Universal Mobile Telecommunications System (UMTS); General Universal Mobile Telecommunications System (UMTS) architecture (V15.0.0; 3GPP TS 23.101 version 15.0.0 Release 15)
This TS defines the basic physical and functional separation of UMTS. The contents of this specification is limited to those features that are common to all UMTS networks independent of their origin. It identifies and names the reference points and functional groupings appearing at this level.