Submitted By : Soumyadeep De (Department of BCA, Batch :2016-19)
Internet the most common and most used terms in the present era has become the Archimedean point of our daily life. Without this it's impossible to survive a single day. In this current time the most popular medium for data transfer is the radio spectrum. For that the most recent technology which is being used daily by everyone of the planet is Wi-Fi. But in 2011, German Physicist Harald Hass introduced a new technology of wireless data transmission which is named as LiFi (he calls it “data through Illumination”).
The LiFi is a new technology in which light is used as a medium of data transfer. Light is such a thing which we can get everywhere, from rooms to streets. So, is this mean we can use free data? The answer is yes. You have to just stand below the lamps and enjoy the live cricket on your mobile.
Hass says his invention, which he calls D-Light, can produce data rates faster than 1 gbps(theoretically) with a higher amount of data dens
LiFi-How it works: -
LiFi is the transmission of data through illumination by taking the fiber out of the fiber optics by sending data through a LED light bulb that varies in intensity faster than human eyes can follow. The LED bulb which are used in this technology are different from the bulbs we use in our houses, office etc. The difference is that these bulbs are just an ordinary bulb with a microchip installed in it. These microchips help the bulb to flicker at a frequency of millions of time per second, allowing them to send data.
The data transmission works on the flickering of LED, i.e. when the LED is ON is transmit logical 1 and when its OFF it transmits logical 0. This method of using rapid pulses of light to transmit information wirelessly is technically referred to as Variable Light Communication(VLC).
The VLC data communication uses visible light between 400thz(7800nm) & 800Thz(375nm) as an optical carrier for data transmission & illumination.
The main components of this communication system are:
- A high brightness white LED, which acts as communication source
- A silicon photodiode, which shows good response to visible wavelength region serving as the receiving element
The concept of LED light we have discussed earlier. So, let’s see how the Photo receptor works.
LiFi is a bi-directional mechanism i.e. both uplink and downlink transmission. It has two
units; one is ceiling unit that connects with a standard LED light bulb & a desktop unit which connects with laptop with a standard USB connection. So, let’s talk about the unit specifically. The ceiling unit has a ethernet & a power input, it connects with the LED light and modulates the visible light & the data transmitted to the desktop unit. As I said earlier there is a microchip which help the LED to modulate the light. Now, switch to the desktop unit; the desktop unit has a photo receiver which receives the data and an infrared transmitter for the uplink transmission. This system can transmit data at a distance of at least 3 to 5 meters. The distance and the rate depend on the LED light which is been used.
The system operates at 50mbps (lowest speed) in full duplex, and the data density is much higher than any unguided medium. The sensitivity of desktop unit is very high i.e., it can work with direct or indirect light. This sensitivity means that we can dim the light to very low amount without affecting the performance of the system.
Harald Hass is planning to launch this system in every part of the world in few years. There is also a company named “Pure-LiFi” founded by Hass himself in 2012. The company launched the latest product (LiFi XC) at October 2017 which wins the Innovation Award at IOP Business Innovation Awards.
As we all know the basic difference between LiFi-WiFi is WiFi uses radio frequency to transmit data & LiFi uses light to transmit data. There is many restriction for WiFi where to use where not bout as LiFi is used through light and light is present every possible place in the earth until an apocalypse came; well that’s an different issue;(pun intended)there is no restriction to use it from up in sky in airplane to deep under sea in a submarine where use of radio based data communication can’t be used.
Wi-Fi – IEEE
Table 1. Comparison between current and future wireless technology
From the day that Li-Fi was unveiled to the public, it has been altering society only a small amount, as it has not taken off with the general public yet. If Li-Fi does gain popularity and widespread use, it has the potential to alter society in many interesting ways.
Li-FI only requires a few different pieces of equipment, that aren’t majorly expensive and are available to the public to buy. Because Li-Fi only requires an LED lightbulb, a solar cell, and a laptop acting as a receiver, Li-Fi could equip over 4.3 billion people who did not have access to Wi-Fi or the internet access to the internet, and not only internet, internet that is 100x faster than the internet in an average first world country’s household.
