Network aspects of the GSM system [mobile communications]

The network functions of the GSM (CEPT´s Groupe Special Mobile) system are discussed. They can be divided into four broad categories: network functions required for basic service provision (call handling, subscriber authentication, emergency call, and supplementary services); network functions required for cellular operation (location registration and handover); additional network functions for call handling (queueing, off air call setup, security-related services); and operation and maintenance-oriented network functions. Several of these functions are unique for mobile networks, e.g., all the functions related to cellular operation. Most of the other functions require different or additional implementation in mobile networks as compared to fixed networks