## 3 Scenario Description and Connectivity Network Configuration
### Ubiquitti Network Devices and Measurements  
Ubiquiti radio transmitters software airOSTM consists of several menus for equipment configuration, wireless links status visualization, and hardware use, as shown in Figure 4. It also facilitates antennas alignment and electromagnetic spectrum scanning. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Characteristic** & **WiBACK** & **Ubiquiti** \\ \hline Frequencies & 5180–5800 MHz & 5150–5875 MHz \\ Antenna gain & 23 dBi & 25 dBi \\ Receive sensitivity & –96 dBm & –96 dBm \\ Transmit power (maximum) & 30 dBm & 26 dBm \\ Transfer rate & 400 Mbps & 150 Mbps \\ Power consumption (maximum) & 15 W & 8 W \\ \hline \hline \end{tabular} Source: self-made.  
\end{table} 
Table 4: WiBACK Node-2-Connect-II and Ubiquiti PowerBeam PBE-M5-400 technical characteristics. It can be seen in airOSTM software a summary of current device configuration and established links. Among the information presented in this summary, the device model and name assigned stand out. It can also be found information about the connected network, such as type of security protocol implemented, current transmission power, and working frequency and channel width. In airOSTM software, hardware use graphical representation in real time (CPU and memory) stands out. Signal strength between Almagra and La Ceiba nodes can be observed through a bar, measuring \(-74\) dBm and presenting green color, which is interpreted as a suitable signal level since the maximum reachable value for this graph is \(-64\) dBm. Finally, bars corresponding to airMax quality to measure link quality (in percentage) and airMax capacity to measure transmission channel percentage use when multipoint links are created (several clients connected to the same device in star topology) are shown [30]. Results of WiBACK Rural Backhaul Network Spectral Measurements in Ovejas and Chalan Municipalities, Sucre, Colombia  
Spectral map measurements allow first to settle the optimal working frequency between Almagra and La Ceiba nodes depending on available frequencies, and indirectly, the installed network nodes present differences in terms of population density depending on the location. The network node located on the Almagra hill stands out among installed network nodes because it is the only one that is not located within a populated center,  
Figure 4: Ubiquiti link stats and data. Source: Ubiquiti radio transmitters software airOSTM. Figure 3: Signal levels between WiBACK network nodes. Source: WiBACK network monitoring software. contrary to installed nodes in Chalan municipal seat and La Ceiba and La Pena townships. Located in Ovejas rural area with a scattered population, repeater tower is installed in one of the highest points of Almagra hill (Figure 5); this low population density characteristic makes it possible to select Almagra node to compare electromagnetic spectrum occupation in a specific bandwidth. To perform this analysis, it is necessary to measure radio signals amount, working frequencies, and power of active devices around node location. This measurement is called spectral analysis, as an electromagnetic spectrum scan is performed. In this case study, electromagnetic spectrum measurements were performed between 5725 and 5825 MHz from the network central point located in the repeater tower-Almagra hill; in this point, communication devices corresponding to Chalan, La Pena, and La Ceiba nodes are linked. Additionally, spectral measurements in the La Ceiba node were performed to compare the electromagnetic spectrum occupation between an area with a scattered population and an area with a higher population density. In Figure 5, delimited perimeters marked in yellow over the map are presented. The left-side figure shows La Ceiba (Chalan municipality township), a higher population density area concentrated in 10 km\({}^{2}\), and the right-side figure shows Almagra hill (Ovejas municipality rural area) surrounding area with a scattered population.