An array of up to 512 real H(f) logarithmic representation values in dB for the respective transmission direction. It is designed to support up to 512 (downstream) sub-carriers. The number of utilized values on downstream direction depends on NSCds, and on upstream direction it depends on NSCus. This value is referred to here as NSC. Each array entry represents the real Hlog(f = i*Df) value for a particular sub-carrier index i, (0 <= i < NSC). The real Hlog(f) value is represented as (6-m(i)/10), with m(i) in the range 0 to 1022. A special value m=1023 indicates that no measurement could be done for the subcarrier because it is out of the passband or that the attenuation is out of range to be represented. This parameter is applicable in loop diagnostic procedure and initialization. Each value in this array is 16 bits wide and is stored in big endian format.