## 2 Data Transmission Requirements and Available Connectivity Technologies
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **802.11p for ITS [24]** & **Wifi [25]** & **LTE/4G [128]** & **mmW Radics [56, WiFi] [20]** & **6G System [22]** & **VHF Digital Radio [27]** & **HF [28]** \\ \hline
**Spectrum** & 5.9 GHz & 2.4/5/6 GHz & 450 MHz-3.7 GHz & 24–86 GHz & up to 3 THz & 30–300 MHz & 3–30 MHz \\ \hline
**Bandwidth** & 10 MHz & 20/40 MHz & from 1.4 to 20 MHz & up to few GHz & up to tens of GHz & 25 kHz channels, can be bundled together, e.g., & up to 48 kHz \\ \hline
**Max bit Rate** & 27 Mbps & \begin{tabular}{c} up to 10 Gbps \\ (802.11 ax) \\ (LTE-A Pro) \\ \end{tabular} & \
\begin{tabular}{c} 75/300 Mbps for \\ UL/DL \\ up to 3 Gbps \\ (LTE-A Pro) \\ \end{tabular} & up to 20 Gbps & 1 Tbps &
\begin{tabular}{c} VDES: up to 30 Mbps in \\ split-offs up to 240 kbps \\ satellite link \\ \end{tabular} & up to 240 kbps \\ \hline
**Tx Range** & \textless{1 km} & \begin{tabular}{c} typically \textless{100 m,} \\ up to 10 km with \\ fixed service \\ \end{tabular} & \begin{tabular}{c} typically \textless{2 km} \\ up to 100 km with \\ high directional \\ antennas \\ \end{tabular} & \begin{tabular}{c} \textless{10 m for 60 GHz WiFi, \\ tens of kilometres with \\ fixed links \\ \end{tabular} & \
\begin{tabular}{c} THz for \\ short range, \\ lower frequencies \\ to for long range \\ \end{tabular} & up to 85 km &
\begin{tabular}{c} thousands of \\ kilometers \\ kilometers \\ \end{tabular} \\ \hline
**Cost** & cheap & cheap & expensive & cheap (WiFi) & not existing yet \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of terrestrial communication systems for autonomous ships. \begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{1}{c}{**Satellite Systems**} & \multicolumn{1}{c}{**Their Characteristics**} \\ \hline \multirow{4}{*}{**Deep-Sea Operations**} & \multicolumn{1}{c}{Emerging LEO mega-constellations such as Telesat [29]} & \multicolumn{1}{c}{\begin{tabular}{c} Composed of hundreds of small satellites that aim to \\ provide tens of Mbts/s connection anywhere in the world. \\ \end{tabular} } \\ \cline{2-3}  & \multicolumn{1}{c}{Next-generation GEO high-throughput satellites (HTS) and very \\  & \multicolumn{1}{c}{high-throughput satellites (VHTS) systems [31,32].} & \multicolumn{1}{c}{Providing tens of Gagbits per second total capacity to serve \\  & \multicolumn{1}{c}{} & \multicolumn{1}{c}{high-throughput satellites (VHTS) systems [31,32].} & \multicolumn{1}{c}{\begin{tabular}{c} Realised and high capacity. For example, 1.6 GHz L band \\ to be resilient even during heavy rain and Ka or QV bands \\ above 20 GHz for high capacity. \\ \end{tabular} } \\ \cline{2-3}  & \multicolumn{1}{c}{\
\begin{tabular}{c} LEO systems for Arctic including mentioned mega-constellations, e.g., \\ the Iridium system with 66 cross-linked satellites [34]. \\ \end{tabular} } & \multicolumn{1}{c}{
\begin{tabular}{c} Polar orbits for Arctic visibility. \\ \end{tabular} } \\ \cline{2-3}
**Arctic Environment** & \multicolumn{1}{c}{\begin{tabular}{c} Highly elliptical orbit (HEO) satellites [33,35]. \\ \end{tabular} } & \multicolumn{1}{c}{\begin{tabular}{c} Long visibility times in the Arctic. \\ \end{tabular} } \\ \cline{2-3}  & \multicolumn{1}{c}{\
\begin{tabular}{c} High-altitude platforms (HAPs) [36]. \\ \end{tabular} } & \multicolumn{1}{c}{
\begin{tabular}{c} Can provide mobile network type of connections from \\ airborne platforms floating 20 km above the sea level. \\ \end{tabular} } \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Satellite systems for maritime autonomous surface ships.