Li-Fi: The Next Generation of Wireless Broadband Internet

This whole article might sound like science fiction for the best part, yet, it is fast becoming a reality. Li-Fi, or Light Fidelity, is a form of broadband to receive broadband from your light bulbs. After you have done the double take, let us move on.

Li-Fi is still a niche market, with its core still in academia and technology evaluation. At one time, estimated CAGR of this market was around 82%, becoming worth $1 billion by 2018. It has not panned out the way it should have, but it is gaining traction.

What is Li-Fi?

First, let me first run a refresher on what wireless communication is at its core. Earlier, I discussed frequencies and wavelengths a lot In my article on 5G. To continue in the same vein, all communication follows a technique called modulation. A modulated wave looks something like this. In essence, it looks like as though the data has been "imprinted" on the waves.

There are various types on modulation. Firstly, there were amplitude modulation, or AM, and frequency modulation, or FM in use. Next, two were new types, phase modulation and amplitude and phase modulation.

All the communication systems modulate and demodulate radio waves. Basically, the radio waves are "imprinted" with the data with the help of a circuit called a modulator. After that, when someone receives the signal, there is a circuit called demodulator to "read" the data imprinted on the waves. Together, this forms the basis of every communication system. However, this description is really very basic and is for the layperson to understand how basic communication works.

Li-Fi will use the same basic principles, just with the waves that we can actually see with our eyes. Moreover, this type will use no connectors, no cables and will rely on the visibility of the source and the receiver of the signal. That means that its range can be anywhere between a few meters to a few hundred meters. However, everything is still very much in the academia and research at the moment.

How will Li-Fi Work?

Infrared and UV rays are the most likely candidates for Li-Fi as we already have experience with these waves. However, Professor Harald Haas, one of the pioneers of Li-Fi and the Chair of Department of Mobile Telephony at University of Edinburgh, envisioned a lighting system which serves two purposes. First, these modules would serve as lighting solution for homes. Second, these LED bulbs will provide high-speed broadband for users.

A typical Li-Fi module will look more or less like a light bulb.

https://www.researchgate.net/profile/Volker_Jungnickel" align="aligncenter" width="383"> View of two tabletop modules under the narrow (c. Ø 20 cm) "single working space" optical spot (2018). On the laptop screen the corresponding up-and downlink data rates (Mbit/s) can be observed.

The Visible Light Communication devices are simple LED lamps which switches the current at high frequencies to transmit data. However, this rapid switches do not show any flickering as it is too fast for humans to pick up. These LED lamps can also be dimmed below human visibility to just provide data as well, emitting just enough light to carry the data. Unlike Wi-Fi, Li-Fi can't penetrate walls but that can be very, very useful, as discussed further on. That does not mean its performance dips; signals reflected off of literal walls have achieved speeds up to 70 Mbps.

Admittedly, this is just a concise view of the process. Naturally the complete process is out of the scope of this article.

Benefits of Li-Fi

Li-Fi can be a game changer in terms of reliability, bandwidth availability, cheapness, security and versatility.

• Bandwidth Availability: The US Federal Communications Commission noted that the current situation is headed to a "spectrum crisis". Wi-Fi in its current form is close to full capacity in terms of spectrum. Fortunately, visible light spectrum is 10,000 times bigger than that of radio waves. Consequently, there will be lesser risk of shortage of frequencies to operate on.
• Reliability: Li-Fi's range is limited to one room, that is, the room in which the source is. That is because visible light can't penetrate walls. However, that does not mean that a person has to be in direct line of sight of the source. Even the light reflected from walls carries significant data. For example, in one experiment the Li-Fi signal reflected off a wall was able to deliver up to 70 Mbps. Therefore, it is highly stable.
• Cheapness: The operation of Li-Fi is highly energy efficient and cheap. However, the high installation costs is one of the major bottlenecks in this technology. It is also efficient in the sense that light used for Li-Fi can also be used for indoor and outdoor lighting.
• Security: Visible Light Communication has an Achilles' Heal, and that is its short range. However, it is also its greatest strength in the sense that the network is perfectly safe from any attacks from the outside. A hacker has to be inside the room where the "router" is, otherwise they can't do anything. This can be a breakthrough in cybersecurity and towards making safer networks.
• Versatility: Li-Fi does not interfere with other sensitive instruments such as ones used in aircrafts, the military and in hospitals. The lack of electromagnetic interference is what makes it so versatile and with widespread applicability.

Applications of Li-Fi

There are a number of key applications which could define the lifestyle of people across the world.

1. Home and Building Automation: Li-Fi technology can prove to be a very effective, reliable and secure method of home automation. So far, attempts at home automation are limited because of the low speeds of broadband and fears of hacking and spying. With Li-Fi, the speeds are mind-blowing and the network can be limited as much as a user likes. For example, by covering the windows and other transparent surfaces, one can limit the network to just their home, providing excellent security.
2. Industrial Automation: Just as with Home Automation, production lines can use the same technology to automate. It also helps save costs and space; without wires, cables and all, it can prove to be very useful in a tight environment such as a production line.  Fraunhofer IPMS developed a component which is very appropriate for industrial applications with time sensitive data transmission.
3. Air Transportation: Li-Fi does not interfere with radio waves. That can allow airliners to come fitted with networking using VLC Devices.
4. Medical Sector and Hospitals: Apart from the blistering speed with which vital data can be transmitted within parts of a hospital, the non-interfering nature of Li-Fi allows for better networking in areas such as ICUs and MRI rooms.
5. Traffic: Vehicles can communicate with each other using Li-Fi via their front and rear lights. Other potential use will be better traffic control and automated vehicles.

The list just goes on.

When is Li-Fi Coming, then?

Not soon. As I've emphasized, it is still a work in progress. But, it is looking extremely likely that this tech will be commonplace by the end of this decade. Li-Fi is the obvious step forward and with the current lack of spectrum, it is all the more crucial. We can only speculate right now, but some companies such as pureLiFi and others have made big strides forward in this direction. All that remains to be seen is when exactly Li-Fi comes out of academia and research into commercialization.