Patent attributes
A method for tracking a terminal device having a cellular modem and a positioning module is disclosed. The method comprises monitoring a location of a terminal device through a cellular network using the cellular modem of the terminal device, while the positioning module of the terminal device is disabled; determining that the terminal device enters a first cell of the cellular network based on signals from the cellular modem; enabling the positioning module of the terminal device in response to the determination that the terminal device enters the first cell; and obtaining from the positioning module a first geographical location of the terminal device in the first cell.