Wireless Underwater Internet That Uses Light Beams and Lasers Used for the First Time

A new wireless internet system that sends signals via beams of light could revolutionize underwater communication, experts say.

Dubbed "Aqua-Fi," the technology is being envisioned as a way of letting divers transmit footage and live data to the surface, or talk without having to solely use hand signals. In testing, a prototype was able to send messages using LEDs and lasers.

The breakthrough, made by researchers from King Abdullah University of Science and Technology in Saudi Arabia, was detailed in a paper published in IEEE Communications this month, showing how optical networks can deliver under-the-sea internet.

"This is the first time anyone has used the internet underwater completely wirelessly," said the paper's author, associate professor Basem Shihada. "People from academia and industry want to monitor and explore underwater environments in detail."

Aqua-Fi, a play on the common term Wi-Fi, uses radio waves to send data from a diver's smartphone to a Raspberry Pi computer attached to the gear on their back.

This "gateway" device sends data, such as photos and videos, via a beam of light to a computer on the surface that is connected to the internet via satellite—working in the same way a Wi-Fi booster is able to extend the range of a home internet router.

Alongside light, underwater communication is possible with radio and acoustic signals. Each has limitations, however. Radio can send data over short distances, while acoustic signals can support long distances but with a very limited data rate.

In comparison, visible light is able to travel far with lots of data, but the beams need to have a clear line of sight between transmitters and receivers. The new Aqua-Fi method takes advantage of both radio and light signals to work, the researchers said.

Here's how the team's prototype worked:

• Radio waves from a diver's smartphone device was used to to send data from the "gateway" device attached to their gear, a Raspberry Pi computer.
• The Aqua-Fi system used green LEDs or a laser to send data from this simple gateway computer to a light detector connected to another computer.
• The first computer converted photos and videos into a series of 1s and 0s, which are translated into light beams turning on and off at very high speeds.
• The light detector was able to sense the variation and turn it back into 1s and 0s, which the receiving computer converted back into the original footage.

According to the researchers, their system was tested by "uploading and downloading multimedia between two computers set a few meters apart in static water." The max data transfer speed was recorded at 2.11 megabytes per second, they noted.

While promising, Aqua-Fi is not ready to roll-out just yet. There are obstacles to overcome before mass adoption is feasible.

For one, the team is considering use of a "spherical receiver" to capture light from all angles as beams have to be aligned with the receiver in moving waters for the concept to work.

"We hope to improve the link quality and the transmission range with faster electronic components," associate professor Shihada added. "We have created a relatively cheap and flexible way to connect underwater environments to the global internet. We hope that one day, Aqua-Fi will be as widely used underwater as WiFi is above water."

While Aqua-Fi is focused on providing wireless internet under the sea, another project at a much more advanced stage is aiming for the opposite domain—Earth's orbit.

SpaceX, the rocket company spearheaded by Elon Musk, announced on Saturday it had successfully launched 58 more Starlink satellites into the skies above, part of a mission to provide unprecedented high speed broadband internet access across the world.