Method for providing location aiding among peers operating in a direct communication mode

• US 20070024498A1
• Filed: 07/29/2005
• Published: 02/01/2007
• Est. Priority Date: 07/29/2005
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Swope, Charles, Korneluk, Jose, Segerson, Charles, Haverkamp, Kristi, Contreras, Nereydo, Klug, Keith, Anderson, Bobby
• Granted Patent: US 7,277,049 B2
• Time in Patent Office: Days
• US Class Current: 342/357.420
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 5/0072 Transmission between mobile stations, e.g. anti-collision systems

Abstract

A mobile communication device (202) outside the service area of a communications network 210 in need of satellite positioning assistance information to perform a location determination (308). The mobile communication device receives the assistance information from a peer mobile communication device (204, 206) over a direct link.

Claims

1. A method of providing satellite positioning assistance information from a first mobile communication device to at least a second mobile communication device, the first mobile communication device having current satellite positioning assistance information, the method comprising:

establishing an information link directly between the first and second mobile communication devices;

requesting the current satellite positioning assistance information from the first mobile communication device at the second mobile communication device;

receiving the current satellite positioning assistance information from the first mobile communication device to the second mobile communication device over the information link; and

performing a satellite positioning location determination at satellite positioning receiver of the second mobile communication device using the current satellite positioning assistance information.

2. A method of providing satellite positioning assistance information as defined by claim 1, wherein the current satellite positioning assistance information includes at least one of satellite ephemeris, satellite almanac, approximate position, and present time of day.

3. A method of providing satellite positioning assistance information as defined by claim 1, wherein establishing the information exchange link includes establishing an asynchronous radio link between the first and second mobile communication devices.

4. A method of providing satellite positioning assistance information as defined by claim 3, wherein requesting the current satellite positioning assistance information is performed before establishing the information exchange link by broadcasting a request message from the second mobile communication device operating in an asynchronous direct radio mode.

5. A method of providing satellite positioning assistance information as defined by claim 3, wherein the second mobile communication device is operated within range of a communications network with which the second mobile communication device is initially associated, the method further comprising initiating an off-network mode prior to establishing the information exchange link.

6. A method of providing satellite positioning assistance information as defined by claim 3, further comprising commencing a satellite positioning location determination prior to receiving the current satellite positioning assistance information, and wherein, while commencing the satellite positioning location determination before receiving the current satellite positioning assistance information, the second mobile communication device periodically checks an asynchronous radio channel to detect the first mobile communication device transmitting the current satellite positioning assistance information.

7. A method of providing satellite positioning assistance information as defined by claim 1, wherein establishing the information exchange link is performed by one of an infrared link, acoustic link, cabled link, or a magnetic induction link.

8. A method of providing satellite positioning assistance information as defined by claim 1, wherein establishing the information link comprises establishing a half duplex link.

9. A mobile communication device, comprising:

a communications transceiver;

a satellite positioning receiver;

a machine readable memory containing instruction code for operating the mobile communication device, including;

establishing an information link directly with a peer mobile communication device;

requesting current satellite positioning assistance information from the peer mobile communication device;

receiving the current satellite positioning assistance information from the peer mobile communication device over the information link; and

performing a satellite positioning location determination with the satellite positioning receiver using the current satellite positioning assistance information.

10. A mobile communication device as defined by claim 9, wherein the instruction code for establishing the information exchange link includes instruction code for establishing an asynchronous radio link with the peer mobile communication device using the communications transceiver.

11. A mobile communication device as defined by claim 10, wherein the instruction code for requesting the current satellite positioning assistance information operates the mobile communication device to commence requesting the current satellite positioning assistance information before establishing the information exchange link by broadcasting a request message in an asynchronous direct radio mode.

12. A mobile communication device as defined by claim 10, wherein the mobile communication device is operated within range of a communications network with which the mobile communication device is initially associated, the machine readable memory further comprises instruction code for initiating an off-network mode of the mobile communication device prior to establishing the information exchange link.

13. A mobile communication device as defined by claim 10, wherein the machine readable memory further comprises instruction code for commencing a satellite positioning location determination prior to receiving the current satellite positioning assistance information, and wherein, while commencing the satellite positioning location determination before receiving the current satellite positioning assistance information, the mobile communication device periodically checks an asynchronous radio channel to detect the peer mobile communication device transmitting the current satellite positioning assistance information.

14. A method of providing satellite positioning assistance information as defined by claim 9, wherein the instruction code for establishing the information exchange link operates one of an infrared link, acoustic link, cabled link, or a magnetic induction link.

15. A method of assisting a peer mobile communication device perform a satellite positioning location determination, comprising:

acquiring a satellite positioning fix at a first mobile communication device, including acquiring satellite positioning parameters;

formatting the satellite positioning parameters into a current satellite positioning assistance information format;

receiving a request from a second mobile communication device for the current satellite positioning assistance information; and

transmitting the current satellite positioning assistance information to at least the second mobile communication device using a direct communication mode.

16. A method of assisting a peer mobile communication device as defined by claim 15, wherein the current satellite positioning assistance information includes at least one of satellite ephemeris, satellite almanac, approximate position, and present time of day.

17. A method of assisting a peer mobile communication device as defined by claim 15, wherein transmitting the current satellite positioning assistance information is performed via an asynchronous radio link between the first and second mobile communication devices.

18. A method of assisting a peer mobile communication device as defined by claim 17, wherein receiving the request for the current satellite positioning assistance information occurs via an asynchronous radio link between the first and second mobile communication devices.

19. A method of assisting a peer mobile communication device as defined by claim 17, wherein the second peer mobile communication device is operated within range of a communications network with which the second peer mobile communication device is initially associated, the method further comprising initiating an off-network mode prior to establishing the information exchange link.

20. A method of assisting a peer mobile communication device as defined by claim 17, wherein receiving the request comprises periodically checking an asynchronous radio channel to detect the request.

21. A method of assisting a peer mobile communication device as defined by claim 15, wherein establishing the information exchange link is performed by one of an infrared link, acoustic link, cabled link, or a magnetic induction link.