Improvement of TCP performance in wireless networks

Transmission Control Protocol (TCP) was designed and optimized to work well over wired networks. It suffers significant performance degradation in wireless networks due to their different characteristics, such as high Bit-Error Rate (BER), large and variable delay and bursty traffic. In this thesis, I propose packet control algorithms to be deployed in intermediate network routers. They improve TCP performance in wireless networks with packet delay variations and long sudden packet delays. The ns-2 simulation results show that the proposed algorithms reduce the adverse effect of spurious fast retransmits and timeouts and greatly improve the goodput compared to the performance of TCP Reno. The TCP goodput was improved by ~30% in wireless networks with 1% packet loss. TCP performance was also improved in cases of long sudden delays. These improvements highly depend on the wireless link characteristics.