Imagine a future where every one of the billions of light bulbs in use today is a wireless hotspot delivering connectivity at speeds that can only be dreamed of with Wi-Fi. That's the goal of the man who invented such a technology, and this week Li-Fi took a step out of the domain of science fiction and into the realm of the real when it was shown to deliver speeds 100 times faster than current Wi-Fi technology in actual tests.
Lifi internet is similar to Wi-fi. It is a wireless, bidirectional technology founded by Professor Harald Haas of University of Edinburgh. Li-fi stands for Light fidelity which takes light from light-emitting diodes (LEDs) as a path to deliver networked, mobile, high-speed communication.
Lifi is a wireless technology using LED lights to transmit data through network. Scientists have receive a speed of 224 gigabits per second in laboratories by using this technology and the expected speed in the in the outside world could be 1giga-byte (1GB) per second.
How Li-Fi Works
As told earlier Li-Fi uses light to transmit data unlike Radio waves. This idea was first coined by Prof. Harald Haas in one of his TED talk in 2011. The definition for Li-Fi can be given as “LiFi is high speed bi-directional networked and mobile communication of data using light. LiFi comprises of multiple light bulbs that form a wireless network, offering a substantially similar user experience to Wi-Fi except using the light spectrum”.
So, yes wherever you have a light bulb you will have an internet connection but here, the term light bulb does not refer to ordinary incandescent lights in our house, these are specially modified LED lights which can transmit data. As we know LED is a semiconductor device and like all semiconductors it has switching properties. This switching property is used to transmit data. The below image explains how a data is transmitted using light.
Every LED lamp should be powered through an LED driver, this LED driver will get information from the Internet server and the data will be encoded in the driver. Based on this encoded data the LED lamp will flicker at a very high speed that cannot be noticed by the human eyes. But the Photo Detector on the other end will be able to read all the flickering and this data will be decoded after Amplification and Processing.
The data transmission here will be very fast than RF. As we all know light travels faster than air that is the light is ten thousand times faster than Radio waves since the frequency of Radio waves are just 300 Giga hertz but light can go up to 790 Tera hertz.
Some Applications of Li-Fi
Li-Fi technology uses visible light as its means of communication, it will not work through walls. This means that to have a Li-Fi network throughout your house, you will need these light bulbs in every room to have seamless connectivity.
Another major issue is that Li-Fi does not work outdoors, meaning that public Li-Fi will not be able to replace public Wi-Fi networks any time soon. While Li-Fi's employment in direct sunlight won't be possible, pureLiFi said that through the use of filters the technology can be used indoors even when sunlight is present.
A number of immediate uses for Li-Fi could be:
• Healthcare: Li-Fi emits no electromagnetic interference and so does not interfere with medical instruments, nor is it interfered with by MRI scanners.
• Mobile Connectivity: Laptops, smart phones, tablets and other mobile devices can interconnect directly using Li-Fi. Short range links give very high data rates and also provides security.
• Hazardous Environments: Li-Fi provides a safe alternative to electromagnetic interference from radio frequency communications in environments such as mines and petrochemical plants.
Check the link below to listen to the TED TALK of Harald
Hass
-Anudita Sharma
II year
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