An adaptive simulated annealing-based computational offloading scheme in UAV-assisted MEC networks

Mobile edge computing (MEC) is an advanced technology that enables fifth-generation (5G) applications. It uses a mechanism to offload computation from mobile devices (MDs) to edge servers at the access point (AP) to improve the quality of computation. By leveraging the strengths of unmanned aerial vehicles (UAVs), we can install edge servers on UAVs to support task offloading. However, this is constrained by the limited computational resources of UAVs and high energy consumption. Due to the complexity of such architecture, the joint optimization of energy consumption and delay by applying classical optimization algorithms cannot work well either. So far, there is no research work that addresses the problem of computation offloading in UAV-based MEC networks considering the UAV-AP-MD architecture that is well applicable in 5G scenarios; this motivates us to propose this work. We first formulate this problem as an optimization problem and then develop an adaptive simulated annealing-based method for joint optimization of energy consumption and delay. We design a mechanism to dynamically increase the cooling rate as a function of decreasing temperature to achieve better convergence, and implement a task queue for MDs and servers. Finally, we perform numerical simulations and find that the proposed method reduces the energy consumption (17%) and delay (50%) of MDs and UAV while it has the best task dropped rate (50%) and fairness (4.2%) compared to other known methods.