A New Protocol to Improve Wireless TCP Performance and Its Implementation

Traditional transport protocols suppose that packet losses are mainly due to congestion. However, wireless networks are characterized by losses due to transmission errors occurring frequently. Traditional TCP interprets these losses as congestion and invokes congestion control mechanisms resulting in degradation of performance. In this paper, we introduce two mechanisms to improve performance of TCP in wireless networks. First, we apply modification to the congestion control algorithm of TCP at sender side without requiring the cooperation either of the network or of the receiver. Secondly, we introduce variable segment size that has a reaction mechanism for non-congestion losses. Through simulation, we find that TCP with those two mechanisms improve the performance of TCP over wireless networks. After the verifying by extensive simulation, we implement our modified wireless TCP protocol on some Linux PCs. The running results are close to the simulation.