Handles the radio link with mobile devices. It includes the Base Transceiver Station (BTS) , which contains the radio transmitters and receivers, and the Base Station Controller (BSC) , which manages radio resources and handovers for multiple BTSs.
Handles authentication, security, and location tracking. GSM – Architecture, Protocols and Services
Uses the Subscriber Identity Module (SIM) to store unique identity information. Security is maintained through a challenge-response authentication mechanism and over-the-air encryption using algorithms like A5. Handles the radio link with mobile devices
A permanent database containing subscriber profiles and their last known location. and the Base Station Controller (BSC)
A temporary database storing information for subscribers currently roaming in its area.