WDM Signal Flows Advanced

An OLA site can also be monitored by the ESC.

• True
• False

DWDM technology uses multiple wavelengths as carriers to transmit the signals of carrier channels over the same optical fiber. Generally, DWDM technology is used with single-mode optical fibers because they have low loss but provide high bandwidth.

• True
• False

In the colorless scenario, the M40V/D40 board is used to add and drop wavelengths.

• True

• False

In a WDM system, a dielectric thin film filter is ideal when the number of wavelengths is smaller than ( ).

• 4
• 10
• 16
• 20

Compared with a dense wavelength division multiplexing (DWDM) system, a coarse wavelength division multiplexing (CWDM) system provides a certain number of wavelengths and a transmission distance within ( ) km, which greatly reduces system cost and has strong flexibility.

• 50
• 100
• 200
• 20

Which of the following site types cannot implement service adding/dropping?

• OTM
• OLA
• FOADM
• ROADM

Which of the following is the main reason why OSC signals are not amplified by the EDFA with service signals?

• Supervisory signals are prevented from interfering with service signals.
• Even if the OA fails, the OSC is still available.
• The optical power of the OSC board is lower than the amplification sensitivity of the OA board.
• The OSC rate is too low. If the OSC is amplified, the energy efficiency is too low.