LiFi is a new form of wireless communication that uses light to transmit data. By sitting near a LiFi-enabled light source, such as a lamp, streetlight or LED television, devices can connect to the internet — no routers necessary.
LiFi Definition
LiFi, or light fidelity, is a wireless communication technology that transmits data through a modulating light source.
What Is LiFi?
LiFi, short for light fidelity, is a form of bidirectional wireless communication that uses visible light sources to send and receive data. Unlike WiFi, which transmits data by way of radio waves, LiFi modulates an LED bulb’s intensity in order to send information — literally transmitting data at the speed of light. Because of its higher frequency, light can transmit more information per trip, making it about one hundred times faster than WiFi.
LiFi technology is fast, cost-effective and can be easily integrated with pre-existing infrastructures. And, because light can’t travel through walls, it is inherently secure. LiFi is particularly useful in environments where radio frequencies are limited, such as at sea or underwater, or in high-density environments like hospitals, airplanes and heavily populated cities.
LiFi was first demonstrated by Harald Haas, a mobile communications professor at the University of Strathclyde, during a 2011 TEDGlobal conference. For now, this kind of data transmission is only possible through visible light. But these capabilities are expected to expand to ultraviolet and infrared wavelengths as the technology becomes more mainstream.
How Does LiFi Work?
LiFi converts light into data via rapid pulses. The light source (typically an LED bulb) primarily acts as a transmitter, flashing at a rate so fast — up to one million times per second — that it is undetectable to the eye. These flashes represent data in the form of a binary code, where bright lights correspond with a value of one and dim lights correspond with a value of zero. The process can be likened to another electrical pulse system, Morse code, which communicates using a dot-dash binary language.
On the receiving end, signals are captured by light detectors. These semiconductor sensors, either photodiodes already built into a device or USB-stick dongles, convert light pulses back into electrical currents, then decode an incoming stream of data into human-readable information, such as images, texts and videos.
Back and forth, these signals are sent bidirectionally between a transmitter and receiver, processing thousands of data streams in parallel all at once.
LiFi vs. WiFi: What’s the Difference?
The main distinction between WiFi and LiFi is the modes of data transfer they use: WiFi transmits data using radio waves, while LiFi uses visible light. This causes them to differ in speed, availability and coverage.
WiFi
- Medium: radio waves
- Speed: 11 to 300 megabytes per second on average; up to 9.6 gigabytes per second
- Bandwidth: 5 gigahertz
- Range: about 32 meters
LiFi
- Medium: light
- Speed: 10 gigabytes per second on average; up to 224 gigabytes per second
- Bandwidth: 200,000 gigahertz
- Range: about 10 meters
These days, one of the most common methods of wireless connection is WiFi, which is known for its versatility across devices and accessibility across wide coverage areas. But as LiFi continues to advance, it is expected to provide higher bandwidth, faster speeds and superior security at the flick of a switch.
“If you think about WiFi as a motorway that allows for four lanes of data traffic to travel, then LiFi offers up more than 9,500 lanes,” Mostafa Afgani, co-founder and chief technology officer at LiFi tech provider pureLiFi told Built In. “This is a massive allowance of new and unused bandwidth.”
What it won’t do, however, is replace WiFi altogether.
“It’s important to note that LiFi is additive to WiFi. They will work together to provide enhanced wireless connectivity,” Afgani said. In fact, the two technologies may eventually become interoperable, enabling seamless cross-device integration thanks to new global standards, namely the IEEE 802.
Advantages of LiFi
Relocating wireless communications to a new section of the electromagnetic spectrum, LiFi promises certain benefits compared to common methods, like WiFi and cellular networks.
Faster
Currently, WiFi speeds oscillate between 11 and 300 megabytes per second, compared to LiFi’s 10 gigabytes per second. Without even considering its theoretical top speed of 224 gigabytes per second, LiFi outperforms the communication standard one hundred-fold.
More Secure
Light can’t travel through walls. So when it is used for data transmission, the signal remains confined within the physical barriers of a room or building. This feature reduces the risk of eavesdropping and unauthorized interception.
More Reliable
Light also travels in straight lines, allowing for a more direct connection from transmitter to receiver. And LiFi isn’t competing with oversaturated radio waves on a congested spectrum because it is confined to a specific area, enabling a more focused and localized transmission path without interference.
More Bandwidth
The light spectrum is 10,000 times broader than the radio spectrum, allowing visual light communications to carry and transmit much larger amounts of data per second when compared to traditional methods like WiFi.
