Light Fidelity or Li-Fi is a wireless communication technology that uses visible light for the wireless transmission of data. It is also sometimes called or categorized under visible light communication and optical communication technologies. Existing operational concepts and experimental concepts involve the use of light-emitting diode or LED lamps. Several concepts have also explored using infrared or ultraviolet radiation. The purported advantages of Li-Fi have positioned it as an alternative to existing Wi-Fi and WLAN technologies.
Pros of Li-Fi: Advantages and Notable Characteristics
1. Faster Data Transmission Than Wi-Fi
A defining advantage of Li-Fi is that it has a higher bandwidth and faster data transmission rate than Wi-Fi. Take note that the visible light spectrum has a bandwidth that is 10000 times larger than the entire radio wave and microwave spectrums. This higher bandwidth comes from the fact that light waves propagate at higher frequencies than radio waves and microwaves. This means that a particular wave of the visible light spectrum can transmit more data.
Researchers Y. S. Hussein and A. C. Annan noted that the expected download rate of Li-Fi is 100 Gbps. Wi-Fi standards such as the Wi-Fi 6 or Wi-Fi 6E and the newer Wi-Fi 7 have a theoretical download speed of 2.5 Gbps but real-world conditions put actual download speeds between 100 Mbps and 200 Mbps. Data transfer rates are dependent on distance and interferences. Li-Fi is seen as a solution to the bandwidth limitations of Wi-Fi.
2. Simple and Inexpensive Deployments
The current operational concepts and experimental applications of Li-Fi technology center on the use of light-emitting diode or LED lamps. This means that a Li-Fi network can be integrated readily with existing lighting systems. Hence, wherever there is a light source, there can be access to the local area network or the internet. LED lamps are also easier and have become inexpensive to produce while their market price has become more affordable.
Several researchers and analysts have predicted that the deployment of this technology would be ten times cheaper than Wi-Fi. It is also important to note that LED lamps are power efficient and have lower power draw than incandescent lamps and fluorescent lamps. A particular LED lamp equipped for Li-Fi must remain turned on to be operational but it can be dimmed below the visible levels for human comfort and to cut down power consumption further.
3. Security Due to the Limitations of Light
Another notable selling point and advantage of Li-Fi is that it is more secure than Wi-Fi. Take note that wireless communication technologies based on radio waves and microwaves are more vulnerable to eavesdropping, unauthorized signal interception, brute force attacks, and unsolicited network connections. This comes from the fact that these forms of electromagnetic radiation can travel further and can go through physical obstructions.
Light waves have a shorter range and cannot penetrate through concrete and wooden walls. This renders the emitted light-based signals of a Li-Fi router hard to intercept and interrupt. The same is true for infrared light and ultraviolet radiation. This means that the signals emitted by a Li-Fi router as pulses of light and the data it transmits and receives remain confined within a closed area such as a room or hall. Access to the network is also limited.
4. Electromagnetic Interferences Resistance
Li-Fi is also less susceptible to the impacts of electromagnetic interferences or EMI that affect wireless communication technologies based on radio waves and microwaves. Electromagnetic fields do not disrupt electromagnetic radiation with higher frequencies such as visible light waves. This is similar to the advantage of fiber optics over electric transmission and optical computing or photonic computing over silicon computing.
Furthermore, unlike radio waves and microwaves, visible light does not produce electromagnetic interference. These advantages make Li-Fi technology suitable in areas with high sources of EMI or specific situations that are electromagnetic sensitive such as aircraft cabins, hospitals, and nuclear power plants. It is also worth mentioning that some medical instruments and radar and communication systems are sensitive to radio frequencies.
5. Expansive and Innovative Future Applications
Improving wireless communication is another advantage of Li-Fi. It can support high-speed internet services and data-demanding applications such as cloud computing. The fact that it offers faster data transfer rates means that it can advance the deployment of the Internet of Things or IoT and the use of smart or interconnected devices. These two technologies require massive data and effective and efficient network connections.
One of the more specific foreseeable applications of Li-Fi centers on residential and building automation. Experts have also conceptualized traffic applications such as the use of street and traffic lights to provide information about current road situations, and the headlights and backlights of vehicles to communicate and automate safety measures. Some have noted that the technology is compatible and suitable for underwater communication.
