A device always identifies a cell tower using its IMSI (International Mobile Subscriber Identifier) number, but the cell tower does not have to. As the cell phones connect to the nearest cell tower that emits the strongest signal on themselves, it is rather easy to lure a device into connecting to a fake cell tower. This is what an IMSI catcher/stingray is.
Stingray happens to be a mobile surveillance device that presents itself as a cell tower and shows itself as a reliable infrastructure. This way, the smartphones you wish to hack into easily connect to these cell towers. One can place these stingrays in fixed locations or in a drone or a vehicle. Apart from detecting the location of the users of the targeted device, these devices also help in intercepting text messages and calls from the targeted devices as well as the devices within the targeted vicinity.
Once you trick your device into connecting to the false towers, you can easily read the unencrypted content and other communications the tower transmits to you.