Whenever you make a call or use mobile data, your phones is connecting to one specific cell tower. To be more precise, your phone is connecting to one of those sector antennas on a particular mast. See image above.
Each of these sector antennas has a unique identification. A CID – Cell ID, and a LAC, Location Area Network.
Using Network Cell Info Lite app on our phone we can actually see this information.
When you are close to a cell tower, you will notice the signal power on your phone go very high.