## 4 Results
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c} \hline \hline  & & & \multicolumn{4}{c}{**Scenario**} & \multicolumn{4}{c}{**Open Sea Travel**} \\ \hline \multirow{2}{*}{CTD} & \multirow{2}{*}{**Network**} & & \multicolumn{2}{c}{**Maritime Year**} & \multicolumn{4}{c}{**Ship at Look**} & \multicolumn{4}{c}{**Near Sea Travel**} & \multicolumn{4}{c}{**Open Sea Travel**} \\ \cline{3-14}  & & **Delay** & **PL** & **rssi** & **\#sync** & **Delay** & **PL** & **rssi** & **\#sync** & **Delay** & **PL** & **rssi** & **\#sync** & **Delay** & **PL** & **rssi** & **\#sync** \\  & & **(s)** & **PL** & **rssi** & **msgs** & **(s)** & **PL** & **rssi** & **msgs** & **(s)** & **PL** & **rssi** & **msgs** & **(s)** & **PL** & **rssi** & **\#sync** \\ \hline \multirow{4}{*}{**SR**} & **Delay** & **NB-IoT** & **6.0** & **27** & **18** & **4.0** & & 32 & 55 & 5.0 & & 20 & 0 & - & - & - \\ \cline{2-14}  & & **BLE M** & **6.0** & **9\%** & **-** & **-** & **na** & **6\%** & **-** & **-** & **na** & **26\%** & **-** & **-** & **-** & **7.0** & **19\%** & **-** & **-** \\ \cline{2-14}  & & **BLE M** & **6.0** & **-** & **-** & **-** & **na** & **-** & **-** & **-** & **-** & **-** & **-** & **3.0** & **27** & **8** \\ \cline{2-14}  & & **NB-IoT** & **-** & **-** & **-** & **-** & **-** & **-** & **-** & **-** & **-** & **-** & **-** & **-** & **-** & **-** \\ \cline{2-14}  & & **BLE M** & **6.0** & **21\%** & **-** & **-** & **9.0** & **12\%** & **-** & **-** & **13.0** & **-** & **-** & **-** & **na** & **-** & **-** & **-** \\ \hline \multirow{4}{*}{**4R**} & **Delay** & **NB-IoT** & **4.0** & **30** & **7** & **4.0** & & 33 & 22 & **4.0** & & 20 & 0 & - & - & - & - \\ \cline{2-14}  & & **BLE M** & **4.0** & **5\%** & **-** & **-** & **-** & **4\%** & **-** & **-** & **9.0** & **27\%**  
Despite these drawbacks, the field trial overall shows very good results. The comparison between the indicators in Table 3 shows, in general, that CTDs transmit better in the \"open sea\" scenario than in the \"near sea\" and terrestrial scenarios. The packet loss values of the 5 GT System with satellite backhauling in operation (\"open sea\") are always lower than the values recorded on commercial cellular networks, while the delay values are equivalent. Moreover, in all scenarios, the performance of the BLE M network in terms of both packet loss and delay is always equivalent to that of the NB-IoT network with even better results in terms of packet loss. The worst-performing scenario is the \"near sea\" travel. This is in line with expectations since, in this scenario, the sailing ship is reached by the cellular signal from shore cells that are up to 21 miles away. In this scenario, the CTDs record lower RSSI values than the other scenarios due to the distance of the commercial land-side base station from the coastline and, consequently, higher packet loss. As for asynchronous messages, they were mainly triggered by the accelerometer. It should be noted that more of them were sent during the terrestrial scenario than during the maritime scenario; also, no asynchronous messages were sent during near-sea navigation. This finding is in agreement with the fact that during loading operations, the ship and containers experience the greatest mechanical stresses; furthermore, navigation in open sea has rougher swell than in near sea. The graphs in Figures 22-25 show latency histograms of some representative containers to evaluate in more detail the differences between the commercial cellular network (land-based and \"near sea\" scenarios), the hybrid satellite/cellular network (\"open sea\" scenario) and the contribution of the BLE M network. The diagrams show that although the average latency values (a few seconds) are comparable in all scenarios, in the open sea, some rare messages can reach latencies of up to 120 s. This is probably due to the characteristics of the satellite link.