Definition
Li-Fi is a new
technology for short range wireless communication system; which is suitable for
data transmission via LEDs by illumination. It uses the visible light, a part
of the electromagnetic spectrum that is still not greatly utilized, instead of
RF part.
Professor Harald Haas, the original founder of Li-Fi technology, in his Technology Entertainment Design (TED) global talk on Li-Fi says: “At the heart of this technology is a new generation of high brightness LEDs, he also explains “Very simply, if the LED is on, you transmit a digital 1, if it Is off you transmit a 0, they can be switched on and off very quickly, which gives nice opportunities for transmitted data. It is possible to encode data in the light by varying the rate at which the LEDs flicker on and off to give different strings of 1s and 0s. illustrates the idea of data transmission using light. The LED intensity is modulated so rapidly that the human eye cannot notice, so the output appears constant; also more sophisticated techniques could dramatically increase Li-Fi data rates such as using array of LEDs, where each LED transmits a different data stream, to provide parallel data transmission. Other ideas are using mixtures of red, green and blue LEDs to alter the light frequency encoding a different data channel. In the next paragraphs, we will talk about the history of the technology, its working principle and its various advantages.
History
Professor Harald Haas from University of Edinburgh, United Kingdom, was first used The term,in
his TED global talk in 2011. Li-Fi idea rates as “one of 50 best inventions of
2011” on TED world site on the internet.
The first project
which explains the idea of Li-Fi was The D-Light project. It was funded from
January 2010 to January 2012 at Edinburgh's Institute for Digital
Communications by Professor Haas; we will explain this project in the next
paragraph.
Here we show the
history of Li-Fi:
Ø 2011, Haas promoted
this technology in TED global talk and helped start a company to market it.
Ø October
2011, companies and industry groups formed the Li-Fi consortium, to promote
high-speed optical wireless systems and to overcome the limited amount of
radio-based wireless spectrum available by exploiting a completely different
part of the electromagnetic spectrum.
Ø 2012, VLC technology
exhibited by using Li-Fi Consortium.
Ø October 2013, Chinese
manufacturers work on Li-Fi development kits.
Ø April
2014, the Russian company Stins Coman announced the development of a Li-Fi
wireless local network called BeamCaster. Their current module transfers data
at 1.25 Gbps.
