# DTN Trustworthiness for Permafrost Telemetry IoT Network
## 8 Conclusions  
This paper analyzes the applicability of the deployment of a remote WSN for the Antarctic region using NVIS technology and the provision of an IoT telemetry service for permafrost studies. This service will be deployed during the 2021-2022 Antarctic campaign of the SHETLAND-NET project. This work focuses on analyzing and comparing transport protocols' trustworthiness in our remote WSN with DTN use case, which uses LoRa at the access network and NVIS links at the backbone network. Due to certain ionospheric characteristics, NVIS links do not work correctly at night. For this reason, values sensed at night are sent opportunistically to the control center as bulk data when the NVIS channel becomes available, which might cause network congestion. In this situation, the choice to use a particular transport protocol might affect the overall system's trustworthiness. In order to study the viability of the service to be implemented before its deployment in the field during the Antarctic campaign and in an attempt to compare the performance of various transport protocols, we use our model to measure and evaluate the trustworthiness of the proposed system. This trustworthiness model consists of four layers that can affect the \(STR\) trustworthiness metric. Three operational modes and six transport protocols were analyzed under different conditions using the Riverbed Modeler simulator. The results show a predominance of the EAATP as the most trustworthy transport protocol, while BBR and Verus have the worst trustworthiness. Adding redundancy to the measured values with multiple sensors and applying a social reputational mechanism improves the robustness of the system's trustworthiness, reaching higher \(STR\) values and never dropping below 0.5, even in high-load scenarios. On the contrary, a consensus mechanism improves the system's trustworthiness if the number of sensors is kept at a low value. The research group decided to deploy eight clusters for each NVIS gateway and seven GTN-P redundant stations per cluster in the Antarctic campaign. The collected results confirm that this scenario achieves the minimum \(STR\) required of 0.7, resulting in a feasible deployment. In this case, the results show that the EAATP can outperform up to 7% of the other analyzed transport protocols in terms of trustworthiness (\(STR\)). However, we recommend sacrificing some redundancy (i.e., trustworthiness) and increasing the number  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \(Pb_{0}\) & **BBR** & **Copa** & **CUBIC** & **EAATP** & **Indigo** & **Verus** \\ \hline \(1\times 10^{-3}\) & 0.757 & 0.797 & **0.798** & 0.797 & 0.795 & 0.783 \\ \(2\times 10^{-3}\) & 0.752 & **0.799** & 0.799 & 0.798 & 0.796 & 0.783 \\ \(4\times 10^{-3}\) & 0.748 & 0.  
of different sensed values, implementing the scenario with 16 clusters and five GTN-P redundant stations. In this case, although slightly worse \(STR\) values are achieved, the requirement of achieving at least an \(STR\) of 0.7 is met, while more data can be remotely monitored from the control center. The EAATP is also the most trustworthy transport protocol in this case, outperforming its competitors by up to 5.1%. Thus, the research group has decided to use the EAATP as the transport protocol for the offered telemetry service. Future work aims to (1) study the viability of using the same network architecture to deploy an integrated sensing and communication system (ISAC) capable of using ionosondes as data transmission signals through NVIS; and (2) analyze the implementation of other DTN architectures and protocols to improve the trustworthiness of the entire system in situations when the availability of the NVIS link is not previously known (daytime). Conceptualization, A.B., A.M. and A.Z. ; methodology, A.M. and A.Z. ; software, A.M.; validation, A.B., A.M. and A.Z. ; formal analysis, A.M.; investigation, A.M.; resources, A.B., A.M. and A.Z. ; data curation, A.M.; writing--original draft preparation, A.M.; writing--review and editing, A.B., A.M. and A.Z.