POSITION SOURCE SELECTION

• US 20090192709A1
• Filed: 06/25/2008
• Published: 07/30/2009
• Est. Priority Date: 01/25/2008
• Status: Active Grant

• Current Assignee: Garmin Limited
• Original Assignee: Garmin Limited
• Inventors: Hsieh, Mei-Lin, Huang, Haitao, Weisshaar, Bernhard P., Yonker, Jason B., Smith, Merlin J.
• Granted Patent: US 8,214,139 B2
• Time in Patent Office: Days
• US Class Current: 701/215
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/45 by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement
• CPC Class Codes: G01S 19/48 by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system
• CPC Class Codes: H04W 4/029 Location-based management or tracking services

Abstract

Techniques are described for position source selection. In an implementation, an electronic device provides a variety of functionality including at least functionality to determine position. The electronic device may be further configured to select between a plurality of position sources to determine position based upon a variety of selection criteria. In an implementation, a last known position may be stored when position is being determined through the plurality of position sources. The last known position may be used as an alternative to determining position via the position sources when one or more of the position sources are unavailable. In another implementation, the last known position may be employed to automatically select one of the plurality of position sources to be used by the electronic device for determining position.

Claims

1. A navigation device, comprising:

a satellite navigation receiver operable to receive signals from a first position source;

a communications module operable to receive signals from a second position source; and

a position subsystem in communication with the satellite navigation receiver and the communications module, the position subsystem operable to;

identify movement of the navigation device;

select one of the position sources based upon the identified movement;

determine position using the selected one of the position sources; and

communicate the determined position to an application to perform a position dependent function.

2. A navigation device as recited in claim 1, wherein the position subsystem is further configured to:

store a last known position through interaction with the position sources;

determine validity of the last known position to perform the position dependent function; and

when the last known position is valid, communicate the last known position to the application instead of determining position through one of the position sources.

3. A navigation device as recited in claim 1, wherein the position subsystem is further configured to:

update a last known position stored on the navigation device when using the selected one of the position sources to determine position; and

select the last known position as the determined position when one or more of the position sources are not available.

4. The navigation device as recited in claim 1, wherein the identified movement of the navigation device is a speed of the navigation device.

5. The navigation device as recited in claim 1, wherein:

the navigation device includes an inertial sensor; and

the position subsystem is operable to identify the movement of the navigation device using the inertial sensor.

6. The navigation device as recited in claim 1, wherein the position subsystem is operable to identify movement of the navigation device using at least one of the position sources.

7. The navigation device as recited in claim 6, wherein the position subsystem is operable to identify movement of the navigation device based on a communication infrastructure element associated with at least one of the position sources.

8. The navigation device as recited in claim 1, wherein the position subsystem is operable to identify movement of the navigation device based on an identification of a cellular tower associated with a cellular network.

9. The navigation device as recited in claim 1, wherein:

the first position source is a plurality of navigation satellites to communicate the signals received by the satellite navigation receiver; and

the second position source is a provider configured to communicate the signals received by the communication module over at least one of a cellular network and the Internet.

10. A method comprising:

determining a position of a device utilizing one or more of a plurality of position sources;

storing a last known position based upon the determined position;

receiving a position request from an application of the device;

selecting a source of position data to fulfill the position request from the last known position and the plurality of position sources based upon selection criteria;

obtaining position from the selected source of position data; and

communicating the obtained position to the application to perform a position dependent function.

11. A method as recited in claim 10, wherein selecting the source of position data to fulfill the position request is further based upon movement detected via an inertial sensor of the device.

12. A method as recited in claim 10, wherein selecting the source of position data to fulfill the position request further comprises:

determining validity of the last known position;

when the last known position is valid, selecting the last known position; and

when the last known position is invalid, selecting one of the plurality of position sources.

13. One or more computer readable media storing instructions executable by a navigation device to:

determine a position of the navigation device utilizing one or more of a plurality of position sources;

store a last known position based upon the determined position;

receive a position request from an application of the navigation device;

select a source of position data to fulfill the position request from the last known position and the plurality of position sources based upon selection criteria;

obtain position from the selected source of position data; and

communicate the obtained position to the application to perform a position dependent function.

14. A method comprising:

determining position at a device using one or more position sources;

storing a last known position of the device based upon the determined position;

determining validity of the last known position; and

when the last known position is valid, selecting the last known position to perform a position dependent function of the device.

15. A method as recited in claim 14, further comprising:

deactivating the one or more position sources when the last known position is stored.

16. A method as recited in claim 14, further comprising:

receiving a request for position from an application of the device; and

communicating the last known position as position to the application responsive to the request.

17. A method as recited in claim 14, wherein the last known position is selected when one or more position sources are unavailable to the device.

18. A method as recited in claim 14, wherein the one or more position sources include navigation satellites, a cellular provider, and an internet provider.

19. A method as recited in claim 14, wherein the device is configured to:

determine position based upon signal data received from a plurality of satellites via a satellite navigation receiver of the device; and

enable access to phone service from a cellular provider via a communication module of the device.

20. A method as recited in claim 14, wherein the position dependent function is an Internet search.

21. A method as recited in claim 14, wherein the position dependent function is a position based search of a point of interest (POI) database.

22. A navigation device comprising:

a satellite navigation receiver to enable receiving of signal data from a plurality of satellites;

a memory; and

a position subsystem operable to;

store data corresponding to a last known position of the navigation device in the memory;

determine validity of the last known position stored in the memory;

when the last known position is valid, select the last known position to perform a position dependent function of the navigation device; and

when the last known position is not valid, activate the satellite navigation receiver to determine position.

23. The navigation device of claim 22, wherein the position subsystem is further operable to update the last known position with a position corresponding to a communication infrastructure element encountered by the navigation device.

24. The navigation device of claim 22, wherein the position subsystem is further operable to:

acquire identifiers for communication infrastructure elements encountered by the navigation device;

store data relating the communication infrastructure elements to position determined through the satellite navigation receiver;

deactivate the satellite navigation receiver; and

while the satellite navigation receiver is deactivated, obtain position of a communication infrastructure element encountered by the navigation device from the stored data to enable position dependent functions.

25. The navigation device of claim 24, wherein the communication infrastructure elements include one or more of:

cellular towers, Wi-Fi access points, beacons, routers, repeaters, and radio towers.