Urke Andreas Ramstad, Kure Øivind, Øvsthus Knut
Faculty of Information Technology and Electrical Engineering, Norwegian University of Science and Technology, Postboks 8900, 7491 Trondheim, Norway.
Faculty of Mathematics and Natural Science, University of Oslo, Postboks 1072, 0316 Oslo, Norway.
Sensors (Basel). 2021 Dec 21;22(1):15. doi: 10.3390/s22010015.
Concepts such as Industry 4.0 and Cyber-Physical Systems may bring forward a new industrial revolution. These concepts require extensive connectivity far beyond what is provided by traditional industrial networks. The Industrial Internet of Things (IIoT) bridges this gap by employing wireless connectivity and IP networking. In order for wireless networks to meet the strict requirements of the industrial domain, the Time Slotted Channel Hopping (TSCH) MAC is often employed. The properties of a TSCH network are defined by the schedule, which dictates transmission opportunities for all nodes. We survey the literature for these schedulers, describe and organize them according to their operation: Centralized, Collaborative, Autonomous, Hybrid, and Static. For each category and the field as a whole, we provide a holistic view and describe historical trends, highlight key developments, and identify trends, such as the attention towards autonomous mechanisms. Each of the 76 schedulers is analyzed into their common components to allow for comparison between schedulers and a deeper understanding of functionality and key properties. This reveals trends such as increasing complexity and the utilization of centralized principles in several collaborative schedulers. Further, each scheduler is evaluated qualitatively to identify its objectives. Altogether this allows us to point out challenges in existing work and identify areas for future research, including fault tolerance, scalability, non-convergecast traffic patterns, and hybrid scheduling strategies.
工业4.0和信息物理系统等概念可能会引发一场新的工业革命。这些概念需要的广泛连接程度远远超过传统工业网络所能提供的范围。工业物联网（IIoT）通过采用无线连接和IP网络来弥合这一差距。为了使无线网络满足工业领域的严格要求，通常会采用时隙信道跳频（TSCH）媒体接入控制（MAC）协议。TSCH网络的属性由调度表定义，该调度表规定了所有节点的传输机会。我们对这些调度器的相关文献进行了调研，根据其操作方式对它们进行了描述和分类：集中式、协作式、自主式、混合式和静态式。对于每个类别以及整个领域，我们提供了一个整体的视角，描述了历史趋势，突出了关键进展，并识别了一些趋势，比如对自主机制的关注。我们将76个调度器中的每一个都分析为其通用组件，以便能够在调度器之间进行比较，并更深入地理解其功能和关键属性。这揭示了一些趋势，比如复杂度的增加以及几个协作式调度器中对集中式原则的运用。此外，我们对每个调度器进行了定性评估，以确定其目标。总体而言，这使我们能够指出现有工作中的挑战，并确定未来研究的领域，包括容错性、可扩展性、非汇聚广播流量模式以及混合调度策略。
