Coded multicasting in cache-enabled vehicular ad hoc network.

Caching popular content at a wireless network edge has attracted significant attention since it can deal with massive content delivery in wireless networks. Furthermore, coded multicasting can impressively reduce network traffic by eliminating duplicate data transmission. In this paper, we study to minimize data traffic and redundant problem by jointly considering coded multicasting and edge caching in vehicular ad hoc networks (VANETs). For a single RSU scenario, a maximum degree priority algorithm is proposed to partition users into multiple multicast groups. And then, we formulate the problem of minimum data traffic and minimum redundant rate data for each multicast group as a multi-objective optimization problem, which is a multi-objective set coverage problem. Subsequently, we propose an efficient heuristic algorithm with a subfile code technique and coded multicasting in each multicast group to solve the problem. For a dense network with coverage of multiple RSUs overlapped with each other, the network flow method is used to reassign users to a specific RSU, and then an effective algorithm is proposed to address the general problem. The simulation results show that our proposed algorithm can improve the bandwidth usage and reduce the redundant rate effectively.