This Recommendation gives a procedure to protect telecommunication lines using metallic components against direct lightning flashes to the line itself or to the structures that the line enters. Lines made by the following types of cables are covered by this Recommendation: Symmetric cable: Cable with a core made of one or many metallic symmetric pairs, which may have a metallic sheath, and/or a plastic covering, and/or a supporting wire; Coaxial cable: Cable with metallic inner and outer conductors separated by a dielectric, which may have a plastic covering and/or a supporting wire; Optical fibre cable: Cable with optical fibres, which may also have metallic components such as an inner strength member and/or an outer metallic sheath.
ITU-T K.47-2012 Referenced Document
ITU-T K.12-2010 Characteristics of gas discharge tubes for the protection of telecommunications installations (Study Group 5)
ITU-T K.46-2012 Protection of telecommunication lines using metallic symmetric conductors against lightning-induced surges (Study Group 5)
ITU-T K.72-2011 (Pre-Published) Protection of telecommunication lines using metallic conductors against lightning Risk management
ITU-T K.47-2012 history
2012ITU-T K.47-2012 Protection of telecommunication lines against direct lightning flashes (Study Group 5)
2008ITU-T K.47-2008 Protection of telecommunication lines using metallic conductors against direct lightning discharges Study Group 5