A wireless base-station system includes a base-station main apparatus, multiple local wireless apparatuses for transmitting/receiving baseband signals for respective mobile terminal devices to/from the base-station main apparatus, and a baseband server. The baseband server distributes a downlink signal, containing the baseband signal to be transmitted from a high-order apparatus to the mobile terminal device via the base-station main apparatus, to the local wireless apparatuses installed in the sub areas in the service area in which the mobile terminal device exists. The baseband server further combines multiple uplink signals which are received from the local wireless apparatuses installed in each sub area in the sub area in which the mobile terminal device exists and which are to be transmitted from the mobile terminal apparatuses to the high-order apparatus. The baseband server further transmits a resulting uplink composite signal to the base-station main apparatus.