Location determination using cached location area codes

• US 8,634,860 B2
• Filed: 01/15/2010
• Issued: 01/21/2014
• Est. Priority Date: 01/15/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Huang, Ronald K., Mayor, Robert
• Primary Examiner(s): SAMS, MATTHEW C
• Application Number:
  US12/688,824
• Publication Number:
  US 20110177826A1
• Time in Patent Office: 1,467 Days
• Field of Search: 4554561-457
• US Class Current: 455/456.6
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Methods, program products, and systems for location determination using cached location area codes are described. A mobile device can store a set of location area codes (LACs) of a cellular communications network on the mobile device. Each LAC can represent a location area of the cellular communications network that encompasses at least a predetermined number of cells. Each LAC can be further associated with an estimated geographic area. The estimated geographic area can be defined as a circle centered at a location and having a radius representing an uncertainty of the location. The mobile device can determine a current LAC of the mobile device based on a wirelessly received signal. The mobile device can determine a current location of the mobile device by performing a lookup in the stored set of LACs using the current LAC.

Claims

1. A method executed by a mobile device, comprising:

receiving a set of location area codes (LACs) of a cellular communications network, each LAC in the set being associated with a plurality of cells of the cellular communications network, the LAC further associated with a geographic area, the geographic area including a first circle centered at a location and having a first radius representing an uncertainty of the location;

determining a current LAC of the mobile device based on a wirelessly received signal;

determining a first estimated location of the mobile device, including performing a lookup in the received set of LACs using the current LAC;

providing a representation of the first estimated location for display on the mobile device;

determining a second estimated location of the mobile device, comprising;

receiving identifiers of access points of a wireless communications network and a set of locations associated with the access points;

calculating an average geographic location using the set of locations;

calculating distances between the average geographic location and locations in the set of locations;

excluding at least one location from the set based on a distance between the average geographic location and the at least one location;

repeating calculating the average geographic location, calculating the distances, and excluding at least one location until an exit condition is satisfied; and

designating the second estimated location of the mobile device using a representation having the average geographic location as a center and at least one calculated distance as a dimension, wherein a size of the representation of the second estimated location is smaller than a size of the representation of the first estimated location; and

providing for display the representation of the second estimated location replacing the representation of the first estimated location.

2. The method of claim 1, where each LAC corresponds to a location area, the location area encompassing at least the plurality of cells.

3. The method of claim 1, further comprising displaying the representation of the first estimated location of the mobile device on a display device as a first circle centered at the first estimated location and having a first radius representing the uncertainty of the first estimated location.

4. The method of claim 3, where providing a representation of the second estimated location for display includes displaying a second circle replacing the first circle, the second circle having a second radius that is less than the first radius.

5. The method of claim 1, where the identifiers of the access points include Media Access Control (MAC) addresses of the access points.

6. The method of claim 1, where the exit condition is satisfied when a number of repetitions reaches a threshold number.

7. The method of claim 1, where the exit condition is satisfied when the radius of the circle reaches below a threshold radius.

8. A system, comprising:

one or more mobile devices configured to perform operations comprising;

receiving a set of location area codes (LACs) of a cellular communications network, each LAC in the set being associated with a plurality of cells of the cellular communications network, the LAC further associated with a geographic area, the geographic area including a first circle centered at a location and having a first radius representing an uncertainty of the location;

determining a current LAC of the mobile device based on a wirelessly received signal;

determining a first estimated location of the mobile device, including performing a lookup in the received set of LACs using the current LAC;

providing a representation of the first estimated location for display on the mobile device;

determining a second estimated location of the mobile device, comprising;

receiving identifiers of access points of a wireless communications network and a set of locations associated with the access points;

calculating an average geographic location using the set of locations;

calculating distances between the average geographic location and locations in the set of locations;

excluding at least one location from the set based on a distance between the average geographic location and the at least one location;

repeating calculating the average geographic location, calculating the distances, and excluding at least one location until an exit condition is satisfied; and

designating the second estimated location of the mobile device using a representation having the average geographic location as a center and at least one calculated distance as a dimension, wherein a size of the representation of the second estimated location is smaller than a size of the representation of the first estimated location; and

providing for display the representation of the second estimated location.

9. The system of claim 8, where each LAC corresponds to a location area, the location area encompassing at least the plurality of cells.

10. The system of claim 8, further comprising displaying the representation of the first estimated location of the mobile device on a display device as a first circle centered at the first estimated location and having a first radius representing the uncertainty of the first estimated location.

11. The system of claim 8, where providing a representation of the second estimated displaying the current location further includes displaying a second circle replacing the first circle, the second circle corresponding to an estimated location of the mobile device and having a second radius that is less than the first radius.

12. The system of claim 8, where the identifiers of the access points include Media Access Control (MAC) addresses of the access points.

13. The system of claim 8, where the exit condition is satisfied when a number of repetitions reaches a threshold number.

14. The system of claim 8, where the exit condition is satisfied when the radius of the circle reaches below a threshold radius.

15. A computer program product tangibly stored on a non-transitory storage device, the product operable to cause a mobile device to perform operations comprising:

receiving a set of location area codes (LACs) of a cellular communications network, each LAC in the set being associated with a plurality of cells of the cellular communications network, the LAC further associated with a geographic area, the geographic area including a first circle centered at a location and having a first radius representing an uncertainty of the location;

determining a current LAC of the mobile device based on a wirelessly received signal;

determining a first estimated location of the mobile device, including performing a lookup in the received set of LACs using the current LAC;

providing a representation of the first estimated location for display on the mobile device;

determining a second estimated location of the mobile device, comprising;

receiving identifiers of access points of a wireless communications network and a set of locations associated with the access points;

calculating an average geographic location using the set of locations;

calculating distances between the average geographic location and locations in the set;

excluding at least one location from the set based on a distance between the average geographic location and the at least one location;

repeating calculating the average geographic location, calculating the distances, and excluding at least one location until an exit condition is satisfied; and

designating the second estimated location of the mobile device using a representation having the average geographic location as a center and at least one calculated distance as a dimension, wherein a size of the representation of the second estimated location is smaller than a size of the representation of the first estimated location; and

providing for display the representation of the second estimated location.

16. The product of claim 15, where each LAC corresponds to a location area, the location area encompassing at least the plurality of cells.

17. The product of claim 15, further comprising displaying the representation of the first estimated location of the mobile device on a display device as a first circle centered at the first estimated location and having a first radius representing the uncertainty of the first estimated location.

18. The product of claim 17, where providing a representation of the second estimated for display location further includes displaying a second circle replacing the first circle, the second circle having a second radius that is less than the first radius.

19. The product of claim 15, where the identifiers of the access points include Media Access Control (MAC) addresses of the access points.

20. The product of claim 15, where the exit condition is satisfied when a number of repetitions reaches a threshold number.

21. The product of claim 15, where the exit condition is satisfied when the radius of the circle reaches below a threshold radius.