Mobile Networks Architecture

Chapter 1

The GSM Network

Section 1.1 in this chapter explains the services provided by the GSM (Global System for Mobile) network, the main ones being the telephone service and the data transmission service. These services are implemented in CS (Circuit Service) mode, for which a resource dedicated to a flow is reserved.

Section 1.2 explains the architecture of a GSM network consisting of two subsystems – the BSS (Base Station Sub-system) access network and the NSS (Network Sub-System) core network – and the MS (Mobile Station).

It also describes the protocol architecture concerning the signaling data enabling the allocation of the resource dedicated to establishment of communications between two mobiles using the same PLMN (Public Land Mobile Network), two mobiles using two different PLMN networks or a mobile and a PSTN (Public Switched Telephone Network) fixed terminal.

Section 1.3 explains the radio interface between the mobile and the mobile network. The description of the transmission channel is essentially concerned with source coding, channel coding, time-division multiplexing of logical channels, modulation and the frequency plan.

Section 1.4 describes the procedures concerning the establishment of an incoming or outgoing call, location (roaming) management and the control of its access to mobile networks.

1.1. Services

The telecommunication services offered by the GSM network are divided into two categories:

– bearer services, which provide the ability to transmit between ...