Abstract: The disclosure relates to a method, an optical receiver and an optical system for compensating, at an optical receiver, signal distortions induced in an optical carrier signal by a periodic copropagating optical signal, wherein the optical carrier signal and the copropagating signal copropagate at least in part of an optical system or network, by: receiving, at the optical receiver, the optical carrier signal, wherein the optical carrier signal is distorted by the copropagating signal; determining, at the optical receiver, a period of a periodic component of the distorted optical carrier signal; determining, at the optical receiver, a periodic distortion of the distorted optical carrier signal; and generating a compensation signal to correct the distorted optical carrier signal according to the determined periodic distortion.

Abstract: Disclosed herein is a method of encoding and/or decoding data for optical data transmission along a transmission link, as well as corresponding transmitters and receivers. The data is encoded based on an adaptive constellation diagram in a 2-D plane, said constellation diagram including a first and a second pair of symbols, wherein the symbols of the first pair of symbols are located at opposite sides of the origin of the 2-D plane at a first distance di from each other, and wherein the symbols of the second pair of symbols are located at opposite sides of the origin of the 2-D plane at a second distance d2 from each other. The method comprises a step of adapting the constellation diagram by varying the ratio of the first and second distances d1, d2 such as to minimize or nearly minimize a bit error rate in the transmitted data.

Abstract: A method and system for managing execution of a local craft terminal application on a local computer system comprising accessing one of the plurality of remote network elements and obtaining therefrom a launcher application program configured to manage execution of the local craft terminal application on the local computer system, launching the launcher application program on the local computer system and determining, using the launcher application program, whether the local computer system contains an appropriate copy of the local craft terminal application, and if the local computer system does not contain the appropriate copy of the local craft terminal application, obtaining the appropriate copy of the local craft terminal application from the first one of the plurality of remote network elements.

Abstract: A Raman pumping device (10) for amplifying a data optical signal in a fiber optic transmission system, comprising first and second ports (12a, 12b) through which the data optical signal may respectively enter and exit the Raman pumping device (10), a Raman pump source (14) for generating a Raman pump signal, and at least one combiner (16) for combining the Raman pump signal with the data optical signal. The Raman pumping device (10) allows for selectively combining the Raman pump signal generated by the same Raman pump source (14), or at least parts of the same Raman pump source (14) codirectionally or counterdirectionally with the data optical signal.

Abstract: A network node (3, 4) comprising at least one client interface port (40) and a database (46, 48) storing data allowing to retrieve for a given client interface, a service associated therewith, for a given service, a client interface associated therewith. A Maintenance End Point (MEP) (50, 52) is established on the network node and is associated with an end-to-end service between a client device (10, 12) connected with said client interface port and a remote client device connected to a remote network node (3, 4). Said MEP is configured to exchange connectivity messages with a corresponding MEP (50, 52) established on said remote network node and to detect a client interface fault and a service fault based on connectivity messages received from said corresponding MEP, or based on missing connectivity messages from said corresponding MEP.

Abstract: An optical network includes an arrangement of optical nodes. An optical node of the arrangement, and corresponding method, perform optical connectivity discovery and negotiation-less optical fiber continuity verification in the optical network. An overall topology of optical connectivity provisioned for the arrangement is discovered by the optical node based on messages received from a management network communicatively coupling the optical nodes to each other. The optical node synchronizes, temporally and sequentially, with the other optical nodes based on the messages received, assigns fiber of the overall topology, based on a verification sequencing method, to verification slots of a verification sequence, and verifies continuity of fiber according to the verification slots of the verification sequence.

Abstract: Disclosed is a receiver for receiving an optical signal comprising a plurality of carriers within a predetermined frequency band. The receiver comprises means for sampling and converting each of the carriers into a set of corresponding digital signals, and a digital processing unit for processing said digital signals of said set of digital signals such as to mitigate transmission impairments of the corresponding optical carriers based on corresponding processing parameters. The digital processing unit is configured for determining such processing parameters by carrying out a corresponding parameter derivation procedure based on one of the digital signals of said set of digital signals. The processing unit is configured for sharing thus determined processing parameters for processing of other digital signals among said set of digital signals based on said shared determined processing parameters, or processing parameters derived from said shared determined processing parameters.

