Radio base station and a mobile communication method

The present invention provides a radio base station and a mobile communication method, a radio base station (BTS) comprises: decision unit (25), based on a predetermined frequency band, the frequency band of the wired transmission path not used, the wired transmission path by the mobile station ( UE) frequency band used is determined from the radio network controller (RNC) transfer rate of data to the radio base station (BTS) transferred; and a notification unit (26), which is configured to notify the transfer rate determined by the radio network controller (RNC). Thus, when the wireless transmission path determination between (UE) and a mobile station in a particular radio base station (BTS) or other specific mobile station buffer having margin does not decrease in the radio base station from the radio (BTS) in control means (RNC) of a radio base station (BTS) forwarded to a specific mobile station (UE) as destination data transfer rate.