A Presentation on

LI-FI TECHNOLOGY for the partial fulfillment of the requirement

for the degree ofBachelor of Technology

in

Computer Science And Engineering

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

What is li-fi? Li-Fi is the transmission of data

through illumination by taking the fiber out of fiber optics by sending data through a LED light bulb.

This varies in intensity faster than human eye can follow.

It is the fast and cheap wireless communication system which is optical which is optical version of the Wi-Fi.

GENESIS OF Li-fi Harald Hass, a professor at the

University of Edinburgh who began his research in the field in 2004, gave a debut demonstration of what he called a Li-Fi prototype at the TEDGlobal conference in Edinburgh on 12th July 2011.

HISTORY OF LIFI

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 TEDGlobal, 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.

Present Scenario 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

Radio Spectrum Issues regarding Radio Spectrum

Radio Spectrum Issues Capacity

RadiowavesCost 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

Radio Spectrum Issues Availability

Available within the range of Base stationsLimited availabityUnavailable in aircrafts

Less secure(passes through the walls)

Security

Electromagnetic Spectrum

Why VLC ?Radio

Waves Infrared

RaysVisible Rays

Ultraviolet Rays X- Rays

Gama Rays

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 bse used with low power.

HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT SPECTRUM.

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 .

CONSTRUCTION OF LI-FI.. Li-Fi product consists of 4

primary sub-assemblies: Bulb RF power amplifier circuit (PA) Printed Circuit Board (PCB) enclosure

CONSTRUCTION OF LI-FI The PCB controls the electric

inputs and outputs of the lamp and houses the microcontroller used to manage different lamp functions.

An RF (Radio-Frequency) signal is generated by the solid-state PA and is guided into an electronic field about the bulb.

Construction of li-fi The high concentration of energy

in the electric field vaporizes the contents of the bulb to a plasma state at the bulb’s center; this controlled plasma generates an intense source of light.

All of these sub-assemblies are contained in an aluminum enclosure.

Comparison between li-fi & wi-fi..

Li- Fi is a term of one used to describe visible light communication technology applied to high speed wireless communication.

It acquires this name due to the similarity to Wi-Fi, only using light instead of radio.

Comparison between li-fi & wi-fi..

Wi-Fi is great for general wireless coverage within buildings and Li-Fi is ideal for high density wireless data coverage in confined area and for relieving radio interference issues, so the two technologies can be considered complimentary.

Comparison between li-fi & current technology..

Technology Speed Data density

Wireless (future) Wi-Gig 2Gbps

** Giga-IR 1Gbps

*** Li-Fi 1Gbps

****

Li-Fi vs Wi-Fi

How li-fi is different? Li-Fi technology is based on LEDs

for the transfer of data. The transfer of the data can be

with the help of all kind of light i.e., Light may be Invisible, Ultraviolet or Visible part of spectrum.

The speed of the internet is incredibly high and the user everything in just a few minutes.

Application area of li-fi technology:

Some of the applications of Li-Fi are given below:

Airways Green information technology Free from frequency bandwidth problem Increase communication safety Multi user communication Lightings points used as hotspot Smarter power plants Under sea Awesomeness

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-Fi2. 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-Fi3. 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 radioways , li-fi is introduced.

Potential Application of Li-Fi4. On Ocean Beds :

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

Application

• 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.

In a meeting room environment, the access area of each channel is the width of the light pool, and can be accessed by multiple users. Each user can receive higher data rates than would be the case for an equivalent Wi-Fi channel. In the Wi-Fi case, each user or group of users directly competes for access to bandwidth. The net result is that the more connections there are, the slower the download speeds are for all. By contrast, in the case of Li-Fi, with its greater number of available access points, each pool of light provides full channel data rates with fewer simultaneous users. The overall net bene??t to each user is up to 1000 times greater speeds. In addition, and in contrast to radio waves, the light does not pass through the walls. Therefore, with minimal precautions to avoid leakage from windows, etc., security is fundamentally enhanced ascompared with Wi-Fi.

SECURITY

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.

Limitations or Challanges Li-Fi technic can not work on dark and

outdoor

Unlike Wi-Fi we can not move to other room because there are wired bulb too

Conclusion And Future Scope

As a growing number of people and their devices access wireless internet, the air waves are becoming increasingly clogged, making it more and more difficult to get a reliable, high-speed signal.

Conclusion And Future Scope attracting a great deal of interest, not least

because it may offer a genuine and efficient alternative to radio-based wireless.

It’s estimated that the Li-Fi market will be worth more than $6 billion by 2018 , according to analysis by MarketandMarkets

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

Li-Fi is an emerging technology which is quick and reliable

Hence let’s proceed to Li-Fi for a brighter ,cheaper and greener future

REFRENCES

1. Our respected teacher- Mrs. Meena Verma2..http://www.electronicsforu.com/electronicsforu/circuitarchives/view_article.asp?sno=778&title%20=%20Li-Fi%3A+A+New+Paradigm+in+Wireless+Communication&b_type=new&id=120423. http://en.wikipedia.org/wiki/Li-Fi 4. International Journal of advances in computing & communications, vol 1, 2013,page no-12www.ijacc.org

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