[kikokikokiko]

I believe the concept of multiplexing made the tower obsolete, orher than the subterranean cables of course.

[ntoskrnl_exe]

I’m not sure that plain old telephone service allowed multiplexing, so it was probably just the latter

[solid_fuel]

It did to an extent, they built the old copper network in tiers. I don't know the exact numbers and I'm sure they varied by area, but the general idea was - your home phone would connect to a local exchange, which served just dozens of local homes, and that exchange would connect to a bigger exchange somewhere higher up the network over a bundle of circuits. And that architecture repeated for a few layers.

But it wasn't 1:1, so you would have lets say 100 homes connected to a local exchange, and that local exchange would have say 20 lines to the next exchange in the network. That placed limits on the amount of concurrent connections you could have from one area - if 21 homes all tried to call people in the next city over, at least one of them would get a signal that all circuits are full and they would have to try again later. It drastically reduced the amount of lines you need between local exchanges though.

[varjag]

It absolutely did, in 3kHz bands. That's how you could also sometimes hear someone else talking.