ITU-T Recommendation G.100.1 Series G: Transmission systems and media, digital systems and networks. International telephone connections and circuits - General definitions. The use of the decibel and of relative levels in speechband telecommunications

ITU-T F-series Recommendations - Supplement 2 SF: Non-telephone telecommunication services. Terms and definitions for telex ITU-T F-series Recommendations - Supplement 1 Series F: non-telephone telecommunication services. Definitions relating to telegraph, telematic and data transmission services ITU-T Recommendation F.910 Operations and quality of service. Human factors. Procedures for designing, evaluating and selecting symbols, pictograms and icons ITU-T Recommendation G.102 Transmission systems and media. General characteristics of international telephone connections and international telephone circuits. Transmission performance objectives and recommendations ITU-T Recommendation G.103 Series G: Transmission systems and media, digital systems and networks. International telephone connections and circuits - General definitions. Hypothetical reference connections Рекомендация МСЭ-Т G.101 Серия G: Системы и среда передачи, цифровые системы и сети. Международные телефонные соединения и цепи. Общие определения. План передачи