CTA Fiber Optics & Physical Layer Technologies 2

Question 1

What is the maximum reach of 10GBASE-LR (10 Gigabit Ethernet over single-mode fiber) per IEEE 802.3ae?

Accepted Answer

10 kilometers

Answer

100 meters

Answer

550 meters

Answer

40 kilometers

Question 2

In a Passive Optical Network (PON), what device splits the optical signal from the central office to multiple subscriber premises?

Accepted Answer

Optical splitter

Answer

EDFA (Erbium-Doped Fiber Amplifier)

Answer

Optical Line Terminal (OLT)

Answer

Wavelength router

Question 3

What is the maximum downstream bandwidth per PON port in XGS-PON (10G Symmetrical PON)?

Accepted Answer

10 Gbps

Answer

1 Gbps

Answer

2.5 Gbps

Answer

25 Gbps

Question 4

What causes optical back-reflection in a fiber link, and how is it typically mitigated?

Accepted Answer

Fresnel reflection at fiber end faces and connectors; mitigated using angled physical contact (APC) connectors or index-matching gel

Answer

Dispersion at connectors; mitigated by chromatic dispersion compensators

Answer

Scattering in the fiber core; mitigated by EDFA amplifiers

Answer

Polarization mode dispersion; mitigated using polarization controllers

Question 5

In DSL technology, what does the term 'attenuation' refer to in the context of loop length?

Accepted Answer

The reduction in signal strength as the electrical signal travels over copper pairs, which increases with loop length

Answer

The noise added by telephone switching equipment

Answer

The delay introduced by DSL modems

Answer

The frequency filtering applied by the DSLAM

Question 6

What type of cable is used in most US residential CATV (cable TV) and HFC networks to connect homes to the distribution network?

Accepted Answer

RG-6 coaxial cable

Answer

Twisted pair copper (UTP)

Answer

Single-mode fiber to the premises

Answer

Multimode fiber (OM3)