This handbook describes general principles and case studies of mitigation
measures for telecom installations against electromagnetic disturbances.
Mitigation of EMC problems related to emission and immunity, overvoltage and
overcurrent are explained by actual examples that have occurred at telecom
To solve the EMC problem, it is useful to examine when, where, and how the
telecom installation, including equipment, is malfunctioning or damaged, and
what noise sources are identified. It is also important to check immunity
levels or resistibility levels of telecom installations before mitigation is
If a telecom installation satisfies the EMC recommendations as specified in
ITU-T K-series Recommendations, then few EMC problems should occur. However,
if several noise sources are superimposed, telecom equipment may malfunction
or become damaged because there are many noise sources in the environment.
Therefore, it is useful to remove major noise sources when solving EMC
This handbook describes several methodologies to solve EMC problems, how to
locate major noise sources, and mitigation tools/devices.
This handbook does not cover measurement methods or how to measure
emissions, overvoltage or overcurrent; for those purposes, the relevant
Recommendations and texts should be referred to. This handbook should be
read in conjunction with the relevant Recommendations detailed below.
This handbook is composed of two parts. Part 1 describes the general
principles of mitigation measures. Part 2, which groups the different case
studies, is published as a hypertext and is freely available on ITU website.
The different case studies may be downloaded and printed individually for
convenience of use.
Part 1 is available from ITU publication website at