The present document is part 1 of a multi-part deliverable which specifies the general engineering of various broadband infrastructures to enable the most effective energy management (and management of other resources) and the appropriate measures for End-of-Life (EoL) treatment of ICT equipment. This multi-part deliverable does not address the following aspects of the broadband network sub-systems: • implications for carbon "footprint"; • resources used to construct the sub-systems; • the nature or method of production of the energy consumed by the infrastructures. The present document provides an overview of the ETSI EN 305 174 series of standards together with a definition of the common and generic aspects to which the other standards in the series conform. Clause 2 and clause 3 contain references, definitions, symbols and abbreviations which relate to this part; similar information will be included in the corresponding clauses of the other parts, thus ensuring that each document can be used on a "stand-alone" basis. Clause 4 describes the network sub-systems applicable to broadband infrastructures and their interconnections that are addressed by the ETSI EN 305 174 series. Clause 5 specifies the format of the other parts of the ETSI EN 305 174 series (other than ETSI EN 305 174-8 [i.6]).