Li-Fi: What is it, and its advantages and drawbacks?

Li-Fi, or light fidelity, can transmit data up to 100 times faster than Wi-Fi

In the near future, Singaporeans may be able to gain very fast Internet access by just switching on the lights in their home, instead of turning on their Wi-Fi router.

This technology, known as Li-Fi, uses light to transmit high-speed data instead of radio waves like in Wi-Fi.

The technology is poised to take off in Singapore over the next few years, with the Government already taking an interest in it.

At the CommunicAsia 2016 technology show last week, the Infocomm Development Authority of Singapore (IDA) highlighted Li-Fi - short for light fidelity - as one of the potential future technologies the Government is looking into.

"It could complement today's wireless technologies and potentially change the way we communicate," said an IDA spokesman.

The technology has already caught the eye of companies here, including telco StarHub, which are exploring its potential applications.

Mr Burchardt showing how Li-Fi works. The pureLiFi chief operating officer says Li-Fi will most likely complement Wi-Fi rather than replace it but his company still has its sights set high.
Mr Burchardt showing how Li-Fi works. The pureLiFi chief operating officer says Li-Fi will most likely complement Wi-Fi rather than replace it but his company still has its sights set high. PHOTO: AZIZ HUSSIN FOR THE STRAITS TIMES

A StarHub spokesman told The Straits Times that "even though Li-Fi is in its early stages, we have been monitoring and evaluating this emerging technology with (Li-Fi research firm) pureLiFi".

Li-Fi works by sending data through the flickering of light in an LED bulb billions of times per second - so fast that the human eye does not even notice the flickering.

Each flicker corresponds to binary data - the 1s and 0s computers read - and a receiver attached to the computer converts this flickering back into data.

The biggest advantage of this technology is speed - blazing fast data transmission speeds up to 100 times that of Wi-Fi.

This means even faster Internet speeds, for instance.

It has already hit speeds of 224Gbps in the laboratory, while tests under real-life conditions have reached up to 1Gbps, a leap from average Wi-Fi speeds of between 300Mbps and 720Mbps.

Li-Fi could also find widespread adoption in aircraft, as Li-Fi signals do not interfere with radio waves that pilots use to communicate.

The concept of Li-Fi was pioneered in Britain in 2011, by University of Edinburgh professor Harald Haas, who is now the chief scientific officer at pureLiFi, a firm which has already released several commercial Li-Fi products.

Singapore is an ideal location to test such technology, said Associate Professor Biplab Sikdar from the National University of Singapore (NUS), because of its high Internet penetration rate.

"The best thing going for Singapore is its existing optical fibre network that connects virtually every home and office in the country," said Prof Biplab.

"To fully exploit the potential of the high speeds offered by Li-Fi, you need a network backbone that is capable of handling high data rates," he said.

However, he added, there are some challenges and limitations to Li-Fi that could prevent it from being a global standard like Wi-Fi.

Internet access is limited to the area where the light shines.

A device has to be within the line of sight of the light source, unlike Wi-Fi which can penetrate most walls.

However, this can be a security advantage, said Prof Biplab, who teaches at NUS' engineering faculty in the electrical and computer engineering department.

"If you want security, someone outside a room cannot listen to your conversation," he said.

Computers or mobile devices will also need to be fitted with sensors that can read the light signals and convert them into data. The sensors are currently about the size of a smartphone and thus not very convenient for mobile users.

Cost is also another factor. As each LED bulb requires a module attached to it to convert incoming data into flickers, it could be expensive to retrofit whole buildings with such equipment.

"It's much easier to cover a large area with Wi-Fi, and with less equipment," said Prof Biplab.

Li-Fi will most likely complement Wi-Fi rather than replace it, pureLiFi chief operating officer Harald Burchardt told The Straits Times. But the company still has its sights set high.

"pureLiFi has very ambitious timelines regarding the incorporation of Li-Fi modules into smart devices such as mobile phones, which will see Li-Fi sit alongside Wi-Fi as a ubiquitous communications technology," said Mr Burchardt.

A version of this article appeared in the print edition of The Straits Times on June 08, 2016, with the headline 'Imagine Internet access at the speed of light'. Print Edition | Subscribe