scope:

This European Telecommunication Standard (ETS) specifies the procedures used at the radio interface (Reference Point Um, see GSM 04.02) for Call Control (CC), Mobility Management (MM) and Radio Resource (RR) management. When the notations for "further study" or "FS" or "FFS" are present in this ETS they mean that the indicated text is not a normative portion of this standard. These procedures are defined in terms of messages exchanged over the control channels of the radio interface. The control channels are described in GSM 04.03. The structured functions and procedures of this protocol and the relationship with other layers and entities are described in general terms in GSM 04.07.