A vehicle location system which provides a plurality of cellular systems that each includes a memory for identifying the cellular subscriber stations that are based in the particular system and visiting cellular subscriber stations based in another of the systems. The plurality of cellular systems include...http://www.google.fr/patents/US5432841?utm_source=gb-gplus-shareBrevet US5432841 - System for locating and communicating with mobile vehicles
System for locating and communicating with mobile vehicles
