## 3 Results  
\(P_{\text{avg}}\) as a function of time is shown for the 25 BSs in Figure 3. As discussed in Section 2, within each fifteen-minute interval, this was conservatively taken as the largest sample of the six-minute time-averaged power reported among all samples in the distribution. For illustration purposes, this is to avoid large overlapping of the markers. Only samples corresponding to a \(P_{\text{avg}}\) larger than 2.5% are depicted in the figure. The maximum \(P_{\text{avg}}\) observed for all BSs ranged between 22.5-25% (i.e., \(P_{\text{avg}}\) = 23.75%), but for most of the cases, \(P_{\text{avg}}\) was found to be within 0% and 2.5% of the maximum (i.e., \(P_{\text{avg}}\) = 1.25%). During the night (from midnight to about 6 a.m.), no BS was found to operate at power levels above 2.5% of the maximum. An example of \(G_{\text{avg}}(\varphi,\theta)\) observed for one BS at an arbitrary time is shown in Figure 4 (in the azimuth plane). The envelope of the antenna radiation patterns for all available beams is also plotted in the same figure together with the radiation pattern of the beam pointing towards boresight. In order to limit the number of computations in the analysis, the \(G_{\text{avg}}\) angular domain was limited to the region of interest \(-90^{\circ}\leq\varphi\leq 90^{\circ}\), i.e., in front of the antenna. \(G_{\text{avg}}\) in Figure 4 is well below the peak envelope gain (e.g., 9 dB in the boresight direction) and it is quite uniform in the azimuth plane, indicating that the time-averaged transmit power is evenly distributed over the scan range of the antenna. Figure 3: \(P_{\text{avg}}\) (as a percentage of the available maximum) for 24 h (starting and ending at 8.30 Am.). Each color identifies a 5G NR BS. For illustration purposes, only samples reporting \(P_{\text{avg}}\) larger than 2.5% are plotted. No dots are shown between midnight up to about 6 Am. indicating that all BSs were operating at a cell-wide power level below 2.5% of the maximum. _EIRP_act was calculated as a function of time according to Equation (1) for all BSs. The envelope pattern of \(\textit{EIRP}_{\text{act}}\) (\(\max\limits_{l}\textit{EIRP}_{\text{act}}(\varphi,\theta,t)\)) for the base station reporting the highest EIRP is plotted in Figure 5 (in red). In the same figure, the envelope of the theoretical maximum EIRP (i.e., obtained assuming constant peak power transmission for each beam) is also shown (green dotted line). The values are normalized to the peak EIRP for the BS. Figure 5 shows that \(\textit{EIRP}_{\text{act}}\) is only a fraction of the theoretical maximum and at least 8.8 dB lower. For the other BSs, the recorded \(\textit{EIRP}_{\text{act}}\) were considerably smaller. The overall results for all 25 BSs, including the 95 th percentile and 99 th percentile of \(\textit{EIRP}_{\text{act}}\) with respect to the maximum theoretical EIRP, are summarized in Table 1. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Max** & **99 th Percentile** & **95 th Percentile** \\ \hline \(-8.8\) dB 1  & \(-18\) dB & \(-20.2\) dB \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Maximum, 99 th percentile and 95 th percentile of \(\textit{EIRP}_{\text{act}}\) with respect to the envelope of the theoretical maximum for all 25 BSs within 24 h. For each BS and for each time \(t\), \(\textit{EIRP}_{\text{act}}\) was considered in the angular direction providing the smallest difference with respect to the theoretical maximum. Figure 4: Example of \(G_{\text{avg}}\) (dB, in red) in the azimuth plane (\(\theta=90^{\circ}\)) for one BS within an arbitrary six-minute interval and normalized to the peak antenna gain. The green dashed line shows the envelope of the antenna gain for all the available beams. In blue is the gain for the beam pointing towards boresight. Figure 5: Envelope of \(\textit{EIRP}_{\text{act}}\) (dB), i.e., \(\max\limits_{t}\textit{EIRP}_{\text{act}}(\varphi,\theta,t)\)) in the azimuth plane (in red) for the BS having the largest observed \(\textit{EIRP}_{\text{act}}\).