This Recommendation specifies objective methods for the measurement of parameters in the transmission of digital cable television signals. It concerns the end-to-end performance measurement of digital cable television signals fi-om the signal source to the user's receiver. Measurement of OFDM modulated TV signals over cable networks is also specified in Annex A. This transmission chain contains the cable distribution system, consisting of full-coaxial or hybrid fibre and coaxial (HFC) cables, and may also contain the satellite links, terrestrial links andor broadband network links that may provide sources for the cable head-end. As there are several and very distinct measurements specific for satellite, microwaves and for terrestrial systems, it seems this is not the appropriate place to define each of them. It is suggested that any measurement of the performance of signals being supplied through a CATV system without trans-modulation, where the original source is taken fi-om satellite (QPSK, BPSK, etc.), terrestrial sources (8-VSB or COFDM) or microwave multi-point distribution systems, be referred to the appropriate ITU-T documents on such systems which are or may be made available