Unmanned aerial vehicles (UAVs) are beginning to make a splash in emergency disaster scenarios owing to its excellent air mobility and flexibility. Considering that large base stations often cannot be deployed to disaster areas in the first place and the variation of communication links between UAVs, we formulate the task scheduling problem for disaster scenarios as a two-stage Lyapunov optimization problem and propose a dispersed computing network consisting of UAVs and ground mobile devices, which is used for collaborative computing. We decouple the long-term stability of the task queues of the nodes in the system in terms of time slots as a deterministic optimization problem by Lyapunov techniques. By jointly optimizing the task size transmitted from the control center to the UAVs, the task size computed locally and offloaded by the UAVs and mobile devices, the energy consumption of the dispersed computation system is minimized while ensuring the stability of the computation queues. The simulation results verify that our proposed algorithm is close to the optimal case in terms of queue stability, and our algorithm is able to reduce the system energy consumption by more than 50% compared to the local computation of UAVs.
15 February 2024 in IEEE Internet of Things Journal
Mobile edge computing introduces a novel computing paradigm for mobile devices, reducing execution latency and energy consumption by offloading tasks to edge servers or other idle mobile devices. In this paper, we consider the utility optimization problem of two typical computing tasks, latency-sensitive tasks and latency-tolerant tasks, among multiple mobile devices and base stations. Mobile devices can choose three computing modes to optimize utility: local computing, task allocation to base stations, and task allocation to other mobile devices through device-to-device communication. To address this problem, we formalize it as a potential game for multi-mobile device multi-base station task offloading. Furthermore, we prove the existence of a Nash equilibrium for the modeled potential game and propose a task allocation scheme for hybrid tasks. This scheme maximizes both energy consumption utility and task execution utility by optimizing task offloading mode selection and task execution order scheduling. Simulation results show that our proposed scheme can substantially enhance user utility and has good scalability with the increase of mobile devices.
27 December 2024 in IEEE Internet of Things Journal
Due to the adaptable deployment and extensive coverage, autonomous aerial vehicles (AAVs) have gained considerable attention in the field of mobile edge computing (MEC). Nevertheless, meeting the requirements of task offloading in AAV-assisted MEC remains challenging due to limitations in computing power and battery life. To address this challenge, we investigate the problem of distributed joint task partial offloading and energy harvesting (EH) in AAV-assisted MEC to minimize both task execution latency and energy cost of the AAV system. We formulate this problem as a mixed-integer nonlinear programming problem and decompose this problem into two subproblems: 1) task offloading strategy problem and 2) task offloading ratio and EH problem. We propose a distributed algorithm to determine task offloading strategies of AAVs iteratively. Given the task offloading strategies of AAVs, the subproblem of task offloading ratio and EH duration is solved by the sine cosine algorithm. Experimental results demonstrate that our proposed algorithm can effectively reduce the task execution latency and energy cost of the AAV-assisted MEC system, and outperforms other baselines significantly.