Abstract: Disclosed herein is a method for transmitting digital data in a super channel, in which a set of carriers are packed in a predetermined bandwidth. The set of carriers comprises higher and lower edge carriers having the highest and lowest wavelengths, respectively, among said set of earners, wherein data is transmitted via the higher and lower edge carriers using a corresponding modulation format, each modulation format using a constellation diagram comprising a number of symbols, wherein a binary address is associated with each symbol.

Abstract: Disclosed herein is a method of assigning a wavelength to a given light path in a wavelength switched optical network, as well as a corresponding routing engine and computer program. The method comprises the following step.

Abstract: A wavelength selective switching device comprises a plurality of input paths for receiving optical signals, a plurality of output paths for emitting the optical signals, and a switching unit for selectively directing the optical signals from the input paths to the output paths. The switching unit comprises a reflective area adapted to be concurrently illuminated by a first optical signal from a first input path among the plurality of input paths, and by a second optical signal from a second input path among the plurality of input paths, the second input path being different from the first input path, and to concurrently direct the first optical signal to a first output path among the plurality of output paths and the second optical signal to a second output path among the plurality of output paths, the second output path being different from the first output path. Said first output path and said second output path are spatially separated by said first input path and said second input path, or vice-versa.

Abstract: A system (10) for detecting a level of dirtiness of a filter mat (20) of an airflow cooling system for telecommunications equipment, the system (10) comprising a detector (12) for detecting fluorescent or reflected light backscattered at at least one part in (22) of the filter mat (20) comprising or treated with a fluorescent or reflective material, wherein the detector (12) comprises a light source (12a) for illuminating said at least one part (22) of the filter mat (20) with sampling light, and a photosensor (12b) for detecting fluorescent or reflected light backscattered at said at least one part (22) of the filter mat (20) caused by the illumination thereof with sampling light, wherein the system (10) is configured for inferring the level of dirtiness of the filter mat (20) from the amount of detected fluorescent or reflected light.

Abstract: The present invention relates to an optical network element (30, 34) comprising a wavelength selective switch, WSS, (432, 136) with one or more input ports, a working output port (38) and a separate protecting output port (40), the WSS (432) being configurable to a working configuration, in which one or more channels are routed from said one or more input ports to the working output port (38), and being configurable to a protecting configuration, in which said one or more channels or a subset thereof are routed from said one or more input ports to the protecting output port (40), or with a working input port (42) and a protecting input port (44) and with one or more output ports, the WSS (136) being configurable to a working configuration, in which one or more channels are routed from the working input (42) port to the one or more output ports, and being configurable to a protecting configuration, in which one or more channels are routed from the protecting input port (44) to the one or more output ports, a c

Abstract: A method of assigning performance indicators to objects of a network employing a computation to assign performance indicators to said objects of said network such that a sum of said performance indicators of objects along a given path in said network in relation to a first threshold value indicates whether said path fulfils a predetermined criterion, and/or indicates whether said path does not fulfil said predetermined criterion. A method of evaluating a performance of a path in a network based on the performance indicators involves the steps of calculating a sum of performance indicators for said objects along said path and evaluating a performance of said path by comparing said sum against a first threshold value.

Abstract: A network element of a software-defined network comprises a data transfer interface (210) for receiving and transmitting data and a processing system (215) for constructing a software-defined data path and a fixed-functionality data path such as for example an IP/MPLS or L2 switching path. The software-defined data path comprises look-up tables for selecting software-defined actions and the fixed-functionality data path defines fixed-functionality actions. The processing system is adapted to convert metadata associated with data managed by the software-defined data path to a data format suitable for the fixed-functionality data path when one or more of the fixed-functionality actions are needed in conjunction with forwarding the data. One of the fixed-functionality actions is selected at least partly on the basis of which one of the look-up tables was most recently accessed, and the determined fixed-functionality action is carried out so as to initiate the one or more needed fixed-functionality actions.

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 n1 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 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 super-position of the detection signals.

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.

Abstract: Enclosed herewith is a method for protecting a link in an optical network configured for transmitting digital data employing a predetermined modulation format which comprises a number of symbols in a constellation diagram. A binary address is associated with each symbol. The modulation format allows for a constellation distortion, according to which the relative positions of constellation points in the constellation diagram are varied in a predetermined way by a predetermined degree.

