Protecting the robustness of ADSL and VDSL DMT modems when applying DSM

Recent techniques for ADSL and VDSL like power backoff (PBO) and dynamic spectrum management (DSM) focus on the crosstalk and try to operate with lower noise margin to increase the performance of the network. However, if the noise increases, the DSM modem may lose showtime, unless the modem can adapt its PSD to compensate for the increase of noise. The intent of the paper is to know what the impact is of DSM on the robustness of these systems (if and how fast the DSM modem can adapt its PSD). Both in ADSL and VDSL there exist reconfiguration protocols that take care of changing noise environments. In this paper, we investigate for DSM the speed and robustness of various online reconfiguration protocols that exist today.