Connecting to the web via LEDs: Li-Fi

Connecting to the Internet is best done through copper wire or high-speed wireless connections. Not many are aware of an additional method – using light beams. This is accomplished not by the usual optical fiber stuff, but by using LEDs. Communication with lights is nothing new – it has been done before. The Scottish scientist, Sir Alexander Graham Bell had invented an arsenal of instruments for communication and these included Photophones.

The first instruments to use light for communication were Photophones. Now, after about 110 years after the invention of photophones and their fading into history, Professor Harald Haas is conducting experiments in wireless communication using light-centric technology. At the University of Edinburgh in Scotland, Professor Haas is using the Alexander Graham Bell building for his experiments.

Professor Haas demonstrated his vision for the future of wireless communication way back in 2011. He was using something as simple as LED bulbs for his experiments. This is also the time when the term Li-Fi was coined. Li-Fi is now used to describe bidirectional networked wireless communication using visible light as a replacement for traditional radio frequencies.

With people implementing the Internet of Things in full swing, it will not be very long before there is a spectrum crunch for the radio frequencies. In this context, light modulation and enabling connectivity through simple LED bulbs will have huge ramifications. Li-Fi can allow you to connect to the Internet as soon as you are within the range of an LED beam. Even your car headlights can be used to transmit data.

Professor Haas is working towards PureLiFi, which can offset the global struggle for the vanishing wireless capacity. PureLiFi is striving to develop and drive technology suitable for secure, reliable and high-speed communication networks. This will help to integrate data and lighting utility infrastructure seamlessly while reducing energy consumptions significantly.

One of the most interesting features of Li-Fi is its security over the conventional networking methods. Although Li-Fi is not yet available on the Internet marketing websites, companies from the security-focused fraternity are highly interested parties. That is because prying eyes of third-parties find Li-Fi significantly harder to infiltrate compared to other current networking technologies.

Li-Fi signals travel over narrowly focused beams and they cannot penetrate walls. Additionally, with LED lights, you have natural light beams; therefore, the uplink and downlink channels can be separated leading to increased security. For example, if you are browsing using two-channel Li-Fi, both beams will have to be intercepted for someone to infiltrate into your computer, provided they first gain entry into the same room as you are in.

In practice, Li-Fi networks use a desktop photosensitive unit to communicate with an off-the-shelf unmodified light fixture using infrared LEDs for its uplink and downlink channels. Within a range of about three meters, you can have uplink and downlink channels delivering a typical capacity of 5Mbps. With Li-Fi, it is possible to achieve speeds as high as 10Gbps as well. As an additional benefit, your workspace remains well lit.

Li-Fi allows you to have your content tailored before delivery. Within a single room such as in an exhibition, you could wander through various beams to pick up information relevant to your current location.