- Light-fidelity (LiFi) is a technology used for free-space communication using visible and near-visible light.
- It is similar to Wireless Fidelity (WiFi), a technology for wireless local area network communication using microwaves.
- Microwaves can pass through walls while transmitting signals whereas visible and near-visible light cannot pass through walls.
- Thus it makes LiFi signal network more secure.
- Scientists have recently added a new layer of security to LiFi.
- Light bounces off from walls and falls on the receiver.
- So wall boundaries can be used effectively for reflecting signals so that communication is maintained even without line-of-sight communication between the signal source and receiver.
- Receiving detectors can receive both direct and reflected signals.
- Walls painted with fluorescent and phosphorescent paints absorb and then emit light with marginal loss.
- The paints continue to emit light even several hours after the original source of light has been switched off.
- This makes the communication signal more effective and secure.
Basic Difference between LiFi and WiFi:
| COMPARISON | LI-FI | WI-FI |
| Full form | stand for light fidelity | stands for wireless fidelity |
| Invented/Coined | Coined by Prof. Harald Haas in 2011 | By NCR corporation on 1991 |
| Operation | it transmits data using light by the help of LED bulbs | it transmits data using radio waves using wifi router |
| Technology | Present IrDA compliant devices | WLAN 802.11/b/g/n/ac/d standard compliant devices |
| Data Transfer Speed | About 1 Gbps | Ranges from 150Mbps to maximum of 2Gbps |
| Privacy | light is blocked by the walls hence provide more secure data transfer | walls cannot block radio waves so we need to employ more techniques to achieve secure data transfer |
| Frequency of operation | 10, 000 times frequency spectrum of the radio | 2.4Ghz, 4.9Ghz and 5Ghz |
| Coverage Distance | about 10 meters | about 32 meters(vary based on transmit power and antenna type) |
| Data density | work with high dense environment | work in less dense environment due to interference related issues |
| Bare minimum Components used | LED bulb, LED driver and photo detector | Routers, Modems and access points |
| Applications | Used in airlines, undersea exploration etc | Used for internet browsing with the help of wifi hotspot |
