Specifications

2009
2010
32
FURTHER INFORMATION
▼ AXT- Alien Cross Talk;
Disturbo indotto su una o più coppie di un cavo dei segnali propagatesi su coppie appartenenti
a cavi diversi.Il fenomeno si rileva allorquando si verificano parallelismi dei cavi superiori a cir-
ca15 metri.
▼ PD- Propagation Delay;
The time required for a signal to propagate from the input to the output of a transmission line.
Expressed in ns. Depends on the length of the cable and the speed of propagation.
▼ DS- Delay Skew.
The difference between the propagation delays of the shortest and longest pairs of a single ca-
ble. Depends on the various steps of stranding of the pairs required to reduce NEXT. Expressed
in ns.
▼ IMPEDANCE
A secondary constant which measures the overall opposition to the passage of an alternating
current along a transmission line due to the combined action of the four primary constants: re-
sistance, inductance, capacitance and conductance. Expressed in Ohm.
▼ CHARACTERISTIC IMPEDANCE
The impedance measured at the input of an infinitely long line.
POWER SUM MEASUREMENT:
Multiple sources of disturbance
Single receiver
▼ PSNEXT- Power Sum Next;
The inductive coupling of the sum of the near end crosstalk of all disturbing pairs on a single
disturbed pair.
▼ PSACR- Power Sum Attenuation
to Crosstalk Ratio;
The ratio between the signal and the sum of disturbances (IL and NEXT) of all disturbing pairs
on a single disturbed pair.
▼ ELFEXT- Equal Level Far End Crosstalk;
The ratio between the received (usable) signal and the disturbance induced on the pair in ques-
tion by a signal transmitted from the far end of the adjacent pair.
▼ PSELFEXT- Power Sum Equal Level
Far End Crosstalk;
The sum of couplings of all ELFEXT originating in all pairs towards a given single pair.
PAIR TO PAIR MEASUREMENT:
Single source of disturbance
Single receiver