Group communication system, group ID number issuing apparatus, and call control apparatus

There is provided a group communication system allowing group communication to be performed by a simple operation as well as a group ID number issuing apparatus and a call control apparatus to be applied to such a group communication system. When a user takes a group organization procedure to the group communication system, a group representative telephone number representing the group is issued. After the group representative telephone number is issued, the group representative telephone number can be used in the same manner as for calling a subscriber to call a group member to perform group communication. The group communication can be performed by limiting to a lower level subgroup, a pair of the group representative telephone number and an identifier can be used instead of the subscriber's telephone number to determine the calling partner to make a call.