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Private 5G networks for industrial users are emerging as one of the leading advanced 5G use cases. This timely work presents a comprehensive experimental analysis of a private 5G network conducted in sparse and dense industrial environments at sub-6 GHz. Measured results of the over-the-air error vector magnitude (EVM) are provided, considering signal-to-noise ratio (SNR) for different 5G new radio modulation and coding schemes (MCSs), bandwidths (BWs) and numerologies (subcarrier spacings) using omnidirectional or directional antenna configurations at the transmitter (TX) and the receiver (RX). Channel sounding measurements are also conducted to characterise the channels in terms of root mean square (RMS) delay spread. The measurement results show that channels in the dense industrial environment have greater RMS delay spreads than in the sparse industrial environment due to strong reflected or scattered multipath components with significant delays. This results in higher EVMs and bit error rates (BERs), i.e., as the RMS delay spread increases, a higher SNR is required to meet the EVM limits. It is also observed that using directional antennas at the TX and RX in both environments reduces the RMS delay spread and hence the inter-symbol interference and the EVM. This allows higher MCS modes (e.g., 64 QAM and 256 QAM) to be used for reliable data transmission, significantly improving the bandwidth efficiency and reducing the latency. When evaluating system performance for different BWs and numerologies, using a lower BW and numerology provides a better system performance (lower EVMs and BERs), especially in dense industrial environments.

Factory automation design engineers building the smart factory can use wireless fifth-generation (5G) broadband networks for added design flexibility. The 5G new radio builds upon the previous cellular communications' standards to include technology for “massive machine-type communication” and “ultrareliable and low-latency communication.” In this work, the authors augment an automated-guided vehicle (AGV) with 5G for additional capabilities (e.g., streaming high-resolution video and enabling long-distance teleoperation), increasing the mobile applications for industrial equipment. Such use cases will provide valuable knowledge to engineers examining 5G for novel smart manufacturing solutions. Our 5G private network testbed is a platform for wireless performance research in industrial locations and provides a development mule for flexible smart manufacturing systems. The rival wireless technology to 5G in industrial settings is Wi-Fi and it is included in the testbed. Furthermore, the authors noted challenges, often unconsidered, facing the move to digital manufacturing technologies. Therefore, the authors summarize the emerging challenges when implementing new digital factory systems, including challenges linked to societal concerns around sustainability and supply chain resilience. The new smart factory technologies, including 5G communications, will have their roles to play in alleviating these challenges and ensuring economies have resilient future factories.

This paper presents sub-6 GHz channel measurements using a directional antenna at the transmitter and a directional or omnidirectional antenna at the receiver at 4.145 GHz in sparse and dense industrial environments for a line-of-sight scenario. Furthermore, the first measured over-the-air error vector magnitude (EVM) results depending on different 5G new radio modulation and coding schemes (MCSs of16 QAM, 64 QAM and 256 QAM) are provided. From the measurement campaigns, the path loss exponents (PLE) using a directional and an omnidirectional antenna at the receiver in the sparse and the dense environment are 1.24/1.39 and 1.35/1.5, respectively. PLE results are lower than the theoretical free space PLE of 2, indicating that indoor industrial environments have rich multipaths. The measured power delay profiles show the maximum root mean square (RMS) delay spreads of 11 ns with a directional antenna and 34 ns with an omnidirectional antenna at the receiver in a sparse industrial environment. However, in a dense industrial environment the maximum RMS delay spreads are significantly increased: maximum RMS delay spreads range from 226 to 282 ns for the omnidirectional and the directional antenna configuration. EVM measurements show that to increase coverage and enable higher MCS modes to be used for reliable data transmission, in both industrial environments using a directional antenna at the transmitter and the receiver is required. The large-scale path loss models, multipath time dispersion characteristics and EVM results provide insight into the deployments of 5G networks operating at sub-6 GHz frequency bands in different industrial environments.