| 摘要 |
A system and method for determining the location of a location tracking device, employs a satellite based location determining infrastructure and a wireless data communications network. A location tracking device which cannot easily obtain valid ephemeris data from the satellite based location, determining infrastructure, requests the necessary data from a data set stored at a tracking device hub via the wireless communications network. The tracking device hub determines and transmits an estimated position of the location tracking device to the location tracking device, along with the appropriate required valid ephemeris data, to allow the location tracking device to determine its location. If the location tracking device is still unable to make a location determination from the satellite based location determining infrastructure, then the estimated location can be provided. The base station topography is self-determined by a process executing in the system and can include base stations from different networks. |
