Monday, December 7, 2015

Light-based 'Li-Fi' beams data 100 times faster than Wi-Fi


A developing technology called Li-Fi promises Wi-Fi speeds 100 times faster than conventional technology using the visible light spectrum.






Do you find those blazing-fast MU-MIMO 802.11ac routers still too darn pokey? One start-up hopes to turn your light bulb into a data transfer connection capable of speeds 100 times faster than current Wi-Fi by 2020.


The company, called Velmenni, is already working on several pilot projects, including a wireless network in an office space that uses LED lights instead of radio waves to transmit data. Velmenni CEO Deepak Solanki recently told International Business Times UK that the company hopes the trials will lead to a consumer roll out over the next three to four years.

The breakthrough technology delivering these speeds is dubbed Li-Fi, and it was first publicly introduced by Professor Harald Haas of Edinburgh University four years ago

Li-Fi uses the visible light spectrum instead of radio waves to transmit data. You can’t just use any old light source, however, as it requires the light to modulate its signal in order to create a data stream. Currently, this is done with standard LED bulbs equipped with a special chip, and then a special receiver capable of interpreting the light signals is attached to the receiving device.

The light modulations aren’t distracting, as they are very slight and imperceptible to the human eye. Haas said during his public introduction in 2011 at TED Global that you could even turn the light down low enough to where it would appear to be off, yet it would still transmit a signal.

In 2011, Haas had a working prototype on stage. He has since gone on to co-found a start-up called pureLiFi that offers two products for transmitting data over light.

Why this matters: While Li-Fi is not yet ready to go mainstream, it does claim to solve several problems that conventional Wi-Fi has. Chief among them is capacity. With radio waves, you have a finite amount of spectrum that is shared by all kinds of different signals. That would be a non-issue with Li-Fi, however, as the visible light spectrum is 10,000 times bigger than what we get with radio waves, according to Haas.

It ain’t all sunshine and roses

While Li-Fi does have potential, it also has limits. Most importantly, visible light can’t travel through walls the way radio waves can—meaning you either have to have an open floor plan or set-up Li-Fi as a complement to your existing Wi-Fi set-up. Similarly, you can block a Li-Fi connection just by putting something solid (like a book) in front of the transmitting light bulb.

Li-Fi also doesn’t work outside in direct daylight since any light signals would be washed out by the overpowering light coming from the sun.

Regardless, even as a complement to regular wireless Internet connections, Li-Fi sounds like it could become a useful tool—if it ever goes mainstream.

Video: https://youtu.be/NaoSp4NpkGg

Source: TEDtalks 

'Harald Haas: Wireless data from every light bulb'

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