# 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
As a result, the total power radiated by a 5G MIMO base station is not spread across the entire coverage area but rather focused on specific regions based on network and traffic conditions. Consequently, despite the potential increase in maximum radiated power, the expected EMF exposure from 5G is anticipated to be similar to, and in most cases lower than, that of previous technologies. The authors discussed the health risks of 5G technologies in a brief overview. However, approaches to mitigate and reduce EMF exposure due to new 5G technologies were not fully investigated. In [2], the authors presented the current state of the art in EMF-aware mobile networking and studied current exposure limits and EMF constraints' impact on 5G network planning. Based on their findings, the authors indicated that installing optimal 5G networks in urban zones will be challenging due to the EMF saturation effect and strict regulation limits. The authors provided a brief discussion on the impacts of 5G technologies (e.g., beamforming) on EMF radiation exposure. Moreover, the authors presented general guidelines for the planning of 5G EMF-aware networks, which consist of the following steps: modeling 5G radio access technologies, selecting techniques for evaluating the EMF level, and validating the EMF exposure based on regulatory limits (e.g., the ICNIRP) in a realistic scenario. Finally, the authors summarized that current 5G challenges might cause inaccurate results for EMF evaluation due to several reasons. Firstly, at the time that the study was carried out, 5G technologies were not fully deployed and standardized, and revisions of regulations about EMF limits were still in progress. There were economic barriers to EMF compliance assessment; in other words, EMF measurement components were still very expensive. Co-existence  
Figure 3: Concerns about EMF exposure in 5G networks. with current pre-5G networks and the lack of urban planning considering existing cellular networks might affect the quality of the EMF exposure evaluation results. According to the authors, the implications of EMF exposure due to 5G technologies such as beamforming were not clearly understood yet. In [28], the authors highlighted concerns over utilizing the mmWave spectrum coupled with MIMO antennas and beamforming techniques in 5G networks regarding EMF exposure. The authors simulated the exposure levels caused by an 8 \(\times\) 8 planar array antenna at 3.7 GHz. The simulation was carried out on a human model in an indoor environment using the Sim4 Life simulation platform. The specific absorption rate (SAR) was used only for the exposure assessment. Based on the findings, the authors concluded that the SAR values for the simulated approach were below the maximum SAR limits (2 W/kg). The authors in [29] investigated the temperature elevation of a human head model exposed to 28 GHz fixed-beam 2 \(\times\) 2, 4 \(\times\) 1, and 8 \(\times\) 1 patch arrays. [PERSON] bioheat transfer equation [30] was used to calculate the temperature of the human head model. Based on the results, the peak temperature due to the 2 \(\times\) 2 array was higher compared to those of the 4 \(\times\) 1 and 8 \(\times\) 1 patch arrays. The results show that the correlation between the average power density (PD) and the peak temperature is strong over an area of a few cm\({}^{2}\). Measuring the exact radiation exposure due to 5G networks is a challenging task that has caught the attention of several researchers. The authors in [22] stressed that the EMF measurements used in 2G, 3G, and 4G networks were not accurate enough to estimate EMF exposure due to radiation from 5G networks. The main reason for this inaccuracy was the utilization of massive MIMO with precise beamforming technologies and high-frequency bands (such as mmWave), leading to a complex radiation pattern from 5G antennae. Thus, overestimation may take place when using existing measurement methods.