## 3 Scenario Description and Connectivity Network Configuration  
A WiBACK backhaul network detailed design to expand connectivity in Ovejas and Chalan municipalities rural areas was presented in the work of [19]. Network design was carried out in three stages: (i) theoretical projection and field study, (ii) calculation of parameters prior to links simulation according to WiBACK technology requirements, and (iii) designed links simulation results. The network projected and installed in 2020 consists of three links as presented in Table 2 and four geographical points (see Table 3), which are communicated wirelessly through radio links in 5 GHz unlicensed band using star topology as presented in Figure 2.  
The primary node is located at Chalan urban area (triangle), which connects with the repeater node located on Almagra hill (rhombus), Ovejas rural area, from there, the signal is retransmitted to La Ceiba (square) and La Pena (circle) townships of Chalan and Ovejas, respectively [19]. Network optimization is carried out in three stages: (i) technology requirements fulfillment according to final field study and network design, (ii) link-level measurements, and (iii) spectral measurement results. Due to financial issues, two types of technologies for radio link transmitters and antennas were installed. WiBACK was the main technology installed, links 1 and 3, and for link 2, airMax technology from Ubiquiti was chosen (see Table 3 and Figure 2). One of the great advantages of using WiBACK technology is its compatibility with any IP network device if the technical requirements necessary to establish point-to-point wireless links \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Population** & **Latitude** & **Longitude** & **Symbol** & **Elevation (m.a.s.l.)** \\ \hline Almagra & 9.55\({}^{\circ}\) & \(-\)75.25\({}^{\circ}\) & Rhombus & 375 m \\ Chalán & 9.54\({}^{\circ}\) & \(-\)75.31\({}^{\circ}\) & Triangle & 295 m \\ La Ceiba & 9.57\({}^{\circ}\) & \(-\)75.30\({}^{\circ}\) & Square & 303 m \\ La Pena & 9.52\({}^{\circ}\) & \(-\)75.18\({}^{\circ}\) & Circle & 218 m \\ \hline \hline \end{tabular} Source: self-made.  
\end{table} 
Table 2: Coordinates and reference symbols of populations located in Figure 2. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Link** & **Origin** & **Destination** & **Color** \\ \hline
1 & Chalán & Almagra & Cyan \\
2 & Almagra & La Ceiba & Yellow \\
3 & Almagra & La Pena & Green \\ \hline \hline \end{tabular} Source: self-made.  
\end{table} 
Table 3: Connectivity links origin and destination referenced in Figure 2.  
Figure 2: Wireless links and node’s location. Source: generated in Google Earth Pro. are met. Technical characteristics of both technologies (communication parameters and energy consumption) are shown in Table 4. Developed by Ubiquitin Networks Inc., airMax technology was designed for outdoor wireless links use with low latency and high transfer rate and point-to-point links or point-multipoint links through free use frequencies [28]. Looking at both technologies, with the exception of maximum energy consumption, technical characteristics present similar values and meet technical requirements to link establishing. The difference between maximum power consumption values is due to the number of antenna connection ports. Ubiquitin PowerBeam radio transmitters (airMAX technology) have connection ports for one antenna only, while WiBACK nodes have the facility for two antenna connections, averaging a maximum of 7.5 W per link (splitting maximum consumption value). According to WiBACK technical data sheet, each node has an average consumption of 9 W; on the other hand, Ubiquitin technical documentation specifies its maximum consumption on 8 W omitting the average consumption. An additional challenge related to devices energy consumption for networks installation in rural areas is presented since electricity supply from commercial networks may not exist.