Aggregating location accuracy data to estimate accuracy of a wireless locating system

• US 20070093257A1
• Filed: 10/21/2005
• Published: 04/26/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Intrado Life & Safety Incorporated
• Original Assignee: Pivotpoint Solutions, LLC
• Inventors: McDougall, Jeff, Durrant, Jeff
• Granted Patent: US 7,634,266 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/06 Testing, supervising or monitoring using simulated traffic
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Location determination accuracy in a mobile telecommunications environment can be estimated based on location determination accuracy data for multiple empirical test calls in a geographic region. A location of a wireless station for each test call is determined using one of multiple wireless locating techniques, and an approximate ratio of wireless locating techniques for the empirical test calls is identified. Subscriber call data relating to location estimates determined using one of the wireless locating techniques is received. Location determination accuracy in the geographic region is estimated by combining the subscriber call data according to the identified ratio. To facilitate determinations of locating accuracy, the geographic region is logically segmented into multiple areas. Each area is associated with a performance profile that relates to a locating accuracy performance. Location determination accuracy is estimated based on one or more areas associated with each wireless call in the geographic region.

Claims

1. A method for ascertaining location determination accuracy in a mobile telecommunications environment, the method comprising:

obtaining location determination accuracy data for a plurality of empirical test calls in a geographic region, a location of a wireless station for each test call determined using at least one of a plurality of wireless locating techniques;

identifying at least an approximate ratio of wireless locating techniques for the empirical test calls;

receiving data relating to subscriber calls in the geographic region, the data including information relating to location estimates determined using at least one of the wireless locating techniques; and

estimating location determination accuracy in the geographic region by combining at least portions of the data relating to subscriber calls according to the identified ratio.

2. The method of claim 1 wherein:

the identified ratio of wireless locating techniques for the empirical test calls is determined based on at least an approximate percentage of the empirical test calls that use each wireless locating technique; and

combining at least portions of the data relating to subscriber calls according to the identified ratio comprises weighting data relating to subscriber calls that use each wireless locating technique using a corresponding percentage.

3. The method of claim 1 wherein the data relating to subscriber calls includes an estimated position error and an identification of a wireless locating technique for each subscriber call.

4. The method of claim 3 wherein the data relating to subscriber calls further includes information relating to at least one network operation, the method further comprising identifying subscriber call candidates for use in estimating location determination accuracy based on the information relating to at least one network operation.

5. The method of claim 3 wherein the location determination accuracy data for each empirical test call comprises a difference between an actual location associated with the test call and an estimated position determined using a wireless locating technique for the test call, the method further comprising:

determining an error bias between the difference and an estimated position error for each test call;

adjusting the estimated position error for the subscriber calls according to the error bias to estimate location determination accuracy.

6. The method of claim 1 further comprising:

segmenting the geographic region into a plurality of areas, each area associated with one of a plurality of location-estimating performance types;

identifying at least an approximate ratio among the location-estimating performance types; and

weighting at least one of the location determination accuracy data for the empirical test calls or portions of the data relating to the subscriber calls according to the identified performance type ratio to estimate location determination accuracy, wherein weighting is based on at least one performance type associated with each empirical test call or subscriber call.

7. The method of claim 6 further comprising identifying the at least one performance type associated with each empirical test call or subscriber call based on the performance type of the areas within an error range of an estimated position.

8. An article comprising a machine-readable medium storing instructions for causing data processing apparatus to:

receive empirical location determination accuracy data for a wireless telecommunication network, the empirical location determination accuracy data determined based on test calls involving wireless stations at known locations;

receive estimated position error data for subscriber calls in the wireless telecommunication network; and

normalize the estimated position error data for the subscriber calls according to characteristics of the test calls to determine estimated location determination accuracy data.

9. The article of claim 8 wherein the estimated position error data is normalized based on a ratio of different wireless locating techniques used for the test calls.

10. The article of claim 9 wherein the machine-readable medium stores instructions for further causing data processing apparatus to identify candidate subscriber calls for use in determining the estimated location determination accuracy data.

11. The article of claim 8 wherein the estimated position error data is normalized based on a ratio of different location-estimating performance types associated with the test calls.

12. The article of claim 11 wherein:

the wireless telecommunications network serves a region that is segmented into a plurality of areas, each area having an assigned performance type and the performance types associated with the test calls based on the area including the known location for each test call; and

a performance type is associated with each subscriber call based on an estimated location for a wireless station involved in the subscriber call.

13. A method for facilitating determinations of locating accuracy in a mobile telecommunications environment, the method comprising:

identifying a geographic region;

logically segmenting the geographic region into a plurality of areas, each area associated with one of a plurality of performance profiles relating to a locating accuracy performance; and

estimating location determination accuracy based on at least one area associated with each of a plurality of wireless calls in the geographic region.

14. The method of claim 13 wherein estimating location determination accuracy comprises normalizing location error data from the plurality of wireless calls according to at least an approximate percentage of the geographic region associated with each performance profile.

15. The method of claim 14 wherein normalizing location error data comprises:

determining the approximate percentage of the geographic region associated with each performance profile;

determining one or more performance profiles associated with each wireless call, the one or more performance profiles corresponding to the at least one area associated with the wireless call; and

weighting location error data for wireless calls associated with each performance profile according to the approximate percentage.

16. The method of claim 15 wherein the wireless calls comprise test calls involving wireless stations at known locations and the location error data comprises empirical location error data.

17. The method of claim 15 wherein the wireless calls comprise subscriber calls and the location error data comprises estimated location error data based on uncertainty observations associated with each subscriber call.

18. The method of claim 15 further comprising:

determining the at least one area associated with each wireless call using the location error data;

identifying at least an approximate percentage of each area associated with each wireless call; and

weighting location error data for each wireless call according to the identified percentages.

19. The method of claim 15 wherein a quantity of different performance profiles is fewer than a quantity of different areas.

20. The method of claim 15 wherein each performance profile corresponds to one of a plurality of land use categories.

21. The method of claim 15 wherein the geographic region is logically segmented into a plurality of grid-based areas.

22. An article comprising a machine-readable medium storing instructions for causing data processing apparatus to:

receive wireless station location data for calls in a telecommunication network;

determine an area including a location identified by the location data for each call, the area having an associated location-estimating performance type and the area comprising one of a plurality of areas in a geographic region;

associate each call with the location-estimating performance type for the corresponding area; and

normalize data for calls associated with each location-estimating performance type according to at least an approximate percentage of the geographic region associated with each location-estimating performance type to estimate a location determination accuracy.

23. The article of claim 22 wherein each area has a size of less than about two hundred fifty square meters.

24. The article of claim 22 wherein the normalized data comprises a measurement of locating accuracy for each call.

25. The article of claim 22 wherein each call is associated with one or more location-estimating performance types based on areas included within an error range of the location identified by the location data.