GSM SYSTEM ARCHITECTURE
GENERAL
GENERAL
Ericsson's GSM system is a system consisting of a mobile phone some frequency bands namely GSM 900, GSM 1800, GSM 1900. GSM Network divided into 3 (three) major systems, namely: Switching System (SS), Base Station System (BSS), and Operation and Support System (OSS).
SWITCHING SYSTEM MOBILE
SERVICES SWITCHING CENTER
MSC in the GSM system uses AXE technology, including system modularity. The MSC controls calls to and from the phone system or other data. MSC also performs other functions such as: the function of the toll gate, network interfaces, common channel signaling, etc.
GATEWAY MSC
Gateway is a meeting point that connects two networks. Gateway is often placed together in the MSC. This type of set-up is referred to the Gateway-MSC (GMSC). All the MSC in the network can function as a gate.
HOME LOCATION REGISTER (HLR)
HLR is a database used to store and manage customer data. HLR database is considered as the most important since the HLR to provide subscriber data equipment, including the status of customer service, customer location information is located, and the activation status of the customer. When a customer purchases a number of mobile operators, they will be registered in the operator's HLR. HLR can be put together with the MSC / VLR or as a stand-alone HLR.
VISITOR LOCATION REGISTER (VLR)
VLR is a database that has a temporary subscriber information needed by the MSC to serve customers who visit from other areas. VLR is always integrated with the MSC. When an MS journeyed to a new MSC area, the VLR will be connected to the MSC and MSC will request data about the MS from the HLR where the MS is registered. Furthermore, if the MS build relationships, the VLR will provide information needed for call set-up without having to coordinate with the HLR every time.
AUTHENTICATION CENTER (AUC)
A unit called the AUC provides authentication parameters and encryption that checks the user identity and ensure stability of each call. AUC protects network operators from various types of fraud that exist in the mobile world today. AUC can be implemented in the HLR for GSM type R6.1/R3.
EQUIPMENT IDENTITY REGISTER (EIR)
EIR is a database containing information about the identity of mobile equipment that prevents calls from theft, insecurity, or lack disabling MS. The AUC and EIR are implemented as part of a stand-alone or a combination of the AUC / EIR.
DATA TRANSMISSION INTERWORKING UNIT (DTI)
DTI consists of hardware and software that provides an interface to various networks for data communications. Through the DTI, customers can use alternate between speech and data channels in a single call the same. DTI among other important functions: as a modem and fax adjustment and ability to adjust speed. Before the DTI, this function is run by the GSM interworking unit (GIWU).
INTERWORKING LOCATION REGISTER (ILR)
ILR is a product that is only used in GSM 1900 network. ILR makes roaming between systems can occur, this means we can explore the network AMPS and GSM 1900 networks. ILR consisting of AMPS HLR and VLR 1900.
ADDITIONAL (SS) FUNCTIONAL ELEMENTS
There are some additional options which devices can be configured into a Switching System. The device is a Message Center (MXE), Mobile Intelligance Node (MIN), Billing Gateway (BGW), and the Service Order Gateway (SOG).
