TODG: Distributed Task Offloading With Delay Guarantees for Edge Computing

• Published in: IEEE transactions on parallel and distributed systems Vol. 33; no. 7; pp. 1650 - 1665
• Main Authors: Yue, Sheng, Ren, Ju, Qiao, Nan, Zhang, Yongmin, Jiang, Hongbo, Zhang, Yaoxue, Yang, Yuanyuan
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; channel allocation; Computation offloading; Constraints; Delay; delay guarantee; Delays; distributed task offloading; Edge computing; Mobile handsets; Optimization; Resource management; Servers; stochastic optimization; Task analysis; Task scheduling
• ISSN: 1045-9219; 1558-2183
• DOI: 10.1109/TPDS.2021.3123535

Edge computing has been an efficient way to provide prompt and near-data computing services for resource-and-delay sensitive IoT applications via computation offloading. Effective computation offloading strategies need to comprehensively cope with several major issues, including 1) the allocation of dynamic communication and computational resources, 2) delay constraints of heterogeneous tasks, and 3) requirements for computationally inexpensive and distributed algorithms. However, most of the existing works mainly focus on part of these issues, which would not suffice to achieve expected performance in complex and practical scenarios. To tackle this challenge, in this paper, we systematically study a distributed computation offloading problem with delay constraints, where heterogeneous computational tasks require continually offloading to a set of edge servers via a limiting number of stochastic communication channels. The task offloading problem is formulated as a delay-constrained long-term stochastic optimization problem under unknown prior statistical knowledge. To solve this problem, we first provide a technical path to transform and decompose it into several slot-level sub-problems. Then, we devise a distributed online algorithm, namely TODG, to efficiently allocate resources and schedule offloading tasks. Further, we present a comprehensive analysis for TODG in terms of the optimality gap, the worst-case delay, and the impact of system parameters. Extensive simulation results demonstrate the effectiveness and efficiency of TODG.