BASE STATION DEVICE, RADIO COMMUNICATION SYSTEM, AND PACKET COMMUNICATION METHOD

摘要

A control unit (115) calculates the timing of the actual time−out on the basis of time−out information and outputs an MCS control signal serving as a control signal for commanding a change of the modulation method to a layer−2 downlink processing unit (111) if the timing of the actual time−out comes soon. The layer−2 downlink processing unit (111) subtracts the number of levels of modulation from data stored in a memory on receiving the MCS control signal from the control unit (115) and modulates the resultant data. A layer−1 transmitting unit (112) subjects the output signal from the layer−2 downlink processing unit (111) to a radio processing and transmits the processed signal from an antenna by radio. In such a way, a time−out is prevented from occurring before a terminal of the transmission part receives an ACK signal even though a radio terminal has transmitted the ACK signal by radio. Degradation of the TCP through−put due to the reduction of the size of the data next transmitted at a time is prevented.