Nowadays, more and more technologies are working for our world. Only in the network area, we can find Wi-Fi, WiGig and Li-Fi.
We have discussed WiGig before, and today we’d like to discuss new topic:
What is Li-Fi technology?
Light Fidelity or Li-Fi is a Visible Light Communications (VLC) system running wireless communications travelling at very high speeds.
How does Li-Fi work?
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.
What the Advantages does Li-Fi have?
This technology means that you can connect the wireless internet if you has LED. Now there are about 14 billion LEDs in the world. In short, almost each street lamp can be a access point.
Besides, Li-Fi not only extends the scope of wireless network, but also delivers bigger bandwidth. Wi-Fi uses radio-frequency signal but the radio-frequency spectrum becomes less and less because the needs of wireless network customers become more and more.
For example, we connect the wireless network in a cafe. We will find the speed becomes slow when many customers are surfing in the internet by Wi-Fi.
Haas said that, the spectral visible light is ten thousand times than radio-frequency spectrum. Li-Fi may deliver us up to 1 Gbps data transfer speed.
Haas believes that his technology has an important advantage, that we’re no longer need to deploy any new infrastructure. He said, “we use the existing equipment. The visible light spectrum have not been used, are not regulated, we can carry out high-speed communication.”
What the Disadvantages does Li-Fi have?
Although Li-Fi can work without radio signal interference, but it still has disadvantage because of the following facts: visible light cannot penetrate walls. This kind of visibility limit to improve the system security, but it is unclear whether the minimum distance of reception.
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. It costs more electric energy.
Li-Fi vs. Wi-Fi
Li-Fi and Wi-Fi are quite similar as both transmit data electromagnetically. However, Wi-Fi uses radio waves while Li-Fi runs on visible light.
Li-Fi is faster than Wi-Fi. It claims to be 100 times faster than standard Wi-Fi.
Visible light cannot penetrate walls. This kind of visibility limit to improve the system security.
However, Li-Fi needs ubiquitous LEDs to offer the signal, while Wi-Fi doesn’t need them. We can connect Wi-FI whenever and wherever we are. After all, we can’t make our LEDs be on every second.
This table shows the comparison between Li-Fi and Wi-Fi.
ParametersLight Fidelity (Li-Fi)Wireless Fidelity (Wi-Fi)Speed for data transferFaster transfer speed (>1 Gbps)Data transfer speed (150 Mbps)Medium through which data transfer occursUsed light as a carrierUsed Radio spectrumSpectrum RangeVisible Light spectrum has 10, 000 time broad spectrum in comparison to radio frequency.Radio frequency spectrum range is less than visible light spectrum.CostCheaper than Wi-Fi because free band doesn’t need license and it uses light.Expensive in comparison to Li-Fi because it uses radio spectrum.Network topologyPoint to pointPoint to pointOperating frequencyHundreds of Tera Hz2.4 GHz
Li-Fi still has its future.
In November 2014, Li-Fi pioneers pureLiFi joined forces with French lighting company Lucibel aiming to bring out Li-Fi enables products, by the end of 2015.
pureLiFi already have two products on the market: Li-Flame Ceiling Unit to connect to an LED light fixture and Li-Flame Desktop Unit which connects to a device via USB, both aiming to provide light and connectivity in one device.
Li-Fi can’t replace Wi-Fi, but they can be partners. We can use Wi-Fi when we’re on the street and use Li-Fi when we’re at home.
