Patent ID: 7460838

Claim:
A control station for setting up radio communication between a plurality of mobile stations conducting radio communication using a press-to-talk switch, the control station comprising: a group information storage device for, when a group application request to establish radio communication between particular mobile stations is received from a communication device, creating a group table to set up radio communication between the particular mobile stations, generating group information by adding group identification information identifying the group table to the group table thus created, and storing the group information therein; a group identification information transmitter for transmitting the group identification information assigned to the group table to the communication device that is a source of the group application request; a registering section for, when a registration request to the group table and the group identification information are received from at least one particular mobile station, retrieving from the stored group information a group table assigned a group identification information matching the group identification information received from the at least one particular mobile station, and registering information of the at least one particular mobile station that is a source of the registration request to a group table assigned the group identification information received from the at least one particular mobile station; a section for transmitting grant information indicating to the communication device that the registration request to the group table is granted, wherein the registering section registers the the registration request to the group table is granted, wherein the registering section registers the information of the at least one particular mobile station to the group table when the grant information is received; and a radio communication establishing section for setting up radio communication between mobile stations registered in the group table.