US Patent 7539505 Method of performing a dynamic push-to-talk service

The invention concerns a method of providing a Push-to-Talk (=PTT) based communication service to subscribers of the PTT service by means of a PTT server which dynamically creates a PTT group. A requesting subscriber sends a call request message to a PTT server. The call request message is analyzed by a request processing unit and the data gathered from the analysis are correlated with profiles of subscribers of the PTT service. Based on the correlation results, the PTT server dynamically creates a PTT group comprising the requesting subscriber and one or more subscribers selected from the other subscribers of the PTT service. The PTT server sends an invitation message to the selected subscribers for establishing a PTT call and establishes a PTT communication connection among the terminal of the requesting subscriber and terminals of selected subscribers an approval message was received from.