Patent ID: 7801550

Claim:
A radio communication system in which a radio terminal transmits uplink user data to a base station through an enhanced dedicated physical data channel and the base station transmits, to the radio terminal, transmission rate control data for controlling a transmission rate of the uplink user data, wherein the base station includes: a first selecting unit configured to select as a reduction target terminal the radio terminal of which an assigned transmission rate is to be reduced, where the assigned transmission rate is the transmission rate that the base station has already assigned to the radio terminal; a first calculating unit configured to calculate a reduction amount of the assigned transmission rate assigned to the reduction target terminal selected by the first selecting unit; a second selecting unit configured to select as an increase target terminal the radio terminal of which the assigned transmission rate is to be increased; a second calculating unit configured to calculate an increase amount of the assigned transmission rate assigned to the increase target terminal selected by the second selecting unit; and a transmitting unit configured to transmit, to the reduction target terminal, the transmission rate control data indicating the transmission rate after the assigned transmission rate is reduced by the reduction amount, and that transmit, to the increase target terminal, the transmission rate control data indicating the transmission rate after the assigned transmission rate is increased by the increase amount, the second selecting unit selects the increase target terminal when the reduction target terminal is not selected by the first selecting unit, the second calculating unit calculates the increase amount not to exceed an allowable receiving transmission rate, when the reduction target terminal is not selected by the first selecting unit, and the allowable receiving transmission rate is equal to or lower than a maximum receiving transmission rate assignable by the base station.