World's fastest Internet speed li-fi technology. World's Fastest Internet speed.

1. Li-Fi TECHNOLOGY

2.  Introduction
 History
 Technology
 Present Scenario
 Radio spectrum
 Issues of radio spectrum
 Electromagnetic spectrum
 Why VLC only
 Light-fidelity
 Working process
 How it works
 Comparison between WI-FI & LI-FI
 Applications of Li-Fi
 Limitations or Challenges
 Conclusion
Content

3.  Light Fidelity (Li-Fi) is a bidirectional, high speed and fully networked wireless
communication technology similar to Wi-Fi. The term was coined by Harald
Haas and is a form of visible light communication and a subset of optical
wireless communications (OWC) and could be a complement to RF
communication (Wi-Fi or Cellular network), or even a replacement in contexts
of data broadcasting. It is so far measured to be about 100 times faster than
some Wi-Fi implementations, reaching speeds of 224 gigabits per second.
 It is wireless and uses visible light communication or infra-red and near
ultraviolet (instead of radio frequency waves) spectrum, part of optical
wireless communications technology, which carries much more information,
and has been proposed as a solution to the RF-bandwidth limitations.
Introduction

4.  Harald Haas, who teaches at the University of Edinburgh in the UK, coined the term "Li-Fi" at his
TED Global Talk where he introduced the idea of "Wireless data from every light". He is Chair of
Mobile Communications at the University of Edinburgh and co-founder of pure Li-Fi.
 The general term visible light communication (VLC), whose history dates back to the 1880s,
includes any use of the visible light portion of the electromagnetic spectrum to transmit
information. The D-Light project at Edinburgh's Institute for Digital Communications was funded
from January 2010 to January 2012. Haas promoted this technology in his 2011 TED Global talk
and helped start a company to market it. Pure Li-Fi, formerly pure VLC, is an original equipment
manufacturer (OEM) firm set up to commercialize Li-Fi products for integration with existing LED-
lighting systems.
 In 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.
 A number of companies offer uni-directional VLC products, which is not the same as Li-Fi - a term
defined by the IEEE 802.15.7 standardization committee.
 VLC technology was exhibited in 2012 using Li-Fi. By August 2013, data rates of over 1.6 Gbit/s
were demonstrated over a single colour LED. In September 2013, a press release said that Li-Fi, or
VLC systems in general, do not require line-of-sight conditions. In October 2013, it was reported
Chinese manufacturers were working on Li-Fi development kits.
 In April 2014, the Russian company Stins Coman announced the development of a Li-Fi wireless
local network called Beam Caster. Their current module transfers data at 1.25 gigabytes per
second but they foresee boosting speeds up to 5 GB/second in the near future. In 2014 a new
record was established by Sisoft (a Mexican company) that was able to transfer data at speeds of
up to 10 GBPS across a light spectrum emitted by LED lamps.
History of Li-Fi

5.  Visible light communications (VLC) works by switching the current to the LEDs off
and on at a very high rate, too quick to be noticed by the human eye. Although Li-Fi
LEDs would have to be kept on to transmit data, they could be dimmed to below
human visibility while still emitting enough light to carry data.
Technology

6.  Radio Spectrum is congested but the demand for wireless data
double each year. Every thing, it seems want to use wireless data but
the capacity is drying up.
Present Scenario
1.4 Million Base Stations 5 Billion

7.  Issues regarding Radio Spectrum
Radio Spectrum

8.  Radio waves
 Cost and Expensive
 Less Bandwidth compared to other spectrums
 Insufficient spectrum for increasing data
Radio Spectrum Issues
 Millions of base stations consume huge amount of
energy for
1. Transmitting the radio waves
2. To cool the base station cabins
 5% Efficiency

9.  Less secure(passes through the walls)
Radio Spectrum Issues
 Available within the range of Base stations
 Limited availability
 Unavailable in aircrafts

