Optimal access mode selection and resource allocation for cellular-VANET heterogeneous networks

In recent years, the vehicular ad-hoc networks (VANETs) have attracted plenty of attention. However, VANETs can hardly meet surging demands of mobile data. Device-to-device (D2D) communication is regarded as a promising method for providing the reliable connectivity between vehicles. The heterogeneous networks including conventional cellular network and VANETs, where the cellular links and the D2D-based vehicle-to-vehicle communication links coexist by reusing the same spectrum resources, result in a more complicated interference scenario. Thus the access mode switch and resource allocation between cellular and VANETs becomes a challenging issue. In this study, the authors formulate an optimal access mode selection and resource allocation scheme as a user aggregate utility maximisation problem with the joint consideration of various network topologies, transmission delay and power reduction. To reduce the high computation complexity, they provide a distributed algorithm that converges to a near-optimal solution via augmented Lagrangian technique. Numerical results show that remarkable throughput gains are achieved relative to the existing work, especially for large-scale networks. The network throughput can be considerably improved as well due to power reduction.