In the era of Industry 4.0, the growing need for secure and efficient communication systems has driven the development of fifth-generation (5G) networks characterized by extremely low latency, massive device connectivity and high data transfer speeds. However, the deployment of 5G networks presents significant security challenges, requiring advanced and robust solutions to counter increasingly sophisticated cyber threats. This paper proposes a testbed and software architecture to strengthen the security of Private 5G Networks, particularly in industrial communication environments.

To prepare future (electrical) engineers for challenges in their professional life, the fundamentals of measurement engineering with the respective sub-aspects are an essential component. This paper describes the design and implementation of a modern laboratory exercise for the precise measurement of small, rapidly changing currents using an example of the varying current consumption of a small micro-controller caused by cryptographic algorithms. Encryption and decryption is implemented for a wireless communication system dedicated for industrial applications to be taught as practical skills embedded into a typical real-world engineering task. To determine measurement uncertainties, the Gaussian error propagation law is employed as described in the Guide to the Expression of Uncertainty in Measurement (GUM). Additionally, students learn about the relationships between signal representation in the time and frequency domain. The paper contains a detailed description of the experimental setup, theoretical knowledge, exemplary measurements as well as experiences and a first evaluation by the students.

In the past few years, there has been a growing sig-nificance of interactions between human workers and automated systems throughout the factory floor. Wherever static or mobile robots, such as automated guided vehicles, operate autonomously, a protected environment for personnel and machines must be provided by, e.g., safe, deterministic and low-latency technologies. Another trend in this area is the increased use of wireless communication, offering a high flexibility, modularity, and reduced installation and maintenance efforts. This work presents a testbed implementation that integrates a wireless framework, employing IO-Link Wireless (IOLW) and a private 5G cellular network, to orchestrate a complete example process from sensors and actuators up into the edge, represented by a programmable logic controller (PLC). Latency assessments identify the system's cycle time as well as opportunities for improvement. A worst-case estimation shows the attainable safety function response time for practical applications in the context of functional safety.

A new FPGA-based approach for a data diode transmitting data unidirectionally from a high security zone to a lower security zone is evaluated and implemented. With the FPGA implementation, the need of additional hardware could be minimized compared to most state-of-the-art data diode realizations. The proposed data diode is designed to use the available backplane bus communication protocol between the programmable logic controller (PLC) and its connected peripherals. To demonstrate the universal approach an open-source platform based on the Revolution Pi (RevPi) and its backplane bus is used. Principally the data diode behaves as a mirror presenting the complete protected system behind the high security zone including the RevPi controller and its devices to the information technology (IT) network. Another controller within the lower security zone is used to imitate the operational technology (OT) process. Our approach is not limited to the above controller and can be applied to any type of PLC. The only requirement is that the communication protocol on the backplane bus is known and can be modified for this purpose.

Security is an essential requirement of Industrial Control System (ICS) environments and its underlying communication infrastructure. Especially the lowest communication level within Supervisory Control and Data Acquisition (SCADA) systems - the field level - commonly lacks security measures.Since emerging wireless technologies within field level expose the lowest communication infrastructure towards potential attackers, additional security measures above the prevalent concept of air-gapped communication must be considered.Therefore, this work analyzes security aspects for the wireless communication protocol IO-Link Wireless (IOLW), which is commonly used for sensor and actuator field level communication. A possible architecture for an IOLW safety layer has already been presented recently [1].In this paper, the overall attack surface of IOLW within its typical environment is analyzed and attack preconditions are investigated to assess the effectiveness of different security measures. Additionally, enhanced security measures are evaluated for the communication systems and the results are summarized. Also, interference of security measures and functional safety principles within the communication are investigated, which do not necessarily complement one another but may also have contradictory requirements.This work is intended to discuss and propose enhancements of the IOLW standard with additional security considerations in future implementations.

In the context of Industry 4.0 and the Industrial Internet of Things, an exponential increase in the interconnection of machines and smart devices can be observed together with an increase of interconnections between Operation Technology (OT) and Information Technology (IT) networks as well as Cloud systems. This development is linked to the user’s expectation for suitable security solutions, where it remains a challenging task to ensure that, e.g. a specific Safety Integrity Level (SIL) level can be maintained in view of possible potential cyberattacks. In this case, a data diode can be a suitable solution. In this paper a data diode prototype is presented being integrated into an industrial network analyzing the communication on the backplane bus of an Open Source Industrial PC called Revolution Pi. The advantage of our approach is that the data diode is totally transparent from the IT to the OT network, because all process data behind the data diode are mirrored into the IT network within a few system cycles. The security and reliability issues related with this approach are also discussed and evaluated.

Wireless networks support highly flexible manufacturing processes and are recognized as a crucial pillar towards the digitization of industrial production (automation). While 5G is currently being marketed as universal solution for future wireless communication, high density of sensor and actuator nodes in industrial manufacturing environments with respect to latency times and reliability, still represents an enormous technical challenge. In the field of production automation standards, IO-Link Wireless (IOLW) is already in operation offering energy-efficient and cost-effective solutions, even with battery-powered smart sensor devices. In this paper, the deterministic ultra-reliable low-latency communication (URLLC) features of 5G are combined with the outstanding performance characteristics of IOLW with respect to robustness and latency to realize even highly demanding safety applications in industrial environments.

