What is Li-Fi?
Light Fidelity or Li-Fi is a Visible Light Communications (VLC) system running wireless communications travelling at very high speeds.
Li-Fi uses common household LED (light emitting diodes) lightbulbs to enable data transfer, boasting speeds of up to 224 gigabits per second.
The term Li-Fi was coined by University of Edinburgh Professor Harald Haas during a TED Talk in 2011. Haas envisioned light bulbs that could act as wireless routers.
Li-Fi vs Wi-Fi
While some may think that Li-Fi with its 224 gigabits per second leaves Wi-Fi in the dust, Li-Fi's exclusive use of visible light could halt a mass uptake.
Li-Fi signals cannot pass through walls, so in order to enjoy full connectivity, capable LED bulbs will need to be placed throughout the home. Not to mention, Li-Fi requires the lightbulb is on at all times to provide connectivity, meaning that the lights will need to be on during the day.
What's more, where there is a lack of lightbulbs, there is a lack of Li-Fi internet so Li-Fi does take a hit when it comes to public Wi-Fi networks.
In an announcement yesterday, an extension of standard Wi-Fi is coming and it's called Wi-Fi HaLow.
This new project claims to double the range of connectivity while using less power. Due to this, Wi-Fi HaLow is reportedly perfect for battery powered devices such as smartwatches, smartphones and lends itself to Internet of Things devices such as sensors and smart applications.
But it's not all doom and gloom! Due to its impressive speeds, Li-Fi could make a huge impact on the internet of things too, with data transferred at much higher levels with even more devices able to connect to one another. (See also: What is the Internet of Things?)
What's more, due to its shorter range, Li-Fi is more secure than Wi-Fi and it's reported that embedded light beams reflected off a surface could still achieve 70 megabits per second.
Differences with Wi-Fi
Li-Fi can be considered as a light-based Wi-Fi. It uses light instead of radio waves to transmit information.
Li-Fi is transmission of data using illumination i.e. sending data through an LED lamp that varies intensity of light faster than what human eye can perceive.
Instead of Wi-Fi modems, Li-Fi would use transceiver-fitted LED lamps that can light a room as well as transmit and receive information.
Wi Fi is great for general wireless coverage within building and Li-Fi is ideal for high density wireless date coverage in confined area and for relieving radio interference issues.
So the two technologies can be considered complimentary.
Here are few Pros and Cons of Li-Fi;
Advantage & Disadvantage
Li-Fi can solve problems related to the insufficiency of radio frequency bandwidth because this technology uses Visible light spectrum that has still not been greatly utilized.
High data transmission rates of up to 10Gbps can be achieved.
Since light cannot penetrate walls, it provides privacy and security that Wi-Fi cannot.
Li-Fi has low implementation and maintenance costs.
Can be used in RF restricted environments where EM waves are restricted.
By not using radio and serving same use case, it eases out interference and congestion of highly occupied radio bands i.e. ISM band used popularly in WPAN technologies.
Light can't pass through objects.
A major challenge Li-Fi is facing; how the receiving device will transmit back to transmitter.
Interference from external light sources like sun, light, normal bulbs, opaque materials.
Line of Sight requirement, so area coverage is limited and indoor mostly.