Future exposure development with 5G massive-MIMO due to higher network utilisation

Prior research has demonstrated that the 5G cells operating at 3.6 GHz are currently not heavy utilized and significant differences exist between instantaneous exposure without load, typical utilisation scenarios and maximum load [1]. Furthermore, studies indicate that the exposure of a passive user in the cell is relying on the location of the active user due to the beamforming capabilities of massive-MIMO antennas. As a result, the exposure for nearby users is considerably higher than for users with a greater distance to the active one [2][3]. Therefore, as the number of 5G users and also data traffic increases in the 3.6 GHz band, a higher instantaneous exposure can be expected, as well as a spatial distribution of instantaneous exposure within the cell due to more users. Other, more intensive users in the cell are assumed to have a minimal effect on the instantaneous exposure of a passive user, provided that the user is adequately far away from an active user and, thus, not exposed by its traffic beam. To estimate the potential development of future exposure to 5G in the 3.6 GHz band, long-term measurements of instantaneous exposure were conducted at two different base stations, while typical utilisation scenarios expected in the future were provoked on a 5G-capable user equipment (UE). The UE was placed at three different locations in the vicinity of the base station to observe the effects of beamforming on the instantaneous exposure at the measurement point. During the measurements, the network operator Deutsche Telekom screened the cell with a quality data monitoring tool to capture data throughput, the number of users, and other metrics. Based on the differences in recorded exposure between the various usage scenarios and the different locations of the UE, this paper aims to predict a potential future development of instantaneous exposure with a higher number of users and increasing data consumption.