A Data Dissemination Strategy in SDN Enabled Vehicular Networks

In a vehicular network, the vehicles generally need to handoff among RSUs (Road Side Units) frequently on highways due to their rapid mobility and the limit of RSU’s radio coverage. This issue may cause a series of problems such as data transmission interruption or increasing of the transmission delay. In this paper, we took advantages of the emerging idea of SDN to improve the performance of the vehicular networks. Specifically, we proposed a SDN-based framework for the vehicular networks. In this framework, we developed three function modules over the SDN application layer. And then by installing appropriate rules on OpenFlow enabled RSUs, the controller can execute a wise scheduling of RSUs’ downlink streams. In addition, based on this framework, we proposed a data dissemination strategy when a vehicle handoff among the RSUs to reduce the latency especially for bulk traffic. Simulation results demonstrate that our solution can significantly reduce the latency and the retransmission rate. In the paper, we adopted classical DCF mechanism in the IEEE 802.11p standard to implement our protocol, which makes our solution practical and compatible with previous drafts.