LiFi vs WiFi | Difference between LiFi and WiFi

This page compares LiFi vs WiFi describes basic difference between LiFi and WiFi technologies. It covers basics of LiFi vs WiFi including their features, working operation, merits, demerits, applications etc. in order to derive difference between Lifi and wifi.

Introduction:

Both LiFi and WiFi technologies are mainly used for internet based applications. LiFi uses light as medium for data communication where as WiFi uses Electromagnetic waves for data communication. LiFi is optical communication technology where as WiFi is radio communication technology. Let us understand them individually before we derive difference between them. LiFi stands for Light Fidelity and WiFi stands for Wireless Fidelity.

Following are the features of LiFi technology as depicted in the figure-1.
• LiFi (Light Fidelity) works based on VLC (Visible Light Communication) principle.
• LiFi transmits data using light intensity modulation.
• It uses LEDs at transmit ends and Photo-detectors at receive ends. LiFi dongle uses photo-detectors as shown in the figure-1. Here LEDs are connected with internet server via lamp driver for internet connection.
• It uses light with wavelength ranging from 380 nm to 780 nm for data communication between LEDs and photo detectors.
• LiFi system supports three modes viz. peer to peer, star and broadcast.
• LiFi system uses modulation schemes such as OOK, VPPM, CSK.
• The PHY and MAC layers of LiFi system are defined in IEEE 802.15.7-2011 standard.
• LiFi technology is used for various applications which include street lights, sign boards, internet etc. • It transfers data very rapidly and securely due LOS (Line of Sight) operation of optical signals.

WiFi Technology

Following are the features of WiFi technology as depicted in the figure-2.
• As shown WiFi AP (Access Point) or Router is connected with internet broadband cable or with cellular network. All the wifi compatible mobile phones, tablets or laptops are connected with AP (or router) to obtain internet.
• WiFi network operates in either of two modes viz. adhoc (i.e. BSS-Basic Service Set) and infrastructure (i.e. ESS-Extended Service Set).
• In BSS WLAN compliant stations (i.e. STAs) communicate directly. In ESS WLAN compliant STAs communicate with APs (Access Points) to access internet.
• WiFi supports different speeds and coverage ranges as per implemented standard in the devices (STAs, APs). 802.11a supports upto 54 Mbps, 11b upto 11 Mbps, 11n supports 72 Mbps/150 Mbps as per BW (20MHz/40MHz), 802.11ac wave-1 supports upto 1.3 Gbps (80MHz, 3 streams, 256QAM), 802.11ac wave-2 supports upto 3.5 Gbps (160MHz, 4 streams, 256QAM) etc. The distance coverage of 70 meters (indoor) to 250 meters (outdoor) can be achieved.
• WiFi network operates in different frequency bands viz. 2.4 GHz, 5 GHz.
• The PHY and MAC layers of WiFi system are defined in IEEE 802.11 standards. There are various versions of 802.11 which include 11a, 11b, 11g, 11n, 11ac etc.

Compare LiFi vs WiFi | Tabular difference between LiFi and WiFi

Following table compares LiFi vs WiFi and derives difference between LiFi and WiFi technologies with respect to various features.

Following table-2 mentions difference between VLC and Wifi wireless technologies. As we know LiFi technology is based on VLC principle. This will help reader to understand the difference between LiFi and WiFi in more detail.

Conclusion : From the above, we can compare LiFi vs WiFi and following difference between Lifi and wifi can be derived.
• LiFi technology is not replacement of widely used wifi technology. Both the technologies LiFi and WiFi co-exist together based on their respective unique features.
• LiFi operates between wavelengths in the range from 380 nm to 780 nm. WiFi operates at different frequency bands viz. 2.4 GHz and 5 GHz.
• LiFi is used to exchange data incredibly rapidly and securely at much lower power level compare to WiFi.