ETSI TS 124 080
ETSI TS 124 080
Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); Mobile radio Layer 3 supplementary service specification; Formats and coding (3GPP TS 24.080 version 3.6.0 Release 1999)
standard published 12/01/2001 by European Telecommunications Standards Institute