Nokia 4A0-205 Exam Practice Test Instant Access

Question 1

Is it possible to mix PSS-24x and PSS-8x shelves In an SWDM configuration?

AYes, as both can be equipped within the same node

BNo, as they are not compatible and cannot be used within the same node

CYes, but the PSS-24X shelf must be configured as a master

DYes, but the PSS-8X shelf must be configured as a master

Answer : B

No, it is not possible to mix PSS-24x and PSS-8x shelves in an SWDM (Short Wavelength Division Multiplexing) configuration. The two shelves are not compatible, and cannot be used within the same node.

Question 2

With reference to trails and services, which of the following sentences is correct?

ATrails are transported over services; that is, trails are clients with respect to services.

BA trail can interconnect three ports, while a service always two.

CServices are transported over trails; that is, services are clients with respect to trails.

DA service is always associated to a single wavelength, while a trail can involve multiple wavelengths.

Answer : C

Services are transported over trails; that is, services are clients with respect to trails. A service is a logical connection that is used to transport data from one point to another. It is created over a trail, which is a physical connection that is established by using multiple wavelengths. As such, services are clients with respect to trails, as they are transported over them.

Question 3

What is a degree-1 node?

AA node with only one direction and therefore a terminal node

BA node with only one express channel and therefore made of two sides

CA node with only east and west sides without directions towards north and south

DA node with one direction only and therefore used as In-Line-Amplifier (ILA)

Answer : A

A degree-1 node is a node that only has one direction, and it is therefore a terminal node. This means that the node only has one input and one output port. It does not have any other ports to connect to other nodes or fibers. This is a common feature of some optical transport networks, such as ring networks, where a degree-1 node serves as the endpoint of the ring.

Question 4

What is the function of a pre-amplifier in an optical network?

AThrough the pre-amplifier, the optical signal is amplified at the receiver side after it travels along the fiber from another node.

BThrough the pre-amplifier, the optical signal is amplified at the transmitter side before it is sent to the line span.

CThrough the pre-amplifier, the optical signal is amplified both the receiver side and at the transmitter side.

DThrough the pre-amplifier, the optical signal is amplified within the node internally to recover internal losses due, for instance, to cascaded filters.

Answer : B

A pre-amplifier is an optical amplifier that is used to boost the power of the received optical signal before it is detected by the receiver in an optical communication system. This is done to overcome the loss of power that occurs as the signal travels through the optical fiber and to ensure that the receiver can detect the signal. The pre-amplification stage is typically located close to the receiver in order to minimize the distance that the signal has to travel between the amplifier and the receiver, which helps to reduce the noise and distortion in the signal.

Question 5

Which of the following sentences about FlexGrid is false?

AFlexGrid allows a more efficient channel spacing.

BChannels in FlexGrid systems are allocated with a granularity of 27.5GHz.

CFlexGrid systems use specific sets of boards. Old generation WDM systems need to be upgraded to support FlexGrid.

DThe FlexGrid is currently standardized by ITU-T.

Answer : C

FlexGrid is a flexible grid technology that allows for variable channel spacing and bandwidth allocation. It uses the same sets of boards as the traditional fixed grid systems and it does not require upgrading the old generation WDM systems.

'Flexible Grid Optical Networks: From Concepts to Realizations' by Diomidis S. Michalopoulos and George K. Karagiannidis

'Flexible Grid and Flexible Spectrum Optical Networks' by Diomidis S. Michalopoulos and George K. Karagiannidis

'Flexible Grid Optical Networks' by Diomidis S. Michalopoulos and George K. Karagiannidis

Question 6

How does a Raman pump work in the 1830 specific implementation?

AThe amplification is done simultaneously for all channels as they enter the board.

BAs the incoming signal power increase, the gain of the amplifier is reduced.

CThe pump light travels in the same direction of the signal, amplifying it while it flows in the fiber towards the following node.

DThe pump light travels in the opposite direction of the signal to be amplified, amplifying it while it arrives from the adjacent node.

Answer : D

In Raman amplification, a pump laser is used to excite the Raman-active molecules in the fiber, which then amplifies the signal light as it travels in the opposite direction. In the 1830 specific implementation, the pump laser is typically a high-power laser that is launched into the fiber in the opposite direction to the signal. The pump light interacts with the Raman-active molecules in the fiber, which then amplifies the signal light as it travels in the opposite direction. This allows the Raman pump to provide a gain that increases with distance, which can be used to compensate for the loss of signal power as it travels through the fiber.

Question 7

Which of the following statements is true about chromatic dispersion (CD)?

ADifferent channels have different bandwidth and this causes different CD performances.

BThe fiber attenuation changes along the fiber, and when the light crosses these differences the CD takes place.

CDifferent wavelengths propagate at different speeds within the same media and therefore different colors travel in the fiber with different speed.

DThe fiber attenuation introduces inter-channel interference.

Answer : C

Different wavelengths propagate at different speeds within the same media and therefore different colors travel in the fiber with different speed. This phenomenon is known as chromatic dispersion and causes light to spread out as it travels through the fiber over distance, leading to signal attenuation and distortion. The fiber attenuation does not introduce inter-channel interference, but it can cause attenuation of the signal. Different channels have different bandwidths, but this does not affect CD performance.

Nokia 4A0-205 Nokia Optical Networking Fundamentals Exam Practice Test