system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how do they make it so you can have thousands of phones in close proximity all sending and receiving signals at the same time without the airwaves getting clogged up into completely unreadable noise?
gpt
It does get clogged.

It's not a free for all where the phones just transmit whenever they want. The cell phone system controls the phones and tells them when it's ok for them to transmit and when not to transmit. It does this based on need so that phones not using a lot of data get less time. This means it's not always obvious how busy the system is. But this sharing system has its limits,  if there are lots of phones all trying to use the network at once then everyones connection slows down.

In really heavily loaded situation connections will drop out. The system tries to do this in a smart way so that data fails first allowing voice calls to still go through. And if there are too many phone calls emergency calls get priority over normal calls.


Edit: getting a little over 5 year old level here but there are several ways to share radio time. A lot of people are talking about each phone talking at a different time (TDMA, time division multiple access). Some are talking about different frequencies (FDMA). And there is also CDMA, code division multiple access, where the signals are encoded in a way to allow them to be separated out at the receiver. 

Cell phone systems initially used either TDMA or CDMA depending on the type of network. The newer standards are horrendously complicated and use a combination of these simultaneously.