Content Replication Scheme Using Stable Matching in Vehicular Networks

Present researches on content replication in vehicular networks mainly utilize the mobile vehicular nodes to carry contents, while the high mobility, the limited resources and the security risks of vehicular nodes prohibit the performance enhancements. In this paper, we propose a content replication scheme using stable matching, namely RSM, in which the roadside units take the role of content carriers. For an efficient solution in terms of the access ratio and the access delay, the original content replication problem is formulated as a stable matching problem of bipartite graph, whose left vertices stand for the contents and whose right vertices for the storage cells of roadside units. Given a preference ranking of each content based on its response quota and a priority ranking of each storage cell based on its encountering latency quota, the weak-ordering stable matching problem is solved in polynomial time through Gale-Shapley algorithm and the stable improvement cycles algorithm. Besides, a multi-replica preprocessing algorithm is designed to substitute several new contents for a content having more than one replica, and thus to overcome the potential one-to-many mapping in stable matching. Experiments show that the RSM scheme achieves a high access ratio and a small storage cost with an acceptable access delay.