The maximum bandwidth of an RF channel is two times the carrier frequency.
So a 2.4 GHz carrier can have a max. bandwidth of 2.4 x 2 = 4.8 GHz.
Because of this 5G and 6G cell phone technologies are moving to higher frequencies to have more bandwidth available. This enables more symbols to be pushed through the channel. The issue with moving to higher frequencies is that the radio waves don’t pass through solid objects, but rather are reflected by them. Because of this, 5G and 6G will likely use phased antenna arrays that can be steered and pointed in an optimal direction. The system will have to be smart enough to figure out the optimal path to bounce the signal off to hit the receiver. It’s like a real world laser mirror game. Ryan Dreifurst explained this to me. He is pursuing his PhD in this field, specifically machine learning as applied to 5G and 6G.
An expanding gas causes heat loss.
Conversly, a compressing gas causes heat gain.
Paul Mullen explained this to me while I was volunteering at the Mission Cafe. The manager was creating nitro cold brew by releasing a nitrogen canister (similar to what is put in an airsoft gun) into a canister with cold brew. The expanding gas cooled down the coffee without diluting it like ice.
A compressing gas heats up, like in an air compressor, or a dehumidifier. This must also be why an outside air conditioner compressor heats up.