# Integration of a Mobile Node into a Hybrid Wireless Sensor Network for Urban Environments +
## 4 Experiments
### Experiments in Networked Mode  
In the experiments for the networked mode, the mobile node was configured to include the Gas and GPS nodes. The gas sensors for the former node were NH\({}_{3}\), O\({}_{2}\), CO\({}_{2}\), VOC as well as temperature and humidity. The Gas and GPS nodes acquired, processed and sent data to the embarked Receiver node according to their own dynamics. Upon data reception from any sensor, the Receiver node updated its internal database and synchronized it with the external database at the server. GPS data was treated as another sensor, updating the location in the database as soon as new data were received according to a programmed rate. The experiments were designed to consider a greater diversity in the routes, including highways and longer distances. They were performed in the city of Malaga. Figure 13 presents a screenshot of the HMI showing the route of one of these experiments, as well as labels for selected locations. The path started at the campus of the University of Malaga (red square) and reached the eastern limit of the city (label 6) to finally go back to the campus. This route was performed in 1 hour and 24 minutes, for a total of 28.3 kilometers covering highways in the western part of the route (labels 1 and 2) as well as urban areas for the rest. Table 2 presents some of the data obtained by the mobile node together with the geo-located labels in the route marked in Figure 13. The measurements recorded by the different sensors were shown in real-time at the HMI, allowing the user to visualize a plot with the evolution of a certain sensor by selecting it in the interface. Figure 14 shows the evolution of the measurements obtained by the NH\({}_{3}\) sensor along the route covered by the experiments. In contrast with the local mode in the networked mode the strategy allows for acquiring a larger amount of data, since the update and synchronization of the databases takes place every time a new \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**EP Node**} & \multicolumn{4}{c}{**Gas Node**} \\ \cline{2-10}
**Item** & \begin{tabular}{c} **Luminance** \\ **(lux)** \\ \end{tabular} & \begin{tabular}{c} **Dust** \\ **(ppm)** \\ \end{tabular} & \begin{tabular}{c} **Noise** \\ **(dB)** \\ \end{tabular} & \begin{tabular}{c} **Temp** \\ **(\({}^{\circ}\)CO** \\ \end{tabular} & \begin{tabular}{c} **Humidity** \\ **(\%)** \\ \end{tabular} & \begin{tabular}{c} **O\({}_{2}\)** \\ **(\%)** \\ \end{tabular} & \begin{tabular}{c} **CO\({}_{2}\)** \\ **(ppm)** \\ \end{tabular} & \
\begin{tabular}{c} **VOC** \\ **(ppm)** \\ \end{tabular} &
\begin{tabular}{c} **GPS Coordinates** \\ \end{tabular} \\ \hline
1 & 25.0 & 0.074 & 83 & 24.00 & 43.7 & 19.585 & 334.300 & 6.05 & 36.723861, \(-\)4.426139 \\
2 & 97.0 & 0.075 & 93 & 25.81 & 47.6 & 17.794 & 334.490 & 5.25 & 36.717833, \(-\)4.426333 \\
3 & 97.5 & 0.082 & 94 & 23.55 & 53.2 & 17.843 & 334.951 & 8.69 & 36.721444, \(-\)4.425111 \\
4 & 98.0 & 0.074 & 91 & 27.10 & 42.1 & 18.569 & 334.615 & 8.46 & 36.723722, \(-\)4.422750 \\
5 & 98.5 & 0.074 & 91 & 25.32 & 51.1 & 18.133 & 334.793 & 7.64 & 36.721278, \(-\)4.413306 \\
6 & 75.2 & 0.072 & 93 & 27.85 & 44.3 & 18.952 & 334.713 & 7.94 & 36.716861, \(-\)4.427944 \\
7 & 98.6 & 0.074 & 93 & 26.29 & 50.0 & 18.423 & 334.694 & 8.13 & 36.719722, \(-\)4.435972 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Data obtained for a city center route in local mode. Figure 12: Area of the city center covered by experiments in local mode. data is obtained by any sensor. Thus, the slow dynamics of a sensor does not limit obtaining more data with a faster one. In this way, Table 2 presents a summary of the data, while a more extensive set of measurements is presented in Appendix A. Table 2 presents the last data obtained for every sensor when the test car reached the locations labelled on Figure 13.  
Figure 14: Measurements for the NH3 sensor obtained in a networked mode experiment, as shown by the user interface.