The Internet of Underwater ThingsApril 20, 2021
By the end of 2018, there were believed to be around 22 billion smart devices in operation globally, with this number expected to reach 50 billion by 2030. The massive majority of these are above ground, transmitting their information through the air – but what about communicating through water? That’s what the Internet of Underwater Things ( IoUT), also known as the Subsea Internet of Things (SIoT), is all about.
We know that the world around us is getting smarter, both in our working and domestic lives, with factories that can tell us what they need in order to keep production running and a washing machine that you can turn on after you’ve left the house and remembered that you’d forgotten to start it. Now subsea industries are adopting some of these technologies.
The concept of the IoUT is a global network of smart, interconnected underwater devices that enable unprecedented monitoring and surveillance of vast areas of our oceans and seas. These might be purely for exploratory purposes, maintenance of underwater structures such as rigs or cables, environmental monitoring, enhanced navigation or even military uses.
What are the challenges of underwater communication?
Transmitting through water is, of course, vastly different to transmitting through air. Radio waves degrade over a short distance in seawater, traveling only at low frequencies below 300Hz and therefore requiring large antennae and power-hungry units. Underwater acoustic communication (similar to dolphin-speak) can be easily hacked into and offers only a low bandwidth. Optical communication involves LED pulses and lasers but even murky water can limit its reliability. Interference is also an issue, with simple waves and currents disrupting transmission, not to mention the increasing volumes of man-made traffic and marine life adding to the noise.
Additionally, the subsea environment is incredibly harsh for hardware; extremely low temperatures and high levels of salinity require robust components.
Once data has been transmitted and captured, most will still need processing to be of any use. With thousands of sensors and cameras planned to be deployed beneath the waves, the concept of Big Marine Data (BMD) is emerging and huge additional resource will be needed close to these devices if edge processing is to be adopted.
Innovative solutions for IoUT success
One method of subsea optical communication is being investigated meticulously by researchers at the King Abdullah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia. They are studying simultaneous lightwave information and power transfer (SLIPT) configurations to transmit energy and data to underwater electronic devices. These devices will use light beams to harvest power and decode information. Researchers found they were able to charge the battery of a camera at the bottom of a tank of sea water via its solar panel by a partially submerged, externally powered laser source. The fully charged camera was able to stream one-minute-long videos back to the laser transmitter.
UK-based CSignum claims to be the only Underwater Wireless Sensor Networks (UWSN) provider that enables transmission of data through the water-air boundary, water column, seabed and subsea structures. Their underwater HydroFi modems use patented Seatooth® technology to transmit data up to 10Mbps between two devices, which is combined with power transfer of up to 12W. Their goal is to connect first-mile subsea data with last-mile WiFi signals for an end-to-end digital infrastructure.
In 2013, the SUNRISE project was launched in Rome – a consortium of European partners tasked with creating a network of underwater testing devices. In 2018, they launched their quest to develop protocols for transmitting and receiving data via acoustic signals by autonomous underwater vehicles (AUVs), or drones. These drones measure levels of salt, methane, carbon dioxide and acidity as well as collecting image and sound data with cameras and microphones. They are designed to use acoustic transmission with a modem located either onshore or in nearby floating vessel. The data is collected from the modem and then transmitted, either via a 2.4 GHz or 2.5 GHz radio signal, to an Internet-connected gateway located onshore. The project started in the lab and will move on to underwater trials.
What are the risks?
It’s amazing what can be achieved when innovative engineers and intrepid scientists get together. But, as with all new developments, there are considerations beyond the lab. What are the implications for the wider world? We’ve already seen the environment suffer through climate change, deforestation and pollution, is it right to jam our waterways with extra sound and light? According to IFAW’s Marine Conservation campaigner, Aurore Morin, noise created by commercial shipping, military sonar and the such like is already a huge threat to dolphins, seals, fish, squid, crustacean, and sea turtles.
Thankfully, Carlos Duarte from KAUST believes current damage is reversible and future impacts can be diminished. However, it’s imperative that future developments in subsea communications prioritize ocean ecosystems and seek to minimize disruption and damage to a delicately-balanced environment.
Subsea computer vision
Active Silicon robust imaging components have been developed with a range of demanding environments in mind and are found in several subsea applications. Our Harrier range of autofocus-zoom cameras and interface boards offer various output options for long- and short-reach video capture and transmission, and their compact size and light weight makes them ideal for underwater exploration and marine applications
Contact us with your subsea vision challenge and we’ll find a solution to solve it.