Patent ID: 8340019

Claim:
A radio communication system in which first radio terminals transmit uplink user data to a base station through an enhanced dedicated physical data channel and the base station transmits, to the first radio terminals, transmission rate control data for controlling a transmission rate of the uplink user data, wherein the base station includes: a determination unit configured to determine whether or not a total of an initial transmission rate and assigned transmission rates exceeds a maximum receiving transmission rate assignable by the base station when the base station receives a communication start request from a second radio terminal, the initial transmission rate being the transmission rate to be firstly assigned to the second radio terminal, the assigned transmission rates being transmission rates which the base station has already assigned to the first radio terminals; a selecting unit configured to select a decrease target terminal from among the first radio terminals, when the total of the initial transmission rate and the assigned transmission rates exceeds the maximum receiving transmission rate, the decrease target terminal being a first radio terminal for which the transmission rate is to be decreased; and a base station side transmitting unit configured to transmit transmission rate decrease data to the decrease target terminal, the transmission rate decrease data being the transmission rate control data for giving an instruction to decrease the transmission rate, and the base station causes the total of the initial transmission rate and the assigned transmission rates to be equal to or less than the maximum receiving transmission rate by transmitting the transmission rate decrease data, wherein the selecting unit selects a first radio terminal of which the transmission rate exceeds a minimum transmission rate, as the decrease target terminal from among the first radio terminals, the minimum transmission rate being the transmission rate at least to be assigned to each of the first radio terminals; wherein after the initial transmission rate of the first radio terminals is decreased by the assigned transmission rates by transmitting the transmission rate decrease data, the base station is configured to assign the initial transmission rate to the second terminal and accept the communication start request received from the second terminal.