A inter-station transmission method of extending time allocated for a transmission path delay of an inter-station transmission path within a predetermined turnaround time, and increasing an inter-station transmission distance. A radio base station reproduces a clock synchronized with a BSU transmission clock DCLK used when transmitting downlink transmission data from a communication control station. The radio base station processes the downlink transmission data. The clock synchronization eliminates a necessity of data format conversion between the communication control station and the radio base station, a buffer accumulating transmission data in preparation for the conversion is not necessary. This reduces a turnaround time of a mobile communication system. When the inter-station transmission method is applied to dedicated short-range communications, having a fixed turnaround time, a distance between the communication control station and the radio base station can be increased by a distance according to the eliminated delay time.