Performance Analysis and Evaluation of VDSL2 Systems: Band-Plan Study

In this paper we discuss the performance of different profiles of VDSL2 systems in a frequency range up to 12 MHz (band- plan 998 and 997, corresponding to the European region) using two different noise scenarios: VDSL2 Mix and VDSL2 only. The use of different power levels at the downstream is evaluated in these scenarios and it is found that there is no need to use maximum power. As operators are commonly interested to achieve higher data rates, we have selected profile 12a as the most suitable when dealing with frequencies up to 12 MHz while consuming 4 times less power at the downstream than profile 8 b and leading to similar performance in the scenarios herein described. The impact of using different cables has been evaluated for both the downstream and upstream direction. An analysis on boosted and non-boosted masks is also provided. A method to evaluate the upstream performance per band has been used in order to obtain the contribution of each upstream band versus the loop length. With this approach and keeping in mind the dependency of the cable when evaluating performance (e.g. TP150 0.5 mm cable), it has been shown that US2 dies out after 700 m, US1 after 1600 m and USO provides more or less a constant performance contribution in the VDSL2 only scenario for band-plan 998. The same behavior for these upstream bands but in different ranges is expected for other type of cables (also for other band- plans, i.e. 997, which is presented in annex B).