Cons of Li-Fi: Disadvantages and Principal Limitations
1. Shorter Range and Limited Connectivity
The limitations of the visible light spectrum as an electromagnetic radiation provide Li-Fi with a more secure connection advantage over Wi-Fi. These limitations also translate to disadvantages. Remember that the data transmitted by a Li-Fi product remains confined within an enclosed space because light cannot penetrate opaque objects and has a shorter range. The signals from a particular Wi-Fi router can go through walls and propagate farther.
For example, in establishments such as houses or buildings, several LED lamps equipped to send and receive data must be placed in rooms, halls, and other sections to expand the coverage of the network. A single Wi-Fi router is enough in average-sized spaces because it has a wider coverage and its signals can go through walls. These limitations of Li-Fi make it unsuitable for use in establishments with a lot of dividers or in public area networks.
2. Unavailability of Compatible Technologies
Another disadvantage of Li-Fi centers on the fact that it will take several years and a market disruption before it becomes more practical than Wi-Fi. Most consumer electronic devices such as laptops, smartphones, and wearables still use hardware for Wi-Fi networking. These devices are not equipped to interface with a Li-Fi transceiver or router because of the absence of relevant hardware components. The technology is not backward compatible.
It is also worth mentioning that the faster data transfer rate of this technology remains negligible or insignificant until internet speed from internet service providers improves. To be specific, in countries notorious for having slow internet speeds, a Li-Fi network would be meaningless. It will take coordination from relevant companies from various industries and sectors to promote and expand the acceptance and adoption of this technology.
3. Light Interference and Light Pollution
The technology might not be susceptible to electromagnetic interference but it is susceptible to the impacts of light interferences. It is possible that other light sources can interfere with the signals coming from and going into a particular Li-Fi router or transceiver. Even sunlight can interfere with the operations of an entire Li-FI network because harsh light renders the receiver component struggling to process pulses of light as signals.
In addition, because enabled LED lamps must remain turned on, the use of these devices can contribute further to light pollution. A particular enabled lamp can be dimmed below the visible level. However, with less intense light, this device becomes more susceptible to interference from brighter sources of light. The workaround is to use this LED lamp at a more adequate level of brightness to compensate for possible interference with other light sources.
4. Potential Cost and End-Use Price Implications
Remember that this technology is theoretically more affordable to implement than Wi-Fi because of the inexpensive cost and less complex processes associated with the production of LED lamps. However, for the simplest reason that the technology is still new and the demand remains low, the installation cost can still be a bit more expensive. It is also important to factor in the costs of upgrading to an entire system that supports a Li-Fi network.
The fact that a single home needs several Li-Fi routers and transceivers to expand the scope of the network coverage and make the internet connection as accessible as possible also marks additional purchases and installation costs. It is important to reiterate the fact that a single Wi-Fi router is more than enough for most average-sized homes. There is also a need to replace older consumer electronic devices that do not support Li-Fi interfacing.
Rundown: Advantages and Disadvantages of Li-Fi
Li-Fi is a promising wireless communication technology with several distinct advantages over Wi-Fi. It has higher bandwidth and faster data transmission speed. Furthermore, its simple and cost-effective deployment using LED lighting systems makes it accessible. It is secure and it is resistant to electromagnetic interferences. However, in considering the limitations and notable disadvantages of Li-Fi, it is important to underscore the fact the Wi-Fi standard will continue to remain dominant in wireless local area networking. It will take several years and an effective market disruption before Li-Fi becomes more accessible and available.
FURTHER READINGS AND REFERENCES
- Gheng Tuck, Y. and Chee Yong, L. 2019. “Low Cost Light Fidelity Li-Fi System Employing On-Off Keying Data Modulation in Half-Duplex Asynchronous Transmission Mode.” IOP Conference Series: Earth and Environmental Science. 268(1): 012015. DOI: 1088/1755-1315/268/1/012015
- Pradhan, J., Kappala, V. K., and Das, S. K. 2020. “Performance Analysis of a Li-Fi System under Ambient Light Conditions.” 2020 National Conference on Communications. DOI: 1109/ncc48643.2020.9056061
- Hussein, Y. S. and Annan, A. C. 2019. “Li-Fi Technology: High Data Transmission Securely.” Journal of Physics: Conference Series. 1228(1): 012069. DOI: 1088/1742-6596/1228/1/012069