Influence of buildings on HPEM vulnerability of it infrastructures

When evaluating the vulnerability of an electronic system against an external threat like High Power Electromagnetics (HPEM), its immediate surroundings have to be included. IT equipment will typically be located inside buildings, whose walls can considerably attenuate and deform electromagnetic waves. The layout of IT and supply cabling shapes the system response as well. A topological abstraction model renders analysis of our complex HPEM attack scenario possible. One can identify three topological zones: the outside as well as the inside of the building, and the IT equipment itself. We have performed radio frequency exposure experiments with reasonably simplified substitutes for the outer area, the building and a cabling scheme including two IT devices as the minimum IT system setup. The results give information about the key parameters of RF coupling from one zone to the next. Finally, some recommendations for protection measures at CI have been derived from the results.