Li-Fi Technology: Meet the new Wi-Fi

Wherever there is an LED light bulb there is an internet signal? That may not be far from the truth today as “Li-Fi” technology is making this a reality.

Li-Fi (or Light Fidelity if you were wondering) is more of a marketing name coined by lead researcher Prof Harald Haas. Actually, the more general term for it is VLC (Visible Light Communication). It is an emerging wireless communications system that uses light as a medium of transmitting information. This is in contrast to the traditional radio frequencies (RF) widely used today; in Wi-Fi for instance. So, we’re basically saying instead of using radio frequency waves in the EM wave spectrum, Li-Fi uses the visible light spectrum as a means to the same end as any other before it – connectivity.

Li-Fi edges out RF based communications techs in more than just a few aspects. To justify this, we take a look at the inherent properties of light juxtaposed with that of radio waves.

Light cannot penetrate opaque materials (that’s a no-brainer), take a block wall for instance. This property becomes advantageous in the security of the system – now, who needs some creepy looking password to lock their wireless network from savvy opportunists next door?

If you ever visited an offshore oil rig, or a nuclear power plant, or even flew a commercial airliner, you most likely did not have your mobile phone or any other wireless electronic device in your possession while in these places – yes, I can imagine not being able to call home or post on your Facebook timeline – that is because of interference which occurs with RF waves. With Li-Fi, you needn’t worry about any of that anymore. Seamless connectivity wherever, whenever? You could be right you know.

LEDs are different from other kind of lamps (for goodness sake they’re semiconductors), they are capable of switching on and off within a billionth of a second (don’t bother, that’s faster than we can come to grasp). Using a digital modulation technique called Orthogonal Frequency Divisional Multiplexing (OFDM); LED light bulbs are made to handle millions of fast on/off changes (binary data as series of ones and zeros) per second. In fact, Li-Fi at its “slowest” is still so many times faster than the best broadband connection available anywhere. This, in part, is because the bandwidth of visible light in the EM spectrum is 10,000 times bigger than the radio frequency spectrum used in existing communication systems. Only recently, researchers achieved data transmission speeds of 10Gbits/s in lab conditions.

LED light bulbs saves up to 50% of electricity used by fluorescent ones. They can have a lifetime of 50,000 hours or more, and depending on use can last anywhere from 6 years to 20 and even as long as 30 years. They’re also incredibly cheap. Li-Fi as a result promises cheaper and more energy-efficient mobile connectivity than wireless radio system solutions.  

What’s more, Li-Fi technology is also a green technology – we needn’t worry about electromagnetic pollution in the form of insidious radiation or the like. It is hoped that as Li-Fi technology evolves, we will see LED bulbs retrofitted and turned into hotspots and access points for broadband networks in homes and offices. With growing demand for mobile connectivity, we can as well think turning all 14 billion lamps worldwide into mobile internet masts so they have internet signal in them somewhere for us.

Finally, while it may seem as though this technology is only in the beta stages of research, it took quite a remarkable step forward when a group of Chinese scientists this past October successfully produced internet signals using microchip embedded LED bulbs, with data rates as fast as 150 Mbps. One of such LED light bulbs connected four different computers to the internet – that is the Li-Fi technology we have been talking about these whole while.