Hello everyone, welcome to another one of my blogs.

This post will be about how radio frequencies are used.

So, we can start at multiple KHz, where there is mostly medical equipment, over ocean communication, and radionavigation. Why.. radionagation tho? Well, these low frequencies are best at going trough water, walls, etc. They simply go trough almost everything.
As we move to hundreds of KHz, there is obviously AM radio, because you can only transfer data as fast as fast as the frequency goes, and with parity etc. this is the first band we can transfer audio in.

Then, we move onto the few MHz, and what can we find here?
We can find some amateur frequencies, and also TV broadcast. We can also find some radio astronomy frequencies, where its used to basically capture an image from space, except not using light, but radio frequencies(using a bunch of antennas and stuff).
At tens of MHz, we can obviously find the FM radio band, and then we can start finding stuff like car remotes, garage openers etc.

As we move higher and higher, we cannot really use the frequencies in water and they don't go trough walls and other obstacles that well, so there is less and less of these usages, moving to the usages where rather the speed is more necesearry then the longevity.

At around 900MHz we start seeing cellular connections, which end at around 2-3GHz. At 2.4GHz we can also see Wifi and Bluetooth, aswell as on 5.2GHz. You may be wondering, why is there so much more avilable channels on 5GHz wifi and than on 2.4? Simply, the spectrum kindof start spreading out as its going trough higher frequencies, therefore there is alot more to be allocated. In fact, frequencies over 300GHz doesn't seem to be allocated by any country, but good luck creating that kind of oscillator.

Anyways, that will be it for today, see you next time!