GIFI ADVANCED TOPIC

1. LIGHT FIDELITY(LI-FI)
G.UPENDRA
13695A0429
ELECTRONICS AND COMMUNICATION ENGINEERING

2. CONTENTS• INTRODUCTION
• HISTORY
• PRESENT SCENARIO
• CONSTRUCTION
• WORKING
• LI-FI VS WI-FI
• LIFI&OTHER TECHNOLOGIES
• ADVANTAGES AND CHALLENGES
• APPLICATIONS
• FUTURE DEVELOPMENTS
• CONCLUSION

3.  Li-fi MEANS “LIGHT FIDELITY”.
 Li-fi IS FAST AND CHEAP OPTICAL VERSION OF WI-FI.
 Li-fi IS A TECHNOLOGY THAT USES THE LIGHT EMITTING DIODES (LED) TO
TRANSMIT THE DATA WIRELESSLY.
 Li-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.
INTRODUCTION

4. INTRODUCTION

5.  This technology was invented by German Physicist
“HARALD HASS”, from the university of Edinburgh,
U.K.
 He demonstrated it in the year 2012.
UNIVERSITY OF EDINBURGH:
HISTORY

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.
1.4 Million Base Stations 5 Billion
Present Scenario

7. Radio Spectrum
Issues regarding Radio Spectrum

8. Radio
Waves
Infrared
Rays
Visible
Rays
Ultraviolet
Rays
X- Rays
Gama
Rays
 IR WAVES ARE HARMFUL FOR OUR EYES HENCE CAN’T BE USED.
 GAMMA RAYS ARE RADIOACTIVE AND ARE DANGEROUS.
 UV RAYS ARE HARMFUL FOR OUR SKIN AND CANNOT BE USED FOR LONG
DURATION.
 X-RAYS ALSO HAS SIMILAR HEALTH ISSUES.

9. The Li-Fi product consists of three primary sub-assemblies:
• Emitter (including bulb).
• RF Driver.
• Power supply.
LIFI CONSTRUCTION

10.  At the heart of LIFIis the bulb sub-assembly where a sealed bulb is embedded in a dielectric
material.
 The dielectric material serves two purposes:
1) waveguide
2) Electric field
FUNCTION OF THE BULB ASSEMBLY

11. RF DRIVER
 Power amplifier (PA) assembly that uses an LDMOS
device.
 Converts electrical energy into RF power.
 The PA is designed for ruggedness and efficiency.
 The RF driver also contains controls circuit for digital
and analog lighting controls.

12. How Li-Fi Works ?

13. LI-FI VS WI-FI
• Wi-Fi has a data transfer rate of
maximum 54Mbps
• Li-Fi has a High speed data transfer
rate over 10Gbps.
• WIFI USES THE RADIOWAVE
PORTION OF THE EM.
• LI-FI USES THE VISBLE LIGHT
PORTION OF THE EM.

14. LI-FI VS WI-FI

15. DIFFERENCE BETWEEN THE
TECHNOLOGIES

16. LI-FI HAS AN UPPERHAND DUE TO PARALLEL DATA TRANSMISSION

17. Capacity:
 10000 times more spectrum than RADIO WAVES.
 Light boxes are already present, so infrastructure is
available already and installed.
Availability:
 Light is present everywhere.
 Data is present where light is present
Efficiency:
 Highly efficient because LED consumes less energy
ADVANTAGES OF LI-FI

18. Limitations or Challanges
 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.
 High installation cost of the VLC systems .
 A major challenge facing Li-Fi is how the receiving
device will transmit back to transmitter.
 Li-Fi requires line of sight.

19. Application Areas
1 . Traffic Lights : 2.Intrinsically Safe Environment :

20. Potential Application of Li-Fi
3.Hospitals(In Few Medical Equipements) : 4.Airlines :

21. Potential Application of Li-Fi
5. On Ocean Beds : 6.Street Lamps (As free Access Points) :

22. FUTURE DEVELOPMENTS
 The concept of Li-Fi is currently attracting a
great deal of interest.
 Efficient alternative to radio-based wireless.
 Li-Fi is an emerging technology which is quick
and reliable.
 Air waves are clogged so let’s use light waves.
 So lets proceed to LI FI for a brighter and
greener future.

23. 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 hotspot.
 we will proceed toward the cleaner, greener, safer and brighter future.
 This may solve issues such as the shortage of radio-frequency bandwidth.
 Allows internet where traditional radio based wireless isn’t allowed such as
aircraft or hospitals.

24. REFERENCES
 http://en.wikipedia.org/wiki/Li-Fi
 seminarprojects.com/s/seminar-report-on-Li-Fi
 http://teleinfobd.blogspot.in/2012/01/what-is-lifi.html
 technopits.blogspot.comtechnology.cgap.org/2012/01/a-lifi-world
 www.lificonsortium.org
 the-gadgeteer.com/2011/08/LI-FI

25. ANY QUESTIONS?