# Evaluating LoRaWAN Connectivity in a Marine Scenario
## 3 Results and Discussion  
During the tests, all end-nodes operated with a bandwidth equal to 125 kHz and a coding speed of 4/5. Therefore, by modifying the value of the scale factor from 7 to 12, the transmission speed values varied from 5.47 Kbit s\({}^{-1}\) down to 0.29 Kbit s\({}^{-1}\), as there is an inverse relationship between the transmission speed and the scale factor. The Adaptive Data Rate algorithm was used in all tests, which automatically allowed to maximize communication efficiency by reducing the energy consumption of the end-nodes. The sampling period of the end-nodes was set to 30 s for the two LT I/O Controllers and the Field Test, 60 s for the end-nodes TIAMO, and 20 s for the spectrometer. In the case of short distances between gateways and end-nodes a high link budget is not necessary as the time-of-flight of the transmitted packet is reduced, whereas it is necessary in the case of longer distances (i.e., in wide-area marine applications). For this reason, the transmissions were made in the maximum sensitivity scenario that, in turn, yields the highest packet loss due to a time-of-flight between 1.4 and 1.9 s. The nominal frequency band was 868 MHz. During the two crossings of the passenger vessel, the performance of the developed LoRAWAN was evaluated in a mixed line of sight and not line of sight (NLOS) scenario. In fact, as the vessel departed from Porto Antico the LOS was guaranteed only for the gateways located at Righi, Mount Fasce and partly for those positioned on Mount Gazzo, Scarpino, and Crevari, whereas as the vessel started the back route from Pegli all gateways were in LOS except Righi (Figure 4). \begin{table}
\begin{tabular}{c c c c c c} \hline
**Gateway Id.** & **Day** & **Position Id.** & **Latitude** & **Longitude** & **Altitude (asl, m)** \\ \hline LG308 1 & 19 October 2020 & Mountain pass Faiallo & 44.47840 & 8.70544 & 768 \\ LG308 1 & 20 October 2020 & Mount Figogna & 44.48910 & 8.86234 & 788 \\ LG308 3 & 19 October 2020 & Mount Fasce & 44.41659 & 9.04482 & 740 \\ LG308 3 & 20 October 2020 & Mount Fasce & 44.41602 & 9.04417 & 748 \\ RAK & 19 October 2020 & Mount Moro & 44.26600 & 7.79067 & 1722 \\ RAK & 20 October 2020 & Mount Moro & 44.26600 & 7.79067 & 1722 \\ \hline \end{tabular}
\end{table} 
Table 2: Positions of the gateways used during the research cruise on R/V Dallaporta. Table 3 summarizes the results of the test performed in coastal waters in terms of packet loss ratio for each pair of end-node and gateway. The total amount of packets transmitted by the Field Test end-node, both automatically and triggered by the operator on board the vessel, was 180. The other employed end-nodes transmitted automatically, and the number of packets sent was 97 for the spectrometer, 45 for the LT I/O Controller 1, and 71 for the end-node TIAMO 3. The LT I/O Controller 2 was not operating due to a battery fault. At the arrival and departure terminal in Pegli, conditions of the sea did not allow the operator to maintain the spectrometer operational, therefore it had to be switched off: this explains the high packet loss ratio for the spectrometer with respect to the gateways located at Crevari and Scarpino, although they were both in LOS condition. LT I/O Controller 1 was operating only for the back passage from Pegli to Porto Antico, and  
Figure 4: Terrain profiles for the two terminals (i.e., Porto Antico and Pegli) of the route of the passenger vessel and the locations of the five gateways in the inland of Genoa. Grey areas show the curvature of the Earth. Ellipses correspond to the eight of the first Fresnel zone at 868 MHz. The optical LOS is the black line. this is the reason why it was experienced an elevated number of missed received packets again for LG308 1 whose sight was partially occluded during the track of the vessel turning back to Porto Antico.