Overview of Ericsson’s GSM Systems.pdf (kỹ thuật mạng viễn thông)

Overview of Ericsson’s GSM Systems Chapter 2 This chapter is designed to provide the student with an overview of Ericsson’s GSM systems: CME 20 and CMS 40 OBJECTIVES: Upon completion of this chapter the student will be able to: • List 3 network components in Ericsson’s GSM system, and briefly describe their function • List 3 optional additional network entities and briefly describe their function t io na en lly B n la k In t GSM System Survey EN/LZT 123 3321 R4A 2 Overview of Ericsson’s GSM Systems 2 Overview of Ericsson’s GSM Systems Table of Contents Topic Page ERICSSON IN GSM......................................................................................27 ERICSSON'S GSM SYSTEM ARCHITECTURE.....................................28 ERICSSON’S SS IMPLEMENTATION..................................................................... 29 ERICSSON’S BSS IMPLEMENTATION................................................................... 30 ERICSSON’S OMC AND NMC IMPLEMENTATION.................................................. 32 ADDITIONAL ERICSSON NETWORK COMPONENTS ............................................. 35 EN/LZT 123 3321 R4A –i– t io na en lly I nt GSM System Survey k B n la – ii – EN/LZT 123 3321 R4A 2 Overview of Ericsson’s GSM Systems ERICSSON IN GSM Ericsson has been involved in GSM since its inception and took an active part in the GSM specification process. F Did you know? Western Europe has the highest penetration for mobile phones now 72%. North America has 45% penetration. EN/LZT 123 3321 R4A Ericsson is the largest supplier of GSM equipment in the world with a market share of approximately 40%. Over 477 GSM networks worldwide are supplied by Ericsson. Ericsson, in partnership with Sony Corporation, is one of the leading suppliers of GSM mobile phones and has sold around 390 million mobile phones to date. – 27 – GSM System Survey ERICSSON'S GSM SYSTEM ARCHITECTURE Ericsson provides ?two systems for GSM networks: • Cellular Matra Ericsson (CME) 20: for GSM 900 and GSM 1800 networks F Did you know? • Cellular Mobile System (CMS) 40: for GSM 1900 networks CME stands for Cellular Matra Ericsson, because the French company Matra was involved in the initial development of Ericsson’s GSM system. Like the GSM system model itself, Ericsson’s GSM systems are split into two primary systems: the Switching System (SS) and the Base Station System (BSS). However, depending on the requirements of a network operator, Ericsson’s GSM systems can incorporate other functions and nodes, such as Mobile Intelligent Network (MIN) nodes, Flexible positioning nodes and post processing systems. Note: Ericsson’s wide range of MSs are not considered to be part of either the CME 20 or CMS 40 product, due to the fact that an MS from any supplier can work with network equipment from any other supplier. Switching System EIR MIN AUC SDP HLR ILR SCF BGW Other PLMNs Public Data Networks MSC/VLR PSTN ISDN GMSC MC SOG SSF DTI OSS Base Station System TRC BSC RBS Signaling Information Speech and signaling information Figure 2-1 Ericsson GSM network system model – 28 – EN/LZT 123 3321 R4A 2 Overview of Ericsson’s GSM Systems Basic or Additional Abbrev. System Full component name Platform Basic MSC/VLR SS AXE Basic Basic Basic Basic Basic Basic Basic Basic Basic Basic Basic Additional Additional Additional Additional Additional Additional GMSC HLR ILR AUC EIR DTI TRC BSC BTS OMC NMC MC SSP SCP SDP SOG BGW SS SS SS SS SS SS BSS BSS BSS OSS OSS SS SS SS SS Mobile services Switching Center/Visitor Location Register Gateway MSC Home Location Register Interworking Location Register AUthentication Center Equipment Identity Register Data Transmission Interface TRanscoder Controller Base Station Controller Base Transceiver Station Operation and Maintenance Center Network Management Center Message Center Service Switching Point Service Control Point Service Data Point Service Order Gateway Billing GateWay AXE AXE AXE Unix/AXE Unix AXE AXE AXE RBS TMOS TMOS MXE AXE AXE Unix Unix Unix Table 2-1 Components of Ericsson network system ERICSSON’S SS