Free Nokia 4A0-255 Exam Dumps Questions & Answers

What isguardband required for?

• A.To reduce non-linear impairments between coherent and non-coherent channels.
• B.To reduce the impact of chromatic dispersion.
• C.To enable each channel to support a higher modulation format.
• D.To properly use the available bandwidth of the fibers.

Consider the exhibit. The grey sites (Site 1 through Site6) from an existing network, which will be extended by adding Site7 and Site8. Which of the following is NOT a common source of interoperability issues for this network extension?

• A.Regeneration requirements at Site5
• B.Cascading in the existing network
• C.Spectrum grid of the extension
• D.Fiber connectors at Site6

Consider the exhibit, where the two highest ports are OT line ports. Which of the following statements is correct?

• A.An OPS is required upstream (left of the OT).
• B.The O-SNCP protection is implemented.
• C.The E-SNCP protection is implemented.
• D.The OCH protection is implemented.

Where is guardbandmandatoryfor EMF?

• A.Between 10G and 40G channels
• B.Between 40G and 100G channels
• C.Between 10G and 200G channels
• D.Between 10G and 100G channels

Which of the following best describes self-phase modulation?

• A.It is s type of impairment that can be compensated usingDCMs
• B.It is a type of modulation format exploiting the phase to carry information.
• C.It is a phase shift suffered by an optical signal caused by its power intensity.
• D.It is a type of impairment cause by spectrally adjacent channels.