The reason 6Ghz was introduced with WiFi 6E and 7 was because 2.4Ghz and 5Ghz was very busy.
My question is why isn’t there anything in between? Why isn’t there a 3Ghz, 3.5Ghz, 4Ghz, etc?
Also, what if things that require very little data transmission used something lower than 2.4Ghz for longer range? (1Ghz or something?)
2.4 GHz and 5 GHz are both “ISM bands.” These are frequencies that regulators have set aside for unlicensed use.
Fun fact: 2.4 GHz is free to use because of microwave ovens. Microwaves are really noisy around 2.45 GHz. Rather than try to regulate their radio emissions, or make people license their kitchen appliances as radio transmitters, the FCC allocated that patch of spectrum for free use. Any device that can tolerate the noise can use that bit of the radio spectrum.
Ah so the stuff in between that has things like radio stations?
I’m not sure what exactly you mean by “in between” here (between 2.4 and 5 GHz?), but commercial radio in the US is at much lower frequencies than wifi bands. AM radio is typically measured in KHz (the range is something like 600-1400, I can’t be bothered to look it up), while FM radio is in MHz (around 87-108 MHz).
Not like commercial AM/FM radio stations playing music, but radio in the more general sense. 5G cell phones and satellite-to-earth communication systems use that frequency range, for example.
makes sense, using WiFi with those frequencies would make it noisy and clogged up, esp. in crowded cities
Some parts of the spectrum in between 2.4 and 5 GHz are used by the mobile communication standards LTE and 5G (also higher frequencies). GSM, DVB-T, and FM radio operate at lower frequencies.
ah that makes sense
But, the key takeaway there is that those portions of the spectrum where mobile bands are are restricted to those uses. 2.4 and 5 are “free bands,” in which any device can use them (assuming compliance with FCC part 15 in the US). If I built a device and operated it at say 4.3GHz, I’d get in big trouble once found.
Indeed, the regulation authority, e.g. the Bundesnetzagentur in Germany, will knock on your door and inspect your radio and wifi devices. That way, some years ago they’ve found a malefunctioning radio alarm clock in my area.