EN 50083-5:1994

This standard defines the characteristics of equipment used in the headends of terrestrial broadcast and satellite receiving systems (without satellite outdoor units and without those broadband amplifiers in the headend as described in EN 50083-3). The satellite outdoor units for FSS are described in standard ETS 300 158, for BSS in standard ETS 300 249. This standard does not relate to subscriber equipment, such as receivers, tuners, decoders, video recorders, etc. This standard covers the frequency range 5 MHz to 1750 MHz, identifies performance requirements for certain parameters, lays down data publication requirements for certain parameters, stipulates methods of measurements, introduces minimum requirements defining quality (Q) grades. As far as possible this standard only deals with the interfaces between headend components and only explains the function of the devices if this is necessary to support the description of the interfaces. Coder, transcoder, encrypter, decrypter etc. are not described in this specification. If such devices are used in headends, the relevant parameters for RF, video, audio and data interfaces have to be met. According to the definitions in clause 2 headends are divided into the following three quality levels: grade 1: local headend/remote headend; grade 2: hub headend, grade 3: MATV headend/individual reception headend. Practical experience has shown these types meet most of the technical requirements necessary for supplying a minimum signal quality to the subscribers. This classification shall not be considered as a requirement but as the information for users and manufacturers on the minimum quality criteria of the material required to install networks of different sizes. The system operator has to select appropriate material to meet the minimum signal quality at the subscriber's outlet and to optimize cost performance, taking into account the size of the network and local circumstances