Patent ID: 7096018

Claim:
A group communication systems comprising: one or more control stations; one or more base stations connected to the control station via a wire line or a wireless line; and a plurality of mobile stations connected to the base stations via wireless lines, wherein the control station or the base station comprises means for controlling a group communication number which is under communication via any of said base and control stations, the group communication number being an identification number for a group communication made up of a group of mobile stations from among said plurality of mobile stations, and the mobile station comprises means for transmitting a group communication number together with a mobile station identification number upon executing location registration of the mobile station, and wherein in response to receiving a group communication number transmitted together with a location registration signal from the mobile station, said control station or said base station comprises means for examining the presence or absence of a call based on the group communication number and a group number controlling register that identifies which group communication calls are active, the mobile station being notified when a relevant group communication call is present so that the mobile station receiving the notification is allowed to participate in the group communication through a calling procedure based on the group number, automatically or through operation by a user of the mobile station.