The technology was originally developed by the D-Light project at the University of Edinburgh and has been exclusively licensed to PureVLC. This technology allowsstandard 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.
Visible Light Communication uses light emitting diodes (LEDs), for the dual role of illumination and data transmission. Using the visible 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 be transmitted at high speeds using LED light. In addition, where security of local communication is important eg defense andfinance applications, D-Light technology offer a secure medium for communication in an office/building environment
A significant attribute of LEDs is their ability to switch on and off thousands of times per second. No other lighting technologyhas 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.
Visible Light Communication System Visible Light Communication system are presently being developed by scientists seeking to create ultra high-speed, high security, biologically friendly communications networks that allow the creation and expansion of seamless computing applications using very large bandwidth high-frequency pulsed light instead of radio waves and microwaves. Such systems use modulated light wavelengths emitted (and received) by a variety of suitably adapted standard sources,such as indoor and outdoor lighting, displays, illuminated signs, televisions, computer screens, digital cameras and digital cameras on mobile phones for communication purposes, primarily through the use of white Light Emitting Diodes (LEDs).
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.
Thesolution 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!
It is two way communications that uses medium of light. It uses photons as medium which carries signals. It is a safe technology to transfer confidential matters. Fluorescent light transmits a meaningful amount of data by frequently flickering. Bandwidth is not limited. Transmitters and receivers devices are cheap, and there is no need for expensive RF units.
LEDs are those which consist of ultraviolet LED surrounded by phosphorous which is then illuminated by actual LEDs and emits white light. 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. Photo diodes are used as receivers which can turns light into electrical signals Every source of lights can be used as transmitter in VLC
Signals in this form can then converted into actual data Even the VLC technology is simple; it has many difficulties in practical application The preferred light sources are fluorescent lights and LEDs. 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 (LEDs fulfills the requirement of frequent switching on and off)
There should be a line of sight between sender and receiver, because visible light cannot penetrate into solid objects. VLC mostly used indoors. Even the VLC technology is simple; it has many difficulties in practical application. Also interference with other electromagnetic waves makes the transmitting data to distort.
WiFi Spectrum Relief - Providing additional bandwidth in environments where licensed and/or unlicensed communication bands are congested Smart Home Network – Enabling smart domestic/industrial lighting; home wireless communication including media streaming and internet access Commercial Aviation – Enabling wireless data communications such as in- flight entertainment and personal communications Hazardous Environments- Enabling data communications in environments where RF is potentially dangerous, such as oil & gas, petrochemicals and mining Hospital and Healthcare – Enabling mobility and data communications in hospitals Defence and Military Applications – Enabling high data rate wireless communication within military vehicles and aircraft Corporate and Organisational Security – Enabling the use of wireless networks in applications where (WiFi) presents a security risk Underwater Communications – Enabling communications between divers and/or remote operated vehicles Location-Based Services – Enabling navigation and tracking inside buildings.
Professor Jurg Leuthold led an experiment thatachieved a data transmission rate of 26 terabits per secondThe need for faster data transmission rates has never been greater. Now ateam of scientists at Germanys Karlsruhe Institute of Technology (KIT) areclaiming a world record in data transmission with the successful encoding of data at a rate of 26 terabits per second on a single laser beam and transmitting it over a distance of 50 km (31 miles). The scientists claim this is the largest data volume ever transported on a laser beam andenables the transmission of 700 DVDs worth of content in just one second
VLC based on white LEDs appears to be an important potential component in expanding useable bandwidth, protecting sensitive electrical equipment and data, creating more biologically friendly communications technology, and helping develop seamless computing applications. VLC offers the advantage of a communications channel in an unregulated, unlicensed part of the electromagnetic spectrum. In applications where a visible beam is desirable for security it can provide high data rates. There are a number of technical and regulatory challenges to be overcome; rapid technicalprogress is being made, but the challenges of standardization will require cooperation and agreement from a number of different bodies. However, success should bring a low-cost high data-rate infrastructure that can increase wireless capacity substantially.