Trying to figure out some sort of method in which it would be possible to detect nearby phone numbers e.g. within a private premises.
My only lead so far is to build a mini mobile base station that would let phones connect to it - even then my theory for this has many holes and blanks.
The above may be completely off or possibly I may be on to something, either way if someone could give me a rough idea of what direction to take it in that would be much appreciated - I do not require any kind of code as I would much rather figure it out myself via a finger pointed in the right direction.
Even if you do not have any solid answers but some tips that could possibly help me piece this together, that'd be great.
This link might be useful. It feature some code and instructions for a personal cell tower. https://julianoliver.com/output/stealth-cell-tower