GSM architecture : Network Subsystem (NSS) (1/6)

GSM architecture : Network Subsystem (NSS)

The Base Station Subsystem forwards the signals to the Network Subsystem (NSS) where
speech and circuit-switched data are controlled and forwarded to other networks if
necessary. The NSS provides data relevant to security and mobility.

The speech signals processed by the transcoder reach the Mobile Services Switching Center
(MSC) via the A interface. The MSC serves as a digital exchange for the forwarding of
messages, connecting mobile subscribers with each other or with subscribers in other
networks such as the Public Switched Telephone Network, the ISDN network, or data
networks.