Minimizing Delay in UAV-Aided Federated Learning for IoT Applications With Straggling Devices

The Internet of Things (IoT) applications generate large volumes of data, which needs to be processed securely, reliably, and promptly for effective decision-making. However, the limited processing capability of IoT devices is a significant bottleneck in processing these datasets. In scenarios like forest fire surveillance, flash flood alert systems, or wildlife activity tracking, where IoT devices are deployed in remote locations and only need coverage for a few weeks a year, thus deploying permanent base stations is not a feasible solution. One potential solution to overcome this challenge is to use Federated learning (FL) with unmanned aerial vehicle (UAV) as mobile edge computing (MEC) servers. FL enables collaborative model training across decentralized IoT devices by keeping data local, eliminating the need for centralized data collection. This approach is especially effective when IoT devices generate large volumes of data, making FL an ideal solution for data-sensitive, resource-constrained environments. In this paper, we propose a UAV-aided FL framework that utilizes the computation capacity of UAV-MEC to process some portion of the datasets from the straggling devices (devices which are unable to process their dataset in reasonable time and are lagging, increasing delay in the whole system). We also incorporate an IoT device importance and selection scheme to further improve system performance. We formulate an optimization problem to minimize system delay, considering UAV-MEC’s computation power, computation and communication power of IoT devices, and quality of service constraints. To solve the problem, we transform the proposed problem by introducing auxiliary variables and epigraph form. We then use the concurrent deterministic simplex with root relaxation algorithm. We also propose a deep reinforcement learning (DRL)-based solution to improve runtime complexity. Simulation results show the effectiveness of the proposed framework compared to existing approaches.