Abstract: Disclosed herein is a dual parallel Mach-Zehnder-modulator (DPMZM) device comprising a DPMZM 10 having first and second inner MZMs arranged parallel to each other. The first inner MZM generates an in-phase component EI of an optical signal in response to a first driving voltage VI, and the second inner MZM generates a quadrature component EQ of said optical signal in response to a second driving voltage VQ. Further disclosed is a calculation unit 52 configured for receiving an in-phase component yI and a quadrature component yQ of a desired base-band signal, and for calculating pre-distorted first and second driving voltages VI, VQ. The calculation of the pre-distorted first and second driving voltages VI, VQ is based on a model of said DPMZM 10 accounting for I-Q cross-talk, and using an algorithm that determines said first and second driving voltages VI, VQ each as a function of both of said in-phase and quadrature components yI, yQ of said base-band signal.

Abstract: A method for determining the position of an irregularity in an optical transmission fiber using an optical time domain reflectometer, the method comprising the steps of emitting a succession of sampling light pulses into the optical transmission fiber, detecting reflected light pulses resulting from the reflection of the sampling light pulses at the irregularity in the optical transmission fiber and generating corresponding time-dependent detection signals, wherein different delays are associated with detection signals corresponding to different sampling light pulses, obtaining a combined signal from the detection signals, and analyzing the combined signal for determining the position of the irregularity in the optical transmission fiber with respect to the optical time domain reflectometer, wherein the combined signal corresponds to a superposition of the detection signals.

Abstract: The invention discloses a method of amplifying an optical signal, in particular a data signal, transmitted from a first location (A) to a second location (B) via a first transmission link (10a), wherein said optical signal is amplified by means of a transmitter side remote optically pumped amplifiers (ROPA) (18) comprising a gain medium (24), wherein the gain medium (24) of said transmitter side ROPA (18) is pumped by means of transmitter side pump power (20) provided from said first location (A), characterized in that at least a part of said transmitter side pump power (20) is provided by means of light supplied from said first location (A) to said transmitter side ROPA (18) via a portion of a second transmission link (10b) provided for transmitting optical signals from said second location (B) to said first location (A).

Abstract: A method for assigning spectral resources comprises assigning spectral resources for a plurality of communication channels. The spectral resources for the plurality of communication channels comprise excess resources that are at least tentatively kept unoccupied. The excess resources of a plurality of communication channels are assigned to be spectrally contiguous.

Abstract: A system for determining a channel margin of a data transmission channel (DTC) using error correction under real-world channel conditions is described. The system includes a monitoring unit, an operating state determining unit and a data processing unit. The monitoring unit monitors data transmission along the DTC and estimates a statistical distribution of errors (H) in the transmission of data. The operating state determining unit determines a current value of an operating state parameter for the DTC. The data processing unit determines a reference channel margin associated with said current value of the operating state parameter for a reference channel and the error correction scheme employed, provides a statistical distribution of errors (HR) associated with said reference channel for said current value of said operating state parameter, compute a deviation of H and HR, and computes a reduction of the reference channel margin.

Abstract: The disclosed apparatus, system and method of the present invention provides improved solutions related to the interconnection of communication cable connectors and communication port receptacles, and more generally, for improved handling and management of communication cable connectors and communication ports. Certain example embodiments suitable for an optical communication application, for example, provide for improved laser safety at the location of an optical communication connector and/or an optical communication port. Moreover, certain example embodiments of the present invention additionally or alternatively otherwise provide for improved communication port, module, device, and/or system handling, administration and/or other management.

