Mobile Device Location Estimation

• US 20120309410A1
• Filed: 06/03/2011
• Published: 12/06/2012
• Est. Priority Date: 06/03/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Marti, Lukas M., Mayor, Robert, Huang, Ronald K., MacGougan, Glenn Donald, Dere, Jason, Grosman, Yefim
• Granted Patent: US 8,494,554 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

Methods, program products, and systems of location estimation using multiple wireless access gateways are disclosed. In general, in one aspect, a mobile device can scan and detect multiple wireless access gateways. The mobile device can determine an initial estimate of distance between the mobile device and each wireless access gateway. The mobile device can receive, from a server, location data of the detected wireless access gateways. The location data can include an estimated location of each wireless access gateway, an uncertainty of the estimated location, and a reach of each wireless access gateway. The mobile device can assign a weight to each estimated location using the uncertainty, the reach, and the initial estimate. The mobile device can estimate the location of the mobile device using the weighted locations.

Claims

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

detecting, on the mobile device, a plurality of wireless access gateways;

determining a closeness between the mobile device and each wireless access gateway, the closeness including an initial measurement of distance between the mobile device and each wireless access gateway;

receiving location data associated with each of the detected wireless access gateways, the location data including an estimated location of each detected wireless access gateway, an uncertainty value associated with the estimated location, and a reach of each detected wireless access gateway;

weighting the estimated locations using the uncertainty values, the reaches of the wireless access gateways, and the closeness; and

determining the location of the mobile device based on the weighted locations.

2. The method of claim 1, wherein each of the wireless access gateways includes at least one of a cell tower, a wireless router, or a Bluetooth™

device.

3. The method of claim 1, wherein determining the closeness is based on at least one of:

a signal strength of a signal from the wireless access device;

a round-trip time of a signal between the mobile device and the wireless access device;

or

a bit error rate of a signal between the mobile device and the wireless access device.

4. The method of claim 1, wherein the estimated location of each wireless access device includes a latitude coordinate and a longitude coordinate of the wireless access device.

5. The method of claim 1, wherein the estimated location of each wireless access device includes an altitude coordinate of the wireless access device.

6. The method of claim 1, wherein the reach of each wireless access device indicates how far away the wireless access device is expected to be observed by a mobile device.

7. The method of claim 1, wherein the uncertainty value indicates an estimation accuracy of the estimated location.

8. The method of claim 1, wherein weighting the estimated locations comprises:

assigning a larger weight to a wireless access gateway having a smaller reach;

assigning a larger weight to a wireless access gateway having a smaller uncertainty value; and

assigning a larger weight to a wireless access gateway that is closer to the mobile device.

9. The method of claim 1, comprising:

identifying an outlier from the detected wireless access gateways; and

excluding the outlier from the operations of weighting the estimated locations and determining the location of the mobile device.

10. The method of claim 9, wherein identifying the outlier comprises:

identifying an estimated location from the received location data, wherein a distance between the estimated location and other estimated locations exceeds a maximum reach among the reaches of the detected wireless access gateways; and

designating a wireless access gateway associated with the identified estimated location as the outlier.

11. The method of claim 1, comprising determining, based on the weighted locations, an estimated uncertainty associated with the location of the mobile device.

12. A computer program product tangibly stored on a non-transitory medium and configured to cause a mobile device to perform operations comprising:

detecting, on the mobile device, a plurality of wireless access gateways;

determining a closeness between the mobile device and each wireless access gateway, the closeness including an initial measurement of distance between the mobile device and each wireless access gateway;

receiving location data associated with each of the detected wireless access gateways, the location data including an estimated location of each detected wireless access gateway, an uncertainty value associated with the estimated location, and a reach of each detected wireless access gateway;

weighting the estimated locations using the uncertainty values, the reaches of the wireless access gateways, and the closeness; and

determining the location of the mobile device based on the weighted locations.

13. The product of claim 12, wherein each of the wireless access gateways includes at least one of a cell tower, a wireless router, or a Bluetooth™

device.

