Abstract: The present invention provides a method and system of OSNR-sensing spectrum allocation with optical channel performance guarantee. The method includes constructing an OSNR evaluation model; acquiring the shortest path between a source node and a destination node; acquiring a plurality of modulation formats and corresponding thresholds, sorting the plurality of modulation formats in descending order, and acquiring a list of the sorted modulation formats; calculating the bandwidth required by the lightpath service based on the bandwidth demand and FEC overhead by using the modulation format with the highest spectrum efficiency; substituting the bandwidth required by the lightpath service into the OSNR evaluation model and obtaining the number of FS actually required by the service; and allocating the spectrum resource required by the current service to the shortest path by using a first-fit algorithm and obtaining the center frequency of the current service on the lightpath.

Abstract: Disclosed is a solution for monitoring an operation of an optical fiber. An arrangement for the purpose includes: an indicator device arranged to: receive, from an optical component, a sample of a signal conveyed in the communication channel; determine an indicator value indicative of an amount of light in the sample of the signal; and a computing device arranged to compare the indicator value to a reference value, and set a detection result to express either that the sample of the signal carries a predefined amount of light or the predefined amount of light is absent from the sample. Also disclosed is a method, a computing device, a computer program product and a communication system thereto.

Abstract: In a signal processing device, a branch section generates, from an input signal which is a current signal, a plurality of branch signals that are proportional to the input signal and have different signal intensities, and supplies the plurality of branch signals to respective different individual paths. A selection section selects one of the plurality of individual paths and outputs a signal supplied through the selected individual path. A determination section determines whether in each of the plurality of individual paths, a magnitude of a signal supplied to the selection section is in a preset allowable range. A control section causes the selection section to select the individual path having a highest gain among the individual paths in which the magnitude of the signal is determined by the determination section to be in the allowable range.

Abstract: A method and apparatus for path computation includes generating a path computation element communication protocol (PCEP) message, whereby the PCEP message comprises a characteristic associated with a level of protection of a Protection Label Switch path (LSP) with a Working LSP; and transmitting the PCEP message for path computation.

Abstract: A device for measuring optical spectra at high speed and with high resolution using tunable optical laser comb sources. In one embodiment there is provided a first tunable comb laser source and a second tunable comb laser source whereby the wavelength of each comb laser source is chosen such that the combination of the two sources provides a continuous spectral coverage over a band in an optical spectrum under a selected wavelength tuning condition. By overlapping the two comb sources in the manner described the deadzone issue is overcome in the most spectrally efficient way possible.

Abstract: The invention provides a protection method against failure of AI-based QoT prediction, comprising calculating a first number of frequency slots and a consumable margin for a working lightpath that meet the traffic demand according to a method for allocating an OSNR margin for a working lightpath; calculating a second number of frequency slots and a consumable margin for the protection lightpath that meet the traffic demand according to a method for allocating an OSNR margin for the protection lightpath; and evaluating utilization of spectrum resource based on the first number of frequency slots and the second number of frequency slots and evaluating reliability of lightpath based on the consumable margin for the working lightpath. The method of the invention is more stable in practical network applications.

Abstract: Provided is a wavelength path communication node device with no collision of wavelengths and routes, capable of outputting arbitrary wavelengths, and capable of outputting them to arbitrary routes. An add/drop multiplexer (11) includes a communication unit (101) that communicates an optical signal with at least one client device and at least one network and a control unit (102) that indicates a transfer destination of the optical signal according to an attribute of the received optical signal to the communication unit (101). The control unit (102) indicates an attenuation amount of the optical signal to the communication unit (101) for each connected device. When a connected device is changed, the control unit (102) instructs the communication unit (101) to change the attenuation amount. The communication unit (101) attenuates the optical signal with the attenuation amount indicated by the control unit (102) and transfers the attenuated optical signal to a transfer destination.

