scope:

The present document describes the framing structure, channel coding and modulation (denoted "the System" for the purposes of the present document) for a digital multi-programme television distribution by cable. The aim of the present document is to present a harmonized transmission standard for cable and satellite, based on the MPEG-2 System Layer ISO/IEC DIS 13818-1 [1], with the addition of appropriate Forward Error Correction (FEC) technique. This System can be used transparently with the modulation/channel coding system used for digital multi-programme television by satellite, see ETS 300 421 (see annex C). The System allows for further evolution as technology advances as described in Reimers' document (see annex C). It is capable of starting a reliable service as of now. The System is based on Quadrature Amplitude Modulation (QAM). It allows for 16, 32, or 64-QAM constellations and permits for future extension to higher constellations, such as 128-QAM and 256-QAM.

The System FEC is designed to improve Bit Error Ratio (BER) from 10^-4 to a range, 10^-10 to 10^-11, ensuring "Quasi Error Free" (QEF) operation with approximately one uncorrected error event per transmission hour.