Investigation of VDSL2 digital lines with bridged taps and various parameters

Abstract

Modern Very-High Speed Digital Subscriber Lines (VDSL2) can potentially increase the transmission rates in access networks up to tens of Mbps in both directions. However, the real transmission performance of VDSL2 technology is heavily influenced by real conditions of symmetrical pairs and quads in local metallic cables. This paper is primarily focused on the bridged taps and their influence on transmission performance of VDSL2 lines. The presence of bridged taps can complexly affect resulting attenuation, impedance and also crosstalk characteristics of transmission lines, moreover while this influence may differ for various types of metallic cables. That is why a comparison for several typical cables used in last-mile segments was performed and is presented here. The simulations and calculations presented in this paper are based on ABCD matrices, and thanks to that the simulations can be performed for various scenarios and situations.