Li-Fi: Connect to the Internet using an LED bulb

Imagine an LED bulb doubling up as an access point for connecting to the internet and ordinary light being used as a medium to carry data.

A whole new world wherein a bulb would not only give us light but also help us access the web might not be too far way, if a new technology called Li-Fi (or Light-Fidelity) goes mainstream.

Prof Harald Haas of the University of Edinburgh, who coined the term Li-Fi in 2011, demonstrated the new technology to a packed auditorium at the Wipro’s Electronics City campus on Wednesday. He streamed a video from the internet on a laptop using light from an LED bulb to access the web.

Prof Haas said Li-Fi is a disruptive technology that could transform business models, create new opportunities, and is poised to be a $113 billion industry by 2022.

He said that the RF (radio frequency) spectrum will not be enough considering the rate of growth of wireless data communication. The visible light spectrum is much larger. The use of the light spectrum for Li-Fi overcomes the issues in traditional wireless communication, like the shortage of spectrum and network disruption because of interference.

In Li-Fi, anyone who has access to light can access the internet. The system also allows users to move from one light source to another without losing their network connection. What about connecting to the internet in the night? The stream of photos can be reduced to a minimal level that won’t produce visible light but enough to carry data.

Prof Haas said though Li-Fi was poised to compete with Wi-Fi, it is not meant to replace it. “We are not looking at an either-or situation.”

Though the inability of light rays to pass through walls and similar structures is seen as a major drawback of this technology, Prof Haas has a totally different view. He said it’s an advantage since restriction by walls provides more security to the network and eliminates the risk of the signal leakage to eavesdropping.

The Li-Flame, described as the world's first true Li-Fi system, was displayed at the Mobile World Congress in Barcelona in March last year. The third generation of products have now been developed and will be on display at the MWC later this month.

WHAT IS LI-FI

Light-Fidelity is a new technology that uses light waves, instead of radio frequency waves, as a medium to carry data. An improvised LED bulb functions as a router

HOW DOES LI-FI WORK

• An ordinary off-the-shelf LED bulb connected to an device, which in turn is connected to the internet.

• Internet data flows in via the device into the bulb, and is carried by light waves.
• At the other end, light waves carrying internet data falls on a receiver or a dongle which is connected to the computer.

BENEFITS OF Li-Fi

• Visible light spectrum is available in plenty, unlicensed and free to use.
• Double benefit of a bulb giving us light as well as internet access
• Low interference leads to very high data speed
• Li-Fi works under water as well
• Not harmful, unlike RF that can interfere with electronic circuitry
• Light won’t pass through walls, making eavesdropping nearly impossible
• LED illumination is already efficient and data transmission needs very little additional power.
• It can achieve about 1,000 times data density of Wi-Fi, since light can be contained in an area

PROGRESS CARD

• July 2011: Prof Harald Haas coins Li-Fi at TEDGlobal
• Jan 2012: PureLifi founded
• Sept 2013: Launch of first product Li-1st
• Dec 2014: Second product Li-Flame developed
• Nov 2015: Prof Haas demonstrates Li-Fi using solar cells at TEDGlobal
• Dec 2015: Latest product LiFi-X developed

(Originally published in The Hindu, February 19, 2016)