Patent ID: 8022867

Claim:
A mobile station comprising: charging and tracking modules adapted to be disengagably coupled together, wherein the tracking module comprises (i) tracking circuitry for determining at least one position of the tracking module using only a user-plane service in a satellite positioning system for wireless cellular communication, and (ii) a chargeable source for supplying power to the tracking circuitry when disengaged from the charging module, and wherein the charging module is operable to charge the chargeable source when the charging module is coupled to the tracking module; and wherein the tracking module further comprises memory for storing the at least one position of the tracking module, wherein the tracking module is operable to provide from the memory the at least one position; and wherein the tracking circuitry comprises: (i) a first receiver for obtaining from the satellite positioning system satellite signals, and (ii) a second receiver for obtaining from the satellite positioning system, via the user plane service, assistance data for determining the position of the tracking module; wherein the second receiver is operable to exchange with a global user-plane center: (i) a request for the assistance data, the assistance data corresponding to a position estimate for the tracking module; and (ii) exchange with the global user-plane center the assistance data.