Abstract
TCP congestion control \cite{JacV.98} has been widely discussed on the different networks under wireline or wireless environment. Many research studies have been raised to help TCP be more sensitive to congestion state of the network by adding explicit notifications in TCP connection or letting the intermediate in the network to join TCP congestion control. In GPRS/EGPRS systems and other 3G cellular networks, the radio network controller chooses among several channel coders according to the signal to interference ratio. Hence, the channel data rate that an individual user experiences is time-dependent and variable. In this paper, we propose a TCP window control mechanism that adapts to the variable channel data rates. Our simulations show that the rate adaptive window adjustment scheme decreases the buffer occupancy and packet transmission delay, and achieves better throughput utilization when compared with the standard TCP Tahoe version and the Reno version.