CONTENTS Case study 1.1 – Acoustic noise troubles caused by an amateur radio base station Case study 1.2 – Acoustic noise troubles caused by switching noise of digital subscriber unit (DSU) Case study 1.3 – Acoustic noise troubles caused by switching noise of an elevator Case study 1.4 – Emission from telephone equipment affecting an amateur radio Case study 1.5 – Acoustic noise troubles caused by an electric fence Case study 1.6 – Electric fence interference Case study 1.7 – Infrared movement-sensing lights Case study 1.8 – Medium wave AM radio interference Case study 1.9 – Electric railway interference Case study 1.10 – RF welder interference Case study 1.11 – Noise caused by street lights Case study 1.12 – TV interference problem due to telecommunication equipment Case study 1.13 – EMC problem on next generation network (NGN) trial Case study 2.1 –Lightning surge troubles on transmission equipment Case study 2.2 – Lightning surge troubles on CSM Case study 2.3 – Damage of LD-SLT and DCS telecommunication equipment Case study 2.4 – Damage of ISM Case study 2.5 – Damage of 2-Mbit/s HDSL system Case study 2.6 – Lightning damage to a payphone Case study 2.7 – Lightning damage to a telephone Case study 2.8 – Earth wire voltage drop in telecommunication centre Case study 2.9 – Malfunction of circuit breaker due to lightning surges Case study 2.10 – Protection of a wireless service connected to a few kilometres of copper cable Case study 3.1 – Power and telecommunication systems grounding Mitigation measures for telecommunication installations 1