determining, if the peak error values are not within the pre-defined thresholds, that the error values as not acceptable;

updating, in response to determining that the error values are acceptable, recent reliable coordinates using the instantaneous location coordinates;

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.

8. The tangible computer-readable storage device of claim 7, 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.