RFLiFi vs WiFi: Key Differences and Comparison
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Li-Fi (Light Fidelity) and Wi-Fi (Wireless Fidelity) are wireless technologies that use different mediums and technologies to offer wireless data communication. LiFi uses optical light signals emitted by LED light bulbs, whereas WiFi uses electro-magnetic waves at radio frequency emitted by routers or Access Points.
Let’s compare LiFi vs WiFi with respect to speed, coverage, security, and working principle, including their respective advantages and disadvantages, in order to highlight the differences between them in the table below.
LiFi vs WiFi: A Comparison
| Comparison Parameters | LiFi | WiFi |
|---|---|---|
| Working principle | Dongles consisting of photo detectors are used as receiver and LEDs are used as transmitter. | Clients or stations (mobile phones, laptops etc.) are used by users where as network consists of routers or access points. |
| Transport medium | Visible light is used as transport medium for data communication. | Radio frequency waves are used as transport medium for data communication. |
| Operating frequency band | Uses infrared and visible light spectrums between 400 THz and 800 THz. This corresponds to 375 nm and 780 nm | 2.4 GHz, 5 GHz and 6 GHz |
| Bandwidth | Unlimited bandwidth | Limited Bandwidths supported by various standards 20 MHz, 40, 80, 160 MHz and Up to 320 MHz |
| Speed | 1 Gbps (Velmenni startup conducted demo), about 40 Gbps (pureLiFi company showcased prototypes and conducted demos) | Different wifi standards support different speeds, WiFi-6 (11ax) supports 600.4 Mbps (with 80 MHz, 1 SS) and 9.6078 Gbps (with 160 MHz, 8 SS). WiFi-7 (11be) supports higher than wifi-6 |
| Coverage range | About 1 to 10 meters (approximately 3 to 33 feet) from light source | various with different wifi standards, WiFi-6 supports up to around 35 meters (~ 115 feet) indoors and up to 120 meters (~ 390 feet) outdoors. |
| Physical Obstruction | Impeded by physical obstacles such as walls | Can penetrate through some physical obstacles such as walls which helps to provide connectivity beyond line-of-sight (LOS) |
| Privacy | Pivacy is not a concern. LiFi uses light waves to transmit data, it offers inherent physical security benefits due to the limited range and line-of-sight (LOS) requirements. Moreover it is blocked by walls. | Privacy is a big concern, EM (Electro-Magnetic) waves used by wifi are easy to be tapped due to its wide coverage and Non LOS range. Morover radio frequency waves are not blocked by walls but can be attenuated. |
| Security algorithms | Uses TLS and other encryption protocols at data link layer and higher layers | WiFi uses WPA2 and WPA3 latest standards for security protocols |
| Data density improvement techniques | Use of multiple LiFi transmitters and spatial reuse techniques are employed to achieve improvement in data density. Data density refers to the amount of data that can be transmitted within a given area. | Latest wifi standard (802.11ax) uses MU-MIMO to achieve enhancement in data density. |
| Electromagnetic (EM) Interference immunity | Immune to electromagnetic interference | It is not immune but susceptible to EM interference from other devices operating in same frequency bands. |
| Interference with devices | Does not interfere with sensitive electronic equipments | May cause interference with certain devices like medical equipments or othwe wireless technology based devices. |
| Availability | Less common, it is still an emerging technology. | Ubiquitous, widely available in most public places and private environments |
| Energy consumption | Usually consumes less energy compared to wifi | May consume more energy especially in high data transmission scenarios |
| Infrastructure Cost | Higher initial setup costs due to specialized LED lighting systems and specific installation setup requirements | Relatively lower initial setup costs as it requires low cost wifi routers or access points |
| Mobility support | Limited mobility due to line-of-sight requirements. | Offers greater mobility within coverage area of RF signals |
| Health concerns | As light is non-ionizing it is considered safe for human health | Some studies raised concerns on health issues due to RF radiation |
| LOS requirement | Requires clear Line-of-Sight (LOS) between light transmitter (i.e. source) and receivers (i.e. detectors) | Works effectively without direct line-of-sight between devices (viz. routers and clients) |
| Typical applications | Ideal for secure and high speed data transmission in specific environments such as hospitals, industrial setups etc. | Suitable for wireless connectivity in various settings such as homes, offices, public spots, railway stations etc. |
| Standard references | IEEE 802.15.7 | IEEE 802.11 series of standards which include 802.11a/11b/11g/11n/11ac/11ax/11be etc. |
| Invented by | LiFi technology was invented by Prof. Harald Haas at the University of Edinburgh, Scotland. In a TED Global talk in 2011, Prof. Haas introduced the concept of LiFi. | WiFi technology was invented by a team of researchers and engineers at IEEE in the 1990s. The first version of IEEE 802.11 standard was released in 1997. |
Conclusion
Li-Fi (Light Fidelity ) and Wi-Fi (Wireless Fidelity) are two distinct wireless technologies that complement each other, each offering unique strengths and use cases. While WiFi provides wide-area wireless connectivity, LiFi excels in situations where security, high-speed data transmission and immunity to RF interference are crucial.
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