A Presentation on LI-FI TECHNOLOGY

M. Sai kumar(10w91a0475)

By

Introduction History Present Scenario Working Process Li-Fi vs Wi-Fi Applications Challenges for Li-Fi Conclusion

Contents:

What is Li-Fi ?

Light-Fidelity

LI-FI is transmission of data through illumination, sending data through a LED light bulb that varies intensity faster than human eye can follow.

Introduction:

Introduction:

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

History of Li-Fi:

Prof. Harald HaasUniversity of Edinburgh.

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:

Issues related to communication:•Capacity•Efficiency•Availability•security

Radio Spectrum Issues: Capacity

Radio wavesCost and ExpensiveLess Bandwidth compared to other spectrumsInsufficient spectrum for increasing data

Millions of base stations consume huge amount of energy for

1.Transmitting the radio waves

2.To cool the base station cabins5% Efficiency

Efficiency

Availability

Available within the range of Base stationsLimited availabilityUnavailable in aircrafts

Less secure(passes through the walls)

Security

Radio Spectrum Issues:

Electromagnetic Spectrum:

Radio

Waves

Infrared

Rays

Visible

Rays

Ultraviole

t Rays

X- Rays

Gama

Rays

Why VLC ?

Gama rays cant be used as they could be dangerous.

X-rays have similar health issues.

Ultraviolet light is good for place without people, but other wise dangerous for the human body.

Infrared, due to eye safety regulation, can only besides with low power. HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT SPECTRUM.

WHO CAN REPLACERADIO WAVES FOR

WIRELESSCOMMUNICATION ?

Light - FidelityLi-Fi

Working Process: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.

We have to just vary the rate at which the LED’s .Flicker depending upon the data we want to encode .Thus every light source will works as a hub for data

transmission .

How Li-Fi Works ?

How Li-Fi Works ?

On one end all the data on the internet will be streamed to a lamp driver when the led is turned on the microchip converts the digital data in form of light .

A light sensitive device (photo detector) receives the signal and converts it back into original data. This method of using rapid pulses of light to transmit information wirelessly is technically referred as Visible Light Communication .

Li-Fi vs Other wireless technologies:

Technology Speed Data density

Wireless (current)

Wi-Fi – IEEE802.11n

150 Mbps *

Bluetooth 3 Mbps *

IrDA 4 Mbps ***

Wireless (future)

WiGig 2 Gbps **

Giga-IR 1 Gbps ***

Li-Fi >1Gbps ****

Li-Fi vs Wi-Fi:

Application Areas:Li Fi technology is still in its infancy .However some

areas where it seems perfectly applicable are:-

POTENTIAL APPLICATION OF LI-FI

1 . Traffic Lights :

Traffic lights can communicate to the car and with each other. Cars have LED-based headlights, LED-based cack lights, and cars can communicate with each other and prevent accidents in by exchanging information.

Potential Application of Li-Fi :2. Intrinsically Safe Environment :

Visible Light is more safe than RF, hence it can be used in places where RF can't be used such as petrochemical plants .

Potential Application of Li-Fi :

Hospitals(In Few Medical Equipements) :

Potential Application of Li-Fi :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 overcome this drawback on radio waves , li-fi is introduced.

4. On Ocean Beds :

Li-Fi can even wok underwater were Wi-Fi fails completely, thereby throwing open endless opportunities for military/navigation operations.

Potential Application of Li-Fi :

• There are millions of street lamps deployed around the world.

Street Lamps (As free Access Points) :

• Each of these street lamps could be a free access point.

Application:

Limitations or Challenges:

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.

Conclusions:• Immense advancements in science has given a great base to develop such a

technology which could rule the communication in future of the coming years• The Li- Fi changes the world’s communication and every path of transformation

to a very speedy, accessible, easy, safe transformation based provision• All we need to do is fit microchip to potential illumination device which does

Illumination and wireless data transformation simultaneously• Future would project 14 Billion lifi transmitters/access points as they would

flourish the planet’s usage in excess availability• Li-Fi overcomes problems in issues likeCapabilityEfficiency Availability Security & safety• Lifi is the technology which is for a Cleaner, Greener & Brighter future of planet

•Li-fi is the technology which forth a Cleaner, Greener Brighter, future for the planet.