Online Energy-efficient Scheduling Algorithm for Renewable Energy-powered Roadside units in VANETs

Road-side unit (RSU) plays an important role in providing connectivity among the vehicles on the road. In rural areas, RSUs are powered using renewable energy, such as solar or wind energy. Hence, the energy consumption across such RSUs should be efficient i.e., energy consumption at RSUs should be minimized and no RSU gets over-utilized while others are under-utilized. The amount of energy consumption depends upon the scheduling of different kinds of data requests at RSU. In this paper, we propose a scheduling architecture for minimizing energy consumption at RSU and attaining uniform energy consumption across neighboring RSUs. This, in turn, increases the request fulfillment percentage at RSUs. The proposed architecture categorizes the incoming request as a Traditional (less computation) or a Smart request (high computation). Two approaches- Hard-deadline Less Computation requirement Approach (HLCA) and Soft-deadline High Computation requirement Approach (SHCA) are proposed for addressing Traditional and Smart data requests, respectively. In HLCA approach, the receiving RSU uses the scheduling metric to select the servicing RSU for request fulfillment. We prove by analysis, how scheduling metric helps in minimizing and achieving uniform energy consumption across the RSUs. In SHCA approach, Fog computing is used for handling high computation requests. Energy consumption at RSUs is further optimized by using Auction game-based relay vehicle selection mechanism. Simulation results demonstrate that our proposed approaches achieve uniform energy consumption across multiple RSUs and 10% more efficient than scheduling algorithms for single RSU model such as Nearest Fastest Set Scheduler (NFS).