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Li-Fi TechnologyPresenter:
Mr. S. Sathees BabuAssociate Professor
CSE departmentPSNACET,Dindigul
Internet of Things
Fitn
ess
Personal Connected Devices
Smart phones
Computers
Televisions
Vehicles
Appliances
Gaming Consoles
Health Monitors
Internet of Things
Content Collection Distribution
Storage Cloud Storage Public / Private Networks
Hacking Privacy Security
BIG DATA
Issues Regarding Radio Spectrum
Capacity Availability
Efficiency Security
Server Internet
Streaming Content
Solid State Lamp
Computer
Internet through a light bulb● Data transmission through illumination● Sending data through a LED light bulb ● Visible electromagnetic spectrum with higher bandwidth than Wi-Fi ● Line of sight limitation● Cheaper and more energy-efficient than wireless radio systems
History• Professor Harald Haas, from the University of Edinburgh
in the UK, is widely recognized as the original founder ofLi-Fi.
• He coined the term Li-Fi and is Chair of MobileCommunications at the University of Edinburgh and co-founder of pureLiFi.
• Haas promoted this technology in his 2011 TED Globaltalk and helped start a company to market it.
• In October 2011, companies and industry groups formedthe Li-Fi Consortium, to promote high-speed opticalwireless systems.
• The first Li-Fi smartphone prototype was presented atthe Consumer Electronics Show in Las Vegas fromJanuary 7–10 in 2014.
Prof. Harald Haas
Disadvantages Of Other Spectrums
Insufficient 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
Radio -Waves
Infra -Red Visible Ultra -
Violet X - rays Gamma -rays
Electromagnetic Spectrum
LiFi is a wireless optical networking technology that uses Visible light for data transmission in Electromagnetic Spectrum
Introduction LiFi is a wireless optical networking technology thatuses light-emitting diodes (LEDs) for data transmission.
LiFi is designed to use LED light bulbs similar to those currently inuse in many energy-conscious homes and offices.
However, LiFi bulbs are outfitted with a chip that modulates thelight imperceptibly for optical data transmission.
LiFi data is transmitted by the LED bulbs and received byphotoreceptors.
LED
Fluorescent Lamp
Transmitting Element
Transmitting elements
A high brightness white LED, Which act as a communication source.
Main Components of Communication System
Avalanche Photo Diode
Image Sensors
Receiving Element(Detector)
A silicon photodiode which shows good response to visible wavelength region serving as the receiving element.
Main Components of Communication System
Working of LI-FI The LEDs can be switched on and off very quickly which gives nice
opportunity for data transfer in the form of Binary code.
Switching ON an LED is logical ‘1’,switching off 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 researchers say that using a micro-LED light bulb they have achieved a data transmission speed of 10Gbps using LI-FI.
Working of LI-FI
PA
PCB
The LIFI product consists of 4 primary sub-assemblies:
Bulb
RF power amplifier circuit (PA)
Printed circuit board (PCB)
Enclosure
LI-FI CONSTRUCTIONWorking of LI-FI
The PCB controls the electrical inputs and outputs of the lamp and houses the microcontroller used to manage different lamp functions. An RF (radio-frequency) signal is generated by the solid-state PA and is guided into an electric field about the bulb. The high concentration of energy in the electric field vaporizes the contents of the bulb to a plasma state at the bulb’s center; this controlled plasma generates an intense source of light. All of these subassemblies are contained in an aluminum enclosure
Working of LI-FI
FUNCTION OF THE BULB SUB-ASSEMBLY
At the heart of LIFI is the bulb sub-assemblywhere a sealed bulb is embedded in a dielectric material. more reliable than conventional light sources that insert degradable electrodes into the bulb.
The dielectric material serves two purposes; a waveguide for the RF energy transmitted by the PA an electric field concentrator that focuses energy in the bulb
The energy from the electric field rapidly heats the material in the bulb to a plasma state that emits light of high intensity and full spectrum
Working of LI-FI
Working of LI-FI
Working of LI-FIBlock Diagram
Advantageous Due To Parallel Data Transmission.
Working of LI-FI
Differences Between Technologies
Differences Between
Technologies
Li-1st, the first Li-Fi product
Applications
Applications
RF Spectrum Relief
Smart Lighting
Mobile Connectivity
Hazardous Environments
Hospital & Healthcare
Aviation
Underwater Communications
Vehicles & Transportation
RF Avoidance
Location Based Services (LBS)
Toys
Advantages
Higher speeds than Wi-Fi. 10000 times the frequency spectrum of radio.More secure because data cannot be intercepted without a clear
line of sight. Eliminates neighboring network interference. Unimpeded by radio interference. Does not create interference in sensitive electronics, making it
better for use in environments like hospitals and aircraft.
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 .
Li-Fi Products
http://www.oledcomm.com/LIFISTORE/index.html
Chinese professor builds Li-Fi system with retail partsresearch costs at almost US$500,000
Strathclyde University develops LED Li-Fi internet connectionThe Engineering and Physical Sciences Research Council (EPSRC) is funding a consortium of UK universities, led by Strathclyde, to develop the technology
Li-Fi Usage
Conclusion
By using Li-Fi in all the lights in and around a building, thetechnology could enable greater area of coverage than asingle Wi-Fi router.
Drawbacks to the technology include the need for a clear line ofsight, difficulties with mobility and the requirement that lightsstay on for operation.
References
http://whatis.techtarget.com/definition/LiFi
http://www.dvice.com/archives/2012/08/lifi_ten_ways_i.php
http://electronicsforu.com/electronicsforu
http://purelifi.co.uk/what_is_li-fi/applicationsof_lifi/
http://en.wikipedia.org/wiki/Li-Fi
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