[lillecarl]

Once the 3G network is dead we can reuse that low-freq bands for 5G with similar range. You only use the high-freq high-bandwidth radios in populated areas.

https://youtu.be/0faCad2kKeg this is Wendover Productions explanation of cell service, there's an error regarding ultra high-freq when he means ultra low-freq, other than that it's a good explanation of how RF works.

An important bit here is that 3G is 16 combinations and 5G is 1000+, this is why it's important to deprecate old tech, we need to reuse frequencies.