Visible Light Communication By: Suhail More ME-E&TC Rollno-E1109 Under Guidance of: Prof C.V Kulkarni Visible Light Communication 11 November 2018

Contents Introduction Why VLC Technology Modulation VLC Consortium Applications Difficulties Conclusion and Outlook Visible Light Communication 11 November 2018

Introduction New communication technology using Visible light. Visible light is only a small portion of the electromagnetic spectrum. Wavelength between 380nm(750 THz) to 750nm(428 THz). Visible Light Communication 11 November 2018

WHY VLC???? It does not cause any health problems. No EM-interference. It is free. Fast switching. Ever-increasing market share of LEDs makes VLC ubiquitously available. Visible Light Communication 11 November 2018

Technology(1/3) Transmitters Theoretically every kind of light source can be used as transmitting device. More promising alternatives are fluorescent lights and LEDs. LEDs are the predominant choice for transmitters. Visible Light Communication 11 November 2018

Technology(2/3) Receivers Photodiode receivers. CCD and CMOS sensors. Visible Light Communication 11 November 2018

Technology(3/3) Visible Light Communication 11 November 2018

Data rates achieved Phosphorus LEDs can achieve up to 40 Mbps. By using RGB LEDs data rates can go up to 100 Mbps. RCLEDs (Resonant Cavity LEDs) can achieve data rates up to 500 Mbps. RCLEDS use Bragg reflectors to enhance the emitted light. Increased spectral purity when compared to conventional LEDs. Visible Light Communication 11 November 2018

Component Set Up Transmitter unit Receiver unit Visible Light Communication 11 November 2018

Modulation Modulation is used to transform the data(given as a sequence of 0s and 1s) into a series of light pulses. Two main alternative modulation schemes: Pulse Position Modulation(PPM): - Amplitude & width of pulse is constant. Frequency Shift Keying (FSK): - Digital information is transmitted through frequency changes of carrier wave. Visible Light Communication 11 November 2018

VL vs RF Comparison Property VL Comm. RF Comm. EMI NO YES Line of Sight Standard Beginning Matured Power Consumption Relatively low Medium Visibility Security Infrastructure LED illumination Access point Mobility Limited Coverage, Distance Narrow, Short Wide, Medium Bandwidth More Less Visible Light Communication 11 November 2018

VLC Consortium The Visible Light Communication Consortium was established in 2003 by Japanese tech- companies. Four Committees: Research & Planning Technical Standardization Popularization Two standards are proposed: JEITA CP-1221 JEITA CP-1222 Standardization efforts for physical and media access layer are also done by IEEE 802.15, Task Group 7. Visible Light Communication 11 November 2018

Applications Smart Home Network Commercial Aviation Hazardous Environments Hospital and Healthcare Defense and Military Applications Underwater Communications Indoor location estimation Vehicle to vehicle communication Visible Light Communication 11 November 2018

VEHICLE COMMUNICATION Many cars have LED lamps. Traffic signage, traffic lights, and street lamps are adopting the LED technology so there are massive applications opportunities here. Visible Light Communication 11 November 2018

HOSPITALS & HEALTHCARE There are advantages for using VLC in hospitals and in healthcare.  Mobile phones and Wi-Fi's are undesirable in certain parts of hospitals, especially around MRI scanners and in operating theatres. Visible Light Communication 11 November 2018

SMART LIGHTING Smart buildings require smart lighting. Smart lighting with VLC provides the infrastructure for illumination, control and communications and will greatly reduce wiring and energy consumption within a building. Visible Light Communication 11 November 2018

UNDERWATER COMMUNICATIONS Radio waves do not propagate for a long distance under water. It was demonstrated that the flashlight visible light transmitter was able to transmit signals for 7 meters distance. Visible Light Communication 11 November 2018

Difficulties Line of sight. Very high light intensity of other source can cause the sensor to misjudge the light from the original source. Short range.(max 15 meters) Visible Light Communication 11 November 2018

Conclusion & Outlook VLC is a promising technology even if it is still in a very early stage. Transmission rates are high as compared to other technology. Using arrays of LED’s more data transmission can be obtained. Visible Light Communication 11 November 2018

References Komiyama, Kobayashi “Study of visible light communication using RGB LED lights” SICE annual conference 2011 D. Langer and J. Vucic , “Optical Wireless Indoor Networks: Recent Implementation Efforts,” Proc. ECOC, Torino, Italy, Sept. 2010. H.Sugiyama, S.Haruyama, M.Nakagawa. “Experimental investigation of modulation method for visible-light communications “2006. T. Komine and M. Nakagawa, “Fundamental Analysis for Visible-Light Communication System using LED Lights,” IEEE Tranaction on Consumer Electronics, vol. 50, pp. 100–107, February 2004. D. O’Brien et al.:” Visible Light Communications: recent progress and challenges”, 2008 IEEE. Ramirez-Iniguez, R. ; Idrus, S. M. ; Sun, Z. (2008) “Optical Wireless Communications : IR for wireless connectivity” CRC Press,USA. VLCC website ; http://www.vlcc.net Visible Light Communication 11 November 2018

THANK YOU Visible Light Communication 11 November 2018