Design and performance of digital transmission systems operating on metallic pairs

Consideration is given to the design and performance of transmission systems operating over metallic cables for use in different parts of the telecommunication network. Particular attention is given to thermal noise, crosstalk, and impulsive noise limited systems in the context of achieving an acceptable error performance. A methodology of performance specification is discussed and the importance of providing immunity against so-called `network effects¿ is emphasized. The status of international studies with respect to the performance specification of digital line systems is reviewed. The actual error performance of some operational and field trial systems is reported and error clustering is found to be significant on some systems.