Maximizing end-to-end TCP connection’s aggregated throughput in connected vehicle networks

Abstract

Transmission control protocol (TCP) handles a considerable proportion of Internet traffic in connected vehicular networks (CVNs) and encounters a persistent issue with the faulty activation of the rate regulation mechanism during random packet losses or latency fluctuations as well as false timeouts during delayed acknowledgments (ACKs). An enhanced Cubic (e-Cubic) TCP is proposed in this work, which employs enhanced congestion control (e-CC) and enhanced retransmission timeout (e-RTO) algorithms to improve TCP's traffic performance in CVN links. The e-CC algorithm facilitates the accelerated cubic growth function by introducing a new window increment pattern and adjusting the appropriate scaling and elapsed time parameters. Furthermore, e-CC implements a dual verification mechanism to identify congestion and regulate unnecessary rate regulation caused by losses in wireless transmission. The e-RTO algorithm computes and sets the optimal timeout duration to receive delayed ACKs during latency spikes in wireless links, thereby reducing the frequency of false timeouts. The simulation results demonstrate that e-Cubic reduces packet delays and packet loss while increasing the total throughput and delivery rate of TCP traffic in CVN links.