Alcatel-Lucent 7750 SR Manual page 72

Ultimately, the W-CDMA core network will evolve to comprise a full mobile IP infrastructure
including Media Gateway (MGW) and Media Gateway Controller (MGC) equipment for VoIP and
other new equipment such as the HSS and CSDF.
The functionality of MSC and SGSN changes when going to UMTS. In a GSM system the MSC
handles all the circuit switched operations like connecting A- and B-subscriber through the
network. SGSN handles all the packet switched operations and transfers all the data in the
network. In UMTS, the MGW takes care of all data transfer in both circuit and packet-switched
networks. MSC and SGSN control MGW operations. The nodes are renamed to MSC-server and
GSN-server.
Page 72 7750 SR OS Services Guide