Task Offloading for Post-disaster Rescue in Vehicular Fog Computing-assisted UAV Networks

Abstract

Due to more flexible mobility, better line-of-sight (LOS) and faster on-demand deployment, unmanned aerial vehicles (UAVs) play a unique role for assisting post-disaster rescues, which often require UAVs to perform computationintensive rescue missions. However, UAVs generally have inherent limited computational capacity and battery storage, which makes it challenging to complete the heavy computing tasks within short period of time during the complicated postdisaster recovery. To overcome this issue, we introduce the vehicular fog computing (VFC) system in which a UAV splits and assigns the heavy tasks to the ground vehicles. First, to evaluate the performance of the VFC-assisted UAV network task offloading, the task processing latency and energy consumption are incorporated into a system utility construction. Moreover, we propose a joint UAV and vehicular task assignment scheme (JUVTAS) with the aim of optimizing the performance of the network. Specifically, we propose a genetic algorithminvasive weed optimization (GA-IWO) algorithm to achieve the approximately optimal task assignment strategy. The GA-IWO algorithm combines the global search ability of genetic algorithm and the local search ability of invasive weed optimization to achieve a better optimization performance. Simulation results show that the proposed JUVTAS is able to effectively reduce the latency and energy consumption for task processing. Moreover, JUVTAS achieves superior performance compared to several conventional methods.