VLC

LI-FI The Future Technology…..

Presented By:Sibasish Singh SamantaRegd. No.: 100101ECR064

Points to be covered :• History of Networks• General network scenario• Why only VLC• Introduction• How it Works • Architecture• Issues of Radio waves• Benefits of Light Waves• Applications• Conclusion

History of Networks

In the olden days.

Wired networking.

Satellites Communications.

Wireless networking.

General network scenario

• Demand for wireless data double each year .• Low speeds.• Also as more and more devices get connected to the

network, clogged airwaves.

WHY ONLY VLC

Radio Waves

Infrared Rays

Visible Rays

Ultraviolet Rays X- Rays

Gama Rays

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

Introduction

• Li-Fi can be thought of as a light-based Wi-Fi. It uses light instead of radio waves to transmit information.

• Instead of Wi-Fi modems, Li-Fi would use transceiver-fitted LED lamps that can light a room as well as transmit and receive information.

What is Li-Fi ?

LI FI- LIGHT FIDEALITY

It is transmission of data through illumination ,i.e. sending data through a LED light bulb that varies in intensity faster than human eye can follow

How it works?

• flickering lights.

• The amplitude of the light is varied .

• Any LED light set if used along with a microchip inside it can used to detect the changes in the light flickering thus helping in converting light into data in its digital form.

• Example video

Architecture

Issues with radio waves

CAPACITY:

• The current system makes use of radio waves.

• With the increasing number of mobile connections the availability of the spectrum is getting congested.

• Radio waves forms only a small fraction of the entire EM spectrum thus making the problem even worse.

EFFICIENCY:

• The current system is high on energy consumption.

• For every unit of energy consumed the data transmitted is relatively less.

• The data speeds in the current system can only reach up to a few hundreds of megabits per second.

AVAILABILITY:

• The availability of the radio waves is yet another major issue now a days.

• These waves are not much available during the flight travel.• It is not advisable to use these devices I places like petrol bunks.

SECURITY:

• These radio waves can easily penetrate through the walls, thus letting anonymous users to use the network.

ECONOMIC:

• Due the limited availability of the radio waves the tariff rates are relatively costlier.

• There can be many transparency issues during the spectrum allocations paving way for many scams like in the case of 2G.

Benefits of light waves

Capacity:• Light is a readily available form of energy and it covers

the major portion of the EM spectrum.• Visible light spectrum is 10000 times more compared to

radio wave spectrum.

EFFICIENCY:

• The data transmission for a unit energy consumption is high in the case of light waves.

• The data transmission can reach up to thousands of gigabits per second thus providing very rich data streaming.

• Here in LI FI data bits can be transmitted parallel thus increasing the efficiency.

Availability:

• Light is readily available in every part of the world.• This makes it easy for people in airplanes to work on the

internet.• There are an estimated 14 billion light sources on earth

and each can be easily converted into a LI FI hotspot.

SECURITY:

• Unlike radio waves light waves cannot penetrate through opaque objects thus providing plenty of network privacy.

• No other person can share a network unless the owner has permitted them to use it.

• The sources can be used as normal lights when there is no use for a hotspot.

ECONOMIC:

• The tariff rates can be very cheap as light waves are a cheap resource.

• There can be transparency in spectrum allocations due to its cheapness.

APPLICATION OF LI-FILi Fi technology is still in its infancy .However some areas where it seems perfectly applicable are:-

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.

SAFE ENVIRONMENTS

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

PUBLIC INTERNET HOTSPOTS

There are millions of street lamps deployed around the world.

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

ON OCEAN BEDS

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

Limitations

• 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.

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 hotspots to transmit wireless data.