This article talks about wireless technologies for the safety and security of the sea, including ship-to-shore radios, GPS-tracking solutions, and RFID transponders.
Wireless technologies have made their way into deep sea applications. According to Brendan Hyland, chairman, WFS technologies Ltd, sub-sea Internet of Things (IoT) is a network of smart, wireless sensors and devices configured to provide actionable operational intelligence such as performance, condition, and diagnostic information.
The best wireless technology possible today is through a complicated network of satellites and multi-hop systems. Within ships and submarines, infrastructure can support local wireless networks. But with the outside world, there has to be a mixture of acoustics and radio technology with good satellite-based communication.
Underwater wireless communication systems
Ship-to-shore radios, global positioning system (GPS)-tracking solutions, radio frequency identification (RFID) transponders for freight monitoring and marine radars are the various forms of wireless communication used underwater. These extend real-time communication to personnel, vehicles, and sensors in the most challenging environments.
For Example, Seatooth Hybrid is a wireless underwater communication system that uses optical, acoustic and RF electromagnetic carrier signals. Its features are:
- Acoustic data rates: 500bps and 1200bps
- Data rates for radio: 500bps, 1.2kbps, and 2.4kbps
- Optical data rates: 10Mbps and 100Mbps
- Depth rate: 200 meters
- Operating temperature: -10°C to +60°C
- Data interfaces: RS232 and RS485
Acoustic transmission
Sound travels far in water and, hence, underwater loudspeakers and hydrophones can cover larger distances. Sonic communication equipment is generally placed in the seabed that is frequently traveled by submarines. These are connected to land stations by underwater communication cables. Submarines hiding near such devices can stay in contact with their headquarters. Gertrude, which is an underwater telephone, can also be used to communicate with submarines.
Very low frequency (3kHz – 30kHz) transmission
This can penetrate seawater approximately 20 meters deep. A submarine at shallow depth can use these frequencies, while a vessel more deeply submerged might need a buoy equipped with an antenna on a long cable. The buoy rises to a few meters below the surface and is small enough to remain undetected by enemy sonar and radar.
Extremely low-frequency transmission
Electromagnetic waves (3Hz – 300Hz) can penetrate seawater to the depths of hundreds of meters, allowing signals to be sent to submarines at their operating depths.
Wireless technologies for diver automation
Seatooth tightrope is a smart, sub-sea wireless identification and location solution for divers and remotely-operated underwater vehicles (ROVs). It has a unique fiber-lighting system that offers a solution for challenging and hazardous sub-sea environments. It provides positive identification of structures, locations, and umbilicals.
when Seatooth LightRope is used by a diver, the ROV automatically switches on when the diver or ROV is five meters away. Its communication range through seawater is 500 meters and 3000 meters deep, with a standard operating temperature of -0°C to +40°C.
Seatooth Wireless Communication and Control System (SWiCOM) is a secure and resilient underwater C4ISR solution for divers. It provides bi-direction support through water/air text communication up to nine meters. It supports remote sensor data exfiltration and communication with unmanned aerial vehicles.