IMPLEMENTATION Mobile services Switching Center/Visitor Location Register (MSC/VLR) The MSCs in all Ericsson GSM networks are AXE exchanges. In all Ericsson GSM networks, the VLR is integrated into the MSC node. This means that signaling between the VLR and the MSC is done internally within the MSC/VLR network node and does not have to be carried over the rest of the network. This has the benefit of reducing the overall signaling load on the network. Gateway Mobile services Switching Center (GMSC) The GMSC is also implemented as an AXE exchange. In effect, it is an MSC with some additional software. EN/LZT 123 3321 R4A – 29 – GSM System Survey Home Location Register (HLR) Ericsson’s HLR is also based on AXE and can be implemented in the same node as the MSC/VLR or as a stand-alone node. Interworking Location Register (ILR) The Interworking Location Register (ILR) exists in CMS 40 networks only. An ILR makes inter-system roaming possible, meaning that a subscriber can roam from a GSM 1900 network to an AMPS network. The ILR consists of an AMPS HLR and a GSM 1900 VLR. In the near future the ILR will make intersystem roaming possible in both directions between all GSM/AMPS/TDMA networks. Authentication Center (AUC) and Equipment Identity Register (EIR) The AUC and EIR are implemented either as stand-alone nodes or as a combined AUC/EIR node. The UNIX-based AUC and the EIR are developed by Sema Group. The AUC may alternatively reside on an AXE, possibly integrated with a HLR. Data Transmission Interface (DTI) The DTI is a hardware platform which implements the GSM-defined InterWorking Function (IWF). It performs data handling functions such as data rate conversion. DTI is implemented on an AXE platform and is integrated in the MSC/VLR. Because it is integrated into the AXE platform, the DTI does not need separate operation and maintenance facilities. ERICSSON’S BSS IMPLEMENTATION Ericsson’s BSS differs slightly from the GSM system model, in that a node called the Transcoder Controller (TRC) is added. However, this does not provide extra functionality - the functions of the TRC are part of the GSM model’s BSC. Transcoder Controller (TRC) The purpose of a TRC is to multiplex network traffic channels from multiple BSCs onto one 64 kbits/s PCM channel which reduces network transmission costs. The TRC can be combined with the BSC or exist as a stand-alone node. – 30 – EN/LZT 123 3321 R4A 2 Overview of Ericsson’s GSM Systems Base Station Controller (BSC) The BSC in all Ericsson GSM networks is based on AXE technology. It can be implemented as a stand-alone node or integrated with either an MSC/VLR or a TRC. Base Transceiver Station (BTS) In Ericsson's GSM systems the BTS is included as part of a product called RBS. The RBS also contains extra functionality which enables the support of several GSM-defined BTSs. Ericsson offers a wide range of RBSs for use in GSM networks: • RBS 2101 • RBS 2102 • RBS 2103 • RBS 2202 • RBS 2301 • RBS 2302 • RBS 2302 MAXITE • RBS 2401 • RBS 3000 series implements the BTS for UMTS, also known as WCDMA Systems. EN/LZT 123 3321 R4A – 31 – GSM System Survey ERICSSON’S OMC AND NMC IMPLEMENTATION Operation and Support System (OSS) is Ericsson’s product to support the activities performed in an OMC and/or NMC. The network operator monitors and controls the network through OSS which offers cost effective support for centralized, regional and local operations and maintenance activities. OSS is based on Ericsson's Telecommunications Management and Operations Support (TMOS) platform. OSS is designed as a complete network management system which can be used to control all the main network elements such as MSC/VLRs, HLRs, ILRs, TRCs, BSCs, EIRs, AUCs and Mobile Intelligent Network (MIN) nodes. OSS can also control BTSs through the BSCs. OSS uses a Graphical User Interface (GUI) enabling easier system use and network management. Operation and Support System NMC OMC OMC HLR AUC/EIR MSC BSC TRC BTS Figure 2-2 OSS provides central supervision of all network elements – 32 – EN/LZT 123 3321 R4A

Overview of Ericsson’s GSM Systems

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