Abstract: In some examples, a multi-wavelength power meter may include a first coupler to separate optical signals from an optical line terminal and an optical network terminal to ascertain a reduced percentage of total power related to the optical signals. A second coupler may receive the separated optical signals, combine the separated optical signals, and output the combined optical signals to an optical fiber. A filter may be communicatively connected to the optical fiber to isolate at least one specified wavelength or wavelength range of the combined optical signals. A photodiode may be communicatively connected to the filter for power measurement of the at least one specified wavelength or wavelength range.

Abstract: A method comprising: receiving a multiplexed optical signal comprising optical channels for N wavelengths, N being a positive integer greater than or equal to two; and separating the multiplexed optical signal into a first multiplexed light and a second multiplexed light, each of the first multiplexed light and the second multiplexed light having the same polarization, and each of the first multiplexed light and the second multiplexed light having N wavelengths; separating the first multiplexed light into a plurality of first lights, each having a different wavelength; separating the second multiplexed light into a plurality of second lights simultaneous with separating the first multiplexed light into the first lights, each of the second lights having a different wavelength; and generating optical parameters for each optical channel in the N wavelengths using the first light and the second light for each wavelength.

Abstract: A wireless transmitter/receiver generates a first signal which notifies timing of a time slot allocated to each wireless station device, a conversion unit converts the first signal into an optical signal, and each of a plurality of antenna units converts the first signal from the optical signal into an electrical signal and transmits the electrical signal wirelessly. The wireless station device transmits a second signal at the timing reported by the first signal. Each of the plurality of antenna units converts the second signal wirelessly received from each wireless station device into an optical signal, and the conversion unit converts the second signal from the optical signal into an electrical signal.

Abstract: This applications relates to methods and apparatus monitoring of subsea cables (100), for example subsea power or telecommunication cables, and in particular to determining a burial status for such cables. The method involves interrogating a sensing optical fibre (107) with an interrogator unit (108) to perform distributed fibre optic sensing. The sensing optical fibre (107) is deployed along the path of the subsea cable (100) and may, in some instances, form part of the subsea cable. A frequency spectrum of the respective measurement signal from at least one sensing portion of the sensing fibre (107), which corresponds to pressure variations (?P(t)) due to surface water waves (109) to determine a burial status. High frequency components of the pressure variation that are detected in any unburied section (106) are attenuated in buried sections (105).

Abstract: Provided by the embodiments of the present invention are a remote optical fiber dispersion compensation device and method, the dispersion compensation device comprising: a distance measurement module, used for measuring a remote distance to a remote access optical fiber; a channel monitoring module, used for monitoring the spectral power of a transmission service wavelength channel; and a remote optical fiber dispersion power equalization module, used for compensating the dispersion of a transmission service signal and adjusting the insertion loss of the wavelength channel according to the measured remote distance of the remote access optical fiber and the monitored spectral power of the transmission service wavelength channel.

Abstract: Methods, systems, and devices for wireless communication are described. A wireless device may identify a configuration for transmitting ranging signals in a vehicle-based communication system. The configuration may identify a plurality of channels to be used for the ranging signals and timing for the ranging signals. The wireless device may transmit the configuration to a receiver and transmit ranging signals based at least in part on the configuration. The receiver may use the ranging signals to determine a distance between the receiver and the wireless device. The receiver may use the determined distance to update positioning information or operate a motor vehicle.

Abstract: An apparatus is described. The apparatus comprises a downstream wavelength selective switch having an input port, an optical path operable to carry an optical signal, an optical source providing amplified spontaneous emission (ASE) light, an optical switch having a first input coupled to the optical path, a second input coupled to the optical source and receiving the ASE light, and an output coupled to the input port of the downstream wavelength selective switch. The optical switch couples either the first input or the second input to the output. Further included is a photodiode operable to monitor the optical signal, detect an optical loss of signal of the optical signal, and output a switch signal to the optical switch such that the optical switch couples the second input receiving the ASE light to the output whereby the ASE light is directed to the input port of the downstream wavelength selective switch.

