With our current technology,
divers use hand signals, radio, or acoustic or digital light signals to
communicate. While these allow effective communication, they have their
limitations. Acoustic signals support long distances, but with a very limited
data rate. Visible light can travel far and carry lots of data, the problem is
that the narrow light beams require a clear line of sight between transmitters
and receivers. Radio, meanwhile, can only carry data through short distances
underwater. At the moment streaming video from under the sea simply isn't
accessible. Researchers, from King Abdullah University of Science and
Technology in Saudi Arabia, built an underwater wireless system that they've
dubbed Aqua-Fi. Aqua-Fi supports internet services, such as multimedia message
sending via either LEDs or lasers.
The LEDs provide a low-energy
short-distance communication option, while lasers need more power but can carry
data further. The researchers built the prototype using green LEDs and a
520-nanometer laser. Both were used to send data from a small computer to a
light detector connected to another computer. The first computer converted
photos and videos into a series of 1s and 0s, which were then transferred via a
light beam that turns on and off at very high speeds to transmit the signal.
The light detector senses the variation in the light speed and translates it
back into the computer language of 1s and 0s. This is converted by the
receiving computer into the streamed footage or other multimedia. During their
tests, the team was able to record maximum data transfer speed of 2.11
megabytes per second and an average delay of 1.00 millisecond for a round trip.
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