US Patent 7230536 Property management apparatus, property management method, and property management system

In the present invention, any change of devices in possession by a user who gets on or gets off, for example, a vehicle is detected by comparing the devices detected by wireless communication at the time of getting on or getting off, thereby enabling the easy and sure prevention of any personal belongings of the passenger from being lost or left without constantly monitoring them. The property management apparatus sums up in time series the detection results by the plurality of property detection apparatuses for notifying the user the place of where the user loses the property.