The fifth generation mobile network (5G) is characterized not only by the expansion of the existing (4G) network, but represents an evolution of the current mobile technologies. Thanks to the use of millimeter waves and massive MIMO (Multi-Input Multiple-Output) technology, it will meet the ever increasing demands of users in terms of connectivity and capacity. The introduction of the new 5G technology is accompanied by problems related to the measurement and evaluation of electromagnetic fields (EMF). The first stage of implementation of 5G requires upgrading existing mobile 2G / 3G / 4G networks, which raises many concerns about the possibility EMF exposure limits to be exceeded. This is especially true for countries with more restrictive legislation than ICNIRP guidelines. The existing methodologies dedicated to EMF measurements of 2G, 3G and 4G networks are not suitable for 5G and can lead to significant overestimation of the exposure. The reason for that is mostly due to the specificity of the massive MIMO and the beamforming. This necessitated the use of a new approach in the assessment of the EMF exposure. This report considers experimental case of evaluating procedure of EMF exposure of the general public from an outdoor 5G massive MIMO antenna. The antenna was located into a shopping center for a demonstration the capabilities of the new 5G technology in front of the public. The power of the massive MIMO antenna was limited to 5 W because it was mounted indoor. For the purpose of the experiment 5G router was placed in different locations in order to steer the beam of the antenna. Test measurements were taken on the path of beam to evaluate the exposure in the premises. Changing the location and the height of the router, we managed to accomplish the safety limits of the EMF exposure (according to the Bulgarian legislation) for the visitors of the demonstration. We performed measurements during Ookla speed test to simulate the maximum traffic. As a result, the study can be used for the further assessment of similar cases and demonstrations for indoor premises.

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