The sections in this article are Attenuation Attenuator Measurement of Attenuation Errors and Uncertainties in Attenuation Measurements

When a signal is sent along any transmission path, many different mechanisms degrade it. Because of finite conductivity, every cable shows a resistive loss. Scattering loss is dominated by Rayleigh scattering, and below 1600nm absorption losses are caused mainly by OH absorption. Wireless transmission paths, such as microwave links, satellite links, and broadcast or mobile communication, are affected by scattering caused by rain, clouds, and multiple reflections. Many different methods and a variety of systems for measuring attenuation have been developed.