Patent ID: 7843384

Claim:
A communication terminal for use in a vehicle comprising: a GPS unit capable of determining a position by using a Global Positioning System with a supply of power from a battery in the vehicle; a communication unit capable of communicating wirelessly with a communication network through a station; and a control unit capable of controlling operation of the GPS unit, wherein the communication unit stops the operation of the GPS unit that is in operation at a time of parking of the vehicle for a first time under control of the control unit, and stores a station number received from the station that serves as a waiting station when the vehicle is put in a parking condition, the communication unit starts, as a first wake-up of the GPS unit, by using the control unit, the operation of the GPS unit that has been stopped when the stored station number at the time of parking and a currently received station number do not match with each other, and sends position information derived from the GPS unit through measurement by the Global Positioning System to the communication network, the communication unit stops the operation of the GPS unit for a second time under control of the control unit after sending, to the communication network, the position information in the first wake up of the GPS unit, the communication unit changes a wake-up condition of the GPS unit for a second wake-up in comparison to the wake-up condition for the first wake-up after stopping of the operation of the GPS unit for the second time, the wake-up condition of the GPS unit being changed by erasing the station numbers with older times of reception operation from the base station and not erasing the station numbers with newer times of reception operation, and the communication unit starts, as the second wake-up, the GPS unit based on the wake-up condition for the second wake-up when the changed wake-up condition for the second wake-up is fulfilled.