The relay unit according to the present invention is a first receiving portion for receiving a first radio signal, a first reception intensity information generating portion for generating a first received intensity information about the received intensity, and a first reception strength information to be transmitted to the receiving device with a first radio signal A transmitter, a first receiver having a first receiver, a second receiving portion for receiving a first radio signal, a second reception intensity information generating portion for generating a second reception intensity information on the received intensity, and a second received intensity information different from the frequency of the second radio signalThe frequency of the frequency or the transmission timing of the second radio signal is provided with a second transmitter which transmits a third radio signal having different transmission timings to the receiver, and a second repeater having the second transmission.本発明に係る中継ユニットは、第1の無線信号を受信する第1の受信部と、受信強度に関する第1の受信強度情報を生成する第1の受信強度情報生成部と、第1の受信強度情報を第1の無線信号で受信装置に送信する第1の送信部と、を有する第1の中継器と、第1の無線信号を受信する第2の受信部と、受信強度に関する第2の受信強度情報を生成する第2の受信強度情報生成部と、第2の受信強度情報を、第2の無線信号の周波数とは異なる周波数、又は第2の無線信号の送信タイミングとは送信タイミングが異なる第3の無線信号で受信装置に送信する第2の送信部と、を有する第2の中継器と、を備える。
