ESTIMATING NETWORK BASED LOCATING ERROR IN WIRELESS NETWORKS

• US 20130021199A1
• Filed: 07/21/2011
• Published: 01/24/2013
• Est. Priority Date: 07/21/2011
• Status: Active Grant

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Fix, Jeremy, Kosseifi, Mario, Meredith, Sheldon
• Granted Patent: US 9,519,043 B2
• Time in Patent Office: Days
• US Class Current: 342/357.43
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence

Abstract

Systems and techniques for determining the accuracy of network based user equipment (UE) locating methods and results thereof are disclosed. Periodic direct measurements of location error for a network based location result are determined by the difference in the network based location result and an assisted global positioning system (AGPS) location result. The location error is associated with a cell-pair contributing to data employed to determine the network based location result. The error associated with the cell-pair is then applied as a measure of accuracy in future network based location results that also employ data associated with the cell-pair to determine the future network based location result.

Claims

1. A method comprising:

receiving approximate location data based on a transmission time of a wireless signal associated with a mobile device;

determining an approximate location of the mobile device based on the approximate location data;

in response to an assisted global positioning system request, receiving at a substantially same time as the receiving the approximate location data, precise location data for the mobile device representing a precise location of the mobile device closer to an actual location than the approximate location;

determining the precise location of the mobile device based on the precise location data; and

calculating an error rate associated with the approximate location including comparing the approximate location and the precise location.

2. The method of claim 1, further comprising:

associating the error rate with a plurality of cell-pairs contributing to the receiving the approximate location data, wherein the receiving the approximate location data includes receiving observed time difference measurements associated with the plurality of cell-pairs.

3. The method of claim 2, further comprising:

receiving new approximate location data based on a transmission time of a new wireless signal associated with the mobile device, including receiving observed time difference measurements associated with a cell-pair included in the plurality of cell-pairs;

determining a new approximate location of the mobile device based on the new approximate location data; and

attributing the error rate to the new approximate location.

4. The method of claim 2, further comprising:

receiving new approximate location data related to a timing of a wireless signal associated with an other mobile device, including receiving observed time difference measurements associated with a cell-pair included in the plurality of cell-pairs;

determining an approximate location of the other mobile device based on the new approximate location data; and

attributing the error rate to the new approximate location.

5. The method of claim 1, wherein the determining the approximate location of the mobile device includes employing timed fingerprinting.

6. The method of claim 1, wherein the receiving the approximate location data includes receiving a radio resource control report.

7. The method of claim 1, wherein the receiving the precise location data includes receiving a radio access network application part report.

8. A method comprising:

receiving approximate location data representative of respective approximate locations of mobile devices based on transmission times of wireless signals associated with the mobile devices;

in response to assisted global positioning system requests, receiving at a substantially same time as the receiving the approximate location data, precise location data for the respective mobile devices representing precise locations of the mobile devices closer to actual locations than the approximate locations; and

calculating error rates associated with the respective approximate locations including comparing the approximate locations and the precise locations for respective ones of the mobile devices.

9. The method of claim 8, further comprising:

associating the error rates with respective ones of cell-pairs contributing to the receiving the approximate location data representative of the respective approximate locations of the mobile devices, wherein the receiving the approximate location data includes receiving observed time difference measurements associated with the cell-pairs.

10. The method of claim 9, further comprising:

determining median error rates for the respective ones of cell-pairs based on the total error rates associated with the respective ones of cell-pairs.

11. The method of claim 10, further comprising:

determining error rates associated with the respective ones of cell-pairs that constitute outliers based on the median error rates of the respective ones of cell-pairs; and

disassociating the error rates that constitute the outliers from the respective ones of cell-pairs.

12. The method of claim 10, further comprising:

receiving new approximate location data representative of a new approximate location of a mobile device included in the mobile devices, including receiving observed time difference measurements between at least two cell-pairs having median error rates associated therewith;

determining a mean error rate based on an average of the median error rates; and

attributing the mean error rate to the new approximate location.

13. The method of claim 10, further comprising:

receiving new approximate location data representative of a new approximate location of a new mobile device, including receiving observed time difference measurements between at least two cell-pairs having median error rates associated therewith;

determining a mean error rate based on an average of the median error rates; and

attributing the mean error rate to the new approximate location.

14. The method of claim 8, wherein the determining the approximate locations of the mobile devices includes employing timed fingerprinting.

15. The method of claim 8, wherein the receiving the approximate location data includes receiving a radio resource control report.

16. The method of claim 8, wherein the receiving the precise location data includes receiving a radio access network application part report.

17. A system comprising:

an approximate location component configured to receive approximate location data representative of respective approximate locations of mobile devices based on transmission times of wireless signals associated with the mobile devices;

a precise location component configured to receive in response to assisted global positioning system requests, precise location data for the mobile devices representing respective precise locations of the mobile devices closer to actual locations than the approximate locations; and

an error component configured to compare the approximate locations and the precise locations for respective ones of mobile devices when the approximate location data and the precise location data for the respective ones of mobile devices is received at substantially the same time, and calculate error rates associated with the respective approximate locations.

18. The system of claim 17, further comprising:

an association component configured to associate the error rates with respective ones of cell-pairs contributing to the approximate location data received at substantially the same time as the precise location data for the respective ones of mobile devices.

19. The system of claim 18, wherein the error component is further configured to determine median error rates for the respective ones of cell-pairs based on the total error rates associated with the respective ones of cell-pairs.

20. The system of claim 19, wherein:

the approximate location component is further configure to receive new approximate location data representative of a new approximate location of a mobile device, wherein the new approximate location data includes observed time difference measurements between at least two cell-pairs having median error rates associated therewith; and

wherein the error component is further configured to;

determine a mean error rate based on an average of the median error rates and attribute the mean error rate to the new approximate location.