Abstract: An optical system and method for seeding an optical transmitter includes a first optical transmitter comprising a first reflective optical amplifier and a second optical transmitter comprising a second reflective optical amplifier. The second optical transmitter is optically coupled to the first optical transmitter. The optical system also includes an optical cavity for seeding the first reflective optical amplifier with a first optical seed signal. The optical cavity is formed between the first reflective optical amplifier of the first optical transmitter and the second reflective optical amplifier of the second optical transmitter. The first reflective optical amplifier is configured to transmit a first optical signal to the second reflective optical amplifier and the second reflective optical amplifier is configured to provide the first optical seed signal by reflecting a portion of the first optical signal back to the first reflective optical amplifier.

Abstract: An apparatus includes a tail-end optical switch configured to be coupled to a broadcast star network that couples the tail-end optical switch to a head-end optical switch by a primary bidirectional optical path and a second bidirectional optical path. The tail-end optical switch having a first optical switch and a second optical switch configured to provide active switching.

Abstract: Methods and systems for redundant light sources by utilizing two inputs of an integrated modulator are disclosed and may include: an optoelectronic transmitter with first and second laser sources for providing optical signals to the transmitter, the transmitter comprising an optical modulator with a first input waveguide coupled to the first laser source and second input waveguide coupled to the second laser source, the optoelectronic receiver being operable to: configure the first laser source to provide an optical signal to the first input of the optical modulator; and if the first laser source does not provide an optical signal, configure the second laser source to provide an optical signal to the second input of the optical modulator. The first laser source may be optically coupled to the first input waveguide and the second laser source optically coupled to the second input waveguide using grating couplers.

Abstract: An optical wireless communication system for a vehicle comprises a photonic device and control electronics configured to control the photonic device. The photonic device comprises a plurality of photonic components arranged in a two-dimensional matrix array, and the control electronics are configured to control individually or in groups the photonic components of the plurality of photonic components. Each photonic component or each group of photonic components is configured, where appropriate conjointly with an optic, so as to emit and/or receive at least one optical wireless communication signal in a propagation direction that is discriminable relatively to a propagation direction of optical wireless communication signals emitted and/or received, respectively, by at least one other photonic component or by at least one other group of photonic components of the plurality of photonic components.

Abstract: A method includes modulating a digital signal via pulse amplitude modulation (PAM) and applying Nyquist shaping to the digital signal to generate a filtered digital signal. The method also includes converting the filtered digital signal into an analog signal and transmitting the analog signal in an optical communication channel via a dense wavelength division multiplexing (DWDM) scheme.

Abstract: A method of image projection including selecting a set of desired chromaticity coordinates of a projection system, the projection system including a plurality of laser sources; determining a set of parameters of an expected operational environment; and configuring each laser source to have a power ratio and a power spectrum density function generating a normalized power spectrum density function of the projection system having the set of desired chromaticity coordinates and a wavelength diversity factor of at least 2 in the expected operational environment. A projection system including an input device configured to receive a set of desired chromaticity coordinates and a set of operational parameters; a plurality of laser sources each having a power ratio and a power spectrum density function configured to generate a normalized power spectrum density function producing the set of desired chromaticity coordinates and a wavelength diversity factor of at least 2.

Abstract: A transmission method includes mapping a data signal to a symbol according to a modulation mode to generate a first electric field signal and a second electric field signal, modulating a light beam based on the first electric field signal and the second electric field signal to generate a first polarized light beam and a second polarized light beam that are orthogonal to each other, multiplexing the first polarized light beam and the second polarized light beam, applying transformation processing of changing each polarization angle of the first polarized light beam and the second polarized light beam to the first electric field signal and the second electric field signal and adding polarization information indicating a change amount caused by the transformation processing for each polarization angle of the first polarized light beam and the second polarized light beam to the first electric field signal and the second electric field signal.

Abstract: A monitoring system for a transmission line that transmits an optical wavelength multiplexed signal between the local station and a remote station, including: a first monitor means for measuring the optical power of an optical signal pertaining to the optical wavelength multiplexed signal transmitted by the local station; a second monitor means for measuring the optical power of an optical signal pertaining to the optical wavelength multiplexed signal received by the local station; and a monitoring control means for transmitting the local station's transponder wavelength information and dummy optical wavelength information, and transmitting the remote station's transponder wavelength information and dummy optical wavelength information.

