Abstract: A communication device includes a communication module to communicate with a first device by at least transmitting or receiving first data in a first data segment included in multiple time segments defined by a shared time shared with the first device and corresponding to a type of the first data, a reception module to receive second data transmitted from a second device independently of the time segments, a relay module to relay, when a destination of the second data includes the first device, the second data to be transmitted in a second data segment being a time segment corresponding to a type of the second data, and transmission module to transmit in an instruction segment, to the second device, instruction data to specify a length of time for which transmission of the second data is suspended. The instruction segment is a time segment for transmitting the instruction data.