# Performance Evaluation of LoRa Considering Scenario Conditions
## 5 Results and Discussion
### Experimental Results

Table 4: Longest range (km) achieved in each scenario by each DR configuration. Figure 12: PDR evolution with the distance for each DR in the urban scenario. CR = 4/8, payload = 20 B. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**DR**} & **Payload = 20 Bytes** & **Payload = 40 Bytes** \\  & **CR = 4/51 CR = 4/8** & **CR = 4/51 CR = 4/8** \\ \hline DR0 & 1810 12499 & 2466 13547 \\ DR1 & 987 1380 & 1315 11905 \\ DR2 & 453 1625 & 616 1887 \\ DR3 & 247 1345 & 329 1476 \\ DR4 & 134 1189 & 185 1271 \\ DR5 & 72 1103 & 103 1152 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Theoretical time-on-air (ms) for the different tested LoRaWAN PHY layer configurations. Previous works in the related literature has demonstrated that the vehicle motion can negatively impact on the reliability level of LoRaWAN transmissions ([PERSON] et al., 2018). For that reason, a nomadic test has also been conducted in the same urban and suburban scenarios in order to verify these observations, compare them with the results obtained under mobility conditions, and quantify the negative effect. A nomadic test consists in conducting a sampling campaign in specific points, i.e., with the car being stopped instead of doing it in motion. The selected sampling points for this experiment are shown in Figure 13. As in the previous experiment, different DR values have been studied; in this case, the CR was fixed to 4/8 and the payload length to 40 B. For the sake of simplicity and for permitting a direct comparison with the coverage results shown in Figures 8 and 9, we focus on discussing the results attained for the two extreme DRs, i.e., DR0 and DR5. Thus, Figure 14 depicts the attained PDR in the different sampling points for the urban (Figure 14a) and suburban (Figure 14b) scenarios. With the aim of enabling the comparison between both scenarios and to provide information about the separation between the sampling points and the base station, a distance axis has been included also in those figures. Observe that considering the most conservative DR (DR0), the results were similar to the outcomes obtained under mobility conditions. In the urban scenario (Figure 14a), only the furthest sampling point, P.E, presented an excessive level of packet loss. The rest of sampling points did not seem to be influenced by the vehicle motion as the results in both tests were similar. The same behavior was observed in the suburban scenario (Figure 14b), with similar maximum link distances in both cases. Note that the sampling point P.7 was in the range limit obtained in the previous test (Figure 9a), which justifies the low level of PDR obtained there, and P.8 was out-of-range in both experiments, so no packets were received in any case. However, the results attained for the highest DR (DR5) slightly differed from one experiment to the other. The nomadic test in the urban scenario (Figure 14a) permitted a longer link range in comparison with the dynamic one (Figure 8b). This was evidenced by observing the sampling points P.C and, especially, P.D, which were out of range in the dynamic test but presented some level of received packets under static conditions. Additionally, in the suburban scenario the results in the sampling points P.5 and P.6 (Figure 14b) also improved those obtained under dynamic conditions (Figure 9b). By analyzing these results, it can be observed that LoRaWAN presents robustness to mobility, and consequently to Doppler effect, when using a low DR, i.e., when employing high values for the SF. However, by making use of higher DRs, end-node mobility emerges as an important element to be considered in order to protect the system reliability. As discussed previously, we face again a trade-off between system robustness and transmission rate, so the mobility characteristics of the scenario under consideration should be added to the afore-discussed environmental conditions when planning and deploying a large-scale LoRaWAN network.