Abstract: Systems, methods, and computer-readable media provide for collection of statistics relating to network traffic between virtual machines (VMs) in a network. In an example embodiment, a virtual switch hosted on a physical server provides network address information of VMs deployed on the physical server to a virtual switch controller. The controller collects this network address information from each virtual switch under its control, and distributes the aggregate address information to each switch. In this manner, the controller and each switch within the controller's domain can learn the network address information of each VM deployed on physical servers hosting switches under the controller's control. Each virtual switch can determine a classification of a frame passing through the switch (e.g., intra-server, inter-server and intra-domain, or inter-domain traffic), and statistics relating to the traffic.

Abstract: According to examples, a wavelength identification and analysis sensor may include a wavelength transmitter, operably connectable to an input or output of a wavelength selective device of a wavelength division multiplex (WDM) network, to transmit test signals on a plurality of wavelengths into the input or output of the wavelength selective device of the WDM network. A wavelength analyzer is to detect returned signals from the input or output of the wavelength selective device of the WDM network, with each returned signal being associated with one of the transmitted test signals. Further, the wavelength analyzer is to analyze the returned signals and identify, based on the analysis of the returned signals, a wavelength associated with the input or output of the wavelength selective device of the WDM network.

Abstract: An integrated apparatus with optical/electrical interfaces and protocol converter on a single silicon substrate. The apparatus includes an optical module comprising one or more modulators respectively coupled with one or more laser devices for producing a first optical signal to an optical interface and one or more photodetectors for detecting a second optical signal from the optical interface to generate a current signal. Additionally, the apparatus includes a transmit lane module coupled between the optical module and an electrical interface to receive a first electric signal from the electrical interface and provide a framing protocol for driving the one or more modulators. Furthermore, the apparatus includes a receive lane module coupled between the optical module and the electrical interface to process the current signal to send a second electric signal to the electrical interface.

Abstract: This application provides a node device implementing connection establishment for a Space Division Multiplexing (SDM) network. A first node receives a path (Path) message, which includes a plurality of label objects, each label object includes a field used to indicate a number of an optical core in a multi-core optical fiber, and idle spectrum information of each optical core. The first node then obtains an intersection set of the idle spectrum information of each optical core indicated in the path message and idle spectrum information of a corresponding optical core on a first link. The first node sends, over the first link, a path message that carries an intersection set result, where the first link is a link between the first node and an adjacent node in a direction from the first node to an end node.

Abstract: A software-defined network controller (SDN controller) defines a first network flow to be selectively implemented by a networking device according to a first network operation profile. The SDN controller defines a second network flow to be selectively implemented by the networking device according to a second network operation profile. The first and second network operation profiles are stored within a memory of the networking device to be selectively implemented based on the status of a profile selection input on the networking device. The profile selection input is a contact input in some embodiments. When the contact input is de-asserted, the networking device implements the first network flow according to the first network operation profile. When the contact input is asserted, the networking device implements the second network flow according to the second network operation profile.

Abstract: Methods and systems for redundant light sources by utilizing two inputs of an integrated modulator are disclosed and may include: an optoelectronic transmitter in a semiconductor die with first and second laser sources for providing optical signals to the semiconductor die, the transmitter comprising an optical modulator with a first input waveguide coupled to the first laser source and second input waveguide coupled to the second laser source, the optoelectronic receiver being operable to: configure the first laser source to provide an optical signal to the first input of the optical modulator; and if the first laser source does not provide an optical signal, configure the second laser source to provide an optical signal to the second input of the optical modulator. The first laser source may be optically coupled to the first input waveguide and the second laser source optically coupled to the second input waveguide using grating couplers.

