# LoRa Technology Propagation Models for IoT Network Planning in the Amazon Regions
## 5 Results
### Uplink Channel Modeling Considering Attenuation by Vegetation
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Spreading** & **Model** & **Intercept** & **Path Loss** & **RMSE** \\
**Factor** & **Model** & **(dB)** & **Exponent n** & **(dB)** \\ \hline \multirow{4}{*}{SF7} & CI & 31.36 & 2.69 & 6.17 \\  & FI & \(\alpha=29.7\) & \(\beta=2.76\) & 6.17 \\  & [PERSON] & - & - & 6.91 \\  & [PERSON] & - & - & 6.91 \\  & \(PL_{\text{wg}}\) & 31.36 & 2 & 8.43 \\ \hline \multirow{4}{*}{SF8} & CI & 31.36 & 2.73 & 6.57 \\  & FI & \(\alpha=26.19\) & \(\beta=2.93\) & 6.55 \\  & [PERSON] & - & - & 7.53 \\  & [PERSON] & - & - & 7.53 \\  & \(PL_{\text{wg}}\) & 31.36 & 2 & 7.98 \\ \hline \multirow{4}{*}{SF9} & CI & 31.36 & 2.78 & 6.68 \\  & FI & \(\alpha=19.16\) & \(\beta=3.23\) & 6.57 \\ \cline{1-1}  & [PERSON] & - & - & 7.87 \\ \cline{1-1}  & [PERSON] & - & - & 7.57 \\ \cline{1-1}  & \(PL_{\text{wg}}\) & 31.36 & 2 & 7.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Summary of the parameters of channel models for SF7, SF8, and SF9 data. difference in SF7 and SF8. However, in SF9, a more noticeable difference is observed due to the sensitivity of the signal and its attenuation caused by environmental vegetation. The O-H model is also featured in [29], where it was modeled in a rural environment with an RMSE value of 6.9 dB, using data measured in SF12 at an operating frequency of 868 MHz. The authors of that study also highlighted the substantial difference between empirical and theoretical data. The proposed model for the uplink channel with dense vegetation yields RMSE results that vary depending on the studied SF. Specifically, the RMSE values for SF7 and SF8 are higher than those obtained from all the other models. In contrast, for SF9, the RMSE value is lower than the Okumura-Hata model's RMSE value. The maximum coverage or range of LoRa technology using SF12 in environments with dense vegetation is 2 km, while the minimum is 250 m, according to studies [28; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 50; 51; 52; 53; 54; 55]. Our study demonstrates that SF9 provides reliable coverage of up to 1.5 km when considering dense vegetation and links over water, with received packet rates exceeding 90%. In contrast, ref. [9] reports a packet reception rate drop to 68% over water for SF12. There is a lack of analyses on the rate of received packets in the literature. In [30], they examined the packet delivery rate at a speed of 100 m/min with SF7, SF9, and SF12, reporting a rate of approximately 30% for SF9 at a distance of 200 m.  
Increasing the SF in LoRa technology enhances the range and airtime of the signal. However, this also increases the signal's sensitivity to multipath and obstructions between LoRa devices. Our objective is to investigate whether a higher SF would result in a greater range in our scenario, which involves dense vegetation. Additionally, we aim to determine if modeling vegetation would yield lower root mean square error (RMSE) values. Based on our results, we confirm that even with dense vegetation and increased sensitivity, SF9 demonstrates the best performance in our study scenario. LoRa link operators can use a model that considers vegetation, SF9, tree height, device height, and distance between devices in applications on riverbanks and with dense vegetation.