Rate and Reach Gains of Vectored DSL in the Current Access Network

Vectoring is a newly introduced technology to enhance the achievable data rates and extend the reach boundaries of VDSL2 and G.fast systems inherently delimited by far-end crosstalk (FEXT). However, the benefits of vectoring vary in today's access network due to factors such as: limited control of operators over local loops, i.e., local loop unbundling (LLU), technological constraints of the required hardware and particularities of the access network itself. Therefore, estimating the impact of vectoring on real networks before its actual deployment is crucial for service providers to evaluate its feasibility, define network segments and upgrades, and avoid wasting infrastructure resources. In this work, we evaluate the performance of vectored systems based on the potential rate and reach gains that can be obtained under realistic access networks conditions. We adapt existing studies of the local loop length distribution to cover various fiber-to-the-X-point (FTTX) topologies and use them to conduct a simulation study of VDSL2 vectoring. Based on the attainable data rates of vectored and non-vectored systems, we calculate indicators to help DSL providers to estimate the potential gains in terms of rate, coverage and the percentage of improved services when adding vectoring to their networks. Our results allow them to identify their network segments that can obtain most noticeable improvements and estimate the coverage rate enhancements if vectoring technology is implemented.