http://sls.iykpqm7jiradoeezzkhj7c4b33g4hbgfwelht2evxxeicbpjy44c7ead.onion/technologies/cell-site-simulators-imsi-catchers
To exploit this, cell-site simulators broadcast signals that are either stronger than the legitimate cell sites around them, or are made to appear stronger. This causes devices within range to disconnect from their service providers’ legitimate cell sites and to instead establish a new connection with the cell-site simulator.