Path quality analysis: In a communicationspath, an analysis that (a) includes the overall evaluation of the component quality measures, the individual link quality measures, and the aggregate path quality measures, and (b) is performed by evaluating communications parameters, such as bit error ratio, signal-plus-noise-plus-distortion to noise-plus-distortion ratio, and spectral distortion.
... Line, District Line or Northern City Line (Great Northern & City Railway) remain open as mainline stations:
Great Missenden tube station[?]
Wendover tube ...