Open Access

Axel Sikora

• After many decades of research and many years of real-life and large-scale installations, the Industrial Internet of Things (IoT) has found high acceptance and widespread implementations. The integration of Operational Technology (OT) networks is rapidly going on. However, there are still many open issues, which are looking for solutions. This paper gives an overview on recent trends in real-time,After many decades of research and many years of real-life and large-scale installations, the Industrial Internet of Things (IoT) has found high acceptance and widespread implementations. The integration of Operational Technology (OT) networks is rapidly going on. However, there are still many open issues, which are looking for solutions. This paper gives an overview on recent trends in real-time, secure, and real-time AND secure communication protocols. For these targets, a multitude of protocols and protocol extensions have been specified. Those are presented together with the required algorithms and tools. Also, the strengths and the remaining challenges of the current solutions are discussed. In doing so, the paper gives an insight into selected relevant projects from the author's teams. In addition, the extensive list of references shall serve interested readers as an entry point for subsequent scientific and implementation works. This paper is a summary of the author's keynote presentation at ICEST2025 conference in Ohrid, North Macedonia.…