Setting means does not respond to a transmission signal from a mobile terminal for a predetermined period of time and sets the mobile terminal to a designation value saturation level excess state during a random access process. Data transmission instruction means allocate M resource blocks and N resource blocks (where N is less than M) to the mobile terminal in the designation value saturation level excess state, respectively, and instruct the mobile terminal to transmit signals in which data are inserted into the allocated resource blocks. Power measurement means measures the power of the signals. Determination means determines whether a difference between the measured values when the numbers of resource blocks are M and N is within an allowable range and determines whether the mobile terminal quickly responds to an output power reduction instruction on the basis of the determination results.