P.R.ENGINEERING COLLEGE, THANJAVUR

Light based 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.

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.

In electromagnetic spectrum, gamma, UV rays are dangerous

for human body. IR rays, due to eye safety regulations, are not used

Introduced by Professor Herald hass, at the university of Edinburgh. Established in 2011 TED global talk The promotion of idea through TED helped to start a company, Pure LiFi Pure LiFi, formerly pure VLC, is an original equipment manufacture firm setup to commercialize Li-Fi products for integration with existing LED lighting systemsIn October 2011, few companies and industries group formed Li-Fi consortium to promote the high speed optical wireless systems

Operational procedure is very simple. 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.

All the data from Internet is streamed into lamp driver.Data from internet is used to modulate the intensity of LED light source.Thus by fast and subtle variations of current, optical output can be made to vary at extremely high speedThe photodetector picks up the signalThe receiver dongle then converts the tiny changes in amplitude into a data stream.

Li-Fi connector and router are the main components for a network Room connector:

Optical signals cannot penetrate through walls, in order to provide an optical WLAN, rooms need to be connected with each other

Li-Fi room connector is a replicator, which sends the data stream from one side of the wall to the other side via an optical fiber.

For smaller rooms, connector act as the only Li-Fi hotspot in the room

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 transmission

without causing interference Places where it is difficult to lay optical fibers like

operation theaters Traffic scenarios, thereby reducing accidents Underwater applications where radio waves cannot

propagate. Industries like petrochemical plants, nuclear power plants ,

petrol pumps etc

In traffic scenario, LIFI can be used to communicate with the LED lights of cars .

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

This might prevent accidents, by exchanging information, when the vehicles are too close

Using LIFI, Street lights can be used to send information about the road condition to the car.

Downloading notes from blogs of teachers Often it is necessary to download

lecture notes from the blogs of respective teachers. With Li-Fi, the download can be done in the hall itself

Interactive classroom with interconnected devices

The classroom will be more interactive with the real-time interconnectivity between 500 devices

Sharing views & queries with the entire class Each person’s queries, views and

clarifications can be shared not only with the teacher, but with the entire class.

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 communication are performed on the basis of radio waves.

Hence passengers face the problem in communication media.

This problem can be overcome by using Li-Fi, since light waves will not interfere with radio waves.

Harald has demonstrated Li-Fi using an ordinary table lamp and a computer located below the lamp.

He successfully transmitted data at speed exceeding 10Mbps using light waves from LED light bulbs .

Also he periodically blocked the beam of light, causing the connection to drop.

The first VLC Smartphone was

presented by Consumer Electronics in

January, 2014 The phone uses Wysips connect – a

clear thin layer of crystal glass is

added to the small screens Smartphone makes them solar

powered.Smartphone could get 15% more

battery life in a dayCan 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 placed in 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