Li-Fi wireless communication moves from niche to industry use

It may not be as revolutionary as Edison’s bulb, but it promises to shine with brighter, faster, and ultra-low-latency connectivity than the lanterns before it. Li-Fi—or Light Fidelity—is light-driven connectivity that uses the power of light for data transmission. In a world dominated by Wi-Fi, this technology presents an intriguing alternative for illuminating specific connectivity needs.

By harnessing the expansive, unlicensed light spectrum for data transfer, Light Communication (LC) offers a compelling and sustainable response to the growing demand on traditional radio-frequency (RF) networks, explains Marc Fleschen, Chairman of the Light Communication Alliance.

The concept originated in Optical Wireless Communication, where unguided visible, infrared, or ultraviolet light is used to carry a signal. This broad field includes two key technologies.

The first is Visible Light Communication (VLC), which transmits signals within the visible spectrum (380–700 nm) using light-emitting diodes (LEDs). VLC works like Morse code, rapidly switching LEDs on and off at frequencies imperceptible to the human eye. The speed of these oscillations enables vast amounts of data to move in fractions of a second.

Li-Fi operates by encoding data in modulated light waves emitted from LEDs. When information is transmitted, the LED’s brightness oscillates at ultra-high frequencies—far beyond human visual perception. These light pulses represent binary codes of 1s and 0s, which a photodetector at the receiving end captures and demodulates back into electronic data. In essence, Li-Fi is light’s own Morse code, turning illumination into information.

As a high-speed, bidirectional, mobile communication system, Li-Fi provides additional capacity for surging downlink demand, complementing both wired and wireless networks.

Another branch is Free-Space Optical (FSO) communication—a point-to-point system usually deployed outdoors that eliminates the need for cabling in backhaul networks. This makes FSO ideal for short-range and indoor applications where traditional cabling is cumbersome or expensive.

Why Li-Fi Stands Out from Wi-Fi

With LEDs, light bulbs emit rapid light pulses instead of radio waves. These pulses, packed with information, allow Li-Fi to communicate at remarkable speeds with receivers that decode this optical Morse code. Some players claim that Li-Fi can be up to 100 times faster than Wi-Fi, offering ‘lightning-fast’ (pun intended) transfer rates due to the vast bandwidth available in the light spectrum.

Unlike Wi-Fi, light waves can even penetrate water and operate effectively in dense or enclosed environments—an advantage for submarines, industrial environments, hospitals, and classrooms. Li-Fi is also less susceptible to interference and hacking. Since light cannot cross walls, light-bound data can be confined to controlled areas, enhancing privacy and network security.

Li-Fi can coexist seamlessly with conventional connectivity such as Wi-Fi and 5G while mitigating electromagnetic interference—critical in hospitals, aircraft, and industrial plants. Because it uses non-ionising radiation, it is considered safe for human exposure, addressing health concerns often associated with prolonged RF exposure. “Li-Fi has been tested rigorously, even on aircraft in mid-air, and proven 100 per cent safe,” assures Fleschen.

Trials have demonstrated potential transmission rates exceeding 224 Gbps, elbowing out WiGig in sheer speed. “The physical confinement of data within a room offers a unique layer of security that Wi-Fi cannot match,” Fleschen explains. “This transforms a perceived limitation into a strategic advantage for high-security or sensitive environments. Li-Fi is not a replacement for Wi-Fi but a specialised, high-value solution for targeted applications such as Fixed Wireless Access.”

Fleschen notes that LC offers unmatched benefits in data speed, military-grade security, immunity to electromagnetic interference, and spectrum efficiency. “Laboratory demonstrations have shown access points aggregating 2 Tbps using Vertical Cavity Surface Emitting Lasers in a Multiple Input Multiple Output configuration with energy consumption below 2 watts—achieving energy efficiency close to 1 pJ/bit, which meets 6G requirements,” he says.

The unregulated visible and infrared spectrum enables reuse without interference, offering an immense, untapped bandwidth that alleviates the spectrum crunch of traditional wireless networks.

Beyond Speed: Unlocking New Potential

Proponents argue that Li-Fi can address the limitations of Wi-Fi and cellular networks—spectrum congestion, security vulnerabilities, and inconsistent user experiences—while reducing infrastructure complexity and power use. It is particularly suitable for environments where radio frequencies are prohibited, restricted, or unreliable, such as hospitals, aircraft, schools, and defence sites.

The potential bandwidth of 360 terahertz (360,000 GHz) is more than 10,000 times wider than the radio portion of the spectrum, enabling exceptionally high data rates in unlicensed frequencies. This also helps offload Wi-Fi traffic in congested wireless LANs. Applications could range from residential broadband to in-flight connectivity, where every seat already has a built-in light source above.

Li-Fi also enhances localisation and asset tracking thanks to its small coverage area. Its higher data density (data rate per unit area) outperforms RF, making it ideal for precise asset monitoring or indoor navigation.

However, Fleschen emphasises that LC and Wi-Fi are fundamentally complementary, not competitive. “The strategic objective is not to replace Wi-Fi but to create a more robust, secure, and versatile communication ecosystem by integrating LC where its unique strengths provide optimal value,” he says.

India’s Li-Fi Opportunity Takes Shape

India’s rapidly expanding digital infrastructure provides fertile ground for experimenting with light-based communication. The government’s focus on 5G, smart cities, and digital inclusion is also stimulating interest in emerging wireless alternatives that can extend broadband to areas where RF networks are either congested or impractical.

