A communication system in which a communication apparatus includes a calculation unit configured to calculate, upon receiving a search signal from a new communication apparatus, a first time length by multiplying a first weighting time length by a relay count in a communication route to a destination, a second time length by multiplying a second weighting time length shorter than the first weighting time length by the signal strength of each communication link in the communication route, and a third time length by adding the first and second time lengths, and a transmission unit configured to transmit a response signal upon passage of the third time length from the receipt of the search signal, wherein upon receiving the response signal from one of the communication apparatuses ahead of any other response signals, the new communication apparatus sets the one of the communication apparatuses as the most adjacent relay point.