1. Li-Fi (Light Fidelity)
Presentation on
Li-Fi (Light Fidelity)
Present by
Subhrangsu Sekhar Dey

2. Contents Introduction History Working process Applications Advantages
Disadvantages
Conclusion

3. Present Wireless Communication demands..
IN Radio spectrum/wireless communication
1.4 Million base stations, 5 billion Mobile stations
600Tb data every day

4. Issues regarding Radiospectrum

5. Capacity
Radiowaves
Cost and Expensive
Less Bandwidth compared to other spectrums
Insufficient spectrum for increasing data
Efficiency
1.Millions of base stations consume huge amount of energy.
2.limited efficiency.
3. Maintainance of base stations.(dec.efficiency)

6. Availability Security: Available within the range of Base stations
Limited availabity
Unavailable in aircrafts
Security:
Less secure(passes through the walls)

7. RADIO WAVES COMMUNICATION TO TO ACHIEVE THE SAME AT LOW COST?
WHO CAN REPLACE
RADIO WAVES COMMUNICATION TO TO ACHIEVE THE SAME AT LOW COST?

9. WHAT IS LI – FI ?
LI-FI is transmission of data through a LED light bulb that varies intensity faster than human eye can follow

10. HISTORY
The technology truly began during the 1990's in countries like Germany, Korea, and Japan where they discovered that LED's could be used to send information.  Harald Haas continues to how the world with the potential to use light for communication
HARALD HASS

11. on 12th July He used a table lamp with an LED bulb to transmit a video of blooming flowers that was then projected onto a screen behind him. During the event he periodically blocked the light from lamp to prove that the lamp was indeed the source of incoming data.
then, Haas demonstrated a data rate of transmission of around 10Mbps -- comparable to a fairly good UK broadband connection. Two months later he achieved 123Mbps.
Back in 2011 German scientists succeeded in creating an800Mbps (Megabits per second) capable wireless network by using nothing more than normal red, blue, green and yellow light spectrum..

12. How LI-FI Works ? Operational procedure is very simple,
if the LED is on, you transmit a digit ‘1’,or data is transmitted
if it is off you transmit a ‘0’ and data is not transmitted
The LEDs can be switched on and off very quickly,
which gives nice opportunities for transmitting data.
Hence all that required is some LEDS and a
controller that code data into those LEDs.

17. WHY ONLY VLC X-rays. Ultraviolet light Infrared Radio waves Gama rays.
Infrared Rays
Visible Rays
Ultraviolet Rays
X- Rays
Gama Rays
Gama rays.
X-rays.
Ultraviolet light
Infrared
Radio waves
HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT SPECTRUM.

18. data shower
For higer-speed technologies, the Li-Fi Consortium defined data Shower with diagram

19. APPLICATIONs OF LI-FI
Li Fi technology is still in its infancy .However some areas where it seems perfectly applicable are:-
TRAFFIC LIGHTS
Traffic lights can communicate to the car and with each other.
Cars having LED-based headlights, LED-based back lights, cars can communicate with each other and prevent accidents by exchanging information.

20. APPLICATIONs OF LI-FI INTRINSICALLY SAFE ENVIRONMENTS
Visible Light is more safe than RF, hence it can be used in places where RF can't be used such as petrochemical plants , airplanes etc.
PUBLIC INTERNET HOTSPOTS
There are millions of street lamps deployed around the world.
Each of these street lamps could be a free access point.

21. APPLICATIONs OF LI-FI ON OCEAN BEDS
Li-Fi can even work underwater were Wi-Fi fails completely, thereby throwing open endless opportunities for military/navigation operations.

22. 3- Airlines
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 overcomes this drawback on radioways , li-fi is introduced.

24. Advantages It is possible to achieve more than 10Gbps,
theoretically allowing a high definition film
to be downloaded in 30 sec.
Mostly powered by LEDs, so it is cost efficient.
Transmission of data is fast and easy.
Led also more safe than CFL(Toxic “Mercury” present)
It’s main advantage is it’s bandwidth.
It is 10,000 times than the radio waves

25. Disadvantages 1.Presence of light is essential.
2.Works better with fluorescent light
and LEDs but very low efficiency with bulbs
3.Light can not panetrate walls
4.Interference may be done by other light source like norm
Bulbs
4.Hight cost on VLC system installations

26. CONCLUSION
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.

27. THANK YOU
ANY QUERIES……..