# Wireless Remote Control for Underwater Vehicles
## 2 Underwater Communication Technologies
### Underwater Acoustic Communications
The Marecomms Robust Acoustic Modem (ROAM), recently developed in partnership with Geospectrum, achieves a throughput of 26.7 kbps at a distance of 600 m while operating in the HF band in shallow water. A test has been performed in the presence of Doppler as the nodes were floating randomly with a speed between 0.5 and 1 knot [67]. With the new version of the modem, the manufacturer expects to achieve 50 kb/s within a range of 1 km. This modem is expected to become available on the market by late 2020 to early 2021. The ROAM modem can also operate in the MF band, providing a bit rate of 13 kbps. The most representative underwater acoustic modems with omnidirectional beam patterns that can also be employed for communications in shallow-water scenarios are summarized in Table 1. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Manufacturer and Model** & **Max Range** & **Bit Rate** \\ \hline \multirow{5}{*}{Sercel MATS3G 12 kHz [33]} & \multirow{2}{*}{15 km} & [20, 200] bps secure data with coding, \\  & & & [0.8, 7.4] kbps high rate with no coding \\ \cline{2-3}  & EvoLogics S2C R 7/17 [29] & 7 km & [1, 7] kbps raw bit rate with no coding, \\  & & & [0.6, 4] kbps net data rate with coding \\ \cline{2-3}  & WHOI MicroModem [12] & [6, 11] km & [0.2, 5.4] kbps in vertical links [68] \\ \cline{2-3}  & LinkQuest UWM10000 [31] & 7 km & 5 kbps raw bit rate, \\  & & & 2 kbps payload data rate \\ \cline{2-3}  & Kongsberg cNODE LF [34] & few kms & up to 4.5 kbps \\ \cline{2-3}  & Benthos ATM 960 LF [28] & 6 & [0.08, 2.4] kbps \\ \cline{2-3}  & AQUATEC AQUAmodem1000 [69] & 10 km & [0.1, 2] kbps \\ \cline{2-3}  & AquaSeNT AM-D2000 [30] & 5 km & [0.375, 1.5] kbps \\ \cline{2-3}  & DiveNET: Sealink R [55] & 2.5 km & [0.56, 1.2] kbps in shallow water \\ \cline{2-3}  & Develogies HAM.NODE [11] & 30 km & 145 bps \\ \cline{2-3}  & DiveNET: Sealink [C\_S] [55] & 8 km & 80 bps in shallow water \\ \hline \multirow{5}{*}{Sercel MATS3G 34 kKHz [33]} & \multirow{2}{*}{5 km} & [20, 300] bps secure data with coding, \\  & & & [1, 24.6] kbps high rate with no coding \\ \cline{2-3}  & LinkQuest UWM2000 series [31] & 1 km & 17.8 kbps raw bit rate, \\  & & & [0.3:6] kbps payload data rate \\ \cline{2-3}  & Subnero WNC [40] & [3, 5] km & 15 kbps \\ \cline{2-3}  & EvoLogics S2C R 18/34 [29] & 3.5 km & [1, 13.9] kbps raw bit rate with no coding, \\  & & & [0.6, 9] kbps net data rate with coding \\ \cline{2-3}  & Popoto Modem [36] & [1, 8] km & [0.08, 10] kbps \\ \cline{2-3}  & AquaSeNT AM-OFDM-13A [30] & 5 km & [1.5, 9] kbps \\ \cline{2-3}  & Sonardyne 6G [38] & 1.5 km & [0.2, 9] kbps \\ \cline{2-3}  & Kongsberg cNODE MF [34] & 1 km & up to 4.5 kb/s \\ \cline{2-3}  & Benthos ATM 960 MF, band C [28] & 1.5 km & [0.08, 2.4] kbps, 15 kbps possible \\  & in very quiet deep ocean environments \\ \cline{2-3}  & Applicon Seamodem [37] & 100 s of m & [0.75,2] kbps \\ \cline{2-3}  & DSPComm Aquacomm Gen2 [39] & 8 km & [0.1, 1] kbps \\ \cline{2-3}  & Blueprint Subsea X150 USBL Beacon[41] & 1 km & 100 s bps \\ \cline{2-3}  & DiveNET: Sealink M [55] & 1 km & 80 bps \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Performance figures of some acoustic modems with omnidirectional beam patterns.