Industrial Internet of Things (IIoT) promises to revolutionize industrial operations and productions through utilizing Machine-to-Machine (M2M) communications. Since each node in such environments generates various types of data with diverse service requirements, MAC protocol holds crucial importance to ensure efficient delivery. In this context, simple to complex MAC schemes are found in literature. This paper focuses on evaluating the performance of two major techniques "slot stealing" and "packet fragmentation" for the IIoT; representative protocols SS-MAC and FROG-MAC have been chosen from each category respectively. We conducted realistic simulations for the two protocols using Contiki. Delay and packet loss comparison for SS-MAC and FROG-MAC indicates the superiority of FROG-MAC due to reduction in the waiting time for urgent traffic. Thus, a simple fragmentation scheme could be deployed for efficient scheduling of heterogenous traffic in the industrial environments.

翻译：工业物联网（IIoT）旨在通过利用机器对机器（M2M）通信彻底变革工业运营与生产。由于此类环境中的每个节点会产生具有多样化服务需求的各类数据，媒体访问控制（MAC）协议对于确保高效传输至关重要。在此背景下，文献中可见从简单到复杂的多种MAC方案。本文重点评估针对IIoT的两种主要技术——“时隙窃取”与“数据包分片”的性能；分别从各类别中选取了代表性协议SS-MAC与FROG-MAC。我们使用Contiki对两种协议进行了真实仿真。SS-MAC与FROG-MAC的延迟与丢包率对比表明，由于减少了紧急流量的等待时间，FROG-MAC更具优势。因此，可采用简单的分片方案以实现工业环境中异构流量的高效调度。