DSL Advances

9.2. Crosstalk in the Loop Plant

Crosstalk generally refers to the interference that enters a communication channel, such as twisted wire pairs, through some coupling path. The diagram in Figure 9.2 shows two examples of crosstalk generated in a multi-pair cable. On the left-hand side of the figure, signal source V_j(t) transmits a signal at full power on twisted wire pair j. This signal, when propagating through the loop, generates two types of crosstalk into the other wire pairs in the cable. The crosstalk that appears on the left-hand side, x_n(t) in wire pair i, is called near-end crosstalk (NEXT) because it is at the same end of the cable as the crosstalking signal source. The crosstalk that appears on the right-hand side, x_f(t) in wire pair ...