TCP performance and its improvement over wireless links

TCP performs reasonably well over the Internet where packet losses are mainly due to network congestion. However, TCP suffers significant throughput degradation over hybrid wireless/IP networks where packet losses are also due to transmission errors in wireless segments and during end-host handovers. In this paper, the micro-scale behavior and packet-level performance of four popular TCP variants over wireless links are assessed, and a modified TCP sender which incorporates a heuristic segment-in-flight estimation algorithm to improve the TCP throughput is proposed. Extensive simulations show that the modified TCP achieves better end-to-end performance, and still keeps the fairness and the compatibility with ordinary TCP variants.