A telecommunications system includes a plurality of network clients (150) including a positioning controller (504) and a communications controller (502); and a positioning server (152) including a coordinating controller (161) for maintaining a database of network clients to be tracked and provide updates...http://www.google.fr/patents/US7848761?utm_source=gb-gplus-shareBrevet US7848761 - System and method for global positioning system (GPS) based presence
System and method for global positioning system (GPS) based presence
