# Electromagnetic Field-Aware Radio Resource Management for 5G and Beyond: A Survey
## 4 EMF Exposure Level and 5G Technologies
### EMF Exposure and 5G Radio Access Technologies
Based on the results, the EMF exposure varied between 1.37 V/m and 3.09 V/m at the position of the MIMO testbed. This result exceeded the maximum limits set by the ICNIRP. However, the exposure level decreased with the increment in the distance between the MIMO testbed and the location of the user. Thus, the authors concluded that these findings might lead to more concerns regarding public safety and the deployment of future wireless mobile networks. The authors in [45] conducted a monitoring experiment for 25 massive MIMO 5G BSs over a day (24 h). The purpose of this experiment was to collect large amounts of data on EMF exposure levels in terms of the antenna radiation patterns and the spatial distribution of the BSs' transmit power for each directed beam. In this experiment, the authors considered massive MIMO BSs located in urban areas in Australia, with the operating frequency being within 3300-3800 MHz. Based on these findings, the authors observed that the BSs utilized only 25% of the maximum average power. Moreover, the average radiation patterns were below the peak envelope gain by 9 dB, and the transmitted power was distributed evenly over the antennas' scan range. Furthermore, the authors compared the calculated (theoretical) equivalent isotropic radiated power (EIRP) assuming constant transmit power for each beam with the reported actual \(EIRP_{act}\). The comparison showed that the maximum \(EIRP_{act}\) was lower than the maximum theoretical EIRP by at least 8.8 dB. The authors concluded that the findings were consistent with the assessments made by the International Electrotechnical Commission (IEC) and provided a helpful evaluation of the EMF exposure of 5G BSs. Based on recent IEC standards, finding the maximum EMF exposure level and the compliance distance requires moving a measurement probe slowly within the area of the measurements [46]. However, this procedure is unclear regarding the speed of the probe movement and the appropriate measurement spacing for compliance distance assessments, as highlighted by the authors of [47]. Thus, the authors conducted a simulation study using experimental measurements to estimate the appropriate spacing for the EMF exposure assessment of an outdoor 3.5 GHz 5G BS in South Korea. Three installation scenarios were considered. In the first scenario, only a few reflecting structures were assumed to be present; thus, the attenuation and wave propagation were mainly due to ground reflection. This scenario was considered to ensure the EMF had a significant effect. In the second and third scenarios, reflecting structures were considered to study the variation in the direct incident field emitted from the BS. The height of the BS in the third scenario was higher than the height of the BS in the second scenario. The EMF exposure level was evaluated through the PD parameter estimated using the ray-tracing software developed in [48] based on the ray frustum algorithm. The findings were also compared with other results obtained from ray-tracing software (e.g., Wireless InSite version 3.3.5). Based on the results, the authors observed that the emitted EMF from the 5G BS was strongly dependent on the installation height of the BS relative to the height of the reflecting structure. Moreover, the results obtained from simulations and experiments indicated that a measurement spacing of 1 m was appropriate to determine the maximum EMF exposure of a 5G BS for the three studied scenarios. The authors concluded that the PD measured at the proposed 1 m compliance spacing did not exceed the exposure limits of 10 \(\mathrm{dBW}/\mathrm{m}^{2}\) set by the ICNIRP [10]. The authors also noted that employing the beamforming feature in 5G communications made it more challenging to conduct EMF exposure measurements for a 5G BS compliance assessment. According to [49], possible EMF issues in the 5G new radio (NR) included the use of new frequency bands and breakthroughs in technology, such as massive MIMO and beamforming.