Li-Fi

Wireless Communication Systems Using Light as a Medium

Transcript

1. By Mithun Madhusoodanan
2. ›  Li-Fi is transmission of data through illumination. ›  LED Bulb varies in intensity faster than the human eye can follow. ›  LED lights can be switched on and off at high speeds. ›  This property is the basics for Li-Fi ›  LED when on gives binary 1 and off gives binary 0 2
3. Present Scenario ›  We have 1.4 million cellular base stations deployed ›  We also have 5 billion of mobile phones ›  Mobile phones transmit 600tb of data every month ›  Wireless communication has become an utility like electricity and water ›  We use it in our everyday life, private life, business life ›  Currently Wi-Fi uses radio waves . 3
4. Issues with radio waves Capacity Availabilit y Efficiency Security 4
5. Capacity ›  We transmit wireless data through radio waves. ›  Radio waves are limited. ›  Radio waves are scarce and expensive. ›  We only have certain range of it. ›  With advent of new technologies like 2G,3G,4G we are running out of spectrum. 5
6. Efficiency ›  There are 1.4 million cellular radio base stations. ›  They consume massive amount of energy. ›  Most of this energy is not used for transmission but for cooling down the base stations. ›  Efficiency of such a base station is only 5% and that rise a big problem. 6
7. Availability ›  Availability of radio waves or RF signals causes another concern. ›  We have to switch off mobile phones in airplanes. ›  Radio waves cannot be used under water ›  It is not advisable to use mobiles at places like petrochemical plants and petrol pumps. 7
8. Security ›  Radio waves penetrates through walls. ›  They can be intercepted. ›  If someone has a knowledge and bad intentions then he may misuse it. 8
9. Alternative to Radio Waves in Electromagnetic spectrum ›  Looking at EM spectrum. ›  Gamma rays are simply dangerous and thus can’t be used for our purpose of communication. ›  X-rays are good in hospitals and can’t be used either. ›  Ultra violet rays are sometimes good for our skin but for long duration it is dangerous. ›  Infrared rays are bad for our eyes and are therefore used at low power levels. ›  We have already seen the short comings of radio waves. ›  So we are now left with Visible Rays. Radio- Waves Infra- Waves Visible Rays Ultra- Violet X-rays Gamma Rays 9
10. Light for Wireless communication ›  Light has been around for millions of years ›  It has created us, has created life and has created all stuffs of life. ›  Light is part of electromagnetic spectrum ›  There are 40 billion light box already installed ›  Flickering lights are annoying but thy may have an upside. ›  Li-Fi uses rapid pulses of light to transmit information wirelessly. ›  It is inherently safe to use and would be great if we can use it for our wireless communication. 10
11. What we have to do? ›  We have to replace the inefficient fluorescent lights with new dignitaries of LED lights. ›  It is a semi conductive e-device. ›  Light intensity can be modulated at very high speeds to send data by tiny changes in amplitude. 11
12. How we do this? ›  Remote controls have an IR led. ›  It creates a single data stream. ›  Replace remote control with light box. ›  With this technology we transmits 1000’s of data stream in parallel at high speeds. 12
13. How it Works? 13
14. Is it a proven technology? ›  Yes, this is already proven. ›  Harald Hass demonstrated his invention using an ordinary table lamp that successfully transmitted data at speeds exceeding 10Mbps . ›  To prove that the light bulb was the source of data stream, he periodically blocked the beam of light, causing the connection to drop. 14
15. Overcoming the four issues in Li-Fi Capacity ›  10000times more spectrum than Radio waves. ›  Light box are already present. ›  We have the infrastructure available and already installed. Efficiency ›  Data through illumination and thus data transmission comes for free. ›  Led light consumes less energy. ›  High efficient. 15
16. Availability ›  Light is present everywhere. ›  Can be used in airplanes ›  It can be underwater where radio waves cannot. Security ›  Light waves doesn’t penetrate through walls. ›  Can’t be intercepted and misused. ›  Data is present where there is light. 16
17. Applications ›  Can be used in the places where it is difficult to lay the optical fiber like hospitals. In operation theatre Li-Fi can be used for modern medical instruments. ›  In traffic signals Li-Fi can be used which will communicate with the LED lights of the cars and accident numbers can be decreased. ›  Thousands and millions of street lamps can be transferred to Li-Fi lamps to transfer data. ›  In aircraft Li-Fi can be used to transmit data. ›  It can used in petroleum or chemical plants where other transmission or frequencies could be hazardous. 17
18. Limitations ›  There should be line of sight between sender and receiver ›  Visible light cannot penetrate through solid objects ›  Interference with other electromagnetic waves makes the transmitting data to distort ›  Light cannot approach the range and penetration of radio waves 18
19. Conclusion 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 Wi-Fi hotspot to transmit wireless data and we will proceed onwards the Cleaner, Greener, Safer and Brighter future. 19
20. Thank You For Your Attention! Li-Fi A Seminar Presentation by Mithun Madhusoodanan 20
21. Questions 21
22. Video Demonstration Li-Fi Demonstration by Harald Hass at TED talk. 22