Efficient Maintenance of AODV Routes in the Vehicular Communication Environment with Sparsely Placed Road Side Units

Thanks to the vehicular communication network, vehicles on the road can communicate with other vehicles or nodes in the global Internet. In this study, we propose an enhanced routing mechanism based on AODV so that road side units (RSUs) can provide continuous services such as video streaming services to vehicles which may be intermittently located outside of the coverage areas of RSUs. In the highway environment with sparsely placed RSUs, the communications between RSUs and vehicles are frequently disconnected due to high vehicular speeds. To resolve this problem, both V2I and V2V communications are utilized. In order to reduce the route recovery time and the number of route failures in the sparsely placed RSU environment, backup routes are established through the vehicles with longer direct communication duration with the RSU. The backup route substitutes the main route upon route disconnection. Also, for the efficient handover to the next RSU, the route shortening mechanism is proposed. For the performance evaluation of the proposed mechanism, we carried out the NS-3-based simulations.