SEMINAR ON

LI-FI(LIGHT FIDELITY)

PRESENTED BY:-PRAGNYA DASH

ID:-B411031

GUIDED BY:-PROF.RAKESH KU. LENKA

IntroductionHistoryPresent ScenarioIssues with Radio Spectrum Working Of Li-FiLi-Fi VS Wi-FiApplicationsAdvantagesDisadvantagesConclusion

Li-Fi means “Light-Fidelity”.

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

Here 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.

llLi-Fi is a VLC(Visible Light Communication) developed by a group of scientists including Dr.Gordon Povey,Prof.Harald Hass and Dr.MostafaAfgani at the University of Edinburgh.

The term Li-Fi was coined by Prof.Hass at TED Global Talk in July,2011.rd LE

. The was coined by Prof .

Haas when he amazed people by streaming high -

definition video from a standard LED lamp at TED Global in July 2011

1.4 MILLION 5 BILLION

CAPACITY

AVAILABILITY

EFFICIENCY

SECURITY

WORKING OF LI-FI The LEDs can be switched on and off very quickly which

gives nice opportunity for data transfer in the form of Binary code.

Switching ON an LED is logical ‘1’,switching of an LED is logical ‘0’.

It is possible to encode the data into the LEDs by using a controller ,we just have to vary the rate at which LEDs flicker depending on the data we want to encode to give different strings of 0s and 1s.

UK researches say that using a micro-LED light bulb they have achieved a data transmission speed of 10Gbps using LI-FI.

HOW LI-FI WORKS

On one end all the data on the internet will be streamed to alamp driver when the LED is turned on the microchip convertsthe digital data in form of light .

A light sensitive device (photo detector) receives the signaland converts it back into original data. This method of usingrapid pulses of light to transmit information wirelessly istechnically referred as Visible Light Communication .

LI-FI VS WI-FI

APPLICATIONS

Traffic Lights

Intrinsically Safe Environment

Hospitals

Aircraft Cabins

Under Sea Water

Street Lamps

ADVANTAGES

Availability

Efficiency

High security

Easy to use

Fast data transfer

Harmless

Low-cost

Capacity

DISADVANTAGES

Light can't pass through objects.

A major challenge in Li-Fi is how the receiving device will transmit back to transmitter.

High installation cost of the VLC systems.

Interferences from external light sources like sun , normal bulbs , opaque materials.

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 hotspot to transmit wireless data and we will proceed towards the cleaner, greener, safer and brighter future.