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Light-Fidelity [Li-Fi}


Published on

Li-Fi stands

for Light-Fidelity is transmission of data through

illumination taking the fibber out of fiber optic by

sending data through an LED light bulb

Published in: Engineering
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Light-Fidelity [Li-Fi}

  1. 1. Mv Dinesh S. Sumanth Sree Vidyanikethan engineering college Tirupati. A presentation by
  2. 2. Light-Fidelity
  4. 4. “It is a visible light communication system that uses light from light emitting diodes (LEDs) as a medium to deliver wireless data to PC’s and mobiles at high-speed in a similar manner as WI-FI”
  5. 5. Present Scenario Radio Spectrum is congested but the demand for wireless data extending very fastly. Every thing, it seems require wireless data but the capacity is drying up. 1.4 Million 5 Billion
  6. 6. Issues With RF Communications
  7. 7. CONTD… CAPACITY: • Radio waves. • cost and expensive. • Less Bandwidth compared to other spectrums. • Insufficient Spectrum for increasing data. EFFICIENCY: • Millions of base stations consume huge energy for 1. Transmitting the radio waves. 2. To cool the base station cabins. • 5% Efficiency
  8. 8. CONTD… AVAILABILITY: • Available within the range of Base stations • Limited availability • Unavailable in air crafts SECURITY: • Less Secure (Data can Pass through walls)
  9. 9. WHY VLC ? • 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
  10. 10. Principle of LI-FI technology  Heart of Li-Fi technology is high brightness LED’s.  The LED bulb will hold a micro-chip that will do the job of processing the data.  The on/off activity of LEDs enables data transmission using binary codes.  Switching on an LED is a logical ‘1’; switching it off is a logical ‘0’.  A light sensitive device (photo detector) receives the signal and converts it back into original data.
  11. 11. How Li-Fi Works ?  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 microchip 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
  13. 13. COMPARISON BETWEEN LI-FI AND WIFI Sl.No Parameters Light Fidelity Wireless Fidelity 1 Speed for data transfer Faster transfer speed (>1 Gbps) DataTransfer 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 thanWi-Fi because free band doesn’t 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 ofTera Hz (THz) 2.4 GHz
  14. 14. APPLICATIONS • Visible Light is more safe than RF, hence it can be used in places where RF can't be used such as petrochemical plants. SAFE ENVIRONMENT
  15. 15. CONTD… AIRLINES: • Airways communication are performed on the basis of radio waves. Using communication causes interference between the two systems. To overcomes this drawback on radio waves , li-fi is introduced.
  16. 16. • Li-Fi emits no electromagnetic interference and so does not interfere with medical instruments, nor is it interfered with by MRI scanners. HOSPITAL & HEALTHCARE:
  17. 17. UNDER WATER COMMUNICATION • Due to strong signal absorption in water, RF use is impractical. Acoustic waves have extremely low bandwidth and disturb marine life. Li-Fi provides a solution for short-range communications.
  18. 18. SMART LIGHTING • Street lamps can be used as a source of Li-Fi hotspots
  19. 19. ADVANTAGES OF LI-FI: Li-Fi removes the limitations that have been put on the user by the Wi-Fi. a) CAPACITY: Visible light has 10000 times wider bandwidth than radio waves . So, Li-Fi has got better capacity and also the equipment's are already available. b) EFFICIENCY: Data transmission using Li-Fi is very cheap. LED lights consume less energy and are highly efficient. c) AVAILABILITY: There are billions of light bulbs worldwide, they just need to be replaced with LED’s for proper transmission of data. d) SECURITY: Light waves do not penetrate through walls. So, they can‘t be intercepted and misused.
  20. 20. LIMITATIONS • Interference from external light sources like sun light in the path of transmission will cause interruption in the communication. • The light waves cannot penetrate walls. • This technology was demonstrated and it was detectable up to a distance of 10 meter. • Installation cost of VLC systems are high • It is easily blocked by somebody simply walking in front of LED source.
  21. 21. CLOSURE: As a growing number of people and their many devices access wireless internet, making it more and more difficult to get a reliable, high-speed signal. This may solve issues such as the shortage of radio-frequency bandwidth  Every light source in homes and offices could potentially be a “Li-Fi” hotspots within 20 years. When this technology becomes feasible like the Wi-Fi, then our life will be awesome on earth. “Forget wireless ,get faster internet through light bulbs..!”
  22. 22. REFERENCES        