# All about Delay-Tolerant Networking (DTN) Contributions to Future Internet
## 3 Related Work
### Underwater
#### 3.4.2 Underwater Applications  
Some applications in which DTN finds implementation in underwater networks are those where traditional communication methods such as Radio Frequency (RF) or optical signals may be ineffective due to signal attenuation, propagation limitations, or environmental factors. These applications include the following:  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Challenges** & **Papers** & **Focus** & **Solution/Protocol** \\ \hline \multirow{8}{*}{\begin{tabular}{c} Heterogeneity, mobility, \\ scalability, variable delay, \\ resource/(energy) constraints, \\ security and privacy \\ \end{tabular} } & \begin{tabular}{c} [7] \\ [113] \\ [5] \\ [114] \\ [115] \\ [116] \\ [121] \\ \end{tabular} & \begin{tabular}{c} BP \\ SNW \\ Epidemic routing \\ MaxPro \\ Prophet \\ MQTT-DTN \\ LTP \\ \end{tabular} \\ \multirow{4}{*}{\begin{tabular}{c} Heterogeneity, mobility, \\ scalability, variable delay, \\ resource/(energy) constraints, \\ security and privacy \\ \end{tabular} } & \begin{tabular}{c} [87,122, 123, 124] \\ [125, 126, 127, 129] \\ [108, 128] \\ [130] \\ \end{tabular} & \begin{tabular}{c} Data collection and monitoring \\ Disaster and energy management \\ Public transportation and mobility \\ Location monitoring \\ \end{tabular} & \begin{tabular}{c} BP, VDTN, epidemic routing \\ Routing protocols \\ Retriev, routing protocols \\ RTLS, LoRaWAN, Zigbee \\ \end{tabular} \\ \multirow{4}{*}{\begin{tabular}{c} [131] \\ [132, 133] \\ [134] \\ [135] \\ [136] \\ \end{tabular} } & \
\begin{tabular}{c} MANETs \\ Mobile computing in disaster \\ UAVs in V2X \\ \end{tabular} &
\begin{tabular}{c} IRB-DTN and DTN2 \\ UGV and UAV \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}
Table 3: Summary of IoT/smart cities-related literature works.  
* _Underwater Environmental Monitoring:_ The systematic collection of data to evaluate and understand ecological conditions and changes in underwater ecosystems, as presented in [150] with a deepwater monitoring system in the Cambos Basin offshore area.
* _Underwater Exploration and Surveillance:_ Utilized to explore and monitor underwater environments for scientific research, safety, or commercial purposes. This application employs technologies such as the Coastal Patrol and Surveillance Application (CPSA) and introduces novel protocols like Reed-Solomon (RS) [151].
* _Underwater Acoustic Communication:_ Involves the transmission of data through sound waves in underwater environments, thus allowing communication among underwater devices, vehicles, and surface stations [152].
* _Underwater Remote Sensing and Mapping:_ The integration of technologies to harvest data from underwater environments to generate detailed maps and comprehend underwater topography, habitats, and resources [152].
* _Underwater Disaster Prevention:_ Deals with the implementation of measures and strategies to mitigate risks and minimize the impact of natural or man-made disasters in underwater environments, such as oil spills, tsunamis, or industrial accidents. An example is the utilization of DTN for the Underwater Internet of Things (UIoT) and its various applications, as demonstrated in [153].