What if we could use light to provide Internet access to the more than 4 billion people living in places where the infrastructure can't support it? using off-the-shelf LED's and solar cells.
The Existing Technology:
Since the invention of Wi-Fi in 1992 by Australian radio astronomer doctor John O'Sullivan through a failed experiment to detect exploding black holes. Wi-Fi has revolutionized digital communication. Without it our current way of life would be somewhat different, Wi-Fi currently makes up to sixty precent of global internet traffic with all that being said Wi-Fi still has some issues, at times with a varying signal and it's not totally secure because your signal could travel through walls and be easily picked up by someone else. The reason for all of this is that Wi-Fi uses radio waves to transmit data. So how do we improve this technology and solve these problems. We must see something that's cheap safe plentiful and more robust for data transfer. The answer is light.
Why Light:
Light is perfect because it's a part of the electromagnetic spectrum, the waves that can carry the energy at a much faster speed than radio wave. Light has a frequency range 10000 times greater than radio waves going up to 790 terra hertz versus a maximum of 300 hertz for radio waves. All this, means is that light has the capacity to transmit vastly more pulses of data in much less time than radio waves. The concept of light being used as a means to transfer internet data has been termed Li-Fi.
So how does this all work?
Li-fi is a wireless communication system that uses your light bulb as a wireless router. Li-fi and Wi-Fi are quite similar as both transmit data electro-magnetically. The difference is Wi-Fi uses radio waves and Li-fi uses visible light from common household LED light bulbs to transmit data. Li-fi is a visible light communication system this means it has a photo detector to receive light and a signal-processing element to convert light to data. As the LED light bulb is a semiconductor light bulb meaning the constant current of electricity supplied to LED light bulb can be dipped and dimmed at extremely high speeds without it being visible to human eye.
For example data is being fed into an LED light bulb with a signal processing technology then it sends data embedded in its stream to a photo detector, the subtle changes of rapidly dimming and dipping of the light is converted by receiver to electrical signals the signals are then converted to binary code that can be converted to data or applications that run on the internet enabled devices. The downside of Li-fi is that the Li-fi signals cannot pass through walls so to get complete connectivity the LED’s with signal processing technology should be installed in every room which should not be an issue as every room would have a light source that transmits light.
Feasibility:
Okay so that sounds great but does it actually works in real Life? The answer is yes. Researchers have reached speeds of 10 gigabits per second in lab conditions. For a perspective South Korea's world record internet speeds are one hundred megabits per second. Li-Fi I has also been successfully tested in a commercial context. There have been trials in offices in Estonia data reporting transmission speed of one gigabit per second still a hundred times faster than current average Wi-Fi speeds. So imagine this, you can walk into any room switch on the light and simultaneously instantly have an internet connection a hundred times faster than your regular Wi-Fi but it doesn't stop there. Researchers at the Oxford university published results of visible light internet at two hundred and twenty three gigabits per second, with those speeds you can download eighteen 1.5 gigabyte movies in one second but of course whether or not the servers would be able to serve those files is a totally different story but still very impressive none the less.
Present stage of Li-Fi:
PureLiFi a company based in Edinburgh is working on this technology and has received a £1.5 million ($2.2 million) investment from venture capitalists, valuing the firm at £14 million ($20.7 million).
Harold Haas the co-founder of PureLiFi, said the following in one of his presentations at a TED conference.
“Light bulbs are installed already. So we have the infrastructure, all these light bulbs can be used for communication and the one thing we need to do is, we have to replace these inefficient incandescent light bulbs and fluorescent lights by new technology of LED light bulbs. LEDs are semiconductors and it has a property where its intensity can be modulated and it can be switched on and off at very high speeds and this is a fundamental property that we use in our technology.” Watch the demonstration of Li-Fi by Harold Haas
Harold hopes to integrate this technology into phone and even phone cameras so that they can send and receive high bit rate information through light. You might be wondering if the light has to be turned on the whole time to receive data Harold says yes but the thing is you can actually dim the light down so the human eye cannot detect that it's on but the receiver can still read it.
Conclusion:
So what's the conclusion here, we could be seeing very cheap light powered internet or Li-Fi everywhere. This could easily lead to the internet of things becoming a reality, a situation where all electronic devices communicate with each other. From your mobile phone communicating with your fridge to sensors on a bridge warning of structural damage and potential failure to civil engineers. If Li-Fi becomes widely available there would be a technological revolution that would lead to a world where internet and transfer of information is no longer an obstacle for the average user.