14. The product of claim 12, wherein determining the closeness is based on at least one of:

a signal strength of a signal from the wireless access device;

a round-trip time of a signal between the mobile device and the wireless access device;

or

a bit error rate of a signal between the mobile device and the wireless access device.

15. The product of claim 12, wherein the estimated location of each wireless access device includes a latitude coordinate and a longitude coordinate of the wireless access device.

16. The product of claim 12, wherein the estimated location of each wireless access device includes an altitude coordinate of the wireless access device.

17. The product of claim 12, wherein the reach of each wireless access device indicates how far away the wireless access device is expected to be observed by a mobile device.

18. The product of claim 12, wherein the uncertainty value indicates an estimation accuracy of the estimated location.

19. The product of claim 12, wherein weighting the estimated locations comprises:

assigning a larger weight to a wireless access gateway having a smaller reach;

assigning a larger weight to a wireless access gateway having a smaller uncertainty value; and

assigning a larger weight to a wireless access gateway that is closer to the mobile device.

20. The product of claim 12, the operations comprising:

identifying an outlier from the detected wireless access gateways; and

excluding the outlier from the operations of weighting the estimated locations and determining the location of the mobile device.

21. The product of claim 20, wherein identifying the outlier comprises:

identifying an estimated location from the received location data, wherein a distance between the estimated location and other estimated locations exceeds a maximum reach among the reaches of the detected wireless access gateways; and

designating a wireless access gateway associated with the identified estimated location as the outlier.

22. The product of claim 12, the operations comprising determining, based on the weighted locations, an estimated uncertainty associated with the location of the mobile device.

23. A system, comprising:

a mobile device configured to perform operations comprising;

detecting, on the mobile device, a plurality of wireless access gateways;

determining a closeness between the mobile device and each wireless access gateway, the closeness including an initial measurement of distance between the mobile device and each wireless access gateway;

receiving location data associated with each of the detected wireless access gateways, the location data including an estimated location of each detected wireless access gateway, an uncertainty value associated with the estimated location, and a reach of each detected wireless access gateway;

weighting the estimated locations using the uncertainty values, the reaches of the wireless access gateways, and the closeness; and

determining the location of the mobile device based on the weighted locations.

24. The system of claim 23, wherein each of the wireless access gateways includes at least one of a cell tower, a wireless router, or a Bluetooth™

device.

25. The system of claim 23, wherein determining the closeness is based on at least one of:

a signal strength of a signal from the wireless access device;

a round-trip time of a signal between the mobile device and the wireless access device;

or

a bit error rate of a signal between the mobile device and the wireless access device.

26. The system of claim 23, wherein the estimated location of each wireless access device includes a latitude coordinate and a longitude coordinate of the wireless access device.

27. The system of claim 23, wherein the estimated location of each wireless access device includes an altitude coordinate of the wireless access device.

28. The system of claim 23, wherein the reach of each wireless access device indicates how far away the wireless access device is expected to be observed by a mobile device.

29. The system of claim 23, wherein the uncertainty value indicates an estimation accuracy of the estimated location.

30. The system of claim 23, wherein weighting the estimated locations comprises:

assigning a larger weight to a wireless access gateway having a smaller reach;

assigning a larger weight to a wireless access gateway having a smaller uncertainty value; and

assigning a larger weight to a wireless access gateway that is closer to the mobile device.

31. The system of claim 23, the operations comprising:

identifying an outlier from the detected wireless access gateways; and

excluding the outlier from the operations of weighting the estimated locations and determining the location of the mobile device.

32. The system of claim 31, wherein identifying the outlier comprises:

identifying an estimated location from the received location data, wherein a distance between the estimated location and other estimated locations exceeds a maximum reach among the reaches of the detected wireless access gateways; and

designating a wireless access gateway associated with the identified estimated location as the outlier.

33. The system of claim 23, the operations comprising determining, based on the weighted locations, an estimated uncertainty associated with the location of the mobile device.