Presented byP.GEETHA

Ph.D scholar-NIT-Trichy

P.GEETHA Associate Professor

Introduction

Comparison

Evolution of Li Fi

Working

Components

Construction

Applications

Advantages

Limitations

Conclusion

Li-Fi is transmission of data through illumination,

sending data through a LED light bulb.

Li-Fi, or light fidelity, is 5G visible light communication systems using light from light-emitting diodes (LEDs) as a medium to deliver networked, mobile, high-speed communication in a similar manner as Wi-Fi and Optical fiber.

Li-Fi could lead to the Internet of Things.

Optical version(Light based) of Wi-Fi

Light is used instead of radio-waves to transmit

information

Transceiver fitted LED lamps acts like Wi-Fi modems

LED lamps can light a room as well as transmit-receive

information

Provides illumination as well as data communication

Radio spectrum is congested, but

the demand for wireless data

doubles each year

Issues regarding radio spectrum,

such as capacity, availability,

efficiency, security are solved

using LiFi.

Speed of data transmission can

be increased.

Fire wire 800 Mbps

USB 3.0 5 Gbps

Thunderbolt 20 Gbps

Wired

Wireless(Current)

Wireless(Future)

Li-Fi 10 Gbps

Giga-IR 1 Gbps

Wi-Gig 2Gbps

Wi-Fi 150 Mbps

Bluetooth 3 Gbps

IrDA 4 Gbps

CAPACITY

Spectrum is 10,000 times greater than that of radio frequency

EFFICIENCY

Highly efficient since LED consumes less energy

AVAILABILITY

Light waves available everywhere.

SECURITY

Cannot penetrate through walls. Hence data cannot be intercepted.

Li-Fi can be the technology for the future where data forlaptops, smart phones, and tablets will be transmittedthrough the light in a room.

Security would not be an issue because if you can‘t seethe light, you can‘t access the data. As a result, it can beused in high security military areas where RFcommunication is prone to eavesdropping.

In electromagnetic spectrum, gamma, UV rays are dangerous

for human body.

IR rays, due to eye safety regulation, can only be used with

low power.

Li-Fi is a Visible Light Communication (VLC), technologydeveloped by a team of scientists including Dr. Gordon Povey,Prof. Harald Haas and Dr. Mostafa Afgani at the University ofEdinburgh.

Prof. Harald Haas

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.

Professor Harald Haas

Original founder of Li-Fi.

Chairman of Mobile Communications at the

University of Edinburgh.

Co-founder of pureLiFi. Prof. Harald Haas

University of Edinburgh,U.K

In October 2011, Li-Fi Consortium- promote high-speed optical wireless systems .

VLC technology was exhibited in 2012 using Li-Fi.

By August 2013, data rates of over 1.6 Gbit/s were demonstrated

over a single color LED.

In September 2013, a press release said that Li-Fi, or VLC systems in general, do not require line-of-sight conditions.

In October 2013, it was reported Chinese manufacturers were working on Li-Fi development kits.

Philips lighting company has developed a VLC system for shoppers at stores. They have to download an app on their smart phone and then their smart phone works with the LEDs in the store.

Operational procedure is very simple.

Normal light power is replaced by LED light power.

The LED bulb will hold a micro-chip that will do the job of processing the data.

If LED is ON, digital data ‘1’ is transmitted & if LED is

OFF, digital data ‘0’ is transmitted.

LEDs varies in intensity so fast that a human eye cannot

detect it.

A controller connected at the back side of these LEDs is

used to code data.

Also called as 5G optical communication.

Parallel data transmission

TRANSMITTER RECIEVER/RECEPTOR END

All the data from Internet isstreamed into lamp driver.

Data from internet is used tomodulate the intensity of LEDlight source.

Thus by fast and subtlevariations of current, opticaloutput can be made to vary atextremely high speed

The photo detector picks upthe signal

The receiver dongle thenconverts the tiny changes inamplitude into a data stream.

A high brightness white LED, Which act as a communication source.

A photodiode which shows good response to visible wavelength region serving as the receiving element.

The LI FI product consists of 4 primary sub-assemblies:

• Bulb• RF power amplifier circuit (PA)• Printed circuit board (PCB)• Enclosure

Li-Fi technology is based on LEDs for the transferof data.

The transfer of the data can be with the help of allkinds of light.

Also, the speed of the internet is incredibly highand we can download movies, games, music etc injust a few minutes with the help of this technology.

Li-Fi connector and router are themain components for a network

Room connector:

Optical signals cannot penetratethrough walls, in order to providean optical WLAN, rooms need tobe connected with each other

Li-Fi room connector is areplicator, which sends the datastream from one side of the wallto the other side via an opticalfiber.

For smaller rooms, connector actas the only Li-Fi hotspot in theroom

Serves as a connector to external

link like DSL.

Covers a radius of about 20 meters

The transmission speed is 100 Mbps.

Suitable for small office or home use

LiFi can be used in

sensitive areas such as aircrafts for data transmissionwithout causing interference

Places where it is difficult to lay optical fibers likeoperation theaters

Traffic scenarios, thereby reducing accidents

Underwater applications where radio waves cannotpropagate.

Industries like petrochemical plants, nuclear power plants, petrol pumps etc

In traffic scenario, LiFi can be used tocommunicate with the LED lights ofcars

Cars can have LED-based headlights,backlights and can communicate witheach other.

This might prevent accidents, byexchanging information, when thevehicles are too close

Using LiFi, Street lights can be usedto send information about the roadcondition to the car.

• Downloading notes from blogs of teachers.

• Interactive classroom with interconnected devices.

• Sharing views & queries with the entire class

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

Used in RF restricted environments like chemical industries,

nuclear power plants, petrol pumps

In home and small offices, Li-Fi can be used to communicate

with devices like

Laptops

Internet access

HD video streaming

Printer

The whole airways communicationare performed on the basis of radiowaves.

Hence passengers face theproblem in communication media.

This problem can be overcome byusing Li-Fi, since light waves willnot interfere with radio waves.

There are millions of street lamps deployed around the world.

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

The first VLC Smartphone was

presented by Consumer Electronics inJanuary, 2014

The phone uses Wysips connect – aclear thin layer of crystal glass isadded to the small screens

Smartphone makes them solarpowered.

Smartphone could get 15% morebattery life in a day

Can communicate using Li-Fi.

Data rate greater than 10 Gbps; Theoretically allowing HD film

to be downloaded in 30 seconds

Can be used anywhere, even in RF restricted areas; Since light

waves will not interfere with radio waves.

Mostly LED light bulbs are used, which consumes less energy.

Hence cost efficient.

As light waves cannot penetrate through walls, the data cannot

be intercepted; Thus provides secured communication.

Efficient alternative to radio based wireless; since it is quick

and reliable.

Visible light cannot penetrate through solid objects.

A major challenge of LiFi is how the receiving device will

transmit back to transmitter.

Interferences from external light sources like sunlight, in the

path of transmission will cause interruption in the

communication.

Data transmission can be easily blocked by any object placedin front of LED source.

Thus, if Li-Fi technology can be put into practical use, every bulb

can be used as an alternative to Wi-Fi hotspots. It provides simple,

faster and efficient wireless data communication. Li-Fi will make us

to proceed towards the cleaner, greener, safer and brighter future.

Thank You…