Li-fi Technology presentation
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Professor Harald Haas began researching Li-Fi, which stands for Light Fidelity, in 2004 and gave the first demonstration of a Li-Fi prototype in 2011. Li-Fi uses LED lights that vary in intensity faster than the human eye can see to transmit data wirelessly. It has advantages over Wi-Fi as the visible light spectrum is not congested like the radio spectrum and Li-Fi could allow download speeds up to 10Gbps, downloading a full HD movie in 30 seconds. While still in development, Li-Fi shows potential for a cleaner, greener and brighter wireless future.
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Li-fi Technology presentation
- 2. Li-Fi means “Light Fidelity”, in simple terms it can be thought of as a light-basedWi-Fi. LI-FI is transmission of data through illumination ,sending data through a LED light bulb that varies in intensity faster than human eye can follow.
- 3. Harald Haas, Professor at the University of Edinburgh, began his research in the field in 2004; he gave a debut demonstration on a Li- Fi prototype at the TEDGlobal conference in Edinburgh on 12th July 2011. Professor Harald Haas
- 4. The LEDs can be switched on and off very quickly, which gives nice opportunities for transmitting data. we can achieve 10Gbps –meaning we can download a full high-definition film in just 30 seconds!
- 6. Radio Waves Infrared Rays Visible Rays Ultraviolet Rays X- Rays Gama Rays HENCE WE ARE LEFT WITH ONLY THE VISIBLE - LIGHT SPECTRUM •Radio Waves: Radio Spectrum is congested but the demand for wireless data is doubling each year. •Infrared Rays: Infrared, due to eye safety regulation, can only be used with low power. •Ultraviolet Rays: Ultraviolet light is good for place without people, but otherwise dangerous for the human body. •X- Rays: X-rays have similar health issues. •Gamma Rays: Gama rays can’t be used as they could be dangerous to human race.
- 8. •Single data stream •20000 bits per second •Not usable for video streaming
- 19. CONCLUSION • This Technology is still in its infancy, the possibilities are numerous and can be explored further. • 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 can proceed towards a cleaner, greener, safer, and brighter future.
- 20. ANY QUESTIONS?
Editor's Notes
- (BOTH) U: Whether you are using wireless internet in a coffee shop Me: Or stealing it from the guy next door U:or competing for bandwidth at a conference, you probably must have got frustrated at the slow speeds which you face where more than one device are tapped into the same network, clogging the airwaves, making it more and more difficult to get a reliable, high speed signal. Me: How abt having internet accessible at the speed of light?? U:Yes it is possible !!..... Me collette fernandes and me anjana shivangi will be discussing abt the LI-Fi technology!
- (COLLETTE) That is, it uses light instead of Radio Waves to transmit information. And instead of Wi-Fi modems, Li-Fi would use Transceiver-fitted LED lamps that can light a room as well as transmit and receive data. Technically there can be any number of access points since simple light bulbs are used. The Visible Spectrum, which is a part of the Electromagnetic Spectrum, is greatly utilized in this technology. It is possible to encode data in light by varying the rate at which LED’s flicker on and off. And sending data through a LED light bulb that varies in intensity faster than human eye can follow. , so the output appears constant, thus, giving a better opportunity for transmission of data
- (ANJANA) He used a table lamp with an LED bulb to transmit a video of blooming flowers that was then projected onto a screen behind him. During the event he periodically blocked the light from lamp to prove that the lamp was indeed the source of incoming data. At TEDGlobal, Haas demonstrated a data rate of transmission of around 10Mbps. Two months later he achieved 123Mbps. Teams at the University of Oxford and the University of Edinburgh are focusing on Parallel Data Transmission by using arrays of LEDs, wherein each LED transmits a different data stream. Other groups are using mixtures of red, green and blue LEDs to gain different frequencies encoding a different data channel.
