Closed group communication method and communication terminal equipment

摘要

In a group communication method which autonomously builds up a closed communication network using a large number of unspecified communication terminals, a calling message including group identification information is broadcast to a large number of unspecified communication terminals from an arbitrary communication terminal, a response message including the group identification information is broadcast from other communication terminal, and a closed communication network is formed of the communication terminal and at least one communication terminal which transmits the response message within a given time whereby a group communication is performed by the communication message using the group identification information.