US Patent 7328044 Mobile device registration system

To provide a mobile device registration system, with which it is impossible to register from a third party's mobile device which is already registered with respect to one vehicle, a mobile device ID with respect to another vehicle to improve security. The system of the present invention includes: a smart unit mounted in a vehicle that has a unique smart ID corresponding to the vehicle and allows registration a mobile device ID; and a mobile device having a unique mobile device ID and allowing registration of the smart ID. In the system, when the smart unit registers the mobile device ID of one mobile device, the smart unit registers its own smart ID into the one mobile device, and unlocking or locking of the vehicle is performed only when the smart unit detects the mobile device having the mobile device ID that is registered in the smart unit.