This document discusses Li-Fi technology, which uses visible light communication to transmit data wirelessly. It provides an overview of how Li-Fi works using LED lights to encode binary data for transmission. The document outlines some of the key advantages of Li-Fi over Wi-Fi such as higher speeds, greater security, and energy efficiency. Potential applications are also presented, along with the economic benefits and future prospects of Li-Fi technology.

2. Content
MAIN ISSUES OF WIRELESS COMMUNICATION
WHAT IS LI – FI ?
HISTROY
A LI-FI ENVIRONMENT
HOW LI-FI WORKS ?
CONSTRUCTION OF LI-FI
LI-FI OVER WI-FI
ADVANTAGES
APPLICATIONS
ECONOMIC VALUE
FUTURE PROSPECTS
REFERENCES

3. Main issues of wireless communication
 Capacity : The range of a base station is limited.
 Efficiency : Base stations consumes a lot of energy. They are
only 5% efficient by records.
 Availability : Radio waves are not available everywhere.
 Security : Radio waves are intercepted as it penetrate through
walls.

4. Radio waves Visible lights

5. What is Li-Fi ?
 Li-Fi is transmission of data through illumination ,sending
data through a LED light bulb that varies in intensity faster
than human eye can follow.

6. Cont……
 Li-fi is a technology that uses the light emitting diodes
to transmit the data wirelessly.
 Li-fi is fast and cheap optical version of wi-fi ,based
on visible light communication(vlc).
 Vlc is a data communication medium,which
uses the visible light between 400 thz (780 nm) and
800 thz (375 nm) as optical carrier for data
transmission

7. HISTROY
 Harald Hass, a professor at the University of
Edinburgh who began his research in the field in
2004, gave a debut demonstration of what he
called a Li-Fi prototype at the TEDGlobal
conference in Edinburgh on 12th July 2011.

8. A LI-FI ENVIRONMENT

9. How LI-FI Works ?
 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.

10. Cont…

11. Cont…
 The heart of this technology is a new generation high
brightness led’s.
 These led’s varies in intensity (that is gets on and off) so
fast that a human eye cannot detect it.
 If led is on , then we transmit a digital signal 1,and if the
led is off , then we transmit a digital signal 0.
 A controller is connected at the back side of these led
bulbs to code data to these led’s.

12. CONSTRUCTION OF LI-FI
Li-Fi product consists of 4
primary sub-assemblies:
 Bulb
 RF power amplifier circuit
(PA)
 Printed Circuit Board (PCB)
 enclosure
PA
PCB
Bulb
LIFI™ Block Diagram

13. Cont……
 The PCB controls the electric inputs and outputs of the lamp
and houses the microcontroller used to manage different lamp
functions.
 An RF (Radio-Frequency) signal is generated by the solid-state
PA and is guided into an electronic field about the bulb.
 The high concentration of energy in the electric field
vaporizes the contents of the bulb to a plasma state at
the bulb’s center; this controlled plasma generates an
intense source of light.
 All of these sub-assemblies are contained in an
aluminum enclosure.

14. ALTERNATIVE OF RADIO WAVES
CAN IT BE INFRARED WAVES ? NO
IR WAVES ARE HARMFUL FOR OUR EYES HENCE USED TA VERY
LOW POWER

15.  CAN IT BE UV RAYS? NO
UV RAYS ARE HARMFUL FOR OUR SKIN AND
CANNOT BE USED FOR LONG DURATION.
 CAN IT BE GAMMA RAYS ? NO
GAMMA RAYS ARE RADIOACTIVE AND ARE
DANGEROUS.
 CAN IT BE X-RAY S ? NO
X-RAY USED IN MEDICAL FIELD.
 SO WE ARE LEFT ONLY WITH VISIBLE LIGHT
SPECTRUM.

16. LI-FI OVER WI-FI

17. Advantages
 Capacity
 Availability
 Efficiency
 High Security
 Easy To Use
 Fast Data Transfer
 Low-cost

18. APPLICATIONS
 Underwater communications: Since radio waves cannot be used
under water because these waves are strongly absorbed by sea water
within feet of their transmission and this renders it unusable
underwater but LIFI is suitable for underwater communication
 Health sector: Since WIFI is not safe to be used in hospitals and
other various health care sectors because it penetrates human body.
LIFI can be implemented and well suit in this sector.
 Internet anywhere: street lamps, light of vehicles can be used to
access internet anywhere in footpaths, roads, malls, anywhere where
light source is available.
 Safety and management: it can be used to update traffic information
at almost every instant and it will be easy for traffic police to deal
with traffic and catch the one who breaks the rule.

19. Economic value
 A free band that does not need license.
 High installation cost but very low maintenance cost.
 Cheaper than Wi-Fi.
 Theoretical speed up to 1 GB per second : Less time
& energy consumption.
 No more monthly broadband bills.
 Lower electricity costs.
 Longevity of LED bulb : saves money.
 Light doesn't penetrate through walls : secured access.

20.  An USB Li-fi Key
designed by
OLEDCOMM for tablet.
 Li-Fi router for PC by
OLEDCOMM, a French
company.
 OLEDCOMM has
recently designed a Li-Fi
Dongle for
Smartphones.

21. Future Prospects
 This report categorizes the global VLC
technology market; based on component,
applications, and geography.
 Li-Fi uses light-emitting diodes (LEDs)
which are rapidly gaining in popularity for
standard light-bulbs and other domestic
and commercial purposes. They are
expected in 20 years.

22. References
 Will Li-Fi be the new Wi-Fi?, New Scientist, by Jamie Condliffe, dated 28 July 2011
 ”Visible-light communication: Tripping the light fantastic: A fast and cheap optical version
of Wi-Fi is coming”, Economist, dated 28Jan 2012.
 Li-Fi – Internet at the Speed of Light, by Ian Lim, the gadgeteer, dated 29 August 2011.
 "Visible-light communication: Tripping the light fantastic: A fast and cheap optical version
of Wi-Fi is coming". The Economist. 28 January 2012. Retrieved 22 October 2013.
 Haas, Harald (July 2011). "Wireless data from every light bulb". TED Global. Edinburgh,
Scotland.
 Tony Smith (24 May 2012). "WTF is... Li-Fi? Optical data transfer's new leading light?". The
Register. Retrieved 22 October 2013.
 Iain Thomson (18 October 2013). "Forget Wi-Fi, boffins’ get 150Mbps Li-Fi connection from
a light bulb: Many (Chinese) hands make light work". The Register. Retrieved 22 October
2013.
 An IEEE Standard for Visible Light Communicationsvisiblelightcomm.com, dated April
2011.Tsonev, D.; Sinanovic, S.; Haas, Harald (15 September 2013). "Complete Modeling of
Nonlinear Distortion in OFDM-Based Optical Wireless Communication". IEEE Journal of
Lightwave Technology 31 (18): 3064– 3076.doi:10.1109/JLT.2013.2278675