the mankind to identify phenomena related with VLC was
Sir Alexander Graham Bell in
the 1880s. Bell was able to
transmit speech using modulated sunlight over a distance
of several hundred yards. But
Professor Hass was the one
who advanced the vision of VLC
into high-speed wireless communication.
Li-Fi is simply hundred times
faster than current Wi-Fi connections. Velmeni, a leading
research organization focused
on Li-Fi research has been able
to send data up to 1GBPs in
their pilot projects using Li-Fi.
It takes only a few second for
an HD film to be downloaded through Li-Fi. PureLiFi has
Source: http://purelifi.com
already invented prototype systems for Wi-Fi communication.
They have introduced wireless modem type equipment that can
PASINDU PERERA
be plugged into PCs making them act like a dongle to receive
Department of Electrical and Electronic Engineering
data from lights. Having a plenty of lights around may increase
(Third Year)
your Li-Fi connection capacity significantly. Security is another
advantage of Li-Fi. Light doesn’t penetrate walls like Wi-Fi. So,
References
Li-Fi connections are more secured since it connects the people
1. Brian Sebele. (2016). Li-Fi: Lighting the Future of Wireless
bounded by walls and won’t leak any information to the outside.
Networks. [Online]. Available at : https://www.sitepoint.com/
It’s a perfect solution for secured local area networks.
[Accessed on September 13th, 2016]
2. pureLiFi. (n.d.). How does LiFi work? [Online]. Available at :
Apart from the internet connectivity Li-Fi has a wide range of
http://www.lifi-centre.com/ [Accessed on September 13th, 2016]
applications. The technology can be related to many infrastruc-
3. Chloe Olewitz. (2015). The Inventor of Light-Based ‘Li-Fi’
tures such as mobile connectivity, transportation, location based
Internet has Completed the First Working Prototype. [Online].
services and underwater communication. It can be considered as
Available at : http://www.digitaltrends.com/ [Accessed on
an enhancement for Internet of Things (IoT).
September 13th, 2016]
The working mechanism of Li-Fi is simple. When a LED light bulb
4. James Morra. (2016). Li-Fi Leaves the Laboratory. [Online].
is applied with a constant current, visible light is emitted as a
Available at : http://electronicdesign.com/ [Accessed on
stream of photons. The variation of the applied current makes a
September 13th, 2016]
variation of light intensity. This variation is detected by a photodetector device and converted back to an electrical current. Thus,
blinking of a LED is identified as a binary pattern.
The story of Li-Fi is yet to be unfolded. NASA is interested in
using Li-Fi to reinforce the International Space Station’s Wi-Fi
system. Hybrid communication networks combining Li-Fi and
Wi-Fi are being implemented. The day you surf the web through
your desk lamp is not so far away.
Gauge Newsletter
University of Peradeniya
27