TCP SPC: Statistic Process Control for Enhanced Transport over Wireless Links

In this paper, we propose a novel TCP congestion control algorithm, named TCP SPC, which improves upon the performance of TCP Reno in wireless networks. TCP SPC exploits statistic process control (SPC) methods that have been used effectively in a variety of monitoring and control applications other than TCP. A TCP SPC sender uses RTT statistics to judge the network status, whereby the congestion window can be adjusted more intelligently. Comparing with conventional TCP, TCP SPC is more robust to sporadic losses due to wireless channel errors. Such errors often cause conventional TCP to over react, leading to unnecessary congestion window reduction. TCP SPC controls the congestion window in a way that is completely transparent to intermediate nodes and the destination. Therefore, it is compatible with any TCP implementation at the destinations. In this paper, we introduce TCP SPC and its implementation in a simulation environment. The simulation results show that TCP SPC can significantly improve throughput and fairness, especially in wireless networks with high-error links.