systems for example rate of decrease in power is equal to 48 db octave while the rate of increase is 21 5 dbm octave also to maintain compatibility with conventional adsl systems the first power level is preferably maintained at a level as currently defined e g u2212 34 5 dbm as shown in fig4 or slightly reduced e g u2212 35 dbm as shown in fig5 both psd masks are with the power levels defined by asdl standards 12 9 dbm for fig4 and 12 5 dbm for fig5 0018 table 2 frequency band u0192 khz values for pots with equation for line x 32 channels dbm hz 0 lt u0192 lt f s u2212 97 5 with max power in the 0 u2212 fs fs 4 khz khz band with increase from fs 15 dbm fs lt u0192 lt f u0 u2212 92 5 21 5 u00d7 log 2 u0192 f s f u0 u2248 25 875 khz f u0 lt u0192 lt f u1 u2212 34 5 f u1 u2248 138 khz f u1 lt u0192 lt f u1a u2212 34 5 u2212 48 u00d7 log 2 u0192 f ue f da u2248 177 7 khz f u1a lt u0192 lt f ue u2212 52 f ue u2248 276 khz f ue lt u0192 lt f uea u2212 52 u2212 48 u00d7 log 2 u0192 f de f uea u2248 478 khz u0192 lt f uea u2212 90 providing other psd masks for transmission of upstream data is also useful for example different power levels as well as different rates of increase and decrease alternatively a psd mask in which.