The radio terminal 10 includes a communication unit 11 configured to transmit a happy bit to the base station. The base station 100 includes: a comparison unit 126 configured to compare a priority class assigned to a control target terminal with a priority class assigned to a comparison target terminal; a first determination unit 127 configured to determine whether a happy bit rate is lower than a predetermined threshold; and a scheduling unit 120a configured to transmit, to the control target terminal, transmission rate decrease data for decreasing the transmission rate, when the priority class assigned to the control target terminal is lower than the priority class assigned to the comparison target terminal and when the happy bit rate is lower than the predetermined threshold.