Abstract: In the present system, the distributor includes: distributing means which distributes downlink communication data, received from said radio base station through said optical transmission path, to said plurality of remote radio base station apparatuses; and combining means which combines uplink communication data received from said remote radio base station apparatuses through the wire transmission path and transmits the combined communication data to said radio base station through said optical transmitting path, and the remote radio base station apparatus include: transmitting means which transmits the downlink communication data, received through said wire transmission path, by radio; and receiving means which transmits uplink data, received by radio, to said relay apparatus through said wire transmission path.

Abstract: An apparatus for a transmission-reception simulation test between a transmitter and a receiver located in the same station includes a testing device coupled to the transmitter and the receiver. The testing device includes, a first frequency converter for microwave frequency to microwave frequency conversion for producing a mixed signal of the output signal of a transmitter having a frequency f.sub.rf1 and a second local oscillator signal having a frequency f.sub.l2, a low-pass filter, and a second frequency converter for intermediate frequency to microwave frequency conversion for producing a mixed signal of the output signal of the low-pass filter and a first local oscillator signal having a frequency f.sub.l1, the output signal of the second frequency converter having a frequency f.sub.rf2 being supplied to a receiver.