COMMUNICATION SYSTEM

PROBLEM TO BE SOLVED: To provide a communication system in which a plurality of terminals A and B communicate via higher order devices 1 to 3 and, while one of the terminals is transmitting, a chance of transmission from other terminals using the same channel can be given. SOLUTION: In the higher order devices, when a communication repeating means repeats communication performed by the plurality of terminals and a notification means receives a transmission request signal transmitted from the terminal which is receiving by using an assigned channel, the notification means transmits a prescribed notification signal to the terminal which is transmitting. In the terminals, a transmission request means transmits a transmission request signal to the higher order device, a communication means performs communication, a notification receiving means receives the notification signal, and an output means performs prescribed output in accordance with the reception of the notification signal. COPYRIGHT: (C)2007,JPO&INPIT