## 1 Introduction  
Industrial production traditionally relies on wired solutions for communication among machines, controllers, and sensors. There are certainly benefits of using wired communication, such as high reliability, low latency, large data rates, and wireless interference-free operation. However, wired technologies lack the flexibility and scalability aspects desired in several industrial applications, which wireless solutions can offer. While wireless technology has traditionally shown limitations on reliability, data rates and timeliness aspects, 5G technology especially with Ultra-Reliable and Low Latency communication (URLLC) features and its integration with Time-Sensitive Networking (TSN) or Deterministic Networking (DetNet), tends to overcome these deficiencies [1, 2, 3, 4], enabling a large range of use cases such as autonomous guided vehicles to remote control and monitoring of machinesand actuators [5; 6; 7; 8]. The usage of smart wireless sensors especially offers a lot of potential for industrial manufacturing, for example, in the context of condition monitoring, process monitoring, and control [9; 10; 11; 12]. They offer an easy-to-use retrofitting solution, providing real-time insights of the machining process, monitoring a wide range of parameters such as vibration, acoustic emission, temperature, or humidity, enables to gather process insights detecting anomalies or signs of tool wear, to interact with the process, and to achieve higher efficiency, quality and lifetime of resources [13; 14; 15].  
Closed-loop applications interacting with safety and control systems have high requirements for the communication infrastructure to avoid costly downtime or injuries. Wireless communication may suffer from outages and packet losses due to propagation losses and interference. The 5G protocol stack is designed to overcome successful packet reception errors through error control mechanisms. When packets need to be retransmitted as part of the error control mechanisms, these lead to higher transmission latencies. In this paper, we analyze the requirements for smart sensor use cases to see if 5G and TSN can meet the requirements [16; 17; 18]. For such analysis, a 5G and TSN prototype is being implemented, supporting Frame Replication and Elimination for Reliability (FRER) to increase the availability and reliability of the communication [19; 20]. This prototype evaluates the impact of FRER on the communication performance for three different 5G setups combined with a wired network supporting different TSN standards.  
For this purpose, the paper is structured as follows: Section 2 describes the use of smart sensors for milling processes in industrial manufacturing and their requirements for wireless communication. Pointing out the high relevance of reliable and stable communication for industrial production. In Section 3, prototype architecture and implementation are given. Different setups are described, combining different frequency spectrums and 5G systems to investigate the use of FRER for reliable and resilient 5G transmission. The detailed performance measurements carried out on the integrated prototype system for the use case requirements and a discussion of the results are presented in Section 4. Section 5 summarizes the paper and provides an outlook.