Improving TCP Performance Over Wireless Links

TCP is the most common transport layer protocol used in Internet today. It has been designed primarily for wired networks. Over the last few years, wireless technology has matured, and several people connect their laptops to the Internet through wireless techniques. The characteristics of wireless links is very different from wired links, particularly in terms of loss behaviour. This results in poor TCP performance over wireless links. In this paper, we have proposed enhancements to TCP so that it can differentiate between a loss due to congestion in the wired network, and a loss due to noise in the wireless link. With this knowledge, TCP can react differently to the two kinds of losses, leading to improved performance. The modified TCP is compatible with existing implementations. Performance of a TCP connection over wired network is not affected by this change. The overhead of our scheme is also very low.