Abstract: An optical time domain reflectometer for determining properties of an optical transmission fiber, the optical time domain reflectometer comprising an electro-absorption modulator comprising a waveguide and two electrodes, wherein the waveguide is arranged between the electrodes, a light source configured for emitting sampling light into the waveguide, wherein the waveguide is connected or to be connected between the fiber and the light source, and a control unit for controlling the operation of the light source and a modulation voltage between the electrodes. The electro-absorption modulator is capable of assuming an absorption state, wherein the electro-absorption modulator is further configured for receiving reflected light pulses resulting from the reflection of the pulses of sampling light in the fiber, wherein the absorption of reflected light pulses in the electro-absorption modulator results in the creation of a photocurrent between the electrodes.

Abstract: Disclosed herein is a decoder 10 for decoding a family of L rate compatible parity check codes, said family of parity check codes comprising a first code that can be represented by a bipartite graph having variable nodes, check nodes, and edges, and L?1 codes of increasingly lower code rate, among which the i-th code can be represented by a bipartite graph corresponding to the bipartite graph representing the (i?1)-th code, to which an equal number of ni variable nodes and check nodes are added, wherein the added check nodes are connected via edges with selected ones of the variable nodes included in said i-th code, while the added variable nodes are connected via edges with selected added check nodes only. The decoder comprising L check node processing units 14, among which the i-th check node processing unit processes only the check nodes added in the i-th code over the (i?1)-th code, wherein said L check node processing units 14 are configured to operate in parallel.

Abstract: A set of media channel (MCh) widths is determined for an optical network. Based on a topology of the network, a first set of original MCh widths are computed for tentative use in the optical network, the first set of original MCh widths defining a target spectral efficiency. A reduced set of new MCh widths are generated from the first set of MCh widths by respectively mapping each of the original MCh widths of the first set of original MCh widths to a corresponding, or respective, new MCh width. An optimization algorithm is used in an example embodiment to facilitate the mapping.

Abstract: A first optical path and a second optical path have a common path branching point. An OTDR sampling optical signal is emitted into the first optical path and into the second optical path through the common path branching point. At least one predefined optical property of the OTDR sampling optical signal emitted into the second optical path is altered and/or of a reflection of the OTDR sampling optical signal received from the second optical path is altered. An OTDR reflected optical signal resulting from a reflection of the OTDR sampling optical signal on the first optical path and/or from a reflection on the second optical path is detected. The OTDR reflected optical signal is analyzed to determine, based on the at least one predefined optical property, whether the OTDR reflected optical signal resulted from a reflection on the first optical path and/or on the second optical path.

Abstract: Disclosed herein is a method of transmitting a data stream from a first location to a second location through an optical network, as well as a corresponding performance monitoring unit, a transmitting arrangement and a receiving arrangement.

Abstract: Disclosed is a service provisioning tool and method for determining favorable implementations of a service in a grid-less optical network, wherein said service provisioning tool is configured to assign total cost values to a given implementations, select the implementation or a group of implementations having the lowest cost, wherein said total cost values are based on —cost values regarding selectable data rates on individual links, —cost values regarding necessity to install additional equipment, —cost values regarding selectable signal frequency bands. One or more of said cost values are dynamically changing as a function of one or more of the degree of utilization, the lifetime of the service, the time available for establishing the service, a modulation format and a signal power.

Abstract: A phase modulation device is provided that comprises a retardation device and a control device. The retardation device is characterized by first and second polarization eigenstates SOPf and SOPs. Light polarized according to the second polarization eigenstate SOPs acquires, upon passing through said retardation device, a delay with regard to light polarized according to the first polarization eigenstate SOPf, which delay corresponds to ?/2±30%, preferably ?/2±20% and most preferably ?/2±10%. The retardation device is arranged to receive input light having a polarization state SOPf; that defines an angle with respect to one of the first and second polarization eigenstates SOPf, SOPs within a predetermined angle range and to emit output light. The control device is configured to control at least one of a change of the angle between the polarization state SOPi; of the input light and the respective polarization eigenstate SOPf, SOPs by less than 0.1*?, preferably less than 0.05*? and most preferably less than 0.