Maximizing Throughput with Minimum Channel Assignment for Cellular-VANET Het-Nets

In this paper, we study the channel assignment problem in cellular-VANET heterogeneous wireless networks. The D2D communication technology can be applied to VANET. Vehicular device-to-device (D2D) network as an underlying network to the cellular network can share the uplink channel resources of the cellular network. Interference as a critical element has an impact on the utilization in channel assignment. To minimize the interference when allocating channels, we present a novel channel assignment algorithm based on reuse distance. Essentially we have limited spectrum resources that can be shared by vehicular transmitters and cellular users in an area, to assign the minimal number of channels to vehicles in a prescribed area is our first concern. Since the interference between co-channel devices is related to their distance, we divide the area to small hexagon regions then use Region-based Channel Assignment Algorithm to assign different channel sets to each region. In this case, three sets of resources can fulfill the channel assignment requirements to all vehicles. We also prove the theoretical guarantee as approximation factor of 3 for the minimal channel assignment problem. To improve the system throughput with limited channel resources in the HetNets, we propose a Local Search Throughput Maximization algorithm to find the vehicular transmitters and cellular users combinations. We prove the optimal approximation factor is (1-ε) and the complexity of our algorithm in each small region. We show the effectiveness and efficiency of proposed algorithm in experiments.