A Scheme for Flexible-Hybrid Subtask Offloading in a Two-Tier UAV- Assisted MEC Network

As a technique to buffer the conflict between computation-intensive tasks and capability-limited devices, unmanned aerial vehicle-enabled mobile edge computing (UAV-MEC) has been witnessed as a promising approach. In this paper, we consider an optimization of dependent and independent subtasks hybrid offloading to maximize the utility, which is decided by the weighted sum of makespan gain and energy consumption gain. Firstly, we design a two-tier UAV-assisted MEC offloading architecture to obtain efficient and cooperative communication between the ground command centers and the UAVs. Secondly, we develop a flexible-hybrid subtask offloading scheme(F-HSO) to obtain the optimal solution of the problem in a parallel and sequential manner. Numerical results show that our algorithm can significantly outperform the other representative benchmarks in utility.