Patent ID: 8121609

Claim:
A method for determining the location of a location tracking device which employs a satellite-based positioning system, when the location tracking device does not have at least some of the ephemeris data required from the satellite-based positioning system to determine its location, comprising the steps of: the location tracking device sending a request to a remote data device, via a wireless data communication link provided by a radio data communications network, the request including (i) a set of identifiers and (ii) respective time delay data, for a plurality of wireless network base stations which the location tracking device can receive signals from; the remote data device receiving, via the wireless data communication link, the request from the location tracking device and processing the set of identifiers and time delay data against a determined topography of radio data communication network base stations to determine an estimated location of the wireless location tracking device; the remote data device selecting, based upon the estimated location, ephemeris data for a plurality of satellites each of which should be visible to the location tracking device, and transmitting to the location tracking device, via the wireless data communications link, the estimated location, the current time, and the selected ephemeris data; and the location tracking device receiving, via the wireless data communications link, and employing the estimated location, the current time, and the selected ephemeris data to receive appropriate signals from the satellite-based positioning system to determine the location of the location tracking device.