Visible Light Communication

VISIBLE LIGHT COMMUNICATION

Hello Friends,

Today I'll tell you the most Recent Technology through you can transmit data from one place to another

i.e V.L.C (VISIBLE LIGHT COMMUNICATION), which is running on the  new fidelity beyond WI-FI that is LIGHT FIDELITY (LI-FI) .

• INTRODUCTION 
  

Wireless optical communications has been used long before radio communications was first considered. However, over the last century radio communication has been the preferred means to transmit data wirelessly. Only now when we are faced with capacity shortages for wireless data communications is free-space optical communication being considered as a candidate for widespread wireless communications applications. With the widespread use of LED light bulbs, visible light communications has become the forerunner in the current optical wireless communications field.

•  WHAT IS VLC ?

  The technology was originally developed by the D-Light project at the University of Edinburgh and has been exclusively licensed to Pure-VLC. This technology allows standard LED light bulbs to be turned into high speed wireless communications devices, a bit like a Wi-Fi, hence the name Li-Fi which is often used.

• WHY WE USE LI-FI INSTEAD OF WI-FI ?  

The wireless communication industry Is now worth $1.2 Trillion/year

But it facing a huge problem, There is a Radio Spectrum crisis new spectrum has run dry while Demand is still DOUBLING EVERY YEAR.

 Radio spectrum is congested but the demand for wireless data doubles each year.  Everything, it seems, wants to use wireless data but the capacity is drying up.  Wireless radio frequencies are getting higher, complexities are growing and RF interference continues to grow.

The solution is Li-Fi. Direct modulation of LED devices is a low cost, secure, and safe way to transmit data, and there is an abundance of free visible light spectrum.  High intensity LEDs used in light bulbs, flash lights and cameras can transmit very high data rates, faster than Wi-Fi!

• ABSTRACT 

  VisibleLight Communication uses light emitting diodes (LEDs), forthe dual role of illumination and data transmission. Using thevisible light spectrum, which is free and less crowded than other frequencies, wireless services can be piggy-backed overexisting lighting installations. With this leading edge technology,data including video and audio, internet traffic, etc, can betransmitted at high speeds using LED light. In addition, wheresecurity of local communication is important eg defense andfinance applications, D-Light technology offer a secure medium for communication in an office/building environmentUsing LEDs is helping to drive this technology in the form of Visible Light Communication (VLC). Data from an experimental systems shows that data density’s of

  0.41 bits/second/Hz/m2
  is being achieved from a VLC implementation This compares with
  4 x 10-4 bits/second/Hz/m2
  reported for wireless radio systems and illustrates that VLC can achieve three orders of magnitude improvements in data density compared with the equivalent RF system.

  LI-FI

  It is free, safe, secure and plentiful.In fact, there is 10,000 times more of it compare to radio spectrum.Using standard LED light bulb we can transmit data faster than current Wi-Fi speed, and with data density 1000 times higher and component cost much lower, THIS IS THE WINNING SOLUTION TO THE RADIO SPECTRUM PROBLEM

  DESCRIPTION ABOUT LI-FI

  

  • ž     It is two way communications that uses medium of light.
  • ž     It uses photons as medium which carries signals.
  • ž     It is a safe technology to transfer confidential matters. 
  •       Fluorescent light transmits a meaningful amount of data by frequently flickering
  •       Even the VLC technology is simple; it has many difficulties in practical application
  •       The preferred light sources are fluorescent lights and LEDs.
  • ž     LEDs are those which consist of ultraviolet LED surrounded by phosphorous which is then illuminated by actual LEDs and emits white light.
  •  ž     As a new idea three distinct LEDs are used which are red, green and blue lights at same time and appears as white in human eyes.
  • ž     Photo diodes are used as receivers which can turns light into electrical signals
  •       žEvery source of lights can be used as transmitter in VLC
  •       More important requirement is that the light source has to meet the ability to switch on and off again in a short period of time that is how data is later modulated (LED's fulfills the requirement of frequent switching on and off)Signals in this form can then converted into actual data.

  • V.L.C

    A significant attribute of LEDs is their ability to switch on and

    off thousands of times per second. No other lighting technology

    has this capability. This switching occurs at ultra-high speeds,

    so far beyond what the human eye can detect, that the light

    appears to be constantly on. Amazingly, the technology can

    transmit a signal even when the light appears off. These

    embedded signals are emitted from the LEDs in the form of

    binary code; 'off' equals zero and 'on' equals one. When LVX

    equipment and devices are placed throughout a building of

    

    geographical area, a comprehensive wireless communication

     network can be created

    

    •  COMPONENTS

       

        The Smart Lighting Development Kit (SLDK) is due for release in 2012. This is a full duplex VLC system that connects to standard LED light fixtures. The SLDK enables VLC technology to be piloted and applications to be developed
      We can provide VLC transceiver components that can address a large number of applications. The transceivers can be developed for smart lighting, smart buildings, mobile connectivity, WiFi spectrum relief, indoor positioning systems, hazardous environments, vehicle & transportation, defence & security, hospital & healthcare, aviation, underwater communications, toys, etc.
      We can provide general purpose VLC transceiver components, or can work with you to provide specialist components adapted to your specific requirements.  Whatever your VLC component or system requirements are, VLC are keen to discuss these with you.

    •  HOW IT WORK ?

    
    

    

    

    

      USES 

    • ž      WiFi Spectrum Relief - Providing additional bandwidth in environments where licensed and/or unlicensed communication bands are congested

    • ž      Smart Home Network – Enabling smart domestic/industrial lighting; home wireless communication including media streaming and internet access

    •        žCommercial Aviation – Enabling wireless data communications such as in-flight entertainment and personal communications

    •        žHazardous Environments- Enabling data communications in environments where RF is potentially dangerous, such as oil & gas, petrochemicals and mining

    •        žHospital and Healthcare – Enabling mobility and data communications in hospitals

    •        žDefence and Military Applications – Enabling high data rate wireless communication  within military vehicles and aircraft

    • ž      Corporate and Organisational Security – Enabling the use of wireless networks in applications where (WiFi) presents a security risk

    • ž      Underwater Communications – Enabling communications between divers and/or remote operated vehicles
    •        žLocation-Based Services – Enabling navigation and tracking inside buildings. 

    
    
    

    

    
    SPEED VARIATION

     

    
    

    Difference b/w WI-FI & LI-Fi