With the growing need for automation and the ongoing merge of OT and IT, industrial networks have to transport a high amount of heterogeneous data with mixed criticality such as control traffic, sensor data, and configuration messages. Current advances in IT technologies furthermore enable a new set of automation scenarios under the roof of Industry 4.0 and IIoT where industrial networks now have to meet new requirements in flexibility and reliability. The necessary real-time guarantees will place significant demands on the networks. In this paper, we identify IIoT use cases and infer real-time requirements along several axes before bridging the gap between real-time network technologies and the identified scenarios. We review real-time networking technologies and present peer-reviewed works from the past 5 years for industrial environments. We investigate how these can be applied to controllers, systems, and embedded devices. Finally, we discuss open challenges for real-time communication technologies to enable the identified scenarios. The review shows academic interest in the field of real-time communication technologies but also highlights a lack of a fixed set of standards important for trust in safety and reliability, especially where wireless technologies are concerned.

翻译：随着自动化需求的不断增长以及操作技术（OT）与信息技术（IT）的持续融合，工业网络需要传输大量具有混合关键性的异构数据，例如控制流量、传感器数据和配置消息。当前IT技术的进步进一步催生了工业4.0和工业物联网（IIoT）框架下的新型自动化场景，使得工业网络现在必须满足灵活性和可靠性方面的全新要求。必要的实时性保障将对网络提出重大挑战。本文首先识别IIoT应用场景，并沿多个维度推导实时性需求，进而弥合实时网络技术与所识别场景之间的鸿沟。我们综述了实时网络技术，并梳理了过去5年间面向工业环境的同行评审研究成果。我们研究了如何将这些技术应用于控制器、系统及嵌入式设备。最后，我们讨论了实现所识别场景所需实时通信技术所面临的开放性挑战。本综述表明实时通信技术领域存在学术关注，但同时也凸显出缺乏一套固定的标准——这对确保安全性和可靠性方面的信任至关重要，尤其在涉及无线技术时。