Terminology » Other Wireless » VLC vs LiFi: Key Differences and Comparison

VLC vs LiFi: Key Differences and Comparison

vlc lifi wireless communication data transmission light fidelity

Visible Light Communication (VLC) and Light Fidelity (LiFi) are two innovative technologies leveraging light for wireless data transmission. While VLC concentrates on communication within the visible light spectrum, LiFi expands upon this by incorporating other light frequencies, like infrared and ultraviolet, potentially delivering faster speeds and a wider range of applications.

This article delves into the key distinctions between VLC and LiFi, providing clarity on how these technologies are shaping the future of wireless communication.

How LiFi Builds on VLC

Li-Fi internet architecture

LiFi technology is built upon the principles of VLC (Visible Light Communication) but offers more advanced capabilities. Here are some key features that differentiate LiFi from VLC:

  • LiFi is based on VLC principles, using light waves for data transmission, but it extends beyond visible light, incorporating infrared and ultraviolet spectrums as well.

  • LiFi transmits data using light intensity modulation, just like VLC, but LiFi achieves much higher data speeds—up to 1 Gbps in standard tests and 40 Gbps in some experiments using infrared.

  • LiFi uses LEDs at the transmitter end and photo-detectors at the receiver end, while VLC is restricted to visible light communication. In LiFi systems, a lamp driver connects LEDs to the internet server, enabling high-speed internet through light.

  • LiFi operates within the 400 THz to 800 THz range of the light spectrum for visible light but can also use non-visible frequencies, unlike VLC.

  • LiFi supports multiple network configurations, including peer-to-peer, star, and broadcast modes.

  • Modulation schemes like OOK (On-Off Keying), VPPM (Variable Pulse Position Modulation), and CSK (Color Shift Keying) are used in both technologies, but LiFi can operate more efficiently at higher frequencies.

  • LiFi is standardized under IEEE 802.15.7, defining its physical and MAC layers, enabling widespread adoption for applications such as street lighting, internet access, and digital signage.

  • A key advantage of LiFi is its Line of Sight (LOS) operation, which makes it faster and more secure than traditional wireless methods, while VLC remains more limited in its scope.

EM spectrum showing VLC, Infrared parts

Difference Between VLC and LiFi Technologies

FeatureVLC (Visible Light Communication)LiFi (Light Fidelity)
Spectrum UsedVisible LightVisible, Infrared, and UV Light
Data SpeedModerate (up to 1 Gbps in lab tests)Higher (up to 40 Gbps in tests using infrared light)
Primary ApplicationCommunication via visible light onlyHigh-speed internet, secure communication, broader scope
IEEE StandardNo specific single standardIEEE 802.15.7 standard for PHY and MAC layers
Network ConfigurationsPrimarily point-to-pointPeer-to-peer, star, broadcast
SecurityLimited to visible light transmissionEnhanced security with Line of Sight (LOS) communication

Key Differences Summarized

Here’s a quick recap of the major differences between VLC and LiFi:

  • LiFi vs VLC in Spectrum: LiFi can use both visible and non-visible spectrums (infrared, UV), whereas VLC is confined to the visible light spectrum.

  • Speed: LiFi has achieved much higher data transmission speeds, reaching up to 40 Gbps in tests, while VLC speeds remain lower.

  • Applications: Both have unique applications, but LiFi’s broader spectrum capabilities give it an edge for high-speed internet and more secure data transmission.

Conclusion

Both VLC and LiFi represent the future of wireless communication, but their differences lie in spectrum usage, data transmission speeds, and application scope. VLC is primarily limited to visible light, while LiFi leverages additional light spectra to offer faster and more secure connections.

As LiFi continues to evolve, it is likely to play an increasingly significant role in high-speed data transmission, offering advantages over traditional wireless technologies. Understanding the difference between VLC and LiFi helps in choosing the right technology for specific communication needs.