The influence of the electrical characteristics of premises cables on the interference immunity of VDSL

The VDSL service has been progressed because it allows high-speed Internet access to be achieved using copper premises cables. Although VDSL offers an inexpensive means of providing FTTH service, the link between the VDSL Transceiver Unit at the Optical Network Unit (VTU-O) and the VDSL Transceiver Unit - Remote Terminal (VTU-R) is influenced by electromagnetic interference induced into the premises cables. There are different types of premises cables in use in Japan such as a single-layer cable, twisted-pair cable, and a star-quad cable. The electrical characteristics of these cables are different (e.g., transmission loss, longitudinal conversion loss, and cross-talk) because they differ in composition. This paper describes the relationship between the electrical characteristics of premises cables and the immunity to interference of the link between the VTU-O and the VTU-R.