ITU-T K.78 PDF

This Recommendation provides principles on the protection of telecommunication centre equipment, such as routing, switching, transmission, access, server, storage, radio, power, air conditioning and supervisory equipment, from damage and disruption due to a high altitude electromagnetic pulse (HEMP).

The overall radiated and conducted immunity is a combination of the inherent equipment immunity, SPD surge mitigation and the electromagnetic screening of building and additional shielding enclosures. This Recommendation discusses the contribution of each element of installation to mitigate the stress on equipment and defines an immunity test level relevant for each condition.