A method for determining network topology of a provider network includes selecting a first network element, selecting a first port on the first network element, and iteratively performing connectivity validation tests using the first port, wherein each connectivity validation test is associated with a type of network element and yields a result that indicates whether a second port on a second network element of the associated type is connected to the first port. A system for discovering topology of a network, the system comprising a topology discovery engine in operable communication with a near network element and operable to identify a first port of a far network element that is connected to a second port of the near network element by remotely altering operation of the near network element to cause the second network element to respond in a manner that identifies the first port.

There are various drawbacks by using existing OTN (Optical Transport Network) frames for communication between OTN cards. Such drawbacks might for example include high latency, low robustness, and/or high coding rate. According to embodiments of the present disclosure, systems and methods are provided for modifying an OTN frame (or creating a new frame with data from the OTN frame) prior to transmission by an OTL (Optical channel Transport Lane) in order to address some or all of the foregoing drawbacks. Note that this embodiment can make use of existing hardware (e.g. hardware used for generating the OTN frame, and the OTL used for transmission).

An optical transceiver, for receiving an optical signal on which a monitor signal is superimposed, includes: an extractor configured to extract the monitor signal from the optical signal received; and a reception processor configured to reproduce a monitor data from the monitor signal extracted by the extractor.

At least two cascaded chains of intelligent support boxes linked by optical cable provide the needed elements to link the electric AC power line and low voltage DC power lines to the many known outlets and switches (wiring devices) and their loads be it AC or DC operated, with the AC and DC lines are separately drawn through separated conduits and ducts safely and accurately controlled by an home controller and/or via a command converter and a distributor.

At least two cascaded chains of intelligent support boxes linked by optical cable provide the needed elements to link the electric AC power line and low voltage DC power lines to the many known outlets and switches (wiring devices) and their loads be it AC or DC operated, with the AC and DC lines are separately drawn through separated conduits and ducts safely and accurately controlled by an home controller and/or via a command converter and a distributor.

The disclosed systems and methods for characterizing an optical fiber in a dense wavelength division multiplexing (DWDM) optical link. The characterizing comprising: i) applying a power dither to data bearing optical signals propagating in the optical fiber, the power dither having a high-power level and a low-power level; ii) computing optical time-domain reflectometer (OTDR) traces corresponding to the high-power level and the low-power level of the power dither; iii) averaging the OTDR traces corresponding to the high-power level and the OTDR traces corresponding to the low-power level into average OTDR traces; computing a differential Stimulated Raman Scattering (SRS) gain from the OTDR traces; and iv) adjusting the average OTDR traces based on the differential SRS gain.

The disclosed systems and methods for characterizing an optical fiber in a dense wavelength division multiplexing (DWDM) optical link. The characterizing comprising: i) applying a power dither to data bearing optical signals propagating in the optical fiber, the power dither having a high-power level and a low-power level; ii) computing optical time-domain reflectometer (OTDR) traces corresponding to the high-power level and the low-power level of the power dither; iii) averaging the OTDR traces corresponding to the high-power level and the OTDR traces corresponding to the low-power level into average OTDR traces; computing a differential Stimulated Raman Scattering (SRS) gain from the OTDR traces; and iv) adjusting the average OTDR traces based on the differential SRS gain.

A method and a device for determining a location of an optical splitter are provided. With the method, optical network units in a PON network are classified into K clusters based on locations of the optical network units with a K-means clustering-based algorithm. Distances between multiple optical network units in the same cluster are small. If it is determined that the number of the optical network units in each of the clusters does not exceed a threshold, a central office is added into the K clusters to obtain K new clusters; and for each of the new clusters, a location of an optical splitter corresponding to the new cluster is determined, so as to ensure that a sum of distances between the location of the optical splitter and locations of all elements in the new cluster is minimized.

A method and a device for determining a location of an optical splitter are provided. With the method, optical network units in a PON network are classified into K clusters based on locations of the optical network units with a K-means clustering-based algorithm. Distances between multiple optical network units in the same cluster are small. If it is determined that the number of the optical network units in each of the clusters does not exceed a threshold, a central office is added into the K clusters to obtain K new clusters; and for each of the new clusters, a location of an optical splitter corresponding to the new cluster is determined, so as to ensure that a sum of distances between the location of the optical splitter and locations of all elements in the new cluster is minimized.

Apparatus (10) for an optical communications network has optical paths for optical traffic, and optical ports (20,40), one of which is an unused input port (20). A security monitoring system (30) has a blocking part (50) comprising an interface (51) coupled removably to the unused input port (20) to occupy it to prevent unauthorized access. A light source is optically coupled to the interface (51) such that, when the interface is coupled to the unused input port, light can be transmitted through the interface (51) into the unused input port (20). An optical detector (60) can detect light reflected back from the interface (51), and there is alarm circuitry (70) configured to output an alarm signal based on the detecting of the reflected light. This monitoring can help make the node more secure from interference such as the introduction of a noise signal. The system can be passive or active, and does not require a change in the installed node configuration and so can be added easily to existing infrastructure.