Li fi presentation


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Li-Fi is transmission of data through illumination by taking thefiber out of fiber optics by sending data through a LED lightbulb that varies in intensity faster than the human eye canfollow.
“At the heart of this technology is a newgeneration of high brightness light-emitting diodes”, saysHarald Haas from the University of Edinburgh, UK.”Verysimply, if the LED is on, you transmit a digital 1,
if it’s offyou transmit a 0,”Haas says, “They can be switched on and offvery quickly, which gives nice opportunities for transmitteddata.”

It is possible to encode data in the light by varying therate at which the LEDs flicker on and off to give differentstrings of 1s and 0s.The LED intensity is modulated so rapidlythat human eye cannot notice, so the output appears constant.

More sophisticated techniques could dramatically increaseVLC data rate. Terms at the University of Oxford and theUniversity of Edinburgh are focusing on parallel datatransmission using array of LEDs, where each LED transmits a different data stream. Other groups are using mixtures of red,green and blue LEDs to alter the light frequency encoding adifferent data channel.

Li-Fi, as it has been dubbed, has alreadyachieved blisteringly high speed in the lab. Researchers at theHeinrich Hertz Institute in Berlin, Germany have reached datarates of over 500 megabytes per second using a standardwhite-light LED.

Li-Fi is typically implemented using white LED light bulbs at the downlink transmitter. These devices are normally used for illumination only by applying a constant current. However, by fast and subtle variations of the current, the optical output can be made to vary at extremely high speeds. This very property of optical current is used in Li-Fi setup.The operational procedure is very simple-,data from the internet and local network is used to modulate the intensity of the LED light source if any undetectable to the human eye. The photo detector picks up signal, which is converted back into a data stream and sent to the client.
The client can communicate through its own LED output or over the existing network. An overhead lamp fitted with an LED with signal-processing technology streams data embedded in its beam at ultra-high speeds to the photo-detector. A receiver dongle then converts the tiny changes in amplitude into an electrical signal, which is then converted back into a data stream and transmitted to a computer or mobile device.

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Li fi presentation

  1. 1. Li-Fi Technology By Vivek kumar jha Reg no- 1001215240 branch- CSE
  2. 2. Contents  Abstract  Introduction  Drawbacks Of Before Technologies  Different Between The Technologies  Working process  Applications  Advantages  Conclusion
  3. 3. Abstract One germen phycist. Harald Haas has come up with a solution he calls “data through illumination” –taking the fibber out of fibber optic by sending data through an LED light bulb that varies in intensity faster than the human eye can follow. It’s the same idea band behind infrared remote controls but far more powerful. Haas says his invention, which he calls D- LIGHT, can produce data rates faster than 10 megabits per second, which is speedier than your average broadband connection.
  4. 4. Introduction Li-Fi means “Light Fidelity”. At the heart of this technology is a new generation of high brightness light-emitting diodes It is possible to encode data in the light by varying the rate at which the LEDs flicker on and off to give different strings of 1s and 0s.
  5. 5. Drawbacks Of Before Technologies
  6. 6. Availability Capacity Efficiency Security
  7. 7. Different Between The Technologies
  8. 8. Working process LIFI offers an integrated light source that is straightforward to integrate into a projector. In this example LIFI consists of 5 primary sub-assemblies:     Printed circuit board (PCB) RF power amplifier (PA) Bulb Optics  Enclosure
  9. 9. Applications Capacity Availability Efficiency Security
  10. 10. Advantages High Security Easy To Use Fast Data Transfer Reliable Harmless ness Low Cost
  11. 11. Conclusion The possibilities are numerous and can be explored further. If his 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.
  12. 12. Reference ireless_data_from_every_light_bulb.html lution/2011/08/new-wireless-technologieslifi-and-dido.html
  13. 13. Any Queries ?