Basic of the Li-Fi Li-Fi work on the base of the optical communication

In the Li-Fi the data should be transmitted in the light form(visible light form)

For the transmit data in the Li-Fi generally LED source use in the Li-Fi

And as the part of receiver side the Photodiode or Photo resistor are used for capture Visible Light.

Li-Fi having more speed to transfer data from router to coordinator than the Bluetooth and Wi-Fi communication.

Li-Fi data rate was up to 100MBps and its up to 10gbps can be increase.

Li-Fi is IEEE 802.15 standardize wireless communication system.

Comparison between Electromagnetic spectrum and

Visible Light spectrum

Network- Wi-Fi allocated network

Network- Li-Fi allocated attocell network

How Li-Fi Operate

LED Driver

Data in form of visible light

TX

Photo detector device

RX

Input Device

As a input device any computer or input transducers are attached

For example a simple audio player can be attached as input device

And Computer can be used as input device if any data stream want to send

or any other form data if we want to transmit

Now those days as Audio transmitting used using visible light

And in some application videos are also transmitted

Input device it‟s a input like keyboard used in PC for typing or as a input

peripheral

LED Driver

Led driver was a LED input to output driver that control voltage and

amplitude of the given input.

The LED driver is a one type of transducer that convert data in one form

to another.

LED driver sends data in form of “1” and “0” .

And LED Blink when “1” transmitted and LED was off when “0”

transmitted.

LED driver control the incoming stream from the input device.

Visible Light

The transmitted data in visible light form so it can use for both purpose for

as general purpose light as well as for data transmitting too.

This visible light actually high speed diming of LED light, that so high speed

ON and OFF LEDs but that speed so high so human eye can not detect

that changes.

That data in ON means „1‟ and OFF means „0‟ form but usually we see only

visible light not its data changes 1‟s and 0‟s.

Photo Detecting Device

Generally as photo detecting device we used Photo Detector.

That photo detector detect light intensity changes and its 1‟s and 0‟s

changes and convert that data in light form to electric form or in current

form .

Here the photo detector work as a Transducer, that convert data in one

form to another.

Photo detector detect slight changes in visible light that strikes on that in

ON and OFF mode changes, and that 1‟ and 0‟s converting in electrical

form and after than it amplifies using amplifier, and getting original massage

or data.

Output Device

As output device any other device used that give us proper output or any

other transducers.

If we normally send voice or any sound stream in visible light form than as

output side normally we used speaker.

Output device is final source that give output signal, and it can be

destination part of signal.

Inventor of LI-Fi

Professor Harald Haas invent the first Li-Fi technology for visible light

communication.

Li-Fi Future expansions

Smart Moll

Advertising of Shops

Smart Cities

Smart Homes

Internet of Things

Future Cellular Communication

Visible Spectrum/Light Communication

Etc….

Reference Professor Harald Haas documentaries- http://www.eng.ed.ac.uk/drupal/hxh

Visible Light Communication Using OFDM- Mostafa Z. Afgani, Harald Haas, Hany Elgala,

and Dietmar Knipp School of Engineering and Science International University Bremen 28759

Bremen, Germany

Optical Wireless OFDM System on FPGA: Study of LED Nonlinearity Effects Irina

Stefan∗, Hany Elgala∗, Raed Mesleh, Dominic O‟Brien and Harald Haas∗, Jacobs University

Bremen, Campus Ring 1, 28759 Bremen, Germany

Self Organising Interference Coordination in Optical Wireless Networks- Birendra

Ghimire and Harald Haas School of Engineering and Science, Jacobs University Bremen, 28759,

Bremen, Germany Institute for Digital Communications, University of Edinburgh, EH9 3JL,

Edinburgh, UK

Optical Wireless Transmitter Employing Discrete Power Level Stepping- Thilo Fath,

Christoph Heller, and Harald Haas, Member, IEEE

High-speed wireless networking using visible light- Harald Haas

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