Digital cellular telecommunications system (Phase 2+) - GSM Cordless Telephony System (CTS), Phase 1 - CTS radio interface layer 3 specification (GSM 04.56 version 8.0.1 Release 1999)
Edition 2000-11-01

Digital cellular telecommunications system (Phase 2+) - GSM Cordless Telephony System (CTS), Phase 1 - CTS supervising system layer 3 specification (GSM 04.57 version 8.0.1 Release 1999)
Edition 2000-11-01

Digital cellular telecommunications system (Phase 2+) - Specification of the Cordless Telephony System Subscriber Identity Module for both Fixed Part and Mobile Station (GSM 11.19 version 7.0.3 Release 1998)
Edition 2000-11-01

Access and Terminals (AT) - Analogue access to the Public Switched Telephone Network (PSTN) - Subscriber line protocol over the local loop for display (and related) services - Part 3: Data link message and parameter codings
Edition 2001-04-01

European digital cellular telecommunications system (Phase 2);Attachment requirements for Global System for Mobile communications (GSM) mobile stations;Telephony (Endorsed by Asociación Española de Normalización in February of 2022.)
Edition 2022-02-01

EUROPEAN DIGITAL CELLULAR TELECOMMUNICATIONS SYSTEM (PHASE 2). ATTACHMENT REQUIREMENTS FOR GLOBAL SYSTEM FOR MOBILE COMMUNICATIONS (GSM) MOBILE STATIONS. TELEPHONY.
Edition 1999-09-21

Telecommunications cables - Insulation, sheath and jacket Materials
Edition 2019

Terminal Equipment (TE) - Telephony for the hearing impaired - Electrical coupling of telephone sets to hearing aids
Edition 2000-02-01

Integrated Services Digital Network (ISDN) - Telephony 7 kHz, videotelephony, audiographic conference and videoconference teleservices - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 3: Test Suite Structure and Test Purposes (TSS&TP) specification for the user
Edition 1999-11-01

Integrated Services Digital Network (ISDN) - Technical characteristics of telephony terminals - Part 7: locally generated information tones
Edition 1999-12-01