SSH ETS 300 939:1997 ed.1

Digital cellular telecommunications system (Phase 2+) (GSM); Mobile radio interface signalling layer 3; General aspects (GSM 04.07 version 5.1.2)

Scope

This European Telecommunication Standard (ETS) defines the principal architecture of layer 3 and its sublayers on the GSM Um interface, i.e. the interface between Mobile Station (MS) and network; for the CM sublayer, the description is restricted to paradigmatic examples, call control, supplementary services, and short message services. It also defines the basic message format and error handling applied by the layer 3 protocols. The corresponding protocols are defined in other Technical Specifications, see subclause 4.3.4. The communication between sublayers and adjacent layers and the services provided by the sublayers are distributed by use of abstract service primitives. But only externally observable behaviour resulting from the description is normatively prescribed by this ETS.