In the coming decades one of the key technologies to be implemented in intelligent buildings will be LiFi, the transfer of data through light
Just imagine: you get back home one evening, unlocking your door with the torch light of your mobile. You sit down on your sofa, download a film 100 times faster than currently possible and enjoy the movie on a fully secure wireless connection. This is already possible in some smart buildings, and could be the norm in the future, thanks to LiFi – or Light Fidelity.
But what is LiFi? The term was coined by Harald Haas, professor of Mobile Communications at the University of Edinburgh, and co-founder of research company pureLiFi. At his 2011 TED Global Talk he introduced the idea of “wireless data from every light bulb”. It is just as simple as that: using visible light – namely LED bulbs – instead of radio waves to transmit data. A kind of technology which, in time, might solve a number of problems. Among them is capacity as radio waves are limited, and security because they pass through walls and can be used by ill-intentioned people.
All these issues – and more – were addressed at the first Global LiFi Congress, which couldn’t have taken place anywhere else but in the “city of lights”, Paris. LiFi integration in smart buildings was at the heart of the event. According to figures given at the congress, the annual growth of the technology is set to reach 80% by 2023, and the LiFi market, which amounted to 0.5 billion dollars in 2016, is expected to reach 75 billion dollars by 2023. It looks like we are on the verge of a huge revolution in our homes.
Dr. Geoff Archenhold from Integrated Systems Technologies has no doubt in this sense. He predicts that “for the next 15-20 years the two technologies will co-exist. The cost of LiFi will potentially be lower than WiFi once large players in the telecoms and electronics industry undertake miniaturisation and integration steps. However, it is clear LiFi will take a huge market advantage. The world record for LiFi data transmission is over 224Gbps, and radio frequency technologies will never achieve such transmission rates.” Moreover, even if the effects of the electromagnetic emissions are still under investigation, for Dr. Archenhold health issues will also play a big role in switching from WiFi to LiFi.
In addition to data transmission via the Internet, indoor positioning where the GPS doesn’t work and the use of light for fire alarms are just some of the future applications possible. As Emmanuel François, president of the French organisation Smart Building Alliance, put it, “LiFi is not just lighting”. And of course it will help solve the big challenge of the century: lower energy consumption.
But shouldn’t a system based on electric lighting be more energy-consuming than traditional WiFi? On the contrary, affirms François: firstly, LiFi runs on LED lighting, which is far more efficient than incandescent lighting; secondly, it illuminates just the workstation, excluding the areas not needed.
But there is another, more relevant point that François makes concerning energy savings: LiFi will push telecoms companies to implement faster infrastructure for data transmission. The fastest technology currently under development is Power over Ethernet, or PoE, which allows a single cable to provide both a data connection and electric power. PoE is a DC power cabling system, so “we can imagine that tomorrow’s buildings will be supplied in direct current, while today they use alternating current. Switching to DC, without an AC adapter, means 25% in energy savings.”
But of course there are challenges ahead. The biggest has to do with standardisation. Dr. Archenhold explains: “Several LiFi solutions on the market have very limited compatibility with traditional LED luminaires and therefore the LED driver/power electronics need to be enhanced.”
“Another big barrier is the integration of LiFi technologies directly into mobile devices. Once the users no longer need to insert any dongles, they will experience a huge improvement in quality of service, security and convenience and will treat LiFi just like WiFi,” he concludes.