WDM allows transmission systems to:

1. A. Transport multiple signals transparently, onto several wavelengths, all together over one single fiber
2. B. Increase the bit rate of each client signal by spreading it over multiple wavelengths
3. C. Share a single signal among multiple fibers doing load balancing, and thus increasing the reliability of the optical transmission
4. D. Allocate different signals to different time slots

Correct Answer: A
WDM (Wavelength Division Multiplexing) allows transmission systems to transport multiple signals transparently, onto several wavelengths, all together over one single fiber. This allows for increased capacity, as many different signals can be transmitted at the same time and along the same fiber. Other advantages include improved signal integrity and reduced signal attenuation.

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

1. A. The amplification is done simultaneously for all channels as they enter the board.
2. B. As the incoming signal power increase, the gain of the amplifier is reduced.
3. C. The pump light travels in the same direction of the signal, amplifying it while it flows in the fiber towards the following node.
4. D. The pump light travels in the opposite direction of the signal to be amplified, amplifying it while it arrives from the adjacent node.

Correct 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.

Which of the following statements is true?

1. A. Logs report both active and historical events.
2. B. Alarms and conditions report a real time status of the node.
3. C. Alarms and conditions report only historical status of the node.
4. D. Logs report a real time status of the node.

Correct Answer: A
A log is a record of events that have occurred within a system, such as a network device or an application. Logs can include information about system activity, configuration changes, and error messages. They can be used for troubleshooting, auditing, and compliance purposes. Logs can report both active (real-time) and historical events that have occurred within a system.
Alarms and conditions, on the other hand, are used to notify operators of real-time status of the node, such as when a threshold is breached or when a specific event occurs. Alarms and conditions are typically used to provide real-time notifications of potential problems or issues, while logs are used to provide a historical record of what has occurred.
Reference: -https://en.wikipedia.org/wiki/System_log-
https://www.cisco.com/c/en/us/td/docs/net_mgmt/ciscoworks_common_services_software/3-1/user/guide/logs/logs.html- https://www.cisco.com/c/en/us/td/docs/net_mgmt/prime/infrastructure/3-4/user/guide/alarms/alarms.html

Where is the OPS card equipped to provide the optical channel protection?

1. A. Between the transponder and the amplifiers
2. B. Between the filters and the amplifiers
3. C. Before the transponder, on the clientside, towards the external device
4. D. Between the transponder and the filter

Correct Answer: A
According to the Nokia's 1830 Photonic Service Switch (PSS) product documentation, the Optical Protection Switching (OPS) card is equipped in the transponder and is responsible for providing optical channel protection between the transponder and the amplifiers. The OPS card monitors the optical signal and switches to a pre-configured protection path in case of signal degradation or loss.

What is the meaning of first, second, and third window in the optical fiber propagation context?

1. A. These windows correspond to three different minimum and maximum optical power levels used for optical transmission.
2. B. These windows are three different wavelength intervals where the WDM optical transmission occurs.
3. C. These three windows are three different angles of incidence of the light injected by the laser into the fiber.
4. D. Different optical transmission windows correspond to different safety requirements and rules for the related lasers operating with these windows.

Correct Answer: B
In optical fiber propagation context, the first, second, and third window refer to different wavelength intervals where the WDM (Wavelength Division Multiplexing) optical transmission occurs.
The first window is the lowest loss window and is typically in the range of 1300-1324nm. This is the most commonly used window for long-haul communications.
The second window is the 1550 nm window and is the most widely used window for long- haul and ultra-long-haul communications. This window has a lower attenuation than the first window, but it also has more dispersion, which can limit the maximum transmission distance.
The third window is the range of 1625-1675 nm, it is also called the L-band window. This window has lower attenuation than the first and second window but its usage is limited due to the high cost of equipment and lack of commercial devices.
These windows are used in WDM systems to increase the capacity of the fiber by transmitting multiple channels of data at different wavelengths on the same fiber. A,C,D are not correct as they are not related to the meaning of first, second, and third window in the optical fiber propagation context.
Reference:
Nokia Optical Networking Fundamentals, Nokia Press (ISBN:978-1-4822-8109-4) https://www.nokia.com/networks/solutions/optical-networking/ https://en.wikipedia.org/wiki/Wavelength-division_multiplexing