Cognitive radio technology assisted vehicular ad-hoc networks (VANETs): Current status, challenges, and research trends

VANET and cognitive radio network (CRN) are both new emerging technologies in wireless networking. The application of CR concept in wireless communication systems for intelligent vehicles has been envisioned as a promising idea towards solving the problem of scarce spectrum. This paper discusses CR technologies for VANETs aimed at opportunistic spectrum access (OSA) for improved vehicular communication efficiency. This survey explored novel approaches and current research challenges associated with the use of CR technologies in VANETs. Our study is different from previous works in that it presents recent advances, open issues, and future research directions on how to effectively design and deploy CR enabled vehicular networks emphasizing on architecture, CR-VANETs and WAVE Standards, MAC schemes for CR-VANETs, spectrum sensing, minimized interference impact through coordination between PUs and SUs, spectrum management, efficient message routing, security and privacy, as well as CR enabled vehicular networks test-beds and simulation platforms. Furthermore, the paper also identified several challenges facing the design and development of CR-VANTs and the required approaches to tackle them.