# Multi-Technology Multi-Operator Site Sharing: Compliance Distance Analysis for EMF Exposure
## 4 Results and Discussion
### Shared Indoor IBS Site  
Most of the traffic in mobile networks is generated from indoor houses and buildings [38], and in some dense areas, huge buildings suffer from weak indoor single strength due to construction loss [39], especially in public places such as airports, commercial malls, cinemas, hospitals, hotels, universities, and commercial buildings. The in-building solution (or indoor-based solution) provides indoor coverage by distributing the signal to several antennae via a series of hubs (splitters), as shown in Figure 10. The IBS gives additional leverage to strengthen the level and quality of wireless signals, thereby ensuring smooth wireless communication for mobile network users. The operators install the IBS inside massive buildings and high-rise towers, where the received coverage from outdoor macro sites is weak due to the construction penetration losses. The IBS combines all the technologies into \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Limits**} & \multicolumn{6}{c}{**Compliance Distance (m)**} \\ \cline{2-7}  & **1 MNO** & **2 xMNO** & **\%** & **3 xMNO** & **\%** & **4 xMNO** & **\%** \\ \hline INCIRP & 14.8 & 20.9 & +41\% & 25.6 & +73\% & 29.6 & +100\% \\ FCC & 13.8 & 19.6 & +41\% & 24.0 & +73\% & 27.7 & +100\% \\ INCIRP & 6.6 & 9.4 & +41\% & 11.5 & +73\% & 13.2 & +100\% \\ FCC & 6.2 & 8.8 & +41\% & 10.7 & +73\% & 12.4 & +100\% \\ INCIRP & 6.5 & 9.2 & +41\% & 11.3 & +73\% & 13.0 & +100\% \\ FCC & 5.9 & 8.3 & +41\% & 10.2 & +73\% & 11.8 & +100\% \\ INCIRP & 2.9 & 4.1 & +41\% & 5.0 & +73\% & 5.8 & +100\% \\ FCC & 2.6 & 3.7 & 41\% & 4.6 & 73\% & 5.3 & 100\% \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The R\({}_{\text{CD}}\) for macro site shared by up to 4 MNOs, referencing the ICNIRP and FCC limits. one Distributed Antenna System (DAS) in which each antenna provides coverage for a certain zone as a hotspot [17; 40]. Figure 10: The horizontal \(R_{\text{CD-H}}\) and vertical \(R_{\text{CD-V}}\) compliance distances for one IBS-DAS antenna installed on the ceiling of a building floor for IBS shared by 4 operators (A, B, C, and D). Figure 9: The compliance Distance for GP at macro site shared by N number of MNOs using the typical RF configuration in Table 4.  
The IBS-DAS consists of many connected antennae that are shared and energized from the same radio transmitters in the splitting system. In this study, we looked at radiation from a single antenna (one zone) using high-density configurations of a single IBS site outfitted with multi-technology. The IBS was operated with six technologies: G900, U900, L800, L1800, L2100, and N3500. The input data for each technology are listed in Table 4. They are similar to those of the macro site but have less Tx power, lower antenna gains, and no mMIMO in 5G. Similar to the macro results, the IBS results expressed that all R\({}_{\text{DC-H}}\) distances were longer than the vertical R\({}_{\text{DC-V}}\) distances, and the ICNIRP had a slightly more restricted R\({}_{\text{CD}}\) compared with the FCC. The general public ICNIRP R\({}_{\text{CD-H}}\) was 0.89 m when there was a single MNO, but it increased to 1.74 m for four MNOs. Additionally, for the general public, R\({}_{\text{CD-H}}\) was 0.4 m when there was a single MNO, while it increased to 0.79 m for four MNOs. Figure 11 shows the R\({}_{\text{CD}}\) for the general public in both the vertical and the horizontal direction. In addition, further processing was carried out to analyze the power density and its related contribution to the total exposure ratio. Figure 12 presents the power density PD (W/m\({}^{2}\)) calculated at a distance (m) from the antennae, and the analysis showed that 5G N3500 had the highest PD compared with the other technologies; it reached high levels at distances very close to the DAS antenna.