EXFO FTB-635 Wideband Copper and DSL Test Module - Manual (Page 261)

Noise Tests
Copper and xDSL Tests 253
WB PSD Noise Test
Summary
In general, with the advent of high speed DSL, we are concerned not only
with metallic pair quality, but also noise which may be reducing SNR, and
hence interfering with signal quality and service. The WB Power Spectral
Density (PSD) Test and features are very informative in today's complex
cable environment of high speed services.
Summary tab displays the pass/fail status of the tests executed. Refer
Copper Tests: Result Summary on page 291 for more information.