Routing: One of the primary functions of the GMSC is to route incoming calls to the appropriate MSC (Mobile Switching Center) based on the number called. When someone from outside the mobile network calls a mobile subscriber, the call first reaches the GMSC, which then forwards it to the appropriate MSC that serves the called subscriber.
Interconnection: GMSC serves as an interface between the mobile network and other networks such as PSTN (Public Switched Telephone Network) or other mobile networks. It handles the translation between different numbering plans and ensures that calls are routed correctly between different types of networks.
Number Translation: If a call comes from the PSTN to a mobile subscriber, the GMSC may need to perform number translation to map the PSTN number to the appropriate mobile number. This translation ensures that the call reaches the correct mobile subscriber within the mobile network.
Technical Aspects:
SS7 Signaling: GMSC relies on SS7 (Signaling System No. 7) signaling to communicate with other elements within the telecommunications network. SS7 provides the signaling and control information necessary for call setup, routing, and teardown.
Database Queries: To determine the appropriate MSC for routing a call, the GMSC may need to query various databases within the network. For example, it may need to consult the HLR (Home Location Register) or other databases to retrieve subscriber information and determine the current location of the subscriber.
Routing Logic: GMSC uses sophisticated routing logic to determine the most appropriate MSC for routing a call. This logic takes into account various factors such as subscriber location, network topology, and routing policies defined by the network operator.
Security: GMSC plays a crucial role in ensuring the security of the network. It implements various security mechanisms to protect against unauthorized access, fraud, and other security threats. For example, it may use encryption and authentication protocols to secure signaling messages exchanged between network elements.
Redundancy and High Availability: To ensure reliable operation, GMSC is often deployed in a redundant configuration with multiple backup nodes. This configuration ensures that even if one GMSC fails, the network can continue to operate without significant disruption.
