## 3 Materials and Methods
### Field Trial  
Before the field trial tests, an end-to-end testbed in a laboratory was implemented to verify the interoperability of all the sub-systems composing the 5 GT System and assess their performance [35]. Then, the field trial deployment of the 5 GT System took place in Genoa at the Intermodal Maritime Terminal (IMT) of the Ignazio Messina & C. cargo ship company on the 12 th and 13 th of April 2023. The event was run by a team of technicians \begin{table}
\begin{tabular}{l l} \hline \hline
**5 GT Use Case Scenario** & **Description** \\ \hline \multicolumn{3}{l}{The CTDs attach the NB-IoT terrestrial cell. The Telco terrestrial domain authenticates them.} \\ \multicolumn{3}{l}{Thus:} \\ \(1\)—Containers are stored in the port terminal. & \(1\)—The CTDs send the data to the NB-IoT terrestrial cell; \\ \(1\)—The terrestrial cell routes the data to the Telco terrestrial domain; \\ \(1\)—Finally the data are routed to the OneM2M IoT platform. & \\ \multicolumn{3}{l}{The CTDs are still connected to the NB-IoT terrestrial cell. Thus:} \\ \(2\)—From the cargo ship the CTDs send the data to the terrestrial cell; \\ \(2\)—The terrestrial cell routes the data to the Telco terrestrial domain; \\ \(2\)—Finally the data are routed to the OneM2M IoT platform. & \\ \multicolumn{3}{l}{The maritime Telco turns on its equipment.} \\ \(3\)—The cargo ship is in “open sea” (i.e., the part of the sea where the maritime Telco is authorized to turn on its equipment), under the coverage of a WWAN network. & \\ \(3\)—The cargo ship is in “open sea” (i.e., the part of the sea where the maritime Telco is authorized to turn on its equipment), under the coverage of a WWAN network. & \\ \(3\)—The cargo ship is in “open sea” (i.e., the part of the sea where the maritime Telco is authorized to turn on its equipment), under the coverage of a WWAN network. & \\ \(4\)—The cargo ship is in open sea only under the coverage of the satellite network. & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: 5 GT System use case scenarios. Figure 10: 5 GT System scenarios. representing all the partners of the consortium and by ESA technical officers as well. The activities were supervised by Ignazio [PERSON] & C. officers and crew. It is important to emphasize that the whole hardware system, although prototypical, was made in compliance with stringent requirements for resistance to the marine environment. In particular, the CTD devices on the containers had undergone IP67 pre-compliance testing with immersion for 48 h at the bottom of a one-meter water column. The field trial validation tests involved the IMT for the terrestrial scenario (see Figure 11) and the Jolly Titanio cargo ship (see Figure 12) travelling from Genova to Mombasa for the maritime scenario. The diagram in Figure 13 shows the physical elements of the deployed network onboard and their locations. Figure 11: Deploying of the CTDs on the containers in the maritime yard. Figure 12: Jolly Titanio cargo ship hosting the field trial tests (source: Ignazio Messina & C.). Figure 16 shows 2 of the 10 CTD-equipped containers being loaded onto the ship. The localization of the rows of containers equipped with CTDs on the travelling ship is shown in Figure 17. A diagram showing the displacement of the stacked containers with the CTD is drawn in Figure 18.  
Figure 14: Satellite terminal installed onboard (KNS antenna). Figure 13: Network elements of the 5 GT System installed on board. Figure 16: Containers with CTDs loading on the deck of Jolly Titanio ship. Figure 15: Cellular base station installed onboard. The equipped containers were only those that would be disembarked in Mombasa, since only in the port of Mombasa are the Jolly Titanio seafarers allowed to disembark from the ship and operate in the yard to retrieve the CTDs. Respecting this constraint, 10 containers (8 of 40 feet and 2 of 20 feet) were equipped; on each of those containers, a pair of CTDs was installed, one with TIM SIM and one twin with AZCOM SIM.