ITU-T G.950 PDF

Introduction

Digital line systems are the means of providing digital line sections. Recommendations on digital line systems may recognize, for digital line sections operating at a given bit rate, specific transmission media and transmission techniques (e.g. coaxial cable, regenerative transmission, etc.). Performance requirements of digital line systems are for the guidance of systems designers and users (equipment design objectives) and may be related to hypothetical digital paths of defined constitution.

All digital line systems operating on the same medium at a given bit rate shall comply with the characteristics of the digital line section at the same bit rate.