Abstract: The present invention discloses an optical power equilibrium method and apparatus. The method includes: configuring a liquid crystal on silicon LCOS as a blazed grating pattern whose phase periodically changes, where each period includes three grating segments, a pixel quantity in each period does not change, and a second grating segment is located between a first grating segment and a third grating segment; monitoring power of wavelength signals in a WDM signal, where the WDM signal includes a first wavelength signal; and reducing a phase modulation depth and a pixel quantity of the second grating segment in each period at a first location if power of the first wavelength signal is greater than preset target power, so that the power of the first wavelength signal is the same as the target power, where the first location is a location at which the first wavelength signal is incident to the LCOS.

Abstract: A system includes an interface for receiving a plurality of data streams from a plurality of data sources. A multiplexor groups the plurality of data streams into a plurality of groups. A plurality of orthogonal frequency division multiplexing (OFDM) processing circuitries apply a same OFDM processing to each of the plurality of groups using a same combination of frequency and time slot combinations on each of the plurality of groups. A modulator modulates each of the OFDM processed groups onto a same signal bandwidth by applying a different, unique orthogonal function to each of the OFDM processed groups. The unique orthogonal functions defined by a path on and between the surfaces of a plurality of concentric orthogonal state spheres defining each of the different, unique orthogonal functions.

Abstract: According to embodiments of the present disclosure, apparatus is provided for protecting an optical link arranged to carry upstream optical signals and downstream optical signals. The apparatus comprises a first detector arranged to selectively detect a downstream optical signal received at a second port having a first wavelength and a second detector arranged to selectively detect a downstream optical signal received at the second port having a second wavelength different from the first wavelength. The apparatus further comprises control circuitry arranged to cause a protection switch to selectively couple a third port to the second port instead of to the first port based on the detecting by the first detector and the second detector. Also provided is a second apparatus for protecting the optical link.

Abstract: A transmitter for transmitting an optical signal in an optical communication system includes a plurality of light sources configured to output optical signals; a plurality of first optical couplers configured to multiplex the optical signals, which are output from the plurality of light sources, to generate a first optical signal, and output the first optical signal through a first output port and a second output port of each of the plurality of first optical couplers; a first monitoring unit configured to monitor the first optical signal which is output through the second output port of each of the plurality of first optical couplers; and a controller configured to control an optical output of each of the plurality of light sources on the basis of a result of the monitoring.

Abstract: According to examples, a wavelength identification and analysis sensor may include a wavelength transmitter, operably connectable to an input or output of a wavelength selective device of a wavelength division multiplex (WDM) network, to transmit test signals on a plurality of wavelengths into the input or output of the wavelength selective device of the WDM network. A wavelength analyzer is to detect returned signals from the input or output of the wavelength selective device of the WDM network, with each returned signal being associated with one of the transmitted test signals. Further, the wavelength analyzer is to analyze the returned signals and identify, based on the analysis of the returned signals, a wavelength associated with the input or output of the wavelength selective device of the WDM network.

Abstract: In some examples, a multi-wavelength power meter may include a first coupler to separate optical signals from an optical line terminal and an optical network terminal to ascertain a reduced percentage of total power related to the optical signals. A second coupler may receive the separated optical signals, combine the separated optical signals, and output the combined optical signals to an optical fiber. A filter may be communicatively connected to the optical fiber to isolate at least one specified wavelength or wavelength range of the combined optical signals. A photodiode may be communicatively connected to the filter for power measurement of the at least one specified wavelength or wavelength range.

Abstract: Embodiments of the present invention relate to method and device for measuring optical signal-to-noise ratio (OSNR). A method for measuring an OSNR of a signal of interest may comprise: obtaining spectrum of the signal of interest, the spectrum including power spectrum density distribution of the signal of interest in a channel bandwidth B; obtaining spectrum of a comparative signal that has the same spectrum characteristics as but different OSNR than the signal of interest, the spectrum including power spectrum density distribution of the comparative signal in the channel bandwidth B; and calculating the OSNR of the signal of interest by using the spectrum of the signal of interest and the spectrum of a comparative signal.