The application of Li-Fi is huge. This technology can be used in various fields, they are as follows:
- You Might Just Live Longer:
For a long time, medical technology has lagged the rest of the wireless world. Operating rooms do not allow Wi-Fi over radiation concerns, and there is also that whole lack of dedicated spectrum. While Wi-Fi is in place in many hospitals, interference from cell phones and computers can block signals from monitoring equipment. Li-Fi solves both problems: lights are not only allowed in operating rooms but tend to be the most glaring (pun intended) fixtures in the room. So, there will not be any problem to transmit data between devices with the help of the light.
- Up in the sky
In airplane we must put our phone in airplane mode or switched off without any interaction to the outer world. Using internet is restricted as it could disrupt the airplane signal. But nowadays airplane started a dial-up speed Wi-Fi on the plane, which is very problematic, and it increases the fare cost.
Despite that if we use the reading light above the passenger’s head to transmit data, it would be much easy and short process.
Curiously, Haas tells us that PureLiFi has been testing with a “major aircraft manufacturer,” which hints at what could be to come for the future of air transport.
- Smarter Power Plants
Wi-Fi and many other radiation types are bad for sensitive areas. Like those surrounding power plants. But power plants need fast, inter-connected data systems to monitor things like demand, grid integrity and (in nuclear plants) core temperature. The savings from proper monitoring at a single power plant can add up to hundreds of thousands of dollars. Li-Fi could offer safe, abundant connectivity for all areas of these sensitive locations. Not only would this save money related to currently implemented solutions, but the draw on a power plant’s own reserves could be lessened if they haven’t yet converted to LED lighting.
- Undersea Awesomeness
Underwater ROVs, those favorite toys of treasure seekers and James Cameron, operate from large cables that supply their power and allow them to receive signals from their pilots above. ROVs work great, except when the tether isn’t long enough to explore an area, or when it gets stuck on something. If their wires were cut and replaced with light — say from a submerged, high-powered lamp — then they would be much freer to explore. They could also use their headlamps to communicate with each other, processing data autonomously
and referring findings periodically back to the surface, all the while obtaining their next batch of orders.
These are the few examples how awesome the implementation of Li-Fi can be.
Advantages & Disadvantages:
In every new system/technology there must be some advantage and disadvantage. Though in case of this technology the number of advantages is greater than the disadvantages, which makes this technology a good and approved by everyone technology.
Let’s see what the advantages and disadvantages are: -
- Data rate greater than 1 Gbps; Theoretically allowing HD film to be downloaded in 30 seconds
- Can be used anywhere, even in RF restricted areas; Since light waves will not interfere with radio waves.
- Mostly LED light bulbs are used, which consumes less energy. Hence its cost efficient.
- As light waves cannot penetrate through walls, the data cannot be intercepted; Thus, provides secured communication.
- Wherever there is a light source, there can be Internet. Light bulbs are present everywhere–in homes, offices, shops, malls and even planes, meaning that high-speed data transmission could be available everywhere
- Efficient alternative to radio based wireless; since it is quick and reliable.
- Internet cannot be used without a light source. This could limit the locations and situations in which Li-Fi could be used.
- Because it uses visible light, and light cannot penetrate walls, physical barriers limit the signal’s range.
- Other sources of light may interfere with the signal. One of the biggest potential drawbacks is the interception of signals outdoors. Sunlight will interfere the signals, resulting in interrupted Internet.
Li-Fi is meant as a complimentary device to be used along with Wi-Fi, but in the future, Li-Fi will be the dominant internet connection device around. Though current devices will need to be retrofitted, and future devices will need to have the technology built-in before it can get too popular, but that will not be a problem for big name brands like Apple, HP, Dell, and other device dealers. “All we need to do is fit a small microchip to every potential illumination device and this would then combine two basic functionalities: illumination and wireless data transmission,” says Harold Haas, the creator of this astonishing technology. Imagine having great internet connection in cars, secure and fast connections in your home, and access to the internet anywhere with a light source. That is the bright future of Li-Fi.