Say Goodbye to WI-FI and Hello to LI-FI


Electrical engineering, electro-optical engineering, communications engineering, illumination engineering, and physics. The engineers in these fields will be working closely together in the near future. Their common goal? Revolutionizing data communications, and at the same time, reducing the world’s energy consumption. What will they be using? The answer will shock you. They’ll be using light emitting diodes - or as you might know them - LEDs. In the future, through using the visible light spectrum, communication will be possible. As a result, we could be saying goodbye to Wi-Fi.

Harald Haas is the Chief Scientific Officer of pureVLC Ltd. Back in 2011, he contributed to a TED Talk event where he hypothesized the future of data transmission through LEDs, that would eventually go on to replace Wi-Fi. He also demonstrated how the subtle changes in the dimness of a light could be fed into a small hole where a converter was receiving binary code via the subtle changes in the dimness of an off-the-shelf LED. What is the significance of this novel approach to data transmission?

“There will be a massive extension of the internet to close the digital divide. And also to allow for what we call the Internet of Things. Tens of billions of devices connected to the internet. In my view, such an extension of the internet can only work if it’s almost energy neutral,” Haas said, in his second TED Talk on the subject. “This is where the solar cell and the LED come in.”

We use LEDs in many different applications in the world today. We use it for our general home lighting, office lighting, even our street lights. Then we have them in display technologies as well; LCD and LED displays benefit from LED technology. Furthermore, intelligent transport systems (LTS) also use them. These would be your car’s headlights and taillights, including traffic lights. Therefore, with the number of LEDs integrated into our world, potential light fidelity (Li-Fi) communication points are - hypothetically - everywhere.

This will be possible with Visible Light Communication (VLC), an optical wireless communication system that would be powered by the modulation of light, the same light available in the visible spectrum. Using LEDs, a light emitting, energy-savvy technology, the fluctuations that would occur through the modulation of the light would be invisible to the human eye and will appear as a normal source of light. However, what the fluctuations would be doing is transferring data to a converter that would convert it to binary code.

Cisco believes that 50 billion devices will be connected to the internet by 2020, through the internet of things. Li-Fi could be an invaluable addition to the spectrum to facilitate these billions of devices that need to be connected and stay connected twenty-four hours a day. VLC will interconnect billions of home-based, business and industrial appliances to the internet of things, thus, thrusting the world into industrie 4.0. VLC has the potential to be a cost-effective wireless communication technology that has the ability to efficiently interconnect devices in a network, with unparalleled ease.

Haas points out that we have 10,000 times the spectrum capacity in the visible electromagnetic spectrum than we do in the radio frequency spectrum. Meaning, there is already infrastructure in place that could facilitate connectivity through LED technologies if light fidelity systems were to be built. Therefore, we could use the technology in many indoor and outdoor communications. One of the applications could improve indoor global positioning systems.

Mohsen Kavehrad and Weizhi Zhang write about the indoor possibilities in a Cambridge University published book named Visible Light Communication. They indicate that VLC would enable and perfect location sensing and management of products inside large warehouses. Li-Fi would also assist with the indoor navigation of a shopping mall or museum (or other large building) with industry-specific data being delivered to phones through Li-Fi. One of the more interesting developments in this technology is that the user might not even have to login with a network key - WiFi is synonymous for needing that input. These connections to smartphones and devices would be facilitated through the image sensors that are built into the devices, which make them perfect receivers for VLC.

Intelligent Transport Systems (ITS) applications are also possible thanks to the LED technology in vehicle headlights and tail lights. This could solidify inter-vehicular communication, car-to-road-infrastructure-communication at short to medium range. The lights in cars and the lights within traffic lights could all be data transmitters. This could increase road safety and could have even greater benefits in the future when self-driving cars take to the roads. The possibilities and benefits that VLC could introduce to the world are uncountable. Experts believe we will also see the medical world adopt VLC technology in hospitals, which would assist with making patient data available almost immediately whereas it would have followed a more delayed process in the past. In the aforementioned book, edited by Professor at the Department of Electrical and Computer Engineering at Ben-Gurion University (BGU) Israel, Shlomi Arnon, VLC technology could also be used for a “multi-sensory” and “multi-dimensional” experience in theme parks and entertainment venues.

How fast can it go? What is the data transfer rate? Image sensor applications could receive a data stream of up to 1.28 gigabits per second. Researchers at the King Abdullah University of Science and Technology (KAUST) claim to have reached 2 gigabits per second using a VLC color converter and laser technology. However, the current technology that allows high-rate VLC achieve between 96 to 500 megabits per second. The IEEE Standards Association has defined the new standard as IEEE 802.15.7 for Short-Range Wireless Optical Communication Using Visible Light.

It works by using a process known as, ‘inverse source coding’. The process would include taking light and turning it off and on quicker than the human eye is capable of seeing. As a result, a target converts the rapidly dimming light into 0’s and 1’s, which we all know as binary code. Haas says a light could be dimmed to the point where it is almost off but could still fluctuate dimming light, thus sending data to a receiver.

So, why VLC? Experts point firstly to the alleviation of electromagnetic fields prevalent in the world today. Congested radio-wave bands will become significantly more congested with the oncoming onslaught of internet-of-things applications wanting to be connected to the internet. VLC could reduce this number by almost one hundred percent. Secondly, light emitting diode technologies are energy efficient. Perfect for a world that desperately wants to cut down on the amount of energy needed to power devices that would be on and using power around the clock. VLC would use already available infrastructure that is already considered to be ‘green’. Thirdly, visible light is not harmful to humans and is inherently safe to use. And finally, in the words of Haas, it will ensure a “cleaner, greener, future.



Works Cited
"802.15.7-2011 - IEEE Standard for Local and Metropolitan Area Networks--Part 15.7: Short-Range Wireless Optical Communication Using Visible Light." IEEE SA

Arnon, Shlomi. Visible Light Communication. Print.

TEDtalksDirector. "Forget Wi-Fi. Meet the New Li-Fi Internet | Harald Haas | TED Talks." YouTube. YouTube, 02 Dec. 2015. Web.