# Multi-Technology Multi-Operator Site Sharing: Compliance Distance Analysis for EMF Exposure
## 4 Results and Discussion
### Shared Macro Site  
The macro site is a general solution that is used by all operators to provide coverage in populated areas [36]. The macro site has radio equipment with higher Tx power than other types of sites (micro, femto, and indoor), and the coverage range can reach long distances depending on the antenna height and site configurations. The macro site can be installed in different civil models, such as on monopoles, self-based towers, cells on wheels (COWs), wall-mounted antennae, or towers at rooftop sites. This study considered passive sharing, as shown in Figure 3 and illustrated in Figure 4.  
Figure 3: Photograph of macro site shared by three MNOs. Typical configurations of macro sites equipped with multi-technology solutions were used as input data for the calculations. The site was operated with six technologies: 2G GSM at 900 MHz (G900), 3G UMTS at 900 MHz (U900), 4G LTE at 800 MHz (L800), 4G LTE at 1800 MHz (L1800), 4G LTE at 2100 MHz (L2100), and 5G NR at 3500 MHz (N3500). The input data for each technology, including Tx/Rx, antenna gain, frequency bandwidth, system load, and transmitting power, are listed in Table 2. For N3500, which has a high grade of mMIMO (64T/64R), we used 0.22 as a realistic power factor. This was taken from the interesting results and findings of the studies [28; 29; 30]; it indicates that the realistic transmitted power of mMIMO reaches 16-22% of the maximum equipment power when it operates at a full system load. The site configuration data were utilized in Equation (6) to compute the vertical and horizontal RCD (RDC-H and RDC-V), as displayed in Figure 5. The calculation outcome expressed that all horizontal RDC-H distances were longer than the vertical RDC-V distances, and the ICNIRP has a little more restricted RCD compared with the FCC. In the main antenna horizontal direction, the general public ICNIRP RCD-H was 14.81 m when there was a single MNO, while it increased to 29.6 m when 4 MNOs shared the macro site. The general public FCC RCD-H was 13.8 m when there was a single MNO, and it increased to 27.7 m for 4 MNOs. Figure 5 summarizes the RCD in both the vertical and horizontal directions for the GP. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Site Setting** & **2G G900** & **3G U900** & **4G L800** & **4G L1800** & **4G L2100** & **5G N3500** \\ \hline Freq. Band (MHz) & 900 & 900 & 800 & 1800 & 2100 & 3500 \\ Freq. BW (MHz) & 5 & 5 & 10 & 20 & 20 & 100 \\ Total Tx & 2 & 1 & 2 & 2 & 4 & 64 \\ Total Rx & 2 & 1 & 2 & 2 & 4 & 64 \\ Power Tx & 40 W & 40 W & 80 W & 80 W & 80 W & 160 W \\ System Load & 95\% & 95\% & 95\% & 95\% & 95\% & 95\% \\ Ant. Gain & 17 dBi & 17 dBi & 16.7 dBi & 16.6 dBi & 17 dBi & 24.8 dBi \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Configuration setup for macro site. Figure 4: The horizontal RCD-H and vertical RCD-V compliance distances for macro site installed on rooftop tower. Further processing was carried out to analyze the total emitted power density and related contribution to the total exposure ratio. Figure 6 depicts the power density PD (W/m\({}^{2}\)) calculated at distance (m) from the antennae in the presence of four MNOs, and the analysis showed that 5G N3500 had the highest PD among the technologies, and all technologies reached high levels at distances very close to the macro site's antenna (less than 3 m). With reference to the ICNIP for the GP, Figure 7 displays the exposure ratio for each technology calculated by Equation (4) in the horizontal direction and TER for the macro site shared by a single MNO, two MNOs, three MNOs, and four MNOs. Figure 5: The R\({}_{\rm CD}\) results for multi-technology multi-operator sharing a macro site, referencing the ICNIRP and FCC standards limits for GP. Figure 6: The power densities (W/m\({}^{2}\)) in the main direction for the macro site shared by 4 MNOs. The results showed that 5G N3500 had the highest contribution at the R\({}_{\rm CD}\) with 34%, followed by 4G L800 with 24%, 4G L1800 and L2100 with 9-10% each, and 2G G900 and 3G U900 with 11% each.