Support for data transmission, originally limited to 9.6 kbps but later improved through upgrades like GPRS and EDGE .
Includes features such as call forwarding, call waiting, and multi-party conferences. GSM – Architecture, Protocols and Services
Manages radio links and dedicated channel allocation. Support for data transmission, originally limited to 9
A temporary database storing information for subscribers currently roaming in its area. Support for data transmission
Primarily high-quality digital voice calls and SMS.
Manages call control (CC), Short Message Service (SMS), and supplementary services. Services and Security