Intellectual Property Rights.........................................................................................................................19
Foreword.....................................................................................................................................................19
1 Scope ...............................................................................................................................................21
1.1 Normative references.........................................................................................................21
1.2 Abbreviations .....................................................................................................................27
2 Configuration of the mobile network..................................................................................................27
2.1 The entities of the mobile system ......................................................................................27
2.1.1 The Home Location Register (HLR)..............................................................27
2.1.2 The Visitor Location Register (VLR)..............................................................28
2.1.3 The Mobile-services Switching Centre (MSC) ..............................................28
2.1.4 The Base Station System (BSS) ...................................................................28
2.1.5 The Gateway MSC (GMSC)..........................................................................28
2.1.6 The SMS Gateway MSC ...............................................................................28
2.1.7 The SMS Interworking MSC..........................................................................29
2.1.8 The VBS/VGCS Anchor MSC .......................................................................29
2.1.9 The Equipment Identity Register (EIR)..........................................................29
2.1.10 The GSM Service Control Function (gsmSCF).............................................29
2.1.11 The Group Call Register (GCR) ...................................................................29
2.2 Configuration of a Public Land Mobile Network (PLMN) ...................................................29
2.3 Interconnection between PLMNs.......................................................................................29
2.4 The interfaces within the mobile service............................................................................29
2.4.1 Interface between the HLR and the VLR (D-interface) .................................29
2.4.2 Interface between the HLR and the gsmSCF (J-interface) ...........................30
2.4.3 Interface between the VLR and its associated MSC(s) (B-interface)............30
2.4.4 Interface between VLRs (G-interface)...........................................................30
2.4.5 Interface between the HLR and the MSC (C-interface) ................................30
2.4.6 Interface between MSCs (E-interface) ..........................................................30
2.4.7 Interface between the MSC and Base Station Systems (A-interface) ..........30
2.4.8 Interface between MSC and EIR (F-interface) ..............................................30
2.4.9 Interface between VBS/VGCS Anchor MSC and GCR (I-interface) .............31
2.5 Splitting of the data storage ...............................................................................................31
3 Overload and compatibility overview.................................................................................................33
3.1 Overload control.................................................................................................................33
3.1.1 Overload control for MSC (outside MAP)......................................................33
3.1.2 Overload control for MAP entities..................................................................33
3.1.3 Congestion control for Signalling System No. 7............................................36
3.2 Compatibility......................................................................................................................36
3.2.1 General ..........................................................................................................36
3.2.2 Strategy for selecting the Application Context (AC) version .........................36
3.2.2.1 Proposed method ................................................................36
3.2.2.2 Managing the version look-up table.....................................37
3.2.2.3 Optimizing the method.........................................................38
4 Requirements concerning the use of SCCP and TC.........................................................................38
4.1 Use of SCCP......................................................................................................................38
4.1.1 SCCP Class...................................................................................................38
4.1.2 Sub-System Number (SSN) ..........................................................................38
4.1.3 SCCP addressing..........................................................................................38
4.1.3.1 Introduction ..........................................................................38
4.1.3.2 The Mobile-services Switching Centre (MSC).....................39
4.1.3.2.1 MSC interaction during handover .........39
4.1.3.2.2