Joint Cotask-Aware Offloading and Scheduling in Mobile Edge Computing Systems
Joint Cotask-Aware Offloading and Scheduling in Mobile Edge Computing Systems
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DOI：
10.1109/access.2019.2931336
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发表时间：
2019-01-01
期刊：
影响因子：
3.9
通讯作者：
Ji, Yusheng
中科院分区：
文献类型：
--
作者：
Chiang, Yi-Han;Zhang, Tianyu;Ji, Yusheng
移动边缘计算（MEC）系统通过在附近部署边缘服务器（ES）为移动设备（MD）提供低延迟云服务。事实上，各种移动应用程序可能会生成协同任务，每个协同任务只有在其所有组成任务都完成后才能完成。现有的工作一直致力于 MEC 卸载和调度的设计，但都没有利用协同任务功能来更好地利用网络计算资源。在本文中，我们研究了MEC系统（Cool-Edge）中的联合协同任务感知卸载和调度问题，并将其制定为混合整数非线性程序（MINLP），其目标是最小化平均协同任务完成时间（ACCT）。为了解决 Cool-Edge 问题，我们提出了两种基于 LP 舍入技术的低复杂度算法来卸载协同任务，并分别根据最早协同任务到达优先规则对其进行调度，并进一步证明了两种算法联合实现的近似因子。最后，我们进行了测试台实验和模拟，以证明我们提出的解决方案的有效性，并且我们还展示了 ACCT 如何随网络环境变化。
Mobile edge computing (MEC) systems provide mobile devices (MDs) with low-latency cloud services by deploying edge servers (ESs) in the vicinity. In fact, various mobile applications may generate cotasks, each of which is completed only if all its constituent tasks are finished. Existing works have been devoted to the design of MEC offloading and scheduling, but none of them exploits the cotask feature to better utilize the networked computing resources. In this paper, we investigate the problem of joint cotask-aware offloading and scheduling in MEC systems (Cool-Edge), and we formulate it as a mixed integer non-linear program (MINLP), the objective of which is to minimize average cotask completion time (ACCT). To cope with the Cool-Edge problem, we propose two low-complexity algorithms to offload cotasks based on an LP rounding technique and schedule them according to an earliest-cotask-arrival-first rule, respectively, and we further prove the approximation factor jointly achieved by the two algorithms. Finally, we conduct testbed experiments and simulations to demonstrate the effectiveness of our proposed solution, and we also show how ACCT varies with the network environment.