A communication system includes a first communication apparatus included in an initial station, the first communication apparatus transmitting a signal to the intermediate station on a later stage, the first communication apparatus receiving a signal sent from the terminal station and passed through the intermediate station, a second communication apparatus included in the intermediate station, the second communication apparatus receiving a signal from a preceding station and transmitting the signal to a later station, the second communication apparatus passing a signal from the later station to the preceding station, and a third communication apparatus included in the terminal station, the third communication apparatus receiving a signal from the intermediate station on a preceding stage, the third communication apparatus transmitting a signal being passed through the intermediate station and being received at the initial station.