Mukhtar Ahmad Farooqi
Access to internet is starting to be considered a basic human right. Imagine a world where the light bulbs in our homes can connect us to high-speed wireless internet with a simple flick of a switch.Li-Fi or Light Fidelity is a Visible Light Communication System that will change the way we connect to and use the internet. Li-Fi is a technology for wireless communication between devices using light to transmit data. In simpler terms Li-Fi can be thought of as a light based Wi-Fi. That is, it uses light instead of radio waves to transmit information. And instead of Wi-Fi modems, Li-Fi would use transceiver fitted LED lamps that can light a room as well as transmit and receive information.Even though the technology truly began during the 1990’s in countries like Germany, Korea and Japan where they discovered LED’s could be retrofitted to send information but the term Li-Fi was coined by University of Edinburgh Professor Harald Haas during a TED Talk in 2011. The idea came on 12th July 2011 when he used a table lamp with an LED bulb to transmit a video of blooming flower that was then projected onto a screen behind him .In his talk he introduced the idea of “wireless data from every light”.He is the co-founder of pureLiFi and as per his TED talk “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. In the future we will not only have 14 billion light bulbs, we may have 14 billion Li-Fi s deployed worldwide for a cleaner, greener, and even brighter future.” Increased data consummation has resulted in the Spectrum Crunch which refers to the increased usage and strain of radio frequency that will eventually prevent wireless broadband from supporting consumer devices and perhaps the only solution to overcome this fear is implementation of Li-Fi technology and is believed to be the next generation of internet where light will be used as a medium to transport data.
The future internet
According to a study done by CISCO, “Traffic from wireless and mobile devices will account for more than 63% of total IP traffic by 2021”. The internet has dramatically evolved in terms of the volume of information available online and the speed at which one can access it. Each of our devices will be connected to the internet, as we move into the Internet of Everything era. From vehicles sending out traffic-related information to sensors on a field delivering real-time information about soil quality, the internet is further extending its influence on humanity. Wi-Fi that utilizes radio frequency won’t be able to handle all that internet traffic. With the number of wireless devices (laptops, smartphones, or other devices) increasing exponentially, radio spectrum is congested and overly saturated, and the demand for wireless data doubling each year, it seems the capacity is drying up. There are security related concerns as well but the biggest challenge is bandwidth. Hence there would be need for an alternative mode of communication and to cope up with these issues Li-Fi technology is gaining popularity. An old adage “Necessity is the mother of invention “comes in handy.
How does Li-Fi work?
Li-Fi and Wi-Fi are quite similar as both transmit data electromagnetically. However, Wi-Fi uses radio waves, while Li-Fi runs on visible light. Li-Fi is a Visible Light Communications (VLC) system which means that it accommodates a photo-detector to receive light signals and a signal processing element to convert the data into ‘streamable’ content.An LED light bulb is a semiconductor light source meaning that the constant current of electricity supplied to an LED light bulb can be dipped and dimmed, up and down at extremely high speeds, without being visible to the human eye. If the LED is on we transmit digital’1′ and if it’s of we transmit a ‘0’.LED’s can be switched on and off very quickly which gives us an opportunity for transmitting data. Data is fed into an LED light bulb (with signal processing technology), it then sends data (embedded in its beam) at rapid speeds to the photo-detector (photodiode). The tiny changes in the rapid dimming of LED bulbs is then converted by the ‘receiver’ into electrical signal. The signal is then converted back into a binary data stream that we would recognize as web, video and audio applications that run on internet enabled devices. LiFi bulbs are outfitted with a chip that modulates the light imperceptibly for optical data transmission. In layman’s language LiFi data is transmitted by the LED bulbs and received by photoreceptors or photo-sensitive detector.
It requires two different sets of hardware devices (Li-Fi Access Point and Li-Fi Dongle) to set up a Li-Fi network-one that can be used indoors (inside a building) and the other for outdoors. The Li-Fi access point is very similar to what we have in Wi-Fi, which is essentially a router. “We plug the Li-Fi access point to a light source, which is LED in this case. The router is plugged in between the LED and the LED driver, and we have a USB dongle that can be used to connect with a laptop, desktop or smart devices,” Solankisaid in a TED talk.
Benefits of Li-Fi:
* Higher speeds than Wi-Fi because it uses common household LED (light emitting diodes) light bulbs to enable data transfer thereby boosting speeds of up to 224 gigabits per second as per the Researchers at Oxford University. This means you can download high-definition movies in a matter of seconds opposed to minutes.
* 10000 times the frequency spectrum of radio. The visible light spectrum is 10,000 times larger than the entire radio frequencyspectrum.
* More secure because data cannot be intercepted without a clear line of sight.
* Prevents piggybacking.
* Useful in electromagnetic sensitive areas such as in aircraft cabins, hospitals and nuclear power plants without causing electromagnetic interference.
* Eliminates neighboring network interference.
* Li-Fi is expected to be ten times cheaper than Wi-Fi
* Unimpeded by radio interference.
* Does not create interference in sensitive electronics, making it better for use in environments like hospitals and aircraft.
* Li-Fi can be used in areas where Wi-Fi is either prohibited or doesn’t work efficiently such as aviation, healthcare, environment etc. In the aviation industry, for example, Li-Fi technology brings a lot of value. One can use it in the cockpit securely without any requirement for cables.
* Eventhough the LiFi seems like an innovative solution but if light source is not present, the internet will not work.
* Short range, low reliability
* Light can’t pass through objects
* High installation costs because of small production and demand
* Outdoor light signals like sunlight will interfere with signals which will result in interrupted internet connections.
Li-Fi technology has evolved significantly during the last few years but it is yet to become an integral part of the wireless infrastructure, alongside Wi-Fi and still there are a lot of possibilities that need to be explored. If this technology can be put into practical use every LED bulb can be used something like Wi-Fi hotspots to transmit wireless data.It is pertinent to mention that Li-Fi isn’t out there to replace Wi-Fi but to compliment it.
Mukhtar Ahmad Farooqi