Wireless connectivity: Light waves deliver security RF cannot

What makes Light Fidelity (Li-Fi) the next big contender in connectivity? Is it the use of lasers, access to an unregulated light spectrum, EMI immunity, wall-level privacy, freedom from spectrum scarcity, or the absence of interference?

The answer is all this and more—though challenges remain around indoor obstructions, LED infrastructure, and hardware requirements. At the centre of this conversation is the Light Communication Alliance (LCA), which brings together the largest Li-Fi manufacturers and industry partners.

In an exclusive interaction with Voice&Data, LCA Chairman Marc Fleschen shares his perspectives on Li-Fi’s current status, the questions still to be addressed, and how the LCA is shaping the technology’s future. Excerpts:

How would you define Light Communication for a non-technical audience?

Light Communication (LC), encompassing technologies such as Li-Fi and Optical Camera Communication, represents a profound shift in connectivity. By harnessing the expansive, unlicensed light spectrum for data transmission, LC offers a sustainable solution to the pressures on traditional radio frequency (RF) networks. It addresses spectrum scarcity, inherent security vulnerabilities, and increasing ICT energy consumption.

How does Li-Fi compare with Wi-Fi and existing wireless systems?

LC offers advantages in data speed, military-grade security, immunity to electromagnetic interference (EMI), and spectrum efficiency. The objective is not to replace Wi-Fi but to complement it—deploying LC where its unique strengths provide maximum value. Together, they form heterogeneous, converged networks with better performance, stronger security, and higher sustainability.

What improvements does Li-Fi bring in terms of speed and bandwidth?

Li-Fi can deliver several gigabits per second for commercial applications. Laboratory demonstrations have shown access points aggregating 2 Terabits per second (Tbps) using Vertical Surface Emitting Lasers (VCSELs) in a Multiple Input Multiple Output (MIMO) configuration, with energy consumption under 2 Watts. That translates to energy efficiency close to 1 pJ/bit—a requirement of 6G. This throughput is enabled by lasers and the reusability of the visible and infrared spectrum, unlike the congested and licensed RF spectrum.

Far from replacing Wi-Fi, Li-Fi complements it—offering secure, high-speed links indoors while RF networks provide mobility and broader coverage.

What advantages does Li-Fi offer in terms of security and privacy?

A standout feature of Li-Fi is physical-layer security. Light waves do not penetrate walls, so signals are confined within a room or defined space. This makes interception extremely difficult and is often described as ‘military-grade security’. What some see as a limitation actually makes Li-Fi ideal for high-security or sensitive applications, including Fixed Wireless Access (FWA) configurations.

What are the enterprise use cases and latency benefits?

Li-Fi is designed to integrate with the Internet of Things, enabling advanced Industry 4.0 use cases. It supports massive device connectivity, ultra-low latency, and secure machine-to-machine communications. This makes it well-suited for industrial control, mission-critical processes, gaming, or video conferencing—applications where responsiveness and reliability are non-negotiable.

How does Li-Fi contribute to sustainability goals?

It promises significant reductions in energy consumption, directly contributing to CO2 emission reduction targets and supporting the transition to a greener digital future.

What are the main limitations or barriers to adoption?

The first challenge is line of sight. Walls or obstructions block signals, which limits pervasive coverage but simultaneously enhances security and interference immunity.

Second, environmental factors play a role. Outdoors, Free-Space Optical Communication (FSO) can be disrupted by fog, rain, or dust. Indoors, strong ambient light can affect signals, though modern systems adapt well.

Finally, infrastructure is key. Adoption requires Li-Fi-enabled LEDs or VCSEL lighting and compatible hardware at the device end. Unlike Wi-Fi, which is ubiquitous, Li-Fi will need careful rollout of compatible equipment.

From Industry 4.0 to gaming, Li-Fi’s ultra-low latency and energy efficiency enable responsive, sustainable, and secure next-generation applications.

How do Li-Fi and Wi-Fi complement each other in practice?

Wi-Fi offers broad mobility and shared resources, while Li-Fi delivers secure, high-speed, dedicated links in confined spaces. Combined, they ensure seamless coverage. Wi-Fi can provide surface-level connectivity and mobility, while Li-Fi supports FWA and in-building density. This complementarity will shape new network architectures.

What is the strategic perspective of the Light Communication Alliance?

The long-term potential of Light Communication Technology (LCT) lies in convergence. It is not about one technology dominating, but about combining wired and wireless optics for end-to-end sustainable solutions. Wired optics deliver stability and capacity, while wireless optics provide flexible, secure access. Together, they optimise performance, reduce energy use, and adapt to diverse vertical markets.

How will Li-Fi co-exist with 5G and 6G networks?

Li-Fi and 5G/6G together create robust networks that combine RF with visible light or infrared (IR). In Industry 4.0, Li-Fi FWA supports secure, high-rate machine communications, while 5G/6G ensure mobility and broader coverage. This synergy creates holistic, future-ready infrastructures.

What role do channel models, reflecting surfaces, and infrared play in Li-Fi development?

Channel models are essential for network optimisation. They combine line-of-sight and non-line-of-sight scenarios to plan deployments. Optical Intelligent Reflecting Surfaces (IRSs), such as metasurfaces, can redirect light waves to extend coverage, reduce error rates, and improve link reliability indoors.

Infra-red (IR) is also key. Li-Fi uses both visible light (350–700 nm) and IR (800–1000 nm). Typically, IR supports upstream traffic, while visible or IR serves downstream. VCSEL-based IR sources are energy efficient and particularly useful in environments dominated by ambient light.

What is the mandate of the LCA, and how critical are its industry members?

The Light Communication Alliance is a global community of industry leaders, researchers, and innovators committed to advancing light communication. Collaboration is critical because no single player can build this ecosystem alone.

Major telecom players like Nokia and Liberty Global bring strong industry validation. Their work in 5G, 6G, and O-RAN strengthens the case for Li-Fi, while their involvement in the LCA ensures alignment with global standards. Their presence provides the weight needed for interoperability and large-scale deployment.

How is Li-Fi being standardised, and what progress has been made?

Standardisation is pivotal. The IEEE 802.11bb standard, ratified in June 2023, marks a breakthrough. It positions Li-Fi as a complementary technology within the Wi-Fi ecosystem, ensuring interoperability with existing wireless infrastructures.

The standard covers both the physical and medium access control layers for operation over the infrared band (800–1000 nm). It supports bidirectional data transfer from 10 Mb/s to 9.6 Gb/s and ensures compatibility across solid-state light sources with varying bandwidths.

This framework paves the way for mass adoption. By integrating optical antennas into devices alongside Wi-Fi protocols, 802.11bb attracts interest from semiconductor firms and handset manufacturers. Once chipsets are embedded in consumer devices, Li-Fi will move from pilots to widespread deployment.