Wireless communication systems are enabler technologies for modern and flexible production concepts, essentially within the Industry 4.0 directive. For reliable low-latency wireless communication, the availability of frequency spectrum is a general prerequisite. IO-Link Wireless (IOLW) is a vendor-independent wireless communication standard, which operates in the 2.4 GHz ISM (Industrial, Scientific, Medical) band and especially addresses the requirements of industrial discrete manufacturing processes. The 2.4 GHz ISM band is used by various other radio systems, making coexistence management a fundamental challenge. Blacklisting and frequency hopping schemes are specified to increase the IOLWcoexistence behavior. In this paper coexistence management methods and tools, which can be employed for IOLW are presented. These tools can be used to enhance the coexistence behavior and thus the reliability, and at the same time, reduce energy consumption. After an introduction and a detailed presentation of IOLW, a software tool is presented that allows to implement an intelligent frequency management by adapting blacklists to the respective coexistence and boundary conditions. This is based on generic measurements, which are also shown in this paper. Finally, a conclusion and an outlook for further integration into an overall system are given.

Wireless technologies are intensively used in industrial environments and wireless sensor/actuator networks play a key role for highly flexible automation plants, especially within the Industry 4.0 initiative. In order to achieve a highly robust system behavior also an attentive antenna selection and placement within a manufacturing cell is of interest resulting in an enhanced system reserve. In this paper different strategies for base station antenna placement are investigated with the focus on star-topologies, i.e. a central base station and a multitude of remotely located wireless sensors and actuators. A probabilistic approach has been chosen for modeling path loss, multipath fading and coexistence behavior with respect to adjoining manufacturing cells. Also cable attenuation for remote antennas connected to the base station are taken into account.

The increase of wireless devices due to the implementation of wireless sensor networks, cyber-physical systems with wireless communication interfaces and mobile monitoring as well as the installation of diagnosis applications into the shop floor improves real-time transparency of machine conditions and production processes. For a minimal invasive integration of such technologies into the brownfield the proposed solution has to consider wireless coexistence, e.g. wireless spectrum-sharing. This paper presents a communication concept dedicated to wireless sensor networks in production environments. As evidence of the functionality of the developed solution measurement results are presented and discussed.

Inertial navigation systems are frequently employed in robotic applications. It is well known that if they are used without the assistance of a reference system, position failures can increase rapidly in the course of time. This article presents various zero-velocity detection routines to reduce the position instability of robots equipped with unaided strapdown inertial navigation systems in standstill. To assess the detection performance under several environmental conditions such as varying temperature investigations are performed by various simulations as a function of noise level. The acceleration sensor signal was generated by a data synthesizer based on typical accelerometer noise characteristics. It can be shown that especially normality tests are independent from environmental fluctuations resulting in a high navigation accuracy.

In indoor environments Received Signal Strength Indicator (RSSI) values are strongly affected by multipath propagation effects resulting in a location accuracy that is often not very reliable. More accurate ranging techniques such as Time Difference of Arrival (TDOA) could be integrated into IEEE 802.11 g/n/ac chip sets requiring hardware modifications. Performance evaluation of five TOA/TDOA estimation algorithms (IFT, group delay, ESPRIT, MUSIC, MinNorm) is carried out employing a stochastic radio channel model conform to WiFi g/n/ac. Mean errors and standard deviations are calculated as a function of coherence bandwidth and Rician K-factor. Localization performance parameters are validated by various measurements in indoor environments. Based on an experimentally verified 1D-simulation model the 2D-location accuracy has been evaluated. It can be shown that even in case of moderate system bandwidths and low Rice coefficients, i.e. WiFi n-std and K > 1, location accuracies in the sub-meter range with TOA setups can be obtained. Typically location accuracy achieved with TDOA setups is only half of the accuracy that can be achieved employing TOA systems. But even in this case significant improvement compared with RSSI-methods for WiFi n/ac could be achieved.

The AS-interface (AS-i) is a simple and cost-effective network solution connecting simple I/O devices to the upper fieldbus levels. A fully loaded AS-i Version I network with one master and 31 slaves has a maximum response time of 5 ms per I/O. The AS-Interface has been chosen as reference system for the development of a wireless fieldbus gateway, which will be presented in this paper. Standard modules have been employed to achieve a price-competitive solution. A high reliability level with wireless system can only be achieved if radio wave propagation characteristics and coexistence to other radio services are taken into account. Especially wireless local area network (WLAN) technologies already installed in the field can affect proper sensor/actuator network operation. Therefore bit and frame error probabilities in the presence of WLAN systems also have been investigated.

Modern factory facilities are characterized by highly flexible manufacturing cells and highly dynamic processes, where clusters of fixed or moving sensors and actuators have to be controlled in a limited space under stringent real-time and reliability constraints. In such demanding industrial environments, wireless systems can also be beneficial by improving flexibility, cutting cables, and enabling solutions, which are cumbersome or even not possible to realize with wireline systems, especially in controlling moving or rotating parts. In this paper, we present a conceptual study of a wireless real-time system dedicated for remote sensor/actuator control in production automation. System development is based on user requirements, which were extracted from customer interviews and a market research. Low level measurements of frequency- and space-selective wireless channels in a factory-like environment were carried out. System design aspects, i.e., network topology, multiple access schemes, and radio technologies, will be thoroughly reviewed. The performance of a first prototype implementation will be discussed with emphasis on timing behavior and power consumption, as sensors and actuators of the wireless system are intended to operate without power lines or batteries