ETSI TS 123 014
ETSI TS 123 014
Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); Support of Dual Tone Multi-Frequency (DTMF) signalling (3G TS 23.014 version 3.1.0 Release 1999)
standard published 01/01/2000 by European Telecommunications Standards Institute
