This chapter covers the background to the current GSM Network structure. It introduces the three GSM variants and the principle of a cellular structure for the network.
This introduces the core components of a GSM network in terms of their functionality. Included are: the Mobile Station, the SIM, the Base Station subsystem and the Network subsystem. Also introduced are the various services available through GSM.
Interfaces and Protocols
This chapter identifies the various interfaces within the GSM network and outlines the function of the protocols associated with each of those interfaces.
The Air Interface
Defines the frequencies used and the method of transmission (TDMA). Also explains the function of the logical channels for Traffic and Signalling. Details the protocols specific to this interface.
The A Interface
Describes the 2M frame structure used and details the SS7 signalling protocol that is at the heart of the network infrastructure.
The MSC Interface
Identifies the alphabetically named interfaces used by the MSC to connect to HLR, VLR, EIR etc. ll of which use SS7 signalling at the network level and at the higher levels such as MAP, INAP, TCAP and CAMEL.
After going through a description of a call setup, this chapter then covers the process of Handover and Roaming. Frequency hopping and Power control are also detailed.
The range of services available are identified and described - such as Short Message Service, Call Waiting, Call Forwarding, Mobility Management, etc..
This covers the enhancements to GSM, such as EDGE and GPRS, that have taken the technology on to the current UMTS (3G) network structure.