Abstract
Software-defined networking (SDN) is a new paradigm that consists in decoupling the control plane from the data plane, which offers the flexibility of configuring and managing networks. Recently, an extension of SDN to vehicular ad hoc networks (VANETs), named software-defined vehicular networks (SDVN), has been emerged to expand the capabilities of VANET in terms of the provided services and to overcome the VANET issues. Also, SDN has gained a lot of interest to be involved in the extensions of VANET, which are vehicular cloud and vehicular fog. In this paper, we overview the use of SDN in VANET. We survey its deployment in the classic vehicular networks, 5G-VANET, vehicular cloud, and vehicular fog. Thereafter, we discuss some case studies of SDN in the vehicular context. Then, we present a taxonomy of the existing architectures followed by the major challenges in the implementation of SDN in the vehicular context. Next, we review the tools used to simulate SDN-based VANET scenarios. Finally, we give some future research directions.