PFC: A packet forwarding control scheme for vehicle handover over the ITS networks

When a vehicle moves on roads, it can receive messages from base stations (BSs) and other vehicles. After it moves far away the transmission range, the vehicle tries to find an available link for continuing packet transmission. The disconnecting from the old link and reconnecting with the new link is called vehicle handover in this paper. How to reduce the message transmission time during vehicle handover becomes an important issue for delivering packets over the intelligent transportation system (ITS) networks. The packet transmission time would be long if the transmission path crosses more hops over the ITS network, which makes more transmission time and increases the handover latency. In order to resolve the above problem, we propose a packet forwarding control (PFC) scheme to select a common ahead point (CAP) as the tunnel source to forward packets. The CAP can forward packets to PAR and NAR with the short transmission path. During vehicle handover, packets sent from the data center to vehicles can be forwarded through CAP to NAR directly without having to travel to PAR. As a result, packets can be sent through a shorter delivery path during handover in the proposed PFC scheme. Simulation results show that our proposed method has less packet transmission time and short handover delay.