Abstract: A BOSA device having an adjustable wavelength in two directions comprises a signal transmitter section and a signal receiver section, wherein the signal transmitter section sequentially includes a laser (1-1), a semiconductor optical amplifier (SOA) (3-1), a splitter (4-1), a data upload and download port (5-1), and a first TEC temperature control module (9-1) to control temperature of the laser (1-1) so as to adjust its output wavelength, and the signal receiver section sequentially includes a filter (7-1), a photo detector (8-1), and a receiving end driving device to change an angle of the filter (7-1) with respect to the optical path so as to make a passing wavelength of the filter adjustable. The first TEC temperature control module (9-1) controls temperature of the laser (1-1), and the receiving end driving device drives the filter (7-1) to change an angle of the filter with respect to the optical path.

Abstract: There is provided an apparatus configured to estimate optical transmission performance in a transmission path of an optical signal, the apparatus including a memory, and a processor coupled to the memory and the processor configured to acquire a first index related to a first transmission performance of an optical signal transmitted through a span group between a first node and an n-th node and a second index related to a second transmission performance of an optical signal transmitted through a span or a span group between the first node and an m-th node, wherein n is an integer of 3 or more, and m is the integer satisfying m<n, and estimate a third index related to a third transmission performance of an optical signal to be transmitted through a span between the m-th node and the n-th node, based on the first index and the second index.

Abstract: A multiport optical switch is used to controllably select a specific incoming optical signal that is to be processed by an associated optical channel monitor (OCM). The OCM includes a tunable optical filter and photodetector arrangement, and is configured to measure the optical spectrum of the incoming optical signal and extract information associated with the various optical channels forming the incoming optical signal (i.e., power, wavelength, OSNR, etc., per channel in the signal). The OCM also includes a processor that generates a pair of output control signals, a first signal to control the wavelength scanning process of the tunable optical filter and a second signal to control the setting of the multiport optical switch. The second signal may also be used to perform “detuning” of a selected input of the multiport optical switch, providing the ability to adjust the power level of an input signal prior to entering the OCM.

Abstract: A passive optical network (PON) includes a first optical line terminal (OLT), a second OLT, and an optical network unit (ONU). The first OLT sends an equalization delay change message to the ONU, wherein the equalization delay change message includes an equalization delay, an upstream channel ID and a downstream channel ID corresponding to the equalization delay. The ONU receives the equalization delay change message. When the ONU tunes from the first OLT to the second OLT, the ONU obtains the equalization delay for upstream transmission according to the upstream channel ID and the downstream channel ID.

Abstract: An optical communication link that includes two nodes interconnected by an optical channel that comprises optical fiber(s), and that is used to communicate an optical signal comprising multiple optical signal wavelengths. The first node provides an optical signal onto the optical channel towards the second node, or receives an optical signal from the optical channel from the second node. A Raman pump provides Raman pump power into the optical fiber of the optical channel to thereby perform Raman amplification of the optical signal in the optical fiber. The second node determines a quality measurement of at least of optical wavelength signals transmitted by the first node to the second node. The second node also transmits information from the quality measurement back to the first node. A controller at the first node controls at least one parameter of the Raman pump in response to this transmitted information.

Abstract: A quantum key distribution system is deployed in an optical fiber network transporting classical data traffic. A source of entangled photon pairs is used to generate quantum keys. Classical data traffic is typically transported over channels in the C-band. If a pair of channels for transport of quantum data is available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in the C-band. If a pair of channels for transport of quantum data is not available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in a combined S-band and L-band. When a periodically-poled lithium niobate waveguide pumped with a laser is used for the source of entangled photon pairs, the output spectral properties are tuned by varying the temperature of the waveguide.

Abstract: A node that is colorless, directionless and contentionless includes an add/drop terminal having an add wavelength selective switch (WSS) and a drop WSS. The add and drop WSSs are each configured to selectively direct any subset of the wavelength components received at any of its inputs to a different one of its optical outputs, provided that the wavelength components of optical beams received by any two of the inputs cannot be simultaneously directed to a common one of the outputs. A plurality of transponder ports are each optically coupled to a different output of the drop WSS and a different input of the add WSS.

