Li-Fi (Light-Fidelity) - A Future Wireless Technology

Current era many people are using internet to accomplish their task through wired or wireless network. As no of users get increased in wireless speed decreases proportionally. Though Wi-Fi gives us speed up to 150mbps as per IEEE 802.11n, it is still insufficient to accommodate no of users. To remediate this limitation of Wireless Fidelity, we are introducing concept of Li-Fi. As per germen physicist Harald Haas data through illumination taking the fiber out of fiber optic by sending data through an LED light bulb that varies in intensity faster than the human eye can follow. It?s the same idea band behind infrared remote controls but far more powerful. Haas says his invention, which he calls D-Light, can produce data rates faster than 10 megabits per second, which is speedier than your average broadband connection. He envisions a future where data for laptops, smartphones, and tablets is transmitted through the light in a room. And security would be a snap?if you can?t see the light, you can?t access the data.Li-Fi is a VLC, visible light communication, technology developed by a team of scientists including Dr Gordon Povey, Prof. Harald Haas and Dr Mostafa Afgani at the University of Edinburgh. Li-Fi is now part of the Visible Light Communications (VLC) PAN IEEE 802.15.7 standard. Light-Fidelity is a label for wireless-communication systems using light as a carrier instead of traditional radio Frequencies [1], as in Wi-Fi. Li-Fi has the advantage of being able to be used in sensitive areas such as in Aircraft and other transportation without causing interference. However, the light waves used cannot penetrate walls. It is typically implemented using white LED bulbs at the Downlink transmitter. This type of devices are normally used for illumination only by applying a constant current. However, by fast and subtle variations of the current, the optical output can be made to vary at extremely high speeds. This property of optical current is used in Li-Fi setup. The operational procedure is very simple-, if the LED bulb is on, you transmit a digital 1, if it?s off you transmit a 0. The LEDs can be switched on and off very quickly, which gives nice opportunities for transmitting data. Hence all that is required is some LEDs and a controller that code data into those LEDs. All one has to do is to vary the rate at which the LED?s flicker [2] 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 LEDs to alter the light?s frequency with each frequency encoding a different data Channel. Such advancements promise a theoretical speed of 10 Gbps ? meaning one can download a full high-definition film in just 30 seconds.