# Investigations on Millimeter-Wave Indoor Channel Simulations for 5G Networks
## 4 Results and Discussion  
Figure 3 presents a single-frequency directional PL model at 39 GHz for both LOS and NLOS scenarios using the three antenna pattern configurations; as seen, for the LOS propagation scenario, the PLE is less than the free space value (n = 2) due to the waveguiding effect; however, omnidirectional PLE has the lowest value, which means that path losses are lower since omnidirectional antennae can collect rays that are due to waveguiding more efficiently. In NLOS, similar behavior was recorded, where PLE ranged from 4.88 to 5.8. Although the directional antenna focuses the beam in a specific direction, its PLs are more dispersed; it is worth mentioning that PL does not consider antenna gain. Figure 4 presents RSS comparisons using an omnidirectional and directional antenna. The RSS is larger using a directional antenna since the beams are focused from both antenna terminals; as distance increases, the difference between RSS values decreases slightly. The purpose of this figure is to show the reader that we use a directional antenna to focus the beams in specific directions and, hence, the RSS will be larger. However, PL is still larger using the directional antenna, as seen in Figure 3 and Tables 3-5. Figure 3: Single-frequency PL model at 39 GHz using (**a**) omnidirectional antenna, (**b**) directional–omnidirectional antenna, and (**c**) directional antenna. Red points represent NLOS data and blue points represent LOS data. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**NLOS**} & \multicolumn{2}{c}{**LOS**} \\ \cline{2-5}  & **PLE (_n_)** & **STD (dB)** & **PLE (_n_)** & **STD (dB)** \\ \hline
28 GHz & 5.29 & 9.24 & 1.58 & 0.63 \\ \hline
39 GHz & 5.8 & 9.97 & 1.63 & 0.63 \\ \hline
60 GHz & 6.98 & 13.07 & 1.72 & 0.76 \\ \hline
73 GHz & 6.75 & 13.564 & 1.83 & 0.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Directional–directional CI path loss model parameters. Figure 4: RSS vs. distance at an NLOS scenario at 39 GHz using a directional and omnidirectional antenna. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**NLOS**} & \multicolumn{2}{c}{**LOS**} \\ \cline{2-5}  & **PLE (_n_)** & **STD (dB)** & **PLE (_n_)** & **STD (dB)** \\ \hline
28 GHz & 4.94 & 9.58 & 1.54 & 0.78 \\ \hline
39 GHz & 5.16 & 11.38 & 1.58 & 0.58 \\ \hline
60 GHz & 4.65 & 7.74 & 1.65 & 0.5 \\ \hline
73 GHz & 4.56 & 8.31 & 1.72 & 0.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Directional–omnidirectional CI path loss model parameters. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**NLOS**} & \multicolumn{2}{c}{**LOS**} \\ \cline{2-5}  & **PLE (_n_)** & **STD (dB)** & **PLE (_n_)** & **STD (dB)** \\ \hline
28 GHz & 4.36 & 8.89 & 1.48 & 0.63 \\ \hline
39 GHz & 4.88 & 10.7 & 1.5 & 0.73 \\ \hline
60 GHz & 4.51 & 10.1 & 1.54 & 0.96 \\ \hline
73 GHz & 4.71 & 11.69 & 1.6 & 1.08 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Omnidirectional–omnidirectional CI path loss model parameters. Tables 3-5 present the PLE values extracted using the MMSE method for LOS and NLOS scenarios and the three antenna pattern configurations. Omnidirectional PLE has the lowest values due to more paths between the transmitter and receiver than other configurations. In contrast, directional PLE values tend to be the biggest values. Using both directional and omnidirectional antennae, the PLE values are in between the values of the previous two antenna configurations. For all configurations, PLE values show a dependency on frequency. In LOS scenarios, the PLE values are less than two due to the waveguiding effect; it tends to increase with frequency. Table 6 compares recorded PLE in this research and other published values from the literature, and the comparison shows good agreement. As seen, this paper presents a comprehensive study of many frequency bands.