11 Nov Li-Fi: Turning Light Bulbs Into Next Gen, Super Fast Wireless Networks
For those of you frustrated with a slow wireless network, a new wireless standard named Li-Fi (Light Fidelity) hopes to bring to light a solution.
The issue with current Wi-Fi technology, is that there is a limit to the bandwidth (set by the physics of electromagnetic waves), which limits the amount of data that can be transmitted at a given frequency. Because of this limit, current Wi-Fi technology only uses the 2.4GHz or 5GHz bands, which cause a large amount of noise in these ranges in densely populate areas. This, of course, slows the speed of the connection.
Transmitting data using waves of higher frequencies would result in much faster Wi-Fi, however, currently you need to acquire a spectrum license from the telecom regulator to use these higher frequencies.
That’s where light comes in.
Numerous research groups hope to solve the problem of slow, unreliable Wi-Fi networks, by transmitting data using light. While light is also an electromagnetic wave, it has about 100,000 times the frequency of a Wi-Fi signal, which means Li-Fi potentially could offer a wireless network 10 times faster than current wireless technologies.
How Does It Work?
Data is transmitted to a LED lightbulb, much like the ones we use everyday. The lightbulb will then flicker up to billions of times per second, so fast that the human eye cannot perceive it. A receiver on a computer or a mobile device (essentially a small camera that can detect visible light), then takes that flickering and extracts the data that was transmitted.
Because LED lightbulbs are solid-state electronics, meaning they can be controlled in much the same way as other electronic components, they can be flicked on and off quickly enough that they are capable of transmitting data around 10 times faster than the fastest Wi-Fi networks at present.
Current Advances In Li-Fi Technology
Not a complete newcomer, the Li-Fi standard was actually proposed two years ago.
In an effort to address consumer demand for faster wireless connectivity, the Li-Fi Consortium was created made up of an international group of technology innovators. The Consortium aims to promote new high-speed topical wireless usage models both indoors and outdoors.
However, Li-Fi technology has only just recently seen significant technological progress.
We’re already seeing other technology being developed in the realm of wireless technology, with chip company Wilocity having already showcased their WiGig (Wireless Gigabit) technology at the Consumer Electronics show earlier this year. In a similar fashion to Li-Fi, WiGig Wi-Fi chips use a higher frequency to transmit the data. While conventional Wi-Fi uses the 2.4GHz and 5GHz bands, WiGig will use the 60GHz band which can theoretically hit speeds of up to 7Gbps. However, this too can be blocked by walls, which limits its real-world application.
Earlier this year, researchers at the University of Strathclyde in Scotland revealed how they were contributing to the development of Li-Fi technology. Because Li-Fi depends heavily on light, it makes sense to start with source of light itself: lightbulbs. At present, commercial LEDs don’t get much smaller than 1mm2. However, the team at the University of Strathclyde are developing LEDs that are just 1um2, which is a thousand times smaller.
This means that, not only can you fit more LEDs into the same space as a larger LED, but theoretically, they can also flicker on and off 1,000 times faster, which translates into data being able to be transferred a million times faster than a normal LED.
In addition to this, a team of researchers at Fudan University in Shanghai, unveiled an experimental Li-Fi network in which four PC’s were connected to the internet via a one-watt LED lightbulb. Chi Nan, an Information Technology Professor at the university, who heads the research team, stated that a lightbulb with embedded microchips can produce data rates as fast as 150 megabits per second.
Unfortunately, as with any new technology, there are bound to be some limitations.
For devices to be able to connect to the internet via Li-Fi, the connected light needs to be on and the device needs to be within sight of the light. So, this means that these wired LED lightbulbs will have to be installed in every room you plan on connecting to the wireless network, and the light needs to remain on as long as you are using it. So, if the light is blocked or absent, the signal would be cut off, meaning the signal would not be able to penetrate walls or work without the LEDs turned on.
As a result, researchers admit that there is still a long way to go before Li-Fi can become a commercial success.
Future Of Li-Fi
While Li-Fi won’t completely replace other wireless networks, particularly with current limitations, it could certainly supplement them. In dense urban areas with high amount of noise, or places where radio signals need to be kept to a minimum (i.e. hospitals, planes), Li-Fi would be incredibly useful. Add this to its ability to reach speeds faster than current Wi-Fi networks, and the future of wireless connectivity looks very bright indeed.