Protocols And Services - Gsm Вђ“ Architecture,

The central node for call routing and management.

Manages radio transmissions over the air interface (Um interface) using a combination of FDMA and TDMA . GSM – Architecture, Protocols and Services

A permanent database containing subscriber profiles and their last known location. The central node for call routing and management

Often called the core network, it performs call switching and manages subscriber mobility. Key components include: GSM – Architecture, Protocols and Services

GSM uses a layered protocol structure for communication between the mobile station and the network:

Uses modified versions of LAPD (called LAP-Dm) for the air interface and SS7 protocols (MTP) for the network interface. Layer 3 (Network): Divided into three sublayers: