Cable Crosstalk Definitions

Crosstalk - The unwanted transfer of energy from one signal path coupled to an adjacent or nearby signal path. An example of cross-talk would be the faint voices sometimes experienced during a phone conversation. Crosstalk can be inductive or capacitive and normally creates unwanted or erroneous data within a computer link or data system.

The measurement technique consists of inserting a pulse signal of known strength in one line called the drive line and measuring the effect of this signal in the adjacent sample line. The result is expressed as % crosstalk and is calculated as follows:

Near End Crosstalk - If we measure the crosstalk in the sample line at the same end of the cable we inserted the signal, it is called near end or reverse crosstalk.

Far End Crosstalk - If we measure the crosstalk in the sample line at the opposite end of the cable that we inserted the signal, it is called far end or forward crosstalk.

Pulse Rate Time - The amount of time it takes a pulse signal to go from a low state to a high state. Normally expressed in nano seconds (10-9).