SWITCHING SYSTEM
Mobile Services Switching Center (MSC)-MSS MGW, Gateway MSC
(GMSC)
The MSC is responsible for setting up, routing and supervising calls to and from the mobile subscriber.
The GMSC is a MSC serving as an interface between the mobile network and other networks such as the PSTN and ISDN.
All MS terminated calls are set up via the GMSC.
Home Location Register (HLR)
The HLR is a database for storing subscriber information specific to that
PLMN. Subscriber information includes location information and information on services assigned to subscribers
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SWITCHING SYSTEM CONT’D
Visitor Location Register (VLR)
The VLR temporarily stores information about the MS currently visiting its service area. In the system the VLR is integrated with
MSC in the same AXE 10 switch.
The HLR can be implemented in a stand alone AXE 10 switch or an integrated (G)MSC/VLR/HLR.
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SWITCHING SYSTEM CONT’D
Authentication Center (AUC)
The AUC generates triplets used in the authentication of a subscriber SIM card and ciphering of speech, data and signaling over the air-interface.
Equipment Identity Register (EIR)
In GSM/PCS, there is a distinction between subscription and access. The EIR is a database responsible for validation of mobile equipment.
Service Center (SC)
The SC is responsible for reading, storing and forwarding a short message between a short message sender and a Mobile
Station. Ericsson offers a SC as a combined messaging system
(e.g. voice, fax), on a MXE platform.
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SGSN AND GGSN
• Gateway GPRS Support Node is the interface towards the external IP packet networks.
The GGSN contains access functionality that interfaces external ISP functions like routers and RADIUS servers.
• The GGSN acts as a router for the IP addresses of all subscribers served by the GPRS network. • Serving GPRS support node: forwards incoming and outgoing IP packets to or from a mobile station within the SGSN area
• Ciphering and authentication
• Connection to HLR, MSC, BSC
• Collection of Charging information
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OSS
Operation and Support System (OSS)
The OSS is Ericsson’s product for the GSM/PCS Operation and Maintenance Center (OMC).
For GSM system administration, OSS supports the operator with functions such as mobile subscriber and cellular network administration and alarm handling.
OSS is implemented through Ericsson’s.
Telecommunications Management and Operations Support
(TMOS) system.
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BASE STATION SYSTEM (BSS)
Base Station System (BSS)
The BSS is divided into the following functional units:
Base Transceiver Station (BTS)
The BTS is the radio equipment needed to serve one cell.
The BTS is the radio equipment, which transmits and receives information over the air to allow the BSC to communicate with MSs in the BSCs service area. A group of BTSs is controlled by a BSC. The BTS must contain GPRS-specific software. The BSC provides all radio-related functions.
It contains the antenna system, radio frequency power amplifiers and digital signaling equipment. Ericsson’s product for the BTS is the Radio Base Station (RBS).
System versions:
· RBS 200 for GSM
· RBS 2000 for GSM
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Base Station Controller (BSC)
The BSC controls and supervises a number of RBSs and radio connections in the system. It handles the administration of cell data, the locating algorithm and orders handovers.
The BSC has the functionality to set up, supervise, and disconnect circuit switched and packet-switched calls.
It is a high capacity switch that provides functions including handover, cell configuration data, and channel assignment. The BSC must be equipped with GPRS hardware and software when used for GPRS
• I/O SYSTEM
• CENTRAL PROCESSOR
• REGIONAL PROCESSORS
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GSM IDENTITIES
MOBILE STATION ISDN NUMBER
(MSISDN)
The MSISDN is a number which uniquely identifies a mobile telephone subscription in the public switched telephone network numbering plan.
