Estimating a location of a mobile device

• US 20070232319A1
• Filed: 03/28/2006
• Published: 10/04/2007
• Est. Priority Date: 03/28/2006
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Bells, Matthew, Wormald, Chris, Klassen, Gerhard
• Granted Patent: US 7,945,270 B2
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

The approximate location of a directed cell of a cellular network is calculated based on locations in the vicinity of which mobile devices were able to detect the directed cell. A mobile device is able to estimate its own location from the approximate locations of one or more directed cells that it can identify. This estimated location of the mobile device may be used to seed its GPS receiver.

Claims

1. A method for determining approximate locations of directed cells, the method comprising:

calculating the approximate location of a directed cell of a cellular network based on locations in the vicinity of which mobile devices were able to detect the directed cell.

2. The method of claim 1, wherein calculating the approximate location comprises:

calculating the approximate location as the median of the locations.

3. The method of claim 1, further comprising:

in response to a query for the location of the directed cell from a mobile device, providing the approximate location to the mobile device.

4. The method of claim 3, further comprising:

in response to the query, providing the maximum signal strength measurement of a signal that identified the directed cell as received by one of the mobile devices.

5. The method of claim 4, further comprising:

in response to the query, providing a statistical characteristic of signal strength measurements of signals that identified the directed cell as received by the mobile devices.

6. The method of claim 1, further comprising:

receiving location reports from the mobile devices, each location report identifying one or more directed cells that are detectable by one of the mobile devices in the vicinity of a particular location; and

collating the location reports into directed cell reports, each directed cell report identifying one or more locations in the vicinity of which one of the mobile devices has detected a particular directed cell.

7. The method of claim 6, further comprising:

defining a geographical area in the cellular network;

determining a directive for the geographical area that specifies how to generate and/or transmit the location reports when located in the geographical area; and

providing a definition of the geographical area and the directive to the mobile devices.

8. The method of claim 6, further comprising:

defining a geographical area in the cellular network;

determining an interest level for the geographical area from which mobile devices can determine one or more directives that specify how to generate and/or transmit the location reports when located in the geographical area; and

providing a definition of the geographical area and the interest level to the mobile devices.

9. A method for estimating a location of a mobile device, the method comprising:

receiving approximate locations of one or more directed cells of a cellular network; and

estimating the location from the approximate locations.

10. The method of claim 9, wherein the approximate locations of the directed cells are provided as coordinates on axes and estimating the location from the approximate locations includes:

estimating the location as a weighted average of the coordinates on each of the axes, where weights used in calculating the weighted average are linear functions of signal strength measurements of signals from which the mobile device identified the directed cells.

11. A mobile device comprising:

a communication interface through which the mobile device is able to communicate with base stations of a cellular network;

a processor coupled to the communication interface;

a global positioning system (GPS) receiver coupled to the processor; and

a memory coupled to the processor, the memory to store code which, when executed by the processor, generates a location report identifying one or more directed cells of the cellular network that are detectable by the mobile device in the vicinity of a location as determined by the GPS receiver.

12. The mobile device of claim 11, wherein the code, when executed by the processor, includes in the location report signal strength measurements of signals received by the mobile device at the location and from which the mobile device identified the one or more directed cells.

13. The mobile device of claim 11, wherein the memory is to store a definition of a geographical area and a directive that specifies how the mobile device is to generate and/or transmit the location report when located in the geographical area.

14. The mobile device of claim 11, wherein the memory is to store a definition of a geographical area and a dictionary, and the code, when executed by the processor, translates, using the dictionary, an interest level for the geographical area to a directive that specifies how the mobile device is to generate and/or transmit the location report when located in the geographical area.

15. A mobile device comprising:

a communication interface through which the mobile device is able to communicate with base stations of a cellular network;

a processor coupled to the communication interface; and

a memory coupled to the processor, the memory to store code which, when executed by the processor, submits a query for the locations of one or more directed cells to a server and estimates a location of the mobile device from approximate locations of the directed cells received from the server in response to the query.

16. The mobile device of claim 15, wherein the approximate locations of the directed cells are provided as coordinates on axes and the code, when executed by the processor, estimates the location of the mobile device as a weighted average of the coordinates on each of the axes, where weights used in calculating the weighted average are linear functions of signal strength measurements of signals from which the mobile device identified the directed cells.

17. The mobile device of claim 15, further comprising:

a global positioning system (GPS) receiver coupled to the processor,

wherein the code;

when executed by the processor, provides the estimated location of the mobile device to the GPS receiver.