US Patent 7155238 Wireless location determining device

The present invention discloses a system and a method to locate moving objects, such as people, pets and vehicles, over a wide area, by attaching small wireless devices, such as Bluetooth transceivers, to said objects and determining the location of said devices. The location of said wireless devices is determined by achieving ad-hoc short range wireless connectivity between said devices and communication devices such as Bluetooth enabled mobile phones that pass by, where said latter communication devices can be located by other means, such as GPS or network-based techniques.