Industrial communication systems represent one of the most important innovations of the last decades in the context of factory and process automation systems. They are networks specifically designed to cope with the tight requirements of these challenging application fields such as real time, determinism, and reliability. Moreover, industrial networks are often deployed in environments characterized by strong electromagnetic interference, mechanical stress, critical temperature, and humidity. Over the last three decades, different classes of industrial networks have been developed according to changing requirements and available communication and information technologies. In this paper, we first provide an account of the state of the art, reviewing classical fieldbuses, real-time Ethernet networks, and industrial wireless networks, along with their most relevant features, applications, and performance figures. We introduce the complex standardization framework and analyze the market status and assumptions for future development. In the second part, we address the future perspectives focusing on new technologies, standards, and fields of application. In particular, we consider the time-sensitive networking (TSN) family of standards, Industrial Internet-of-Things (IIoT) systems, high-performance wireless LANs, industrial applications of cellular networks, and Ethernet networks for automotive communication.

Reliability, power consumption, and latency are the three main performance indicators of wireless sensor networks. Time slotted channel hopping (TSCH) is a promising technique introduced in the IEEE 802.15.4 standard that performs some steps ahead in the direction of the final dream to meet all the previous requirements at the same time. In this paper, a simple and effective mathematical model is presented for TSCH that, starting from measurements performed on a real testbed, permits to characterize both the network and the surrounding environment. To better characterize power consumption, an experimental measurement campaign was purposely performed on OpenMote B devices. The model, which was checked against a real 6TiSCH implementation, can be employed to predict network behaviour when configuration parameters are varied, in such a way to satisfy different application contexts. Results show that, when one of the three above indices is privileged, unavoidably there is a worsening of the others.

Nowadays, large enterprises, critical infrastructures, and utilities are complex systems, and consist of a number of subsystems, often located far away from each other, that coordinate their operations over geographic networks. Typically, they are interconnected through the Internet and communicate by means of transport control protocol (TCP)/IP-based protocols. When system-level resilience is required, extremely high dependability is demanded from the network. In this article a solution is described and evaluated that loosely resembles SDN architectures. A redundant version of MQTT is used for the data plane, whereas an adaptive mechanism is implemented in the control plane that evaluates the quality of paths and dynamically selects the best choice. To maximize dependability, yet keeping resource consumption to acceptable levels, concepts borrowed from reinforcement learning are exploited. An experimental campaign corroborated our expectations and showed the practical feasibility of our proposal.

In this paper the RBIS synchronization protocol is presented, which has been specifically conceived for industrial infrastructure WLANs. It combines the concepts of the sender/receiver and receiver/receiver approaches: similarly to RBS, timestamps are recorded only on received frames while, like IEEE 1588, it permits slaves to synchronize to the same master clock. Compared to RBS, RBIS has several advantages. Every single wireless sub-network, in fact, can be easily synchronized with an external time source located on the wired backbone. Moreover, when software implementations are considered that rely on unmodified conventional WiFi equipment, RBIS is able to feature noticeably better timing accuracy than IEEE 1588.