  Vehicular Ad hoc NETworks (VANETs) as the basic infrastructure can facilitate
applications and services of connected vehicles (CVs). Cognitive radio (CR)
technology is an effective supplement and enhancement for VANETs. It can reduce
the impact of deficiency of spectrum resource in VANETs. Although CR-VANETs can
utilize the unused licensed spectrum effectively, the distributed nature of
CR-VANETs may open a door for different attacks, such as spectrum sensing data
falsification attack. In this paper, we propose a joint RSU and vehicle-based
light-weighted cloud for CR-VANETs. Based on this cloud computing model, we
propose a new service named Spectrum Sensing as a Service (SSaaS), which can
perform a cooperative spectrum sensing in CR-VANETs with cloud computing
assistance to secure the spectrum sensing procedure. As a result, a reliable
service can be obtained in CR-VANETs. Simulation results show that the cloud
computing in CR-VANETs can effectively reduce latency and improve the security
of CR-VANETs.