Abstract: An optical transmission system includes: a first light source configured to output a light wave of a first wavelength among a plurality of wavelengths; a second light source configured to output a light wave of a second wavelength; and a first detection section configured to detect abnormality in the light wave from the first light source, wherein upon detection of abnormality, a multiplexed optical signal including an optical signal of a modulated light wave generated using the light wave from the second light source in place of an optical signal of a modulated light wave generated using the light wave from the first light source is transmitted.

Abstract: Disclosed is a method and an apparatus for selecting a wavelength in a hybrid Passive Optical Network (PON) system. The method of selecting a wavelength by a wavelength selecting apparatus in a hybrid passive optical network system includes: performing synchronization with any one of a plurality of downstream wavelengths; when the synchronization is succeeded, determining whether to select the synchronized downstream wavelength for a registration to an optical line terminal; and when it is determined to select the synchronized downstream wavelength, performing the registration to the optical line terminal through the synchronized downstream wavelength.

Abstract: A sensor system is disclosed, wherein the sensor system provides output data only when the error between a plurality of measured absorption wavelengths of a gas cell and a plurality of known absorption lines for the gas cell is less than or equal to a user-defined error margin.

Abstract: An apparatus and method for providing a differential latency, DL, between an upstream, US, transmission and a downstream, DS, transmission via an optical transmission link (OTL), said apparatus comprising a measurement unit (2) configured to measure the round trip delays, RTD, of at least two measurement signals having different measurement wavelengths; and a processing unit (3) configured to derive an upstream, US, delay of at least one optical signal at an upstream wavelength from the at least two measured round trip delays, RTD, and to derive a downstream, DS, delay of at least one optical signal at a downstream wavelength from the at least two measured round trip delays, RTD, wherein the differential latency, DL, is calculated on the basis of the derived delays, RTD.

Abstract: Embodiments of the present disclosure provide an apparatus and method for detecting channel spacing and a system. The apparatus for detecting channel spacing includes a first estimating unit configured to estimate a frequency offset of a center channel according to a received signal, a second estimating unit configured to estimate a frequency offset of a neighboring channel according to the received signal, and a determining unit configured to determine channel spacing according to the frequency offset of the center channel estimated by the first estimating unit and the frequency offset of the neighboring channel estimated by the second estimating unit. With the embodiments of the present disclosure, estimation accuracy of channel spacing may be ensured, and influence of non-ideal factors on estimation value may be reduced.

Abstract: An optical line terminal (OLT) comprising a processor configured to process a first power consumption data associated with a first optical network unit (ONU) for a plurality of wavelength channels in a multiple-wavelength passive optical network (PON), and select a first target wavelength channel from the plurality of wavelength channels based on the first power consumption data in order to reduce power consumption at the first ONU, and a transmitter coupled to the processor and configured to transmit to the first ONU a tuning control message instructing the first ONU to tune to the first target wavelength channel.

Abstract: A method (10) of controlling optical signal power levelling in an optical communication network node configured to apply an optical attenuation, ?, to a pass-through optical signal. The method comprises: a. performing the following steps i. to iii. until an attenuation variation value, ??, is greater than a preselected attenuation variation threshold value (18), ??TH: i. measuring (12) an optical signal power of an optical signal; ii. calculating (14) a difference, ?P, between the measured optical signal power and a target optical signal power; iii. calculating (16) a value for the attenuation variation, ??, to be applied to the optical attenuation taking account of ?P; b. obtaining (20) a current value of the optical attenuation, ?n, and obtaining (22) a new optical attenuation value, ?n+1, in dependence on the current value of the optical attenuation, a current value of the attenuation variation, ??n, and at least an earlier value of the attenuation variation, ??n?1; and c.

Abstract: Systems and methods for conveying wavelength tuning information from a pluggable optical transceiver to a host device determining the wavelength tuning information of the pluggable optical transceiver operating in the host device; appending the wavelength tuning information as part of existing data communicated between the pluggable optical transceiver and the host device; and providing the existing data with the wavelength tuning information incorporated therewith to the host device.