# Evaluating LoRaWAN Connectivity in a Marine Scenario
## 3 Results and Discussion
The calculated _PRR_ values clearly reproduce a channel without multipath, as expected considering the transmission over the ocean without any major obstacles. In order to estimate the range of LoRaWAN for marine applications, both in coastal areas and on wider basin scale, the GPS position of both vessels used during the tests was recorded simultaneously to the other data: this allowed the calculation of the precise distance between the end-nodes installed on the vessels and the gateways on land for each packet sent (Figure 10). Figure 10a shows the estimated distance for the Field Test end-node during the test in coastal waters, whereas Figure 10b,c also show the results for the TIAMO 3 and the LT 1/O Controller 1 end-nodes for the days of 19 October and 20 October, respectively. Results evidence the feasibility to obtain reliable IoT transmission considering end-nodes installed on mobile platforms moving at sea, both in coastal and in offshore scenarios. Successful transmissions were obtained with a distance between gateways and end-nodes of more than 100 km in free LOS, and this achievement demonstrates the high sensitivity of the LoRa transmission up to \(-140\) dBm in an operational marine scenario. It is worth noting that the same results in terms of range are achieved by commercial end-nodes (i.e., Field Test and LT 1/O Controller 1) and the developed ones (i.e., TIAMO 3 end-node). The maximum estimated distance is summarized in Table 5.  
Figure 10: Computed distance between the end-nodes and the gateways along the time of the voyage for the two test cases: (**a**) the passenger vessel traveling in front to the port of Genoa, and (**b,c**) the R/V Dallaporta during the oceanographic cruise ICOS20. The approximations of the received power obtained applying Friis and Hata models (Equations (3)-(6)) in the coastal scenario, with gateways on hills close by the city and end-nodes installed on the passenger vessel, slightly overestimate the effective received power measured by \(RSSI\) and \(SNR\) through Equation (9). All received messages show values falling below the Hata model using the expression for the free space, but the received power is quite consistent with the formulation of the Hata model on the hypothesis of the semi-urban environment: this condition can be assumed correct for the performed tests due to the particular orography of the coast close to Genoa and a high degree of urbanization of the coast. In a few exceptions, the received packets present a power higher than expected on the basis of the Friis model (Figure 11a). In the open ocean scenario, results demonstrate that the Friis model represents better than the Hata model the condition of path loss in a free space hypothesis and when the presence of buildings is negligible along the LOS independently of the distance. Power estimates are comparable for the three sites despite the difference of about 70 km between Mount F  
Figure 11: Curves of expected power signal obtained using the [PERSON] model and the Hata model (in semi urban configuration) versus real estimates of expected power signal for the tests performed with end-nodes on-board (**a**) the passenger vessel during the coastal test in front of the port of Genoa, and (**b**) the R/V Dallaporta during the oceanographic cruise ICOS20 in the Ligurian basin. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Gateway Id.** & **Position Id.** & **Latitude** & **Latitude** &
\begin{tabular}{c} **Maximum Distance between** \\ **Gateway and End-Node (km)** \\ \end{tabular} \\ \hline LG308 1 & Mountain pass Faialo & 44.47840 & 8.70544 & 78.26 \\ LG308 3 & Mount Fasee & 44.41659 & 9.04482 & 70.00 \\ RAK & Mount Moro & 44.26600 & 7.79067 & 113.22 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Maximum achieved distance among nodes and gateways. models (Friis, Hata free space, Hata semi-urban), the Friis curve has better performance, and the Hata semi-urban model approximates better the real data with respect to the Hata model for free space (Figure 11b).