Chapter 11 - Field Testing of Structured Cabling Flashcards
When placing an entrance sleeve through a building wall for outside plant cable entry, ensure that the raceway ____ toward the outside of the building.
a) Slopes downward
b) Slopes upward
c) Slopes upward or downward
d) is parallel to ground level
A) Slopes downward
What is return loss?
A measurement of the reflection of signal power resulting form the insertion of a device in a transmission line.
What is insertion loss deviation?
Insertion loss deviation is a measure of the worst-case difference in magnitude between the expected insertion loss and the actual measured insertion loss.
What is near-end crosstalk (NEXT) loss?
NEXT loss is a measurement conducted on balanced twisted-pair cabling. NEXT is a measure of the signal coupling between any two pairs along the entire length of the cabling. NEXT occurs when signal on one pair of wires is picked up by an adjacent pair of wires. So the higher the NEXT loss, the better the performance of the cable link since it means that most of the crosstalk is gone.
What is attenuation-to-crosstalk ratio-far-end (ACR-F)
ACR-F is the performance parameter that had ben called equal level far-end cross talk (ELFEXT).
It measures the crosstalk on a disturbed pair at the opposite end from where the signal is transmitted and is normalized by the attenuation loss of the disturbed wire pair.
What is power sum crosstalk?
Power sum crosstalk is used to specify a combination of crosstalk from every source.
What is attenuation-to-crosstalk ratio-near-end (ACR-N)?
ACR-N, previously called ACR, expresses the ratio between the signal strength arriving at the end of a link and the disturbance caused by the NEXT coupling from a disturbing wire pair.
What is alien crosstalk?
Alien crosstalk is the noise disturbance external to any one cabling link. Industry standards defines two test parameters to capture the alien crosstalk coupling:
- PSANEXT
- PSAACR-F
What is the worst case attenuation coefficient (dB/km) for single mode loose tube for Outside Plant (OSP)?
0.4 dB/km
What is the worst-case attenuation coefficient (dB/km) for singlemode tight buffered for inside use?
1.0 dB/km
What is the worst case attenuation coefficient (dB/km) for 50/125 laser-optimized OM3 and OM4 at:
850nm?
1300nm?
850nm = 3.5 dB/km for om3 3.0 fo om4? 1300nm = 1.5 dB/km
What is the worst-case attenuation coefficient (dB/km) for 50/125um and 62.5/125um multimode grandfathered at:
850nm?
1300nm?
850nm = 3.5 dB/km 1300nm = 1.5 dB/km
