Towards a compatible Level-2 DSM algorithm to protect downstream multiuser xDSL legacy systems

Higher levels of Dynamic Spectrum Management (DSM) are strongly desired; however, we still need methods that are compliant with the current spectrum management specifications and DSM-proven, at the same time. Therefore, we propose a simple yet efficient pre-Level-2 DSM algorithm to protect legacy xDSL systems from new technology implementations (e.g. VDSL2). We show by extensive simulations how effective our proposed algorithm performs over different scenarios. We have also evaluated the penalty (performance) function for VDSL2 lines. We have found that VDSL2 lines suffer from performance degradation in the order of up to ~4.5 Mbps, depending on the primary access network (PAN) length and the cable in use. We have also shown that previous methods as followed in [17, 18, 19] correspond to a specific case of our proposed algorithm.