Patent ID: 7539174

Claim:
A mobile communication system in which data is transmitted and received through a wireless transmission line between a mobile station device and a network-side device, the system comprising: a receiving-side device; and a transmitting-side device, the receiving-side device comprises a retransmission request transmitter configured to transmit, to a transmitting-side device, a retransmission request for requesting retransmission processing on each data unit of the data when a reception error is detected in the data unit, and the transmitting-side device comprises a retransmission time storage configured to store a retransmission time at which the retransmission processing is performed on the data units, a retransmission controller configured to perform the retransmission processing on the data unit related to the retransmission request when the retransmission request is received from the receiving-side device, and the retransmission controller is configured to control so as not to perform the retransmission processing on the data unit related to the retransmission request when the retransmission time of the data unit is stored and a difference between the retransmission time and a current time is shorter than a retransmission prohibition period, even when the retransmission request is received from the receiving-side device, and a retransmission prohibition period manager configured to update the retransmission prohibition period by adding a difference between target acknowledgement waiting buffer usage and current acknowledgement waiting buffer usage divided by transmission bandwidth to a current retransmission prohibition period.