Issues and Improvements in TCP Performance over Multihop Wireless Networks

TCP performance in contention-based multi-hop wireless networks is shaped by two main factors, which are unlike the wired network case. First, the maximum throughput for a given topology and flow pattern is reached at an optimal congestion window. We provide an improved analysis of this effect. Second, the control traffic uses higher proportion of the channel bandwidth than in the wired case. Our results show that the much smaller TCP ACKpackets consume channel resource comparable to the much longer data packets, over high-speed connections. Motivated by this understanding, we reformulate and enhance an existing idea for improving TCP performance by further lowering the number of control packets. Extensive simulations show that our strategy increases the TCP throughput up to 205% compared to the regular TCP, in long-hop wireless networks and 35% in a complex network.