Distribution-aware cache replication for cooperative road side units in VANETs

Increased storage capacity, computing and communications power, coupled with advances in wireless networking technology, bring a potential to enable new applications for vehicular ad hoc network (VANETs), in which a large number of roadside units (RSUs) are deployed to facilitate the service for drivers and passengers in vehicles. In this paper, we focus on a cache replication strategy design for distributed RSUs allocated in a sequence. By exploring the relationship between the RSU allocation and content replication, we found that not only the local traffic flow but also the replication status of neighboring RSUs would affect the content replication efficiency of each RSU. The naive replication of most popular demand items may not always the best solution especially when the RSUs are aggregated in a small area. Accordingly, a distribution-aware replication cooperation (DRC) strategy is developed with the consideration of content replication efficiency and RSU allocation. The results have demonstrated the superiority of our proposed solution, as well as the scalability in the various scenarios with diverse request demands.