Recent progress of ITU-T recommendations on lightning protection

This paper presents recent documents produced by ITU-T Study Group 5 about the protection of telecommunication systems against lightning. These documents are known as Recommendations and provide protection procedures for the design, construction and maintenance of telecommunication networks. After presenting a general overview of the lightning protection documents, four of them are described in detail: K. 47 (protection of lines against direct flashes), K. 46 (protection of lines against lightning induced surges), K. 56 / K. dbs (protection of radio base stations). The innovative aspects of these Recommendations are highlighted, in order to provide an overview of the advances in the art of lightning protection carried out within ITU-T SG-5. ITU-T K. 47 is currently modelling the protective effect provided by guard-wires, while ITU-T K. 46 is introducing new concepts to allow the implementation of protection based on a risk assessment approach. Finally, ITU-T K. 56 and ITU-T K. dbs provides quantitative measures to protect standard and newly developed radio-base stations against direct lightning flashes.