This TS specifies the Network Service used on the Base Station System (BSS) to Serving GPRS Support Node (SGSN) interface (Gb interface).
The protocol stack on the Gb interface is defined in the stage 2 TS 23.060
The Network Service entity provides network services to the BSSGP entity specified in TS 48.018
The layer 1 of the Gb interface is specified in TS 48.014
. In this TS, the communication between adjacent layers and the services provided by the layers are distributed by use of abstract service primitives. But only externally observable behaviour resulting from the description is normatively prescribed by this TS.
The service primitive model used in this TS is based on the concepts developed in ITU-T Recommendation X.200.