Several pilot projects are exploring Li-Fi for classrooms, rural health centres, and underground facilities where fibre or Wi-Fi coverage is limited. The technology’s immunity to electromagnetic interference and ability to confine data within a physical boundary make it particularly suited to defence, aviation, and healthcare environments.

Experts note that Li-Fi’s high data density and spatial reuse could help address India’s persistent last-mile and indoor-coverage gaps. By combining Li-Fi with optical-fibre backbones and 5G networks, service providers could deliver low-latency broadband to high-density zones—without additional spectrum-licensing costs.

However, the path to adoption remains steep. Industry leaders point out that Li-Fi needs strong policy support, cost-effective components, and standardised integration into Wi-Fi ecosystems before it can scale. Still, India’s optical-fibre footprint, semiconductor push, and Make in India initiatives may create a conducive environment for local Li-Fi manufacturing and R&D over the next few years.

Trials That Lit the Way Forward

Li-Fi first captured global attention when Prof Harald Haas, Chair of Mobile Communications at the University of Edinburgh, coined the term during his TED talk in 2011. His company went on to launch the first commercial Li-Fi systems at MWC Barcelona in 2014. Since then, adoption has been fragmented but steadily expanding.

In the UK, mobile operator O2 conducted a pilot with pureLiFi, installing nine Li-Fi-enabled LED bulbs in its Slough headquarters. The system allowed data to be transmitted via light, creating a bi-directional, high-speed, fully networked communication setup simply by modulating bulb brightness.

In Spain, ADIF, the state-owned railway infrastructure manager, trialled Li-Fi at Málaga’s María Zambrano station to complement 5G, where Wi-Fi signals typically degrade.

In the Netherlands, the Dutch armed forces explored Li-Fi through KIXS (part of JIVC) in collaboration with TNO and Trulifi by Signify. For military operations in remote locations where traditional networks face logistical constraints, Li-Fi offered a compelling alternative. It was tested for secure rooms, ammunition bunkers, and Fast Field Data Links, where a broadband link across runways was established in ten minutes, delivering 50 Mbps—without any cables.

Because Li-Fi uses only a light beam, it meets aviation-safety regulations and cannot be intercepted, jammed, or tracked beyond the light cone. “As Li-Fi works via light and does not cause radio interference, we have proved its great value for the Dutch armed forces,” said Lt Col Harm de Jong, senior officer at KIXS. “The next step is to integrate Li-Fi into our IT standards and processes.”

For defence use, Li-Fi can be installed in tents or field posts using simple fixtures and accessed securely with USB keys, offering a quick, cable-free solution to mission-critical communication needs.

Challenges on the Horizon

Despite the optimism, Li-Fi is not yet a mainstream technology. Its ecosystem, standards, and cost structure still need consolidation before widespread adoption. Wi-Fi, equipped with powerful antennas and higher transmit power, still offers superior range.

According to the Light Communication Alliance Annual Report 2022, Li-Fi standards need both pace and ecosystem coordination for smooth growth. The initial Draft 1.0 of the IEEE 802.11bb specification was submitted to the working group for approval, defining the LC spectrum from 800 nm to 1,000 nm to ensure interoperability between systems. It also proposed that all 802.11bb devices reuse existing 802.11 PHY modes and chipsets—a design choice expected to accelerate adoption by leveraging the Wi-Fi supply chain.

The standard, officially ratified in June 2023, marked a pivotal moment for the industry. Fleschen calls it a “monumental achievement” that strategically positions Li-Fi as a complementary and integrated technology alongside Wi-Fi. “For the first time, Li-Fi solutions can exist inside the Wi-Fi ecosystem, enabling seamless coexistence and interoperability with existing wireless infrastructures,” he says.

Still, challenges remain. “Li-Fi requires a clear line of sight between transmitter and receiver,” Fleschen adds. “Physical obstructions such as walls will block light signals. While this restricts coverage, it is also Li-Fi’s greatest security and interference-immunity advantage.”

Ecosystem readiness, standardisation, and cost of hardware—particularly laser-based transmitters—remain hurdles that manufacturers and regulators must address collaboratively.

Even as Li-Fi moves toward maturity, research continues to push boundaries in optical communication. Innovations such as ultrasonic beams from 3D-printed metasurfaces are being tested to create localised sound pockets—inaudible to bystanders but useful for secure speech zones or personalised audio in vehicles and public spaces.

Similarly, metasurfaces using nanomaterials can now split a single light beam into multiple directions, offering a glimpse of how next-generation optical systems might evolve. These developments indicate that the future of communication may extend beyond Li-Fi, towards hybrid optical–acoustic models.

Drawing an analogy from history, when Edison’s bulb brightened the world, it was not his alone—Joseph Swan had lit the way earlier, and tungsten filaments later transformed the bulb’s efficiency. Likewise, Li-Fi may only be at its bamboo stage, awaiting its own ‘tungsten moment’ to propel it into everyday use.

Li-Fi represents more than just another connectivity technology. It symbolises a paradigm shift—moving communication literally into the light. It holds immense promise for niche environments where security, bandwidth, and electromagnetic compatibility matter most.

While Wi-Fi and cellular networks will continue to dominate mainstream connectivity, Li-Fi’s specialised strengths—speed, safety, and spectrum freedom—make it a critical complement in the evolution towards 6G and beyond.

It may not yet be the light sabre that slays Wi-Fi, but it is certainly the next bulb in the series—shining a little brighter, faster, and smarter each time. And perhaps, like Edison’s spark, it will illuminate not just our rooms but the very future of connectivity.