A user designated as a group leader of a group of users manages location information for the group of users using a base device. In particular, a client device is identified for each user in the group of users and an area within which each user in the group of users is to remain is defined. Subsequently,...http://www.google.fr/patents/US7660872?utm_source=gb-gplus-shareBrevet US7660872 - Managing location information for a group of users
Managing location information for a group of users
