Patent ID: 8009621

Claim:
A radio communication system in which a base station transmits, to a radio terminal, transmission rate control data for controlling a transmission rate of uplink user data, wherein the radio terminal includes a terminal side transmitting unit configured to transmit, to the base station, control data indicating whether the transmission rate assigned to the radio terminal is sufficient, and the base station includes: a comparison unit configured to compare a first priority class assigned to a control target terminal with a second priority class assigned to a comparison target terminal, the control target terminal being the radio terminal whose transmission rate is to be controlled and the comparison target terminal being the radio terminal whose transmission rate is to be compared with the control target terminal; a first determination unit configured to determine whether a happy bit rate is lower than a predetermined threshold, the happy bit rate being a ratio of control data indicating that the transmission rate is sufficient for the comparison target terminal, to all of control data consisting of the control data indicating the transmission data is sufficient and control data indicating that the transmission rate is insufficient received from the comparison target terminal; and a base station side transmitting unit configured to transmit, to the control target terminal, transmission rate decrease data for decreasing the transmission rate, when the first priority class assigned to the control target terminal is lower than the second priority class assigned to the comparison target terminal and when the happy bit rate is lower than the predetermined threshold, wherein the transmission rate control signal is transmitted to the control target terminal and the comparison target terminal, and the control data is transmitted from the control target terminal or the comparison target terminal.