What is lifi?
There is a lot to do about wireless communication. We notice it in our blogs; how often something is read about 5G or WiFi . Questions are often asked about all that radiation, whether it is harmful and whether it is all safe. That is why I want to tell you something about a possible alternative, or perhaps an addition to radio signals: lifi.
Phone off
There are places where a transmitter interferes. Where you should not have your phone on. You then put it in airplane mode, for example in the airplane or hospital. Or at another place where sensitive equipment is located. These devices can become obsolete because of your phone. But they are places where wireless communication is very useful. That is a problem, but fortunately: there is a solution for this and it is called lifi.
Via lights
No, not a sweetie, but lifi. That is a technique that does not use antennas, but lights. And we all know lights that can turn on and off very quickly: the LED. The word lifi comes from wifi, our wireless internet – but with light.
Safe flicker
Someone came up with the smart idea to use lamps. Our eyes can see the blinking of a lamp, until it blinks very quickly and then it looks as if it gives an even light. By doing the fast flashing, faster or slightly slower, it is possible to send data. The light from a lamp does not affect an electrical device. So it does not disturb anything on an airplane or in a hospital. In the office it can also have advantages, because it cannot pass through a wall. Wifi can go through the wall. Around us we see a lot of other Wi-Fi networks in the area. Here at home I see 30 passing by and more at our office.
How does lifi work?
Computers talk to each other in ones and zeros, you may already know that. You can write a letter in a block of eight ones and zeros in a row. In the computer or on a wire you use a clock and put tension on a wire. Without the clock you never know what a zero would be, namely if there is no voltage on the wire. And without the clock you don’t know when two ones will come in a row. With WiFi you also have a bit of that clock, that is the basic wave that passes through the air. With WiFi, this can be about 2.4 GHz or about 5 GHz (billion vibrations per second). A so-called channel in your modem shifts that basic wave or clock signal slightly back and forth, so that you don’t get in the way of your neighbors. That’s about the same with lifi. One lamp flashes and an electronic eye sees it. The flashing goes at a certain speed, which you cannot see yourself – but what that electronic eye makes something of. You must therefore have new equipment for lifi. For example, you buy special lamps and a device that converts it for your laptop.
Lifi a good alternative?
Is that lifi a good alternative then? Of course there are always disadvantages to technology. If you use light, the sender and receiver must be able to see each other. Especially when the speed is very high. Then being able to see each other becomes increasingly important. This has to do with how clearly the signal can be distinguished from other light sources, and how much light you can use. Of course it gets a bit tricky when a whopper of a spotlight is flashing above your head. With slower communication, the light can also be passed through the white wall. With light by researchers already very high speeds through the air reached : 7.7 Gbps, which is much faster than our current wifi. So it is fast.
Supplement to 5G network
But it can also be used as a supplement to the 5G network. The 5G network has much less transmission power and must be aimed at your phone much better than 4G or WiFi. This is necessary to have a smoothly responsive connection, with a difficult word and a low ‘latency of lag’. Many more transmitters are needed for this. And you don’t build it in a mast, because that is much too far from your phone. Perhaps it will be possible to do this with the street lighting in a while.
