Linear crosstalk between different 4-wire chains of circuits (analogue and mixed)
As a network performance objective, the signal-to-crosstalk ratio which may exist between two 4-wire
chains of circuits comprising international and national circuits is r
ITU-T G.134-1989 history
1989ITU-T G.134-1989 Linear Crosstalk - General Characteristics of International Telephone Connections and Circuits (Study Groups XII and XV) 2 pp