William Webb

10 seconds that might be a low frequency of waves but if you had 10 every second that would be a much higher frequency of waves and you get the same thing in radio waves there's a wide range of different frequencies

So every single use of radio, and there are thousands of them, television and radio and cellular and so on, is allocated its own little bit of the radio spectrum.

And therefore, they don't interfere with each other.

If you go back to the old days of tuning a radio with a dial, that tuning range would be well below, as it turns out, it's a much lower frequency range.

than is used by Bluetooth.

So that radio would never get up to the Bluetooth frequency, which is 2.45 gigahertz, which is 2.4 billion waveforms per second.

There's a lot of history to that, which is actually quite interesting.

And in fact, we'll head through to the kitchen where we can pick up on some of that because it relates to microwave ovens.

So microwaves actually use exactly the same frequency as Bluetooth.

In fact, a microwave is actually a very powerful radio transmitter and nothing more than that.

And it blasts your food with radio waves and it does so at a particular frequency.

And that frequency, 2.4 gigahertz or 2.4 billion waveforms per second, is exactly the same frequency that we use for Bluetooth.

And indeed, the reason that Bluetooth uses it is because way back when microwaves first started to be thought about, people thought, well, actually, it's going to create interference.

The radio signals will leak out a little bit from the microwaves.

That will make them fairly useless for other purposes.

And so it became known as junk spectrum.

And that meant that anybody could actually do anything they wanted with it.

And so people started to experiment initially with Wi-Fi and then eventually with Bluetooth in those bands because they were available, free to use.

And so actually, it was just a very convenient place to drop in Bluetooth.

So in fact, the microwave oven, in a strange way, is the reason that we use those particular frequency bands for Bluetooth.