Patent ID: 8665713

Claim:
A radio communication system in which a radio terminal transmits, to a base station, uplink user data via 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 base station side transmitter unit configured to transmit, to the radio terminal, transmission rate decrease data instructing a decrease of the uplink transmission rate assigned to the radio terminal, when the uplink user data is not transmitted from the radio terminal to the base station using the transmission rate assigned to the radio terminal, wherein the radio terminal includes a terminal side transmitter unit configured to transmit, to the base station, uplink scheduling information including at least buffer information of the radio terminal indicating a buffer amount of the uplink user data stored in the radio terminal, the base station further includes a determination unit configured to determine whether the buffer information is obtained, and the base station side transmitter unit transmits, to the radio terminal, the transmission rate decrease data when the buffer information is not obtained.