TCP New Westwood: A Send-Based TCP Modification in Wired-cum-wireless Networks

The traditional TCP (Transmission Control Protocol) was designed for wired networks which is relatively reliable. However, wireless link is not reliable, and may be interfered by environment. The losses caused by the interference are often misinterpreted by the TCP sender as the loss due to congestion, and this will lead to the poor performance of TCP and the poor utility of the precious bandwidth of wireless link. It is important to shield the TCP sender from wireless error. We propose a new TCP variant called TCP New Westwood which is a sender-based TCP modification to improve TCP performance in heterogeneous wired-wireless network. TCP New Westwood proposes a novel approach of discriminating the reason of packet losses and also adopt it in fast retransmission and fast recovery algorithm. We also propose a new fast recovery algorithm. The simulation results show that the proposed scheme improves transmission performance, especially in networks with high packet loss rates.