LIFI TECHNOLOGY

By

Y . Sowmya.(IT)

BVRITH

INTRODUCTION

Li-Fi means “Light Fidelity”. LI-FI is visible light communication system where the

light is provided by light emitting diodes (LED’s) which acts as medium to deliver networked, mobile, high speed communication just as WI-FI or Optical fiber.

It is possible to encode the data into the light by varying the rate at which the LED’s flicker ON and OFF which is too quickly to be noticed by the human eye.

HISTORYProfessor Harald Haas from the University of Edinburghcoined the term Li-Fi in in TED global talk in 2011.

Harald Haas continues to wow the world with the potential to use light for communication

Harald Haas

PRESENT SENARIO

1.4 millions 5 billion

ISSUES REGARDING RADIO SPECTRUM

CapacityCapacity AvailabilityAvailability

EfficiencyEfficiency SecuritySecurity

Insuffient spectrum for increasing data

Low power application

Which is not used so far.

Dangerous for human body

Used for hospitals

It is not used generally

DISADVANTAGES OF OTHER SPECTRUMS

WORKING OF LI-FI

The LEDs can be switched on and off very quickly which gives nice oppurtunity for data transfer in the form of Binary code.

Switching ON an LED is logical ‘1’,switching of an LED is logical ‘0’.

Hence it is possible to encode the data into the LED’s by using a controller ,we just have to vary at which LED’s flicker depending on the data we want to encode to give different strings of 0’s and 1’s.

UK researches say that using a micro-LED light bulb they have achieved a data transmission speed of 10Gbps using LI-FI.

MAIN COMPONENTS OF COMMUNICATION SYSTEM

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

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

Receiving elements Transmitting elements

ADVANTAGEOUS DUE TO PARALLEL DATA TRANSMISSION.

DIFFERENCES BETWEEN TECHNOLOGIES

APPLICATIONS

In vehicles and traffic lights, reducing accidents and traffic congestion

In Aircraft cabins

Hospitals(In few medical instruments)

. Street lamps(as free access points)

PETROLEUM AND CHEMICAL PLANTS

ADVANTAGES

Availability Efficiency High security Easy to use Fast data transfer Harmless Low-cost Capacity

DISADVANTAGES Light can't pass through objects. A major challenge facing Li-Fi is how the receiving device

will transmit back to transmitter. High installation cost of the VLC systems Interferences from external light sources like sun , light ,

normal bulbs , opaque materials .

CONCLUSION

The possibilities are numerous and can be explored further.

Inspite of disadvantages 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.

REFERENCE

Google Wikipedia Lifeconsortium.org Newtecarticles.com Seminarprojects.com Trjcjournals.org Extremetech.com