ETSI TS 124 091
ETSI TS 124 091
Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); Explicit Call Transfer (ECT) supplementary service - Stage 3 (3G TS 24.091 version 3.0.0 Release 1999)
standard published 01/01/2000 by European Telecommunications Standards Institute
