Successful Internet-Speed Data Transfer Between Underwater Computers
The quest for instant underwater communication took a step forward earlier this month, as researchers from the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia have demonstrated an effective wireless communications system using light as a means of transmission.
Connecting divers to the Internet while they are underwater would undoubtedly be of huge benefit to scientific research of the world's oceans. Data and imagery could be processed as it is gathered, rather than waiting for footage to be brought to the surface, analysed and then have another dive expedition prepared and deployed.
By the same token, there is an increasing demand from a new generation of divers raised in the age of social media for the ability to instantly share underwater selfies with the world. The ability to add footage of a passing whale shark to a virtual meeting would undoubtedly be prized by certain groups of divers.
Currently, underwater communication is possible by radio waves over very short distances; acoustic signals have a much greater range but the rate of data transmission is too low to be useful for anything other than simple signalling. Combining the two technologies has made it possible, for example, to track a group of divers underwater in real-time, but would not allow them to send images to people at the surface.
Light can travel much further through water than radio waves and can carry a huge amount of data, but it is only possible if the water is reasonably clear and there is a direct line of sight between transmitter and receiver.
The team from KAUST has developed an underwater wireless system – dubbed 'Aqua-Fi' – that would be able to support Internet communication using LEDs for low-powered short-range communications, or lasers, which can be used over longer distances but require more power.
In a paper published on IEEE.org, lead author Bassem Shihada describes how his team used green LEDs and lasers to transmit data from a small, simple computer known as the 'Raspberry Pi' to a light-sensitive receiver connected to a second device. Between computers in close proximity underwater, they recorded a maximum data transfer speed of 2.11 Megabytes per second, approximately 17Mbs (megabits per second), as Internet connections are usually labelled.
For the purposes of future underwater communication, the team envisage that Aqua-Fi would use radio waves to connect a submersible smart device to a 'gateway' device strapped to the diver's tank, which would then connect to a relay station on a buoy or the underside of a boat, which could then connect to the Internet via 4G/5G or satellite services.
While the initial testing has proven successful, a real-world implementation of Aqua-fi is likely to take some time. 'We hope to improve the link quality and the transmission range with faster electronic components,', said Shihada. 'The light beam must also remain perfectly aligned with the receiver in moving waters, and the team is considering a spherical receiver that can capture light from all angles.
'We have created a relatively cheap and flexible way to connect underwater environments to the global internet,” he said. 'We hope that one day, Aqua-Fi will be as widely used underwater as WiFi is above water.'