Abstract: The present invention relates to performing chromatic dispersion estimation in a receiver of an optical communication system. Here, the signal received by the receiver includes frames, each comprising a training portion and a data portion. The training portion comprises a plurality of identical pattern sequences. Different settings are applied to an equalizer to generate a plurality of equalized signals from at least one of the received frames. Then, at least one correlation value is calculated between a first pattern sequence and a second pattern sequence of the equalized signals and a final correlation value is derived from the respective correlation values. The setting of the equalizer corresponding to the equalized signal providing the highest final correlation value is selected to provide the chromatic dispersion estimation.

Abstract: A Raman pumping arrangement for amplifying a data optical signal (40) has a Raman pump (12) for generating a Raman pump signal (44;45), an optical supervisory channel receiver (14) for receiving an optical supervisory channel signal (42) an amplification fiber (15) arranged such that the data optical signal (40), the optical supervisory channel signal (42), and the Raman pump signal (44;45) are transmitted therethrough; and a control unit (13) configured for controlling the operation of the Raman pump (12); wherein the control unit (13) is configured for setting the Raman pump (12) in an operation mode or a start-up mode; wherein in the operation mode, the Raman pump (12) provides an operation pumping power (120), and wherein in the start-up mode, the Raman pump (12) provides a start-up pumping power (122).

Abstract: In a method and system for decoding a differential M-ary phase or quadrature amplitude modulated signal, the incoming signal is decoded according to a plurality of different decoding rules, wherein said plurality of decoding rules correspond to different values of a resulting frequency difference or mismatch between a signal frequency and a local oscillator reference frequency. The invention allows to increase a tolerance window for the maximal allowable frequency offset, and thus helps to speed up an initial locking process or to allow for equipment which has a lower tuning granularity.

Abstract: A cable clamp for clamping a cable with respect to a through hole of a solid object is presented. The cable clamp includes first and second elements (102, 103) and retainer devices (105) for keeping the first and second elements with respect to each other so that the cable gets clamped between the first and second elements and the cable clamp gets locked to the edges of the through hole with the aid of first claws extending over the edges of the through hole on a first side of the solid object and with the aid of second claws capable of extending over the edges of the through hole on the second side of the solid object. The cable clamp can be inserted into the through hole when the first and second elements are tilted with respect to each other so that the first claws are nearer to each other.

Abstract: A method and a device are provided for processing data in an optical network. The method includes the steps of events of a login scan are recorded by a first optical network element; the events are conveyed to a second optical network element; and the events are processed by the second optical network element. A communication system is described that includes the device.

Abstract: Disclosed herein is a modulator (50) for polarization-division multiplexing (PDM) transmission. The modulator (50) comprises first and second DP-MZMs (12, 28) associated with first and second polarizations, each DP-MZM (12, 28) having an input for an in-phase and a quadrature driving signal for modulating the in-phase and quadrature components of an optical signal according to respective transfer functions, and a detector (58) suitable for detecting light comprising at least a portion of the light outputted by the first DP-MZM (12) and a portion of the light outputted by the second DP-MZM (28). The modulator (50) is adapted to superimpose a first pilot signal on one of the in-phase and quadrature driving signals of the first DP-MZM (12) and on one of the in-phase and quadrature driving signals of the second DP-MZM (28), and a second pilot signal on the respective other of the in-phase and quadrature driving signals of the first and second DP-MZMs (12, 28).

Abstract: An optical network has an optical line termination coupled to a backbone network, in particular to an optical long haul network and a local exchange coupled to an optical access network. The local exchange provides an optical connection between an optical network unit of a tree topology and the optical line termination, which is part of a ring topology. There is also described a method for processing data in such an optical network.

Abstract: A method and a device for processing data in a communication network, wherein a first node is served by a second node and communicates with a third node. The first node informs a fourth node to process data destined for the third node. The second node, the first node and the fourth node are connected via a transport network that is capable of a point-to-multipoint connection.

Abstract: A communication network has a plurality of network elements (NEs) and links between the NEs. A method includes computing, at a central controller, a data path from the source NE to the destination NE along a number of intermediate NEs, sending, from the central controller, central control messages to all or at least a plurality of NEs among the source NE, the intermediate NEs and the destination NE, the central control messages including explicit path information, the explicit path information in at last some of the central control messages comprising more information than needed by the recipient NE for its set-up for data transport along the path, and sending distributed control messages between NEs of the path, the distributed control messages being based on at least one central control message received by one of the NEs.