Method and system for associating a cell-sector with time-dependent location parameters

• US 8,712,438 B1
• Filed: 05/24/2012
• Issued: 04/29/2014
• Est. Priority Date: 05/24/2012
• Status: Active Grant

• Current Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: McMullen, Michael P., Nelson, Rodney D., Wilson, Benjamin
• Primary Examiner(s): SIVJI, NIZAR N
• Application Number:
  US13/479,677
• Time in Patent Office: 705 Days
• Field of Search: 455/414.1, 4554561-4566, 701/206, 342/457
• US Class Current: 455/456.2
• CPC Class Codes: G01S 5/0244 Accuracy or reliability of position solution or of measurements contributing thereto
• CPC Class Codes: H04M 3/42 Systems providing special services or facilities to subscribers specially adapted for wireless communication networks H04W4/00
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A set of location fixes is obtained for a plurality of mobile stations, wherein each mobile station is served by a serving area of a wireless network at a respective date and time of day. The set of location fixes is used to determine different geographic parameters that apply to the serving area for different time periods (e.g., different days of the week and/or times of day). A location server may receive a request to locate a mobile station that is being served by the serving area at a current date/time. The location server may select a representative location and at least one uncertainty parameter based on the geographic parameters that apply to the serving area for the time period corresponding to the current date/time, and report the representative location and at least one uncertainty parameter in response to the request.

Claims

1. A method, comprising:

receiving from a requestor a request to locate a mobile station;

in response to said request, determining that a serving area provided by a base transceiver station of a wireless network is serving said mobile station at a current date and a current time of day;

in response to determining that said serving area is serving said mobile station at said current date and said current time of day, accessing data storage that stores geographic parameters associated with said serving area, wherein said stored geographic parameters associated with said serving area include respective geographic parameters for each of a plurality of time periods;

selecting a representative location associated with said serving area based on said stored geographic parameters associated with said serving area and at least one of said current date and said current time of day;

selecting at least one uncertainty parameter associated with said representative location based on said stored geographic parameters associated with said serving area and at least one of said current date and said current time of day; and

reporting said representative location and said at least one uncertainty parameter to said requestor.

2. The method of claim 1, wherein said serving area is a cell-sector.

3. The method of claim 1, wherein said representative location defines a center of a circle and said at least one uncertainty parameter defines a radius of said circle.

4. The method of claim 1, wherein said representative location defines a center of an ellipse and said at least one uncertainty parameter defines a major radius and a minor radius of said ellipse.

5. The method of claim 1, wherein said representative location defines a location of a polygon and said at least one uncertainty parameter defines at least one dimension of said polygon.

6. The method of claim 1, wherein said stored geographic parameters associated with said serving area comprise a set of predefined locations associated with said serving area, wherein each of said predefined locations is associated with a respective time period;

and

wherein selecting a representative location associated with said serving area based on said geographic parameters associated with said serving area and at least one of said current date and said current time of day comprises selecting the predefined location in the set of predefined locations that is associated with a time period that corresponds to at least one of said current date and said current time of day.

7. The method of claim 6, wherein each of said predefined locations is associated with a particular day of the week.

8. The method of claim 7, wherein each predefined location that is associated with a weekday is further associated with a particular range of times within that weekday.

9. The method of claim 1, wherein said stored geographic parameters associated with said serving area comprise a set of predefined uncertainty parameters associated with said serving area, wherein each of said predefined uncertainty parameters is associated with a respective time period;

and

wherein selecting at least one uncertainty parameter comprises selecting the predefined uncertainty parameter in the set of predefined uncertainty parameters that is associated with a time period that corresponds to at least one of said current date and said current time of day.

10. The method of claim 9, wherein each of said predefined uncertainty parameters is associated with a particular day of the week.

11. The method of claim 10, wherein each predefined uncertainty parameter that is associated with a weekday is further associated with a particular range of times within that weekday.

12. The method of claim 1, wherein said stored geographic parameters associated with said serving area comprise a set of predefined polygons associated with said serving area, wherein each of said predefined polygons is associated with a respective time period;

wherein selecting a representative location associated with said serving area based on said stored geographic parameters associated with said serving area and at least one of said current date and said current time of day comprises;

selecting as a representative polygon a predefined polygon in the set of predefined polygons that is associated with a time period that corresponds to at least one of said current date and said current time of day; and

determining said representative location based on said representative polygon.

13. The method of claim 12, wherein selecting at least one uncertainty parameter associated with said representative location based on at least one of said stored geographic parameters and at least one of said current date and said current time of day comprises determining said at least one uncertainty parameter based on said representative polygon.

14. A method, comprising:

obtaining, for a serving area provided by a base transceiver station of a wireless network, during a collection period, a set of location fixes for a plurality of mobile stations, wherein each of said location fixes is obtained for a respective mobile station being served by said serving area at a respective date and time of day within said collection period, wherein said mobile stations are configured to wirelessly communicate with said wireless network;

defining a plurality of time periods;

dividing said set of location fixes into a plurality of time-period-subsets, such that each time period in said plurality of time periods is associated with a respective time-period-subset of said set of location fixes; and

for each given time period in said plurality of time periods, (i) determining a set of geographic parameters that cooperatively define a geographic area encompassing at least some location fixes in said given time period'"'"'s respective time-period-subset, and (ii) storing, in data storage, a record that associates said set of geographic parameters with said serving area and said given time period.

15. The method of claim 14, wherein at least some location fixes in said set of location fixes are obtained using wireless signals from satellite-based transmitters.

16. The method of claim 14, wherein at least some location fixes in said set of location fixes are obtained using wireless signals from terrestrial-based transmitters.

17. The method of claim 14, wherein each of said time periods in said plurality of time periods corresponds to one or more time intervals within said collection period, and wherein dividing said set of location fixes into a plurality of time-period-subsets comprises assigning each respective location fix to one of said time-period-subsets based on when said respective location fix was obtained.

18. The method of claim 14, wherein determining a set of geographic parameters that cooperatively define a geographic area encompassing at least some location fixes in said given time period'"'"'s respective time-period-subset comprises determining at least one of:

(a) a representative location that defines a center of a circle and an uncertainty parameter defines a radius of said circle;

(b) a representative location that defines a center of an ellipse and uncertainty parameters that define a major radius and a minor radius of said ellipse; and

(c) a representative location that defines a location of a polygon and at least one uncertainty parameter that defines at least one dimension of said polygon.

19. A system, comprising:

a processor;

data storage; and

program instructions stored in said data storage, wherein said program instructions are executable by said processor to cause said system to perform functions, said functions comprising;

receiving a request to locate a mobile station;

in response to said request, determining that a serving area provided by a base transceiver station of a wireless network is serving said mobile station at a current date and a current time of day;

in response to determining that said serving area is serving said mobile station at said current date and said current time of day, accessing data storage that stores geographic parameters associated with said serving area, wherein said stored geographic parameters associated with said serving area include respective geographic parameters for each of a plurality of time periods;

selecting, from said stored geographic parameters, geographic parameters for a time period in said plurality of time periods corresponding to at least one of said current date and said current time of day;

selecting a representative location and at least one uncertainty parameter based on said selected geographic parameters; and

reporting said representative location and said at least one uncertainty parameter.

20. The system of claim 19, wherein said functions further comprise:

determining said set of geometric parameters associated with said serving area based on a set of location fixes obtained for mobile stations served by said serving area during a collecting period.

21. The system of claim 19, wherein said records of geographic parameters associated with said serving area comprise a set of predefined locations and a set of predefined uncertainty parameters associated with said serving area, wherein each of said predefined locations and said predefined uncertainty parameters is associated with a respective time period.