Abstract: A wireless detonation system (1) includes a blasting operation device (40), a detonator (10), and a relay device (30). The blasting operation device (40) is disposed at a distance from a blasting face (71) and wirelessly transmits a first downstream signal at a first frequency. The detonator (10) is loaded in a blast hole (72) in the blasting face (71), and has a receiving coil (12) for wirelessly receiving a second downstream signal at a second frequency lower than the first frequency. A relay device (30) includes a first transmitting-receiving antenna (35) that wirelessly receives the first downstream signal, a relay processor (32) that wirelessly receives the first downstream signal and processes it into the second downstream signal to be wirelessly transmitted at the second frequency, and a second transmitting-receiving antenna (37) that transmits the second downstream signal.

Abstract: A communication system that can improve throughput when performing data transmission with respect to a plurality of devices, is provided. The communication system includes a transmitter and a receiver. The transmitter includes a transmitting section which is capable of transmitting a composite packet containing a plurality of packets. The receiver includes a receiving section capable of receiving the composite packet, a data acquisition section configured to take out a packet addressed to own station from the received composite packet, and a transmission control section configured to provide instructions for transmitting a receipt acknowledgement signal after a waiting time period has elapsed after the reception of the composite packet, the waiting time period being provided according to a data location of the packet addressed to the own station in the composite packet.