A remote radio head disposed between a baseband unit and a host unit. The remote radio head may transmit and receive a digital optical signal to the baseband unit, transmit and receive an analog optical signal to the host unit, and convert the digital optical signal and the analog optical signal, a frequency of the analog optical signal transmitted and received by the remote radio head and the host unit may be an intermediate frequency of a baseband, the host unit may be disposed between the remote radio head and a radio unit, the host unit and the radio unit may transmit and receive the analog optical signal, and the frequency of the analog optical signal transmitted and received by the host unit and the radio unit may be the intermediate frequency with a baseband signal.