11.  Gama rays cant be used as they could be dangerous.
 X-rays have similar health issues.
 Ultraviolet light is good for place without people, but other wise dangerous
for the human body.
 Infrared, due to eye safety regulation, can only be used with low power.
HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT SPECTRUM.
Why only VLC
Radio
Waves
Infrared
Rays
Visible
Rays
Ultraviole
t Rays
X- Rays
Gama
Rays

13. Light - Fidelity

14.  Operational procedure is very simple, if the led is on, you transmit a digital 1, if its
off you transmit a 0. The LEDs can be switched on and off very quickly, which
gives nice opportunities for transmitting data. Hence all that us required is some
LEDs and a controller that code data into those LEDs. We have to just vary the
rate at which the LED’s .
 Flicker depending upon the data we want to encode .
 Thus every light source will works as a hub for data transmission .
Working Process

15.  On one end all the data on the internet will be streamed to a lamp driver
when the led is turned on the microchip converts the digital data in form of
light .
 A light sensitive device (photo detector) receives the signal and converts it
back into original data. This method of using rapid pulses of light to
transmit information wirelessly is technically referred as Visible Light
Communication .
How Li-Fi Works ?

16.  Li-Fi can be thought of as a light-based Wi-Fi. That is, it uses light instead of
radio waves to transmit information.
 Instead of Wi-Fi modems, Li-Fi would use trans receiver-fitted LED lamps that
can light a room as well as transmit and receive information.
 WI-FI is great for general wireless coverage within buildings, and Li-Fi is ideal
for high density wireless data coverage in confined area and for relieving radio
interference issues .
 So the two technologies can be considered complimentary.
Comparison between Li-Fi and Wi-Fi

17. Li-Fi vs Wi-Fi

18.  Li Fi technology is still in its infancy .However some areas where it seems
perfectly applicable are:-
Application Areas
 Traffic Lights :
Traffic lights can communicate to
the car and with each other.
Cars have LED-based
headlights, LED-based back
lights, and cars can
communicate with each other
and prevent accidents in by
exchanging information.

19.  Visible Light is more safe than RF, hence it can be used in places where RF
can't be used such as petrochemical plants .
Application of Li-Fi

20.  Hospitals (In Few Medical Equipmentes) :
Application of Li-Fi

21.  Whenever we travel through airways we face the problem in
communication media, because the whole airways communication are
performed on the basis of radio waves. To overcome this drawback on
radio ways, li-fi is introduced.
Application of Li-Fi

22.  Li-Fi can even work underwater where Wi-Fi fails completely, thereby
throwing open endless opportunities for military/navigation operations.
Application of Li-Fi

23.  There are millions of street lamps deployed around the world.
 Each of these street lamps could be a free access point.
Application
 Street Lamps (As free Access Points) :

24.  Light can't pass through objects.
 Interferences from external light sources like sun light, normal bulbs, and
opaque materials in the path of transmission will cause interruption in the
communication.
 Li-Fi requires line of sight.
 A major challenge facing Li-Fi is how the receiving device will transmit back
to transmitter.
Limitations or Challenges

25.  The possibilities are numerous and can be explored further. If this
technology can be put into practical use , every bulb can be used
something like a Wi-Fi hotspots to transmit wireless data.
Conclusion

26. References
 www.nasa.gov/science/toolbox/emspectrum1.html
 http://missionscience.nasa.gov/
 http://www.ted.com/talks/harald_haas_wireless_data_from_every_light_bulb
 http://gimt.edu.in/clientFiles/FILE_REPO/2012/NOV/23/1353645362045/69.pdf (E-Book)
 http://ids.nic.in/technical_letter/Tnl_Jan2014/LI-FI%20(Light%20Fidelity)-
The%20Future%20Technology.pdf (E-Book)
 http://www.lifi.eng.ed.ac.uk/lifi-news/2016-01-07-0734/what-lifi
 http://www.homepages.ed.ac.uk/hxh/Li-Fi_PAPERS/what_is_LiFi_invited_ jlt_ecoc15.pdf (E-Book)
 http://purelifi.com/
 http://www.ijirae.com/volumes/Vol2/iss6/01.JNAE10083.pdf
 http://newtecharticles.com/new-li-fi-technology-to-access-internet/