The ETS describes a baseline transmission system for digital terrestrial TeleVision (TV) broadcasting. It specifies the channel coding/modulation system intended for digital multi-programme LDTV/SDTV/EDTV/HDTV terrestrial services. The scope of the specification is as follows: - it gives a general description of the Baseline System for digital terrestrial TV; - it identifies the global performance requirements and features of the Baseline System@ in order to meet the service quality targets; - it specifies the digitally modulated signal in order to allow compatibility between pieces of equipment developed by different manufacturers. This is achieved by describing in detail the signal processing at the modulator side@ while the processing at the receiver side is left open to different implementation solutions. However@ it is necessary in this text to refer to certain aspects of reception.