A breakdown determination system includes a switching device that switches a transmission path of optical signals between an upper network and a lower network, one or more intermediate communication devices that relay communication between the upper network and the lower network, a selection device that selects a standby port of the intermediate communication devices, a measurement device that connects to the selected standby port via the switching device and measures an optical signal of the connected standby port, a determination device that determines whether an intermediate communication device including the selected standby port breaks down based on a result of measuring the optical signal, and a storage device that stores a result of determining whether the intermediate communication device breaks down.

Methods and systems for automated health assessment of fiber optic links of a fiber optic communication system are described. Tables are used to describe the fiber optic links, including access addresses to communication modules used in the links. Telemetry data representative of operation of the communication modules can be read via the access addresses into a central station. OTDR/OFDR measurement data of fiber optic segments used in the links can be read via the access addresses into the central station. The telemetry and/or OTDR/OFDR measurement data can be used by the central station for comparison against reference data to assess health of the links. The communication modules locally and continuously capture the telemetry data to detect transient events that may be the result of tampering of the links.

A computationally efficient real-time photonic cyclic autocorrelation function (CAF) analysis device and method are disclosed. In embodiments, the CAF analyzer generates a photonic carrier which is converted into upper and lower comb signals (comprising a set of N tones) by upper and lower optical frequency comb generators (OFCG), the lower comb signal offset from the upper. An inbound radio frequency (RF) signal is received and modulates the upper and lower comb signals via amplitude modulation. An optical delay line (e.g., ring resonator) introduces a delay into the modulated lower comb signal. The upper and lower comb signals are demultiplexed into their modulated frequency component and sent to a bank of N coherent I/Q receivers, which generate a slice of the CAF for the received RF signal based on the selected delay.

Disclosed is a frequency swept source apparatus including a mode locking laser that outputs an input optical signal having first to n-th frequency components, a transmission delay controller that generates first to m-th sub-optical signals, each of which includes at least one component of the first to n-th frequency components, and outputs a delay optical signal obtained by sequentially delaying the first to m-th sub-optical signals. The transmission delay controller includes a demultiplexer that outputs the first to m-th sub-optical signals to first to m-th channels based on the input optical signal, respectively, a path delay unit that adjusts lengths of optical paths of the first to m-th channels so as to be different from one another, a refractive index controller that adjusts a refractive index of each of the first to m-th channels, and a multiplexer that combines the first to m-th sub-optical signals.

A passive optical communication network includes two optical line terminals configured respectively to receive a communication signal from information systems and at least two optical network units configured to receive the communication signal. At least two optical switches, one part of which is connected at input to a first terminal via a primary nominal operating path and to the second terminal via a secondary path, and the other part of which is connected at input to a second terminal via a primary nominal operating path and to the first terminal via a secondary path. Each switch being connected at output to at least one optical network unit. A command controller connected to the switches and configured to control the switches such that, when a fault is detected on a primary path, the switch associated with the path is toggled.

Techniques for maintaining equipment of a PON include determining a current optical profile for each segment of a plurality of segments of a PON, and detecting that the current optical profile of a particular segment is outside of a designated operating range. Based on the detection, drifts over time of the optical profile of the segment and of optical profiles of one or more other segments that share respective common endpoints with the segment are determined and compared, and based on the comparison, a component of the PON (e.g., an endpoint or an optical fiber) is identified as requiring maintenance. Each segment's optical profile corresponds to characteristics of optical signals delivered over the segment (e.g., attenuation, changes in frequencies, changes in power outputs, etc.), and current optical profiles of the PON's segments may be repeatedly updated over time to continuously monitor for components that need maintenance.

In order to predict properties of a first device, data is obtained relating to properties of second devices having characteristics in common with the first device. The data comprises values of a first parameter at specific values of a second parameter. The data is organized in a first matrix with each row or column representing one value of the second parameter, and each column or row contains for one of the second devices the value of the first parameter at each of the values of the second parameter for which data is available. The first matrix is factorized into a second matrix and a third matrix. The second matrix represents a relationship between the second parameter and hidden features. The third matrix represents a relationship between the second devices and hidden features. The second matrix and/or the third matrix is used to predict at least one value of the first parameter and at least one respective specific value of the second parameter outside a predetermined range.

A method for processing low-rate service data, an apparatus, and a system, where the method includes: mapping low-rate service data into a newly defined low-rate data frame, where a rate of the low-rate data frame matches a rate of the low-rate service data, the data frame includes an overhead area and a payload area, the payload area is used to carry the low-rate service data, a rate of the payload area in the low-rate data frame is not less than the rate of the low-rate service data, and the rate of the low-rate service data is less than 1 Gbps; mapping the low-rate data frame into one or more slots in another data frame, where a rate of the slot is not greater than 100 Mbps; mapping the other data frame into an optical transport unit (OTU) frame; and sending the OTU frame.

If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.

Embodiments of this application provide a method and an apparatus for obtaining optical distribution network (ODN) logical topology information, a device, and a storage medium. The method includes: obtaining identification information of each first ONU that is connected to a first passive optical network (PON) port and whose optical path changes and feature data of the first ONU in a first time window, where the feature data includes receive optical power and/or an alarm event; obtaining, based on the feature data of each first ONU, a feature vector corresponding to each first ONU; and performing cluster analysis on the feature vector corresponding to each first ONU, to obtain topology information corresponding to the first PON port. ONU topology information is obtained by analyzing an ONU feature.