system
Given the following post, respond as if you're commenting on Reddit:
human
How difficult is it to provide cell service on underground services such as subways?

If we can have cell assisted Internet access on above ground services like trains why can we not do the same underground?
gpt
Very good question. It depends. If you put your transmitter above ground, it is almost impossible to get the signals deep underground and it would be a waste of energy to try to. If you put transmitters inside a tunnel you can actually reach quite far with them because the signals would reflect a lot. So we could do it. We probably don't because it takes a lot of money and it isn't really worth anyone's time since you will be above ground soon anyway.