- COLLETTE slide ie, To transmit a digital 1, the LED is set ON, and to transmit a digital 0, the LED is set OFF. So what we require at all are some LED’s and a controller that codes data into those LEDs. We have to just vary the rate at which the LED’s flicker depending upon the data we want to encode. Further enhancements can be made in this method, like using an array of LEDs for Parallel Data Transmission, or using mixtures of red, green and blue LED’s to alter the light’s frequency with each frequency encoding a different data channel. Slide To serve the ever-increasing demand for high-speed wireless connectivity Radio waves are replaced by light waves in a new method of data transmission which is being called Li-Fi. A flickering light can be incredibly annoying, but has turned out to have its upside, being precisely what makes it possible to use light for wireless data transmission
- COLLETTE Here is a diagram on how a Li-Fi environment would look!! EXPLAIN THE PICTURE!!
- COLLETTE Hence we are now left with only, “THE VISIBLE - LIGHT SPECTRUM”, which is the most safest and cheapest. VLC is a data communication medium, which uses visible light between 400 THz (780 nm) and 800 THz (375 nm) as optical carrier for data transmission and illumination.
- ANJANA Any LED light set, if used along with a microchip inside it can be used to detect the changes in the light flickering thus, helping in converting light into data in its digital form This is like sending a morse code signal using a torch but at a very fast speed This high speed flickering of the light helps in data transmission in the form of a rapid stream of binary code that, although invisible to naked eye, can be detected by a light sensitive device. Thus every light emitting source can be used as a hub for data transmission. On one end all the data on the internet will be streamed to a lamp driver. When the LED is turned on the microchip converts this digital data in the form of light. On the other end this light is detected by a photosensitive device. Next this light is amplified and processed and then fed to the device. A data rate of greater than 100 Mbps is possible by using high speed LEDs with appropriate multiplexing techniques. By parallel data transmission using LED arrays, VLC data rate can be increased, where each LED transmits a different data stream. LED is BETTER compared to other sources of light(ex fluorescent lamp, incandescent bulb etc.) in Visible light communication.
- COLLETTE
- ANJANA Li Fi technology is still in its infancy .However some areas where it seems perfectly applicable
- Traffic lights can communicate to the car and with each other. Cars have LED-based headlights, LED-based cack lights, and cars can communicate with each other and prevent accidents in by exchanging information.
- Operating rooms do not allow Wi-Fi because of radiation concerns. While Wi-Fi is in place in many hospitals, interference from cell phones and computers can block signals from monitoring equipment. Li-Fi solves both problems: lights are not only allowed in operating rooms, but tend to be the most glaring (pun intended) fixtures in the room. Can be used in the places where it is difficult to lay the optical fiber like hospitals. In operation theatre LiFi can be used for modern medical instruments
- There are millions of street lamps deployed around the world. Each of these street lamps could be a free access point to public. I know you’ll would enjoy it the most!! ;)
- Whenever we travel through airways we face the problem in communication, because the whole airways communications are performed on the basis of radio waves. Airline Wi-Fi is very costly and dangerous. Li-Fi could easily solve these problems by introducing speeds as high as 9.8 Mbps to each seat's reading light.
- Wi-Fi and many other radiation types are bad for sensitive areas, Like those surrounding power plants. But power plants need fast, inter-connected data systems to monitor things like demand, grid integrity and (in nuclear plants) core temperature,etc . The savings from proper monitoring at a single power plant can add up to hundreds of thousands of dollars. Li-Fi could offer safe, abundant connectivity for all areas of these sensitive locations. This would save money related to currently implemented solutions.
- We all know, salt water conducts electricity and using radio waves is very dangerous in submarines etc. Underwater remotely operated vehicle (ROV) is a tethered underwater robot, they operate from large cables that supply their power and allow them to receive signals from their pilots above. ROVs work great, except when the tether isn’t long enough to explore an area, or when it gets stuck on something. If their wires were cut and replaced with light- say from a submerged, high-powered lamp- then they would be much freer to explore. They could also use their headlamps to communicate with each other.
- Say there’s an earthquake in New York or a hurricane. The average New Yorker may not know what the protocols are for those kinds of disasters. Until they pass under a street light. Remember, with Li-Fi, if there’s light, you’re online. Li-fi can be used in Subway stations and tunnels which are common dead zones for most emergency communications less stressing cities could opt to provide cheap high-speed Web access to every street corner.
- The concept of Li-Fi is currently attracting a great deal of interest, because it may offer a genuine and a very efficient alternative to radio-based wireless.