Li-Fi is the term some have used to label the fast and cheap wireless-communication system, which is the optical version of Wi-Fi. The term was first used in this context by Harald Haas in his TED Global talk on Visible Light Communication(VLC). The technology was demonstrated at the 2012 Consumer Electronics Show in Las Vegas using a pair of Casio smartphones to exchange data using light of varying intensity given off from their screens, detectable at a distance of up to ten meters. For more recent trends in electronics please visit radeshyamece.blogspot.com
1. LIGHT FIDELITY(LI-FI)
K.B.MAHESH KUMAR K.R.SHYAM
114P1A0453 114P1AO438
ELECTRONICS AND COMMUNICATION ENGINEERING
YOGANANDA INSTITUTE OF TECHNOLOGYAND SCIENCES
MOHAN REDDY NAGAR, ELAMANDYAM (V), RENIGUNTA (M), TIRUPATI.
2. CONTENTS
• INTRODUCTION
• HISTORY
• CONSTRUCTION
• LI-FI VS WI-FI
• WORKING
• GIGA SPEED TECHNOLOGIES
• 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. 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
5. The Li-Fi product consists of three primary sub-assemblies:
• Emitter (including bulb).
• RF Driver.
• Power supply.
LIFI CONSTRUCTION
6. 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
7. 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.
9. 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 1Gbps.{1024 Mbps}
• WIFI USES THE RADIOWAVE
PORTION OF THE EM.
• LI-FI USES THE VISBLE LIGHT PORTION
OF THE EM.
10. WHY ONLY VLC?
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.
16. 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
17. RF Spectrum Relief Smart Lighting Mobile Connectivity
Hazardous Environments Hospital & Healthcare
Aviation Underwater Communications Vehicles & Transportation
Location Based Services (LBS)
APPLICATIONS
Li-Fi has found its applications in many fields. Some of them are given below:
18. 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.
19. 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.