Experimental Trials of 5G Transmission in 28 GHz and 3.7 GHz Bands and Investigation of Realistic Performances in Manufacturing Factory

The 5th-generation mobile communication system (5G) has already launched commercially since 2019 and has been introduced worldwide. 5G attracts much attention as a promising technology that can solve future industrial and social issues. Since industrial 5G use cases need not only high-speed and large-capacity communications, but also high-reliability and low-latency communications, higher requirements and performances are required compared to communication services for consumers. This paper introduces 5G experimental trials using millimeter-wave and sub-6 GHz bands in an actual manufacturing factory. The experimental trials evaluate and compare some performances of 5G wireless transmission in 28 GHz and 3.7 GHz bands using an autonomous mobile robot (AMR) in the factory. In addition, this paper describes a fixed-position experimental trial in a more realistic factory environment where humans and robots move. This experimental trial visualizes more realistic 5G performances and evaluates them from the perspective of differences in location and height in the factory. Experimental results demonstrate both advantages and disadvantages in 28 GHz and 3.7 GHz bands and the effectiveness of 28 GHz compared to 3.7 GHz in the manufacturing factory. Furthermore, from results of the fixed-position experimental trial, some issues and solutions for promoting industrial 5G in the factory are considered.