LiFi vs GiFi: Key Differences and Comparison

This article breaks down the core differences between LiFi (Light Fidelity) and GiFi (Gigabit Wireless) technologies.

LiFi Technology

LiFi, short for Light Fidelity, leverages Visible Light Communication (VLC) principles for data transmission.

Figure 1: Li-Fi internet architecture

Here’s a rundown of LiFi’s key features:

• VLC-Based: LiFi operates based on VLC (Visible Light Communication).
• Light Intensity Modulation: It transmits data by modulating the intensity of light.
• LEDs and Photo-detectors: LiFi systems use LEDs at the transmitting end and photo-detectors at the receiving end. As illustrated in Figure 1, the LiFi dongle contains photo-detectors. LEDs are connected to an internet server via a lamp driver for seamless internet connectivity.
• Wavelength: LiFi utilizes light with wavelengths ranging from 380 nm to 780 nm for data communication between LEDs and photo-detectors.
• Network Topologies: LiFi supports peer-to-peer, star, and broadcast network configurations.
• Modulation Schemes: LiFi employs modulation schemes such as OOK (On-Off Keying), VPPM (Variable Pulse Position Modulation), and CSK (Color Shift Keying).
• Standardization: The PHY (Physical) and MAC (Medium Access Control) layers of a LiFi system are defined in the IEEE 802.15.7-2011 standard.
• Applications: LiFi finds applications in streetlights, signboards, and internet access, among others.
• Security: Data transfer is rapid and secure due to the Line of Sight (LOS) nature of optical signals.

GiFi Technology

GiFi stands for Gigabit Wireless, a technology focused on high-speed wireless data transfer.

Here’s a look at the key aspects of GiFi:

• Single-Chip Transceiver: GiFi utilizes a single-chip transceiver developed using CMOS (Complementary Metal-Oxide-Semiconductor) process.
• 60 GHz Operation: It operates at 60 GHz, utilizing the unlicensed band from 57 to 64 GHz.
• High-Speed Data Transfer: GiFi enables wireless transfer of audio/video at speeds up to 5 Gbps within a 10-meter range, with very low power consumption.
• Development: It was developed by NICTA (National Information and Communication Technology Research Center) in Australia.
• Architecture: The main component of a GiFi architecture is a subscriber station, which interfaces with multiple APs (Access Points).
• Standardization: GiFi is defined in the IEEE 802.15.3C standard, forming a wireless PAN (Personal Area Network) in the millimeter-wave frequency band.
• LOS Communication: Antennas are typically mounted on roofs to support Line-of-Sight (LOS) communication.
• TDD/FDD Support: GiFi uses TDD (Time Division Duplexing) topology for transmission and reception with a single antenna and can also support FDD (Frequency Division Duplexing) topology using two antennas.
• Advantages:
  • Offers very high data rates (up to 7 Gbps with BPSK modulation).
  • Low interference.
  • Simple modulation schemes.
  • Requires an antenna separation of only 1.25 mm.
  • Approximately ten times faster than WiFi.
• Disadvantages:
  • Short-range: Limited to about 10 meters due to high signal attenuation at 60 GHz.
  • Susceptible to Obstruction: Can be easily blocked by objects.
  • No RTS/CTS: Unlike WiFi, GiFi does not use RTS/CTS (Request to Send/Clear to Send) mechanism.

LiFi vs GiFi: Comparison Table

The following table highlights the key differences between LiFi and GiFi: