Cross-layer design for TCP performance improvement in Vehicular Communication Networks

In Vehicular Communication Networks, the nodes move in high speed, the topology changes frequently and the channel quality is not stable, which are considered to be the most important factors leading to the deterioration of TCP performance. In this paper, we first analyze the problems of traditional TCP existed in Vehicular Communication Networks. Subsequently, a four-state transition diagram is given and a new TCP congestion control mechanism based on Cross-layer design is proposed, which can predict the reason of packet loss by providing TCP with helpful route and movement information, and can apply appropriate congestion control strategy under different conditions. The simulation results show that the improved TCP performs better than TCP Reno in Vehicular Communication Networks, especially when the channel quality is poor and the nodes move in high-speed.