In my Optoelectronics class this semester, we study how principles in optics are applied to modern day communications technology. My professor pointed out that within a few years there may be a huge market for LED lights. LEDs may be a crucial component in allowing devices to send data between each other within sight.
Most data in this day and age is sent digitally. Digital data is represented by a series of 0′s and 1′s, which can physically represent no current (0) or a pulse of current (1). This is a very good system because a very complicated signal can be represented by just 2 values. Manipulating the order in which they appear determines what kind of signal you send.
Similarly, light can also be used as a binary system. Instead of using a current, it uses on/off light to represent 0′s and 1′s. Therefore, if you have a receiver that can detect these pulses of light, you can send data digitally using light. Imagine embedding these light sending/detecting technologies in mobile devices. It would completely change the way we send information to each other. Instead of sending data through Wifi, it would be through Lifi – Light Fidelity.
Some drawbacks you may notice are for example, that there may be very annoying flickering from the LEDs of devices as they send digital data through Lifi. But light detectors can be sensitive enough to detect slight variations in the brightness of light emitters. As opposed to turning the light completely off to represent a 0, it would just make it slightly less bright than the brightness setting for a 1. These variations would be so small that our human eyes would not be able to perceive them. Instead, what you would probably see is the LED turn on for the duration of the time it is sending the data. Another problem is that you have to be able to physically see the other device or else there is no possible way to send data using light. This is true, but it also offers certain levels of security protection that wifi does not offer. For example, if a hacker wanted to steal the data you were sending through Lifi, he/she would have to physically intercept the light beam somehow. Finally, you may say that if you can only send data, like a text message, to another device within viewing distance, you may as well just walk up to the person and tell them. But of course, this data sending is not limited to text messages by any means. For instance, you can send documents, photos, videos, and essentially any type of data you would send to a computer.
The promise of Lifi and LED communications technology are very great and, in my opinion, incredibly exciting. Watch an incredible TED talk below on Lifi and an awesome demonstration.
Harald Haas: Wireless data from every light bulb