CULLED SATELLITE EPHEMERIS INFORMATION FOR QUICK, ACCURATE ASSISTED LOCATING SATELLITE LOCATION DETERMINATION FOR CELL SITE ANTENNAS

• US 20120122479A1
• Filed: 12/30/2011
• Published: 05/17/2012
• Est. Priority Date: 10/15/2004
• Status: Active Grant

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Inventors: Lamprecht, Leslie Johann, Martin, Jeffrey Thomas, PITT, Lance Douglas
• Granted Patent: US 8,681,044 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/28 Satellite selection

Abstract

Locating satellites (e.g., GPS) are culled into a preferred group having a longest dwell time based on a time passing through an ellipsoid arc path through a cone of space, and communicated to mobile devices within a particular region (e.g., serviced by a particular base station). The culled locating satellites may select those visible, or more preferably those locating satellites currently within a cone of space above the relevant base station are selected for communication by a mobile device within the service area of the base station. The inverted cone of space may be defined for each antenna structure for any given base station, and each has 360 degrees of coverage, or less than 360 degrees of coverage, with relevant locating satellites. Thus, cell sites may be specifically used as reference points for culling the ephemeris information used to expedite Assisted GPS location determinations.

Claims

1-16. -16. (canceled)

17. A method of distributing culled satellite information, comprising:

defining an inverted cone above a geographic location;

defining respective ellipsoid arc paths for a plurality of locating satellites passing through said inverted cone;

culling, for locating satellites above said geographic location, a total number of possible locating satellites passing through said inverted cone to a less-than-total number of possible locating satellites based on said respective ellipsoid arc paths for said plurality of locating satellites;

identifying a preferred order of search of said less-than-total number of possible locating satellites; and

periodically transmitting said preferred order of search of said less- than-total number of possible locating satellites from a central location to a wireless device within a vicinity of said central location.

18. The method of distributing culled satellite information according to claim 17, wherein:

said vicinity is a service area of said central location.

19. The method of distributing culled satellite information according to claim 18, wherein:

said service area is a cellular service area.

20. The method of distributing culled satellite information according to claim 17, wherein:

said wireless device is a cellular telephone.

21. The method of distributing culled satellite information according to claim 17, wherein:

said plurality of locating satellites are global positioning system (GPS) satellites.

22. The method of distributing culled satellite information according to claim 17, wherein:

said central location is a cellular base station.

23. The method of distributing culled satellite information according to claim 17, wherein:

said periodic transmission corresponds to a periodic update of ephemeris data relating to said possible locating satellites.

24. The method of distributing culled satellite information according to claim 17, wherein:

said periodic transmission occurs every 24 seconds.

25. The method of distributing culled satellite information according to claim 17, wherein:

said periodic transmission is transmitted only upon a change in said culled list of locating satellites.

26. The method of distributing culled satellite information according to claim 17, wherein:

said periodic transmission occurs in response to a request from said wireless device.

27. The method of distributing culled satellite information according to claim 17, wherein:

said culling occurs at each of a plurality of geographic locations.

28. The method of distributing culled satellite information according to claim 17, wherein:

said geographic location is a cellular base station.

29. The method of distributing culled satellite information according to claim 17, wherein:

said plurality of locating satellites are Global Positioning System (GPS) satellites.