What is Li-Fi?
Light Fidelity or Li-Fi is a
Visible Light Communications (VLC) system running wireless communications
travelling at very high speeds.
Li-Fi uses common household LED
(light emitting diodes) lightbulbs to enable data transfer, boasting speeds of
up to 224 gigabits per second.
The term Li-Fi was coined by
University of Edinburgh Professor Harald Haas during a TED Talk in 2011. Haas
envisioned light bulbs that could act as wireless routers.
How it works
Li-Fi and Wi-Fi are quite similar
as both transmit data electromagnetically. However, Wi-Fi uses radio waves
while Li-Fi runs on visible light.
As we now know, Li-Fi is a
Visible Light Communications (VLC) system. This means that it accommodates a
photo-detector to receive light signals and a signal processing element to
convert the data into 'stream-able' content.
An LED lightbulb is a
semi-conductor light source meaning that the constant current of electricity
supplied to an LED lightbulb can be dipped and dimmed, up and down at extremely
high speeds, without being visible to the human eye.
For example, data is fed into an
LED light bulb (with signal processing technology), it then sends data
(embedded in its beam) at rapid speeds to the photo-detector (photodiode).
The tiny changes in the rapid
dimming of LED bulbs is then converted by the 'receiver' into electrical signal.
The signal is then converted back
into a binary data stream that we would recognise as web, video and audio
applications that run on internet enables devices.
Li-Fi vs Wi-Fi
While some may think that Li-Fi with its 224 gigabits per second
leaves Wi-Fi in the dust, Li-Fi's exclusive use of visible light could halt a
mass uptake.
Li-Fi signals cannot pass through walls, so in order to enjoy
full connectivity, capable LED bulbs will need to be placed throughout the
home. Not to mention, Li-Fi requires the lightbulb is on at all times to
provide connectivity, meaning that the lights will need to be on during the day.
What's more, where there is a lack of lightbulbs, there is a
lack of Li-Fi internet so Li-Fi does take a hit when it comes to public Wi-Fi
networks.
In an announcement yesterday, an extension of standard Wi-Fi is
coming and it's called Wi-Fi HaLow.
This new project claims to double the range of connectivity
while using less power. Due to this, Wi-Fi HaLow is reportedly perfect for
battery powered devices such as smartwatches, smartphones and lends itself to
Internet of Things devices such as sensors and smart applications.
But it's not all doom and gloom! Due to its impressive speeds,
Li-Fi could make a huge impact on the internet of things too, with data
transferred at much higher levels with even more devices able to connect to one
another.
Name : Manisha Kumawat
Class : BCA-II
