lifi presentation

Bharadwaj Hetashree P. (2013_415)

Kumar Sagar D. (2013_441)

Soni Himesh N. (2013_481)

Index1. Abstraction2. History3. LI-FI Genesis4. Introduction5. Definition6. Video of LI-FI7. Electro Magnetic Spectrum8. Features9. LI-FI Technology10. Architecture of LI-FI11. LI-FI Environment12. Working Process13. Future Enhancement14. Types Of LI-FI15. Comparisons16. Applications17. Merits18. De-Merits19. Conclusion20. References

AbstractWhen you are using wireless internet in a coffee shop, stealing it from the guy next door, or competing for bandwidth at a conference, you’ve probably gotten frustrated at the slow speeds you face when more than one device is tapped into the network. As more and more people and their many devices access wireless internet, clogged airwaves are going to make it increasingly difficult to latch onto a reliable signal. But radio waves are just one part of the spectrum that can carry our data. What if we could use other waves to surf the internet? One German physicist, DR. Harald Haas, has come up with a solution he calls “Data Through Illumination”—taking the fiber out of fiber optics by sending data through an LED light bulb that varies in intensity faster than the human eye can follow. It’s the same idea behind infrared remote controls, but far more powerful. Haas says his invention, which he calls D-Light, can produce data rates faster than 10 megabits per second, which is speedier than your average broadband connection. He envisions a future where data for laptops, smartphones, and tablets is transmitted through the light in a room. And security would be a snap—if you can’t see the light, you can’t access the data.

History

In Older Days

Wired Networking

Satellites Communication

Wireless Networking

Li-Fi Genesis Harald Haas, a professor at the University of Edinburgh who began his research in the

field in 2004, gave a first demonstration of what he called a Li-Fi prototype at the TED Global conference in Edinburgh on 12th July 2011.

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.

At TED Global, Haas demonstrated a data rate of transmission of around 10Mbps --comparable to a fairly good UK broadband connection. Two months later he achieved 123Mbps.

Introduction One germen phycist. Harald Haas has come up

with a solution calls Li-Fi.

Li-Fi can be thought of as a light based Wi-Fi.That is, it uses light instead of radio waves to transmit information.

“Data through Illumination” D-light taking the fiber out of fiber optic by sending data throughan LED light bulb that varies in intensity faster than the human eye can follow.

Definition Li-Fi is transmission of data through Illumination, I.e.

sending data through LED light bulbs

Li-Fi stands for Light Fidelity.

Video Of Li-Fi

Electro Magnetic Spectrum

Features

Capacity

Bandwidth: The visible light spectrum is plentiful (10,000 more than RF spectrum), unlicensed and free to use.

Data density: Li-Fi can achieve about 1000 times the data density of Wi-Fi because visible light can be well contained in a tight illumination area whereas RF tends to spread out and cause interference.

High speed: Very high data rates can be achieved due to low interference, high device bandwidths and high intensity optical output.

Planning: Capacity planning is simple since there tends to be illumination infrastructure where people wish to communicate, and good signal strength can literally be seen.

Efficiency

Low cost: Requires fewer components than radio technology.

Energy: LED illumination is already efficient and the data transmission requires negligible additional power.

Environment: RF transmission and propagation in water is extremely difficult but Li-Fi works well in this environment.

Safety

Safe: Life on earth has evolved through exposure to visible light. There are no known safety or health concerns for this technology.

Non-hazardous: The transmission of light avoids the use of radio frequencies which can dangerously interfere with electronic circuitry in certain environments.

Securitycontainment: It is difficult to eavesdrop on Li-Fi signals since the signal is confined to a closely defined illumination area and will not travel through walls.

Control: Data may be directed from one device to another and the user can see where the data is going; there is no need for additional security such as pairing for RF interconnections such as Bluetooth.

Li-Fi Technology

Li-Fi means “Light Fidelity”.

It is possible to encode data in the light by varying the rate at which the LEDs flickers ON and OFF to give different strings of 1’s & 0’s

Architecture Of Li-Fi

Li-Fi Environment

Working Process

Li-Fi offers an integrated light source that is straight forward toIntegrated into a projector. In this example LIFI consists of 5 primarySub-assemblies:

Printed circuit board (PCB) RF power amplifier (PA) Bulb Optic Enclosure

Future EnhancementUsing an array of LEDs for parallel data transmission or using mixture of red, green and blue LEDs to alter the light’s frequency with each frequency encoding a different data channels.

Such advancements promise a theoretical speed of 10 Gbps

It means that one can download a full high definition film in just 30 seconds.

Types Of Li-Fi

Comparison

Application There are numerous applications of this technology, from public internet access through street lamps to auto-piloted cars that communicate through their headlights.

In RF Restricted Environment In Hospitals Street Lamps In AircraftUnder water etc.

In RF Restricted Environment

In Hospitals

Street Lamps

In Aircraft

Under water

Merits

High Security Easy to use Fast data transfer Harmlessness

De-Merits

High installation cost of the VLC communication.

Interferences from external light sunlight, normal Bulbs in the path of transmission will cost interruption in the communication

Conclusion If this technology can be put into practical use, every bulb can be used something like a Wi-Fi hotspot to transmit wireless data and we will proceed toward the cleaner, greener, safer and brighter future. The concept of Li-Fi is currently attracting a great deal of interest, not least because it may offer a genuine and very efficient alternative to radio-based wireless. As a growing number of people and their many devices access wireless internet, the airwaves are becoming increasingly clogged, making it more and more difficult to get a reliable, high-speed signal. This may solve issues such as the shortage of radio-frequency bandwidth and also allow internet where traditional radio based wireless isn’t allowed such as aircraft or hospitals. One of the shortcomings however is that it only work in direct line of sight.

References1)http://www.lifi.com/pdfs/techbriefhowlifiworks.pdf2)http://www.ripublication.com/ijaer.html4) http://en.wikipedia.org/wiki/Li-Fi5) seminarprojects.com/s/seminar-report-on-lifi