PURPOSE: To accommodate a traffic localized in a district and hourly fluctuated flexibly and to attain the excellent profitability by providing a common radio transmitter-receiver and a switching circuit on this system and coupling the antenna of a radio base station and the radio transmitter-receiver optically.

CONSTITUTION: The radio transmitter-receiver making communication with a mobile terminal equipment 10 is not provided in each radio zone but installed as a common radio transmitter-receiver 40 in one or two more locations altogether and the switching circuit 30 is provided which connects the optical combination of radio transmitter-receivers as the common transmitter-receivers 40 to the antennas 20-23 of the radio base station of a radio zone. Then the antennas 20-23 of the radio base station and the radio transmitter-receiver are coupled optically. Thus, each radio base station uses the radio transmitter-receiver in common and the economical and flexible mobile communication system is realized.