When Thomas Edison invented the electric lightbulb, he could hardly have imagined that one day his creation would be used not only to illuminate homes around the world, but also to transmit data that would enable people to download information from satellites in space to small hand-held devices. However, with the introduction of Li-Fi, household lighting could soon double as a form of data transmission that’s up to 100 times faster than Wi-Fi.
Li-Fi, which was first invented by Harold Haas of the University of Edinburgh in 2011, uses visible light communication (VLC) to send data at extremely high speeds. Essentially, this works like an incredibly fast signal lamp, flashing on and off in order to relay messages in binary code (1s and 0s). In previous lab-based experiments, the technology was able to transmit up to 224 gigabits per second. To put this in perspective, Wi-Fi is capable of reaching speeds of around 600 megabits per second.
The technology has now been deployed in real-life situations for the first time, thanks to the work of Estonian start-up Velmenni, which has begun trialling Li-Fi in offices and other industrial settings in Tallinn. In these environments, they were able to achieve connection speeds of around one gigabit per second.
Aside from its superior speed, Li-Fi also boasts a number of other benefits over Wi-Fi. For instance, the fact that the signal is carried by optical light means that it cannot travel through walls, therefore enhancing the security of local networks. Obviously, this produces a number of limitations as well, since it suggests that connection will be lost if a user leaves the room, representing a major hurdle that must be overcome if the technology is to be successfully implemented. However, if this barrier can be surmounted, then the use of the visible spectrum could allow Li-Fi to send messages across a much wider range of frequencies than Wi-Fi, which operates between the frequencies of 2.4 gigahertz and 5 gigahertz.
As such, it has been suggested that Li-Fi could provide the answer to increasing frequency congestion as Internet usage continues to rise across the world. According to the Cisco Visual Networking Index Global Mobile Data Traffic Forecast, global monthly data usage is expected to exceed 24.3 exabytes by 2019 – a volume which current wireless connections are not able to handle.
In a recent TED talk, Haas insisted that household LED lightbulbs could easily be converted into Li-Fi transmitters, providing Internet users with more efficient connections. “All we need to do is fit a small microchip to every potential illumination device and this would then combine two basic functionalities: illumination and wireless data transmission,” he said. It is also worth mentioning that the speed at which these LEDs flicker in order to relay data is too fast for the human eye to perceive, so users will not have to worry about annoying flashes in their ambient light.
Image credit: Illustration showing how Li-Fi could be operated in an office setting, with data being transmitted by ambient LED lights using visible light communication. Boston University
While it remains to be seen if Li-Fi can feasibly be implemented across the world, VLC is already finding a number of useful applications. For instance, Disney is currently developing a number of products that use the technology, including a range of toys such as a magic wand that can activate lightbulbs on a princess dress.