Terminal device, management device, storage medium adapted for communication between multiple terminal devices within a group

1. A terminal device used in a communication system where a group including a plurality of terminal devices is formed and communication is performed by using at least one base station device to assign a channel to each group, the terminal device comprising:

an authentication processing unit that performs an authentication process for authenticating a user using the terminal device when a predetermined user operation is performed;

a reception unit that receives information on a situation of authentication of a plurality of terminal devices belonging to an ordinary group from the base station device,

wherein the terminal device belongs to the ordinary group, and

wherein both a terminal device for which user authentication is completed and a terminal device for which user authentication is not completed being allowed to subscribe to the ordinary group;

a selection unit that selects at least one of:

(i) only the ordinary group, the ordinary group being selected when the authentication processing unit has not completed an authentication process for authenticating a user using the terminal device, or

(ii) one of an authenticated group, formed only by terminal devices for which an authentication process for authenticating a user is completed in the authentication processing unit, and the ordinary group, as a destination of transmission; and

a transmission unit that transmits data via a channel assigned by the base station device to terminal devices belonging to the group selected by the selection unit.

2. The terminal device according to claim 1 , wherein:

when the ordinary group is selected in the selection unit, the reception unit uses the channel assigned by the base station device to the ordinary group for reception, and

when the authenticated group is selected in the selection unit, the reception unit uses the channel assigned by the base station device to the authenticated group for reception.

3. The terminal device according to claim 1 , further comprising:

a notification unit that outputs information related to the ordinary group and the authenticated group selectable in the selection unit.

4. A non-transitory computer-readable recording medium having embedded thereon a program for a terminal device used in a communication system where a group including a plurality of terminal devices is formed and communication is performed by using at least one base station device to assign a channel to each group, the communication being performed from a terminal device included in a group to which a channel is assigned to another terminal device included in the group, the program comprising:

performing an authentication process when a predetermined user operation is performed;

receiving information on a situation of authentication of a plurality of terminal devices belonging to an ordinary group from the base station device,

wherein the terminal device belongs to the ordinary group, and

wherein both a terminal device for which user authentication is completed and a terminal device for which user authentication is not completed being allowed to subscribe to the ordinary group;

selecting:

only the ordinary group when an authentication process for authenticating a user using the terminal device has not been completed, or

one of two groups of different categories including:

an authenticated group, formed, of the plurality of terminal devices belonging to the ordinary group, only by terminal devices for which an authentication process for authenticating a user is completed, and

the ordinary group; and

transmitting data via a channel assigned by the base station device to terminal devices belonging to the selected group.