More Cost Effective
LiFi doesn’t require any additional hardware, installation or maintenance costs. Rather, it’s only a matter of swapping out a lightbulb or plugging in a new lamp. LiFi also turns off with the lights, which can help reduce energy costs and save on long-term operational expenses.
More Energy Efficient
LiFi embeds itself into existing energy-efficient LED lighting infrastructure, so no additional energy is required to transfer data beyond what is already used to light up a room. By leveraging a dual purpose between lighting and data transmission, it lowers overall energy consumption.
Disadvantages of LiFi
As with any newcomer technology, there are some setbacks. Here are some that have been identified so far:
Limited Range
Though light transmits data faster than radio waves, it has a much shorter range. To work, devices must be in contact with a LiFi-connected light, which only allows about 10 meters of coverage compared to WiFi’s 32 meters, according to LiFi.co.
Lighting Interference
While there may not be as much signal interference from other data transmissions, natural light peeking through a window and any other bright, ambient lighting in a room may actually interfere with LiFi frequencies. This collision may scatter LiFi-carrying photons, reducing the strength of a signal. Even so, LiFi sensors are primarily focused on the modulations of incoming and outgoing light sources, so any constant stream is likely to be ignored or managed by optical filters, Haas explained in his demonstration.
Niche Market
At the moment, there are only so many devices outfitted with built-in LiFi capabilities. In the meantime, existing tech can connect with LiFi systems via plug-and-play solutions, like USB dongle attachments and antennas that connect via baseband chips.
Why Is LiFi Important?
All wireless communication — including cell phone networks — rely on the same radio frequencies we’ve been using since upgrading from telegraph systems in the 1890s. But as more devices connect online, the demand for high-speed data transmission grows. Some estimates show a 60 percent jump in global data per year, with 20 times more data usage by 2030. The thing is, radio frequencies are a finite resource.
Emerging tech like LiFi can help relieve these overcrowded networks and prevent worst-case scenarios like a radio bandwidth-shortage known as a “spectrum crunch,” as warned by the United State’s Federal Communications Commission.
“WiFi is not well positioned to meet these demands,” according to Shaman Mohandas Bhat, a software engineer at telecommunications company Cisco, describing LiFi as a preferred alternative because of its untapped bandwidth and easy installation to existing light fixtures. “It’s a good complimentary technology that will reduce congestion across WiFi networks.”
New WiFi 7 standards, spectrum sharing, beamforming and the deployment of 5G networks are some ways in which wireless companies have worked with policymakers to better manage the radio frequency spectrum over the past decade. LiFi could be the next big thing that opens up tons of new data capacity, Alexander De Ridder, chief technology officer at AI-integration platform SmythOS, told Built In.
“Moving our most bandwidth-hungry tasks over to LiFi could help decompress clogged up Wi-Fi networks,” he said.
Keep in mind that it’s not just the number of devices that’s increasing, it’s also the volume of data being generated and consumed. On one account, the average American household had 17 internet-connected devices in 2023, according to market research group Parks Associates. Another research organization, Consumer Affairs, counted 21 devices.
“I wouldn't be surprised if 10 years from now, LiFi and WiFi are working hand-in-hand to deliver fast, reliable connections,” De Ridder added.
Frequently Asked Questions
What is LiFi?
LiFi stands for light fidelity, a wireless communication technology that transmits data using visible light, typically LED lightbulbs.
Who invented LiFi?
Harald Haas, a professor of mobile communications at the University of Strathclyde, first coined the term “LiFi” and demonstrated the wireless technology in 2011 on the TEDGlobal stage. Haas, nicknamed “the father of LiFi,” now heads the university’s LiFi Research and Development Centre and has since co-founded visible light communications company pureLiFi.
How does LiFi work?
LiFi transmits data by rapidly pulsing light undetectable to the human eye. These flickers represent data in the form of a binary code, with bright lights as ones and dimmed lights as zeros. Light-detecting receivers then capture these signals, convert them into electrical currents and translate the data into readable formats. Typically, these systems use LED light bulbs outfitted with specialized chips that help send, receive and process information.
Is LiFi better than WiFi?
It depends. LiFi is one hundred times faster and has more bandwidth than WiFi. It also offers better security, more reliable connectivity and low interference at an affordable price. But LiFi can only reach about one third of WiFi’s range and is not as versatile as the current industry standard.
Is LiFi available?
Yes; LiFi products, including plug-and-play starter kits, are currently on the market.
