When any remote unit (113–118) desires to create a talk group, it transmits an inbound message to a group call database (112). The inbound message includes the identity of the requesting communication device, and the participants of the talk group. Upon receiving the request, group the call database...http://www.google.com.au/patents/US7184790?utm_source=gb-gplus-sharePatent US7184790 - Method and apparatus for establishing a talk group
