Evaluation of binder management for partially controlled DSL vectoring systems

Crosstalk between physically co-located lines is a pressing issue in VDSL2 access networks. In order to enhance the crosstalk mitigation capabilities of the latest extension to VDSL2, vectoring G.993.5, full control over all lines within the same cable binder is required. However, this is not always possible in practical deployments due to regulatory, structural, or late technology adoption constraints. In these cases a technique to minimize interference from non-controlled lines, known as binder management, aims at rearranging the line configuration within each binder. In this work, we quantify the advantages of binder management in a partially controlled setup. We initially establish a model of a commonly used 50-pair cable binder and provide its far-end crosstalk (FEXT) characterization. We then carry out an extensive simulation study for various degrees of control over the lines and realistic line length distributions to yield tangible metrics on vectoring performance for downstream transmission. Our results show that binder management is of limited use in partially controlled systems. Consequently, we provide an additional comparison study to help DSL providers to evaluate the remaining gains of upgrading to VDSL2-vectoring in such scenarios for different levels of dominance in the cable binder.