Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


Li-Fi (Light Fidelity)

No description

Vinay Patil

on 10 July 2014

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Li-Fi (Light Fidelity)

Introduction to Project Title
Circuit Description
Block Diagram
Li-Fi (Light Fidelity) Based Visible Light Communication


Thank you!!!!
Thank You

The technology truly began during the 1990’s in countries like Germany, Korea & Japan where they discovered LED’s could be retrofitted to send information.

Li-Fi is a VLC (visible light communication) technology developed by a team of scientists including Dr.Gordon Povey, Prof. Harald Haas and Dr.Mostafa Afgani at the University of Edinburgh . The term Li-Fi 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 . Li-Fi is typically implemented using white LED light bulbs. These devices are normally used for illumination by applying a constant current through the LED.

As the world is moving at a rapid pace, with the vast growing gadgets, their usage and their developments led to the advancement in the Wi-Fi which provides a technology so called Li-Fi. Li-Fi is a technology that makes use of LED light which helps in the transmission of data much faster and flexible than data that can be transmitted through Wi-Fi. Light reaches nearly everywhere so communication can also go along with light freely. Light Fidelity is a branch of optical wireless communication which is an emerging technology. By using visible light as transmission medium, Li-Fi provides wireless indoor communication. The bit rate achieved by Li-Fi cannot be achieved by Wi-Fi. Dr. Harald Haas,the professor at the university of Edinburgh school of Engineering, first time publically displayed the proof of Light Fidelity (Li-Fi),a method of Visible Light communication(VLC).


The visible light communication (VLC) refers to the communication technology which utilizes the visible light source as a signal transmitter, the air as a transmission medium, and the appropriate photodiode as a signal receiving component.It promotes usage of visible light for data transmission

Introduction to the project title

Circuit Diagram of TX
Block Diagram
It has been shown that even though most existing efforts are still in a very early stage, VLC is a promising technology with a wide field of prospective applications. An ever-growing interest in VLC throughout the world can be expected to lead to real-world applications in the future. In some fields of application it poses a favor- able alternative to conventional solutions (infrared, WLAN etc.). The main goals for the future are increasing the transmission rate and improving standardization.
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 toward the cleaner, greener, safer and brighter future. This may solve issues such as the shortage of radio frequency bandwidth and also allow internet where traditional radio based wireless isn’t allowed such as aircraft or hospitals. One of the shortcomings however is that it only work in line of sight.


Device Control
Li-Fi (Light Fidelity) based Visible Light Communication
Li-Fi means “Light Fidelity”.
At the heart of this technology is a new generation of high brightness light-emitting diodes. It is possible to encode data in the light by varying the rate at which the LEDs flicker on and off to give different strings of 1s and 0s.In Li-Fi we are using VLC (Visible Light Communication) technology. Using this technology we will be working on Voice communication and Device control.

visible light communication (VLC) refers to the communication technology which utilizes the visible light source as a signal transmitter.

In literal terms any form of information that can be sent using a light signal that is visible to humans could be considered to be VLC.
Li-Fi design process basically include realizations of following parameters.
Voice communication
Device Control

Department of Electronics and Communication Engineering
AITM Belgaum.

Under the Guidance of
Prof. Anilkumar C.K
H.O.D Department of ECE
AITM Belgaum

Present detailed experimental work on the prototypes and discuss the performance.
Suggest a guideline for the design and implementation of future development of the prototypes.
To effectively use light as a medium for wireless communication.
To achieve Voice Communication using light as the communicating medium.
To remotely control devices using light as communicating medium.
Develop a communication system in real time which is safe from radiation hazards unlike Wi-Fi (which uses radio communication).

As shown in the Block Diagram, this simplified Block Diagram consists of a Set of Transmitter
Job of the Transmitter is to pick-up Audio input from microphone, amplify it, filter and process it so that, this enhanced audio signal can be fed to VLC Modulator Unit. Once the input audio frequency is received, the modulator mixes / superimposes incoming audio over light energy. Thus, transmitted data, which is superimposed over the Visible Light transmits in the form variable signal so that, at the receiving end, both the signals can be separated to derive meaningful data. And the receiver unit consists of, Receiver Module, inbuilt De-Modulator and a Pre-Amplifier. After the initial separation, Amplification and filtration, the signal can further be fed to other audio circuits for enhancement of the received audio data.

Voice Communication
The basic principle involved in Li-Fi Technology is that if the light emitter is on, a digital 1 is transmitted, if it is off a digital 0 is transmitted. In simple words, a light emitter which can switch fast enough and a controller that can interpret the data.
In the above block diagram a device is being controlled using light as the communication media. It consists of Transmitter and Receiver module, Control Circuitry, Input Control Panel and a device to be controlled. The control circuitry consists of a micro controller, interprets the input from the input control panel and generates signals necessary for transmission. It performs the opposite function on the receiving section. In the Transceiver module the LED transmits the data in the form by going on and off with a speed higher enough such that the flickering goes undetected by the human eye. The light receiver (photo detector) receives the data which is decoded by the micro controller consequently driving the device.

Circuit Diagram of RX
For voice data communication within buildings.
For data communication between two amplifiers in the same lab.
The project can be used in large auditoriums
This project can also be used in cinema halls for sound track transfer to screen speakers.
This can be used for position detection
Intelligence transport system
It can be used in places where it is difficult for radio waves to penetrate and are sometimes restricted like hospitals. In operation theatre Li-Fi can be used for modern medical instruments.
In traffic signals Li-Fi can be used which will communicate with LED lights of the cars and accident numbers can be decreased.
Thousand and millions of street lamps can be transferred to Li-Fi Lamps to transfer data.
In aircraft Li-Fi can be used for data transmission.
It can be used in petroleum or chemical plants where other transmission or frequencies could be hazardous

Pooja Oulkar 2AG09EC021
Deepak Gachhi 2AG09EC009
Vinay Patil 2AG10EC424
Full transcript