TECHNOLOGYBy

T.ARUNKUMAR,MCA

Bannari Amman Institute of Technology,Sathyamangalam.

Introduction

• Li-Fi stands for Light-Fidelity

• Li-Fi technology, proposed by the German physicist—Harald Haas

• provides transmission of data through illumination by sending data through an LED light bulb that varies in intensity faster than the human eye can follow.

At present

• The current wireless networks that connect us to the internet are very slow when multiple devices are connected.

• Fixed bandwidth

In future

• There is no fixed bandwidth in LiFi

• Can enjoy higher data transfer rates.

The Technology

• Li-Fi uses visible light instead of Gigahertz radio waves for data transfer.

• It is based on Visible Light Communication (VLC)

• uses visible light between 400 THz (780 nm) and 800 THz (375 nm) as optical carrier for data transmission and illumination.

Components

• a high brightness white LED which acts as transmission source.

• a silicon photodiode with good response to visible light as the receiving element.

primary sub-assemblies

• Bulb

• RF power amplifier circuit (PA)

• Printed circuit board (PCB)

• Enclosure

How it works?

• The PCB controls the electrical inputs and outputs of the lamp.

• An RF (radio-frequency) signal is generated by the solid-state PA and is guided into an electric field about the bulb.

• plasma generates an intense source of light.

The Logic of LiFi

• If the LED is on, a digital 1 is transmitted.

• If the LED is off, a digital 0 is transmitted.

Recent advancements

• it is possible to achieve more than 10 Gbps of speed.

• which would allow a high-definition film to be downloaded in just 30 seconds

COMPARISON OF SPEED OF VARIOUS WIRELESSTECHNOLOGIES

TECHNOLOGY SPEED

Wi-Fi – IEEE 802.11n 150 Mbps

Bluetooth 3 Mbps

IrDA 4 Mbps

Li-Fi >1 Gbps

Problems in WiFi

• Capacity

• Efficiency

• Availability

• Security

Advantages of LiFi

• Capacity

• Efficiency

• Availability

• Security

Disadvantages of LiFi

• Light cannot penetrate into walls

• it only works in direct line of sight.

Applications of LiFi

• Education systems

• Medical Applications

• Cheaper Internet in Aircrafts

• Underwater applications

• Disaster management

• Applications in sensitive areas

• Traffic management

• Replacement for other technologies

THANK YOU