Transmission using light has been around for some time, in remote controls on TVs, for example. Since then, many labs have been working on ways to get a greater amount of information more quickly and efficiently transmitted. In 2011, Geman Harald Haas, a professor at University of Edinburg, coined the term Li-Fi, aiming at a proposal in which each lamp becomes an internet access hotspot.
For the system to work, the LED lamp will transmit the signal, making small swings in its light (in nano seonds, totally imperceptible), and will need a device that has a specific receiver for this, a light sensor that interpret his signal. “None of our current cell phones have this” says Thiago Ribeiro Claro, coordinator of the degree in Technology for Internet Systems at the Senac University Center.
Unlike Wi-Fi, which uses radio signals for transmission, with a current limit of 867 Megabits per second, the Li-Fi works with non-visible light reaching mich higher speeds. “As the technology is very new, several searches, looking for the best way to transmit data are occurring. Until last year the speed record was 10Gbps, which would already be much faster than Wi-Fi”, explains the coordinator. “This year, Oxford researches were able to transmit data at 224 gigabits per second. This would allow 18 movies to be downloaded in 1 second. It is dificult to predict what the speed of yhis technology will be when it becomes a commercial product available, because that still depends on the standards that will be adopted, but it will certainly be much faster than Wi-Fi”, says the expert.
Another advantage of Li-Fi lies in the security of data transmission, because the light does not cross walls, making it dificult for intruders to access. In addition, with the lamps sending signals to the cell phone inside a closed environment, it is possible to know precisely its positioning. “For example, a supermarket with Li-Fi may offer an app where you search for a product and the app displays an accurate map indicating how to get to the correct shelf. Malls, airports and major events can also enjoy this”, says Thiago Claro.
For now, Li-Fi only works well indoors. According to the coordinator, Li-Fi technology would be best used if it were to complement Wi-Fi. “In a company that replaces Wi-Fi with Li-Fi, the phone would be completely disconnected from the network if it was placed in a pocket or drawer”, he explains.
Although promissing, this technology is still in research. There is, therefore, a long way to go before it can be adopted as a standard by the market.