French researcher Suat Topsu has come up with new communications technology which promises to revolutionise our digital life all over again. First there was wifi, now there’s lifi: light bulbs which also provide internet access.
Paris transport authority RATP is already planning to equip all the tunnels of the Paris metro with lifi by the end of 2020, making it the first such connected underground system in the world.
As well as providing a secure internet connection, lifi can also use audio messaging to help tourists and visually impaired people navigate the concourses and tunnels.
“It’s a good place to install it,” said The University of Versailles’ Professor Topsu, “because it is a confined space, the temperature is constant, and there’s no rain.”
All digital technology stores and transmits data (text, images, apps, programmes, videos, etc) as long strings of binary code, which is made up solely of the digits 0 and 1.
Wifi converts this binary code into radio waves for transmission, and then converts them back into binary code at reception.
‘Light-fidelity’, or lifi, is based on the fact that one characteristic of LED lightbulbs is that they flash on and off millions of times a second.
Professor Topsu has used this characteristic to develop a tiny electronic component that harnesses this flashing light to send and receive binary code without converting it. This means it can work up to 100 times faster than standard wifi.
“Lifi won’t replace wifi, it will just complete the offer,” said Professor Topsu, who is also president and founder of Oledcomm, a start-up company that intends to market and sell lifi products.
“At the moment, consumers need a dongle to be lifi-ready, but in the future the technology will be incorporated into our smartphones, tablets and laptops so they will automatically connect to the best network available, whether that is lifi, wifi or satellite.”
The network used will not make any difference to the performance of the device connected, he added. “All the big phone manufacturers know about lifi, and we are talking to them about making lifi-ready products.
‘‘First we have to install the network, and then the phone companies will follow.”
Lifi is cheaper than wifi because it uses existing infrastructure (such as lampposts), requires no extra energy, and does not even need special bulbs. The component that makes them able to transmit data is small and can be installed behind an ordinary LED bulb.
It is already being tested in Palaiseau (Essonne) where 77 street lights have been equipped with lifi components so residents can use their own dongles to go online wherever they happen to be in that area, including at home.
The range of potential applications is enormous: lifi supermarket trolleys, which know where everything is on the shelves, or a lifi-equipped museum which could use it to deliver a guided visit or a commentary about the exhibits. Hospitals could use it to transmit internal medical data and once towns are equipped with lifi networks, driverless cars will be able to communicate with their surroundings. The current challenge is to develop lifi and explore all possibilities.
Oledcomm won the contract to supply 66 metro stations and is also working with hospitals, museums, local authorities, and companies including EDF, SNCF, Paris Airport, Airbus, Thales and Peugeot to develop lifi experiments.
The Smart Lighting Alliance (SLA) association is a French collective working in the sector that aims to promote the benefits of smart lighting, as well as to ensure that lifi technology remains a French world leader and is not overtaken by similar inventions in other countries.