we are the 6th sem Information Science and Engineering students from Sri Venkateshwara College of Engineering Bangalore
Text of Li fi
Powerpoint Templates Page 1 Ms. AREEFA BANU INFORMATION SCIENCE AND ENGINNEERING SRI VENKATESHWARA COLLEGE OF ENGINEERING LI-FI TECHNOLOGY PRESENTED BY Mr. SHANTOSH RAJ INFORMATION SCIENCE AND ENGINEERING SRI VENKATESHWARA COLLEGE OF ENGINEERING And UNDER GUIDANCE OF Mrs.Pankaja R Assistant professor, Department of CSE Sri Venkateshwara College Of Engineering
Powerpoint Templates Page 2 Introduction What is Wi-Fi ??? Issues regarding Wi-Fi (Radio Spectrum) What is Li-Fi??? Principle of Li-Fi Technology Visible Light Communication Construction and Working of Li-Fi Comparison between Wi-Fi and Li-Fi Future Applications of Li-Fi Advantages and Disadvantages Conclusion References CONTENTS
Powerpoint Templates Page 3 WHAT IS Wi-Fi?? WHAT IS Wi-Fi ???
Powerpoint Templates Page 7 Li-Fi (Light Fidelity) Li-Fi (Light Fidelity )can be thought of as a light-based Wi-Fi. Technology uses The Visible Spectrum The term was first used by Harald Haas in his TED Global talk on Visible Light Communication in 2011 In October 2011 a number of companies and industry groups formed the Li-Fi consortium, to promote high-speed optical wireless systems. Researchers at the Heinrich Hertz Institute in Berlin, Germany, have reached data rates of over 500 megabytes per second using a standard white-light LED.
Powerpoint Templates Page 8 LI-FI ENVIRONMENT
Powerpoint Templates Page 9 PRINCIPLE OF LI-FI TECHNOLOGY The heart of this technology is a new generation high brightness leds. Visible Light Communication. These leds varies in intensity (that is gets on and off) so fast that a human eye cannot detect it. If led is on , then we transmit a digital signal 1,and if the led is off , then we transmit a digital signal 0. A controller is connected at the back side of these led bulbs to code data to these leds.
Powerpoint Templates Page 10 If led is on , then we transmit a digital signal 1, and if the led is off , then we transmit a digital signal 0.
Powerpoint Templates Page 11 VISIBLE LIGHT COMMUNICATION Li-Fi is a faster and cheaper version of Wi- Fi, which is based on visible light communication (VLC). The visible light communication is a data communication technique using visible light between 400 THz and 800 THz as an optical carrier for data transmission.
Powerpoint Templates Page 12 WHY VLC???
Powerpoint Templates Page 13 Gama rays,X-rays,Ultraviolet rays are harmful for the human body. Infrared rays are also dangerous, due to eye safety regulation, and can only be used with low power. Radio waves are expensive and they are less secure. Hence we are left with only the VISIBLE - LIGHT SPECTRUM which is not harmful for humans . Radio Waves Infrared Rays Visible Rays Ultraviolet Rays X- Rays Gama Rays
Powerpoint Templates Page 14 CONSTRUCTION AND WORKING OF Li-Fi
Powerpoint Templates Page 15 CONSTRUCTION and WORKING OF Li-Fi (conti..) Li-Fi is implemented using white LED light bulbs at downlink transmitter. By fast variations of the current, optical output can be made to vary at extremely high speeds. An overhead lamp fitted with an LED with signal processing technology streams data embedded in its beam at ultra high speeds to the photodiodes. A receiver dongle then converts the tiny changes in amplitude into an electrical signal, which is then converted back into a data stream & transmitted to a computer or mobile device.
Sl.No Parameters Light Fidelity Wireless Fidelity 1 Speed for data transfer Faster transfer speed (>1 Gbps) Data Transfer speed (150 Mbps) 2 Medium through which data transfers occurs Used Light as a carrier Used Radio spectrum 3 Spectrum Range Visible light spectrum has 10,000 time broad spectrum in comparison to radio frequency Radio frequency spectrum range is less than visible light spectrum. 4 Cost Cheaper than Wi-Fi because free band doesnt need license and it use light. Expensive in comparison to Li-Fi because its uses radio spectrum. 5 Network topology Point to point Point to point 6 Operating frequency Hundreds of Tera Hz (THz) 2.4 GHz COMPARISON BETWEEN LI-FI AND WI-FI
In vehicles and traffic lights, reducing accidents and traffic congestion
Street lamps(as free access points)
Petroleum and chemical industries
Availability Efficiency Harmless High Security Ease of use Fast Data Transfer Low Cost
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 .
The possibilities are numerous and can be explored further. In spite 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.
Jyoti Rani1, Prerna Chauhan2, Ritika ripathi3,1Student, ,2Student,ad ,3Assistant Professor, ECE, Dep't. " Li-Fi (Light Fidelity)-The future technology In Wireless communication" ISSN 0973-4562 Vol.7 No.11 (2012) Shailander kaushik, System Analytic,Nuclear Software export Ltd, "An overview of technical aspects for wifi networks technology " ,ISSN-2277-1956. Visible Light Communications Consortium,www.vlcc.net, 2008 Sathya.T,Prof.E.Divya,Prof.S.Raja,student,assistant professor, head of department, ECE, CTKEC,"Visible Light Communication for Wireless Data Transmission ". Coimbatore, India Feb. 2014. Harald Haas "Wireless Data From Every Light bulb" TED Global Edinburgh, July 2011. M.Muthamma , Assistant Professor, ECE, GCET, Hyderabad , A.P., India ." A survey on Transmission of data through illumination - Li- Fi " Dec 2013.
Mrs.Pankaja R Assistant Professor , Department of Computer Science and Engineering For guiding us throughout the preparation of this paper presentation Special Thanks to