Device-to-device communication can be achieved by a number of different technologies. The two categories of connection are wired or wireless. A cable connection is the oldest method and is still very much used. I, like most people, would rather connect wirelessly but I still find myself using a variety of cables. So why is that?
To answer the question, I looked at the pros and cons of wired versus wireless device-to-device connections.
Advantage: fast connection, no need for pairing or security.
Disadvantage: need cable available, need to physically connect cable.
Advantage: no need for cable, no need to physically connect device.
Disadvantage: need to pair for security, slower than cable, reliability.
On looking at both, it seems that the security issue is the main factor that makes me use a cable, and not because I personally was worried about security (although I should be). It was the inconvenience of having to actively pair the devices for security reasons. The system forces me to accept this pain so that I do not pair with the wrong device and to avoid my data being intercepted. This is a major disadvantage of radio because it goes everywhere and it is difficult to direct to data to where you want it to go.
Visible Light Communication Advantages
Now consider VLC. With visible light you can shine a beam of light in a very controlled way. Not only that, you can see exactly where it goes. VLC therefore has inherent security so there is no need to confirm or accept the device pairing. The short range data rates of a VLC system can also be very large – e.g. 1Gbit/s could be achieved. In an earlier blog on positioning I mentioned that mobile devices already have sensors suitable for VLC (e.g. LED flash/torch and ambient light detector), so device-to-device VLC could be achieved relatively easily, and it would be much easier to use than wireless radio connections.
Radio goes everywhere but you can shine visible light where you want it!