This section of IEC 835-2 deals with measurements pertaining to the adaptive equalizers used in digital microwave radio-relay systems. These measurements are intended to characterize the system equalizer in the presence of selective fading and may also be performed on systems without adaptive equalizers. To take account of those properties of the system which are especially influenced by the use of frequency and/or time domain equalizers, the results of measurements performed on the system are presented by so-called signatures. Additional measurements provide further means to characterize the pe rformance of the system.