SGSN

Serving GPRS support node

The Serving GPRS Support Node (SGSN) is the node that is serving the MS/UE. The SGSN supports GPRS and/or UMTS. The SGSN keeps track of the location of an individual MS/UE and performs security functions and access control. The SGSN is connected to the GERAN base station system through the Gb or Iu interface and/or to the UTRAN through the Iu interface. A SGSN is responsible for the delivery of data packets from and to the mobile stations within its geographical service area. Its tasks include packet routing and transfer, mobility management (attach/detach and location management), logical link management, and authentication and charging functions. The location register of the SGSN stores location information (e.g., current cell, current VLR) and user profiles (e.g., IMSI, address(es) used in the packet data network) of all GPRS users registered with it.