LI-FI TECHNOLOGY

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ABSTRACT

Li- Fi (light-fidelity) refers to 5G visible light communication system. using light emitting diode as a medium to hi-speed communication. in the similar manner WI-FI as the internet as become a major demand people are in a search of new life of data communication .These the concept of LI-FI is the data communication on fast flickering of light which is not visible to human eyes.It has gained huge popularity in the 2 years of invention such technology has brought not only greener but also safer and cheaper future of communication

Contents

Introduction What is Wi-fi ? Issues regarding Wi-Fi(Radio spectrum) What is Li-Fi? Principle of Li-Fi Technology Visible Light Communication Construction and Working of Li-Fi Comparison between Wi-Fi and Li-Fi Future Applications of Li-Fi Advantages and Disadvantages Conclusion

Introduction

Li-Fi means Light Fidelity. In simple terms, Li-Fi can be thought of as a light-based Wi-Fi.

It uses light instead of radio waves to transmit information. Li-Fi would use transceiver-fitted LED lamps that can light in a room as well as

transmit and receive information.

Issues Regarding Wi-Fi

Capacity

Availability

Efficiency

Security

Harald Haas

HISTORY

Harald Haas, a professor at the University of Edinburgh who began his research in the field in 2004, gave a debut demonstration on 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.

Li-Fi(Light-Fidelity)

Li-Fi can be tought as light based Wi-Fi. Li-Fi technology uses the visible spector. The term Li-Fi was first used by Harald haas in his Ted golbal talk on visible light

communication in 2011 In oct 2011 num of companies & industrial group formed consturin for the LI-FI

promation to provide high speed optical WI-FI system

Principles of LI-FI

If led is on transmit a digital signal 1 & off transmit signal 0. A controller is connected to the back of the bulbs to code the data to these

leads.

Visible light communication

As the li-fi is based on the visible light communication it is Li-fi is a faster & cheaper version of Wi-Fi (wireless fidelity).

VLC is using 400thz to 800thz for an optimal carrier for data transaction.

Why Visible Light..?

Why VLC….?

As we know that the GAMA rays , X-rays, ULTRAVIOLOTE rays are harm full to human body so we don’t use this rays.

INFRAFER rays are also dangerous due to cyc regulation & this are used with low power.

RADIO waves are expensive & they are less secure. So we are only left with the visible light spectrum which are not harm full.

Construction & working of li-fi

LI-FI is implemented using a white LED light bulbs at downlink transmitter.

As the variation of current is fast the output’s can be made to vary at very high speed.

An overhead lamp is fitted with an LED with signal processing technology streams data embedded in its beam at ultra high speed to photodiodes.

A receiver dongle then converts the tiny change in amplitude into an electrical signals which is the converted into data streams & transmitted to mobiles or computers.

Comparison between LI-FI and WI-FI

WI-FI stands for wireless fidelity. Transmits data using radio waves with

the help of WI-FI router. Interference issues form nearby access

point. Can’t pass through seawater as

interference is more. Can’t work in dense region. It can pass through the walls we have

to employ the security. WI-FI can be employed in open

environment.

LI-FI stands for light fidelity. Transmits data light with the help of

LED bulbs. Don’t have any interference similar to

radio frequency waves. Can pass through salty sea water as the

interference is low. Works in dense region. Can’t penetrate through walls so

security is not needed to employ. LI-FI is effected by the sun light so it

should work in closed environment.

WI-FI LI-FI

Future applications

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

Traffic application

Street lights

Under water

LI-FI in Airplanes

Advantages

Availability Efficiency Harmless High security Ease of use Fast data transfer Low cost

Disadvantages

Can’t transmit through wall. How the receiving device will transmit back to the transmitter. High initialization cost of VLC system. Interference from external light sources like sunlight ,normal bulbs &

opaque materials. Low range coverage. The security can’t be provided for the li-fi if the person is under the light.

Conclusion

The possibilities are numerous & can be explored in future. In split of disadvantages if this technology can be put into use every bulb

can be used like WI-FI hotspot. By using LI-FI we can promote to the CLEANER,GREENER,SAFER& BRIGHTER FUTURE.

Any Quries…?

Thank you