Abstract: In a method for interrogating at least one optical sensor coupled to an optical path, at least two time-shifted optical signals are fed into the optical path and reflected optical signals of the at least two probe signals created by the at least one optical sensor are detected. Each detected reflected optical signal is assigned to one of the at least one optical sensor and a correct optical frequency is assigned to each detected reflected optical signal. An absolute value or a value range or a change of a value or value range of the parameter to be sensed is determined from the one or more of the following physical conditions: the optical reflection signals, the reflectivity of the at least one optical sensor, and the frequency of each detected optical reflection signal, or from one or more dependencies that link these physical conditions.

Abstract: A method for providing a maximum channel capacity per optical channel in an optical wavelength division multiplexing, WDM, transmission system is described. The WDM transmission system includes transceivers using multiple optical channels in a WDM channel grid to transport optical signals modulated with a modulation format with a signal symbol rate, SR, via an optical transmission link, OTL, along an optical path from a transmitting transceiver to a receiving transceiver. A channel capacity of the optical channel is maximized while a calculated channel margin, CM, is maintained above a preset minimal channel margin value.

Abstract: There is provided a technique of securing clock synchronization between master clock node (MCN) and client clock node (CCN). During a cycle of exchanging PTP messages between MCN and CCN, MCN generates an associated paired message for each PTP message generated thereby and informative of t1 or t4 timestamps provided by MCN and sends each paired message to a validation entity (VE) via a secured channel between MCN and VE. When PTP messages traverse transparent clock nodes (TCN) between MCN and CCN, each TCN generates a paired message for each version of PTP message updated thereby and sends each generated paired message to VE via a secured channel between respective TCN and VE. VE uses the received paired messages to provide a validation of the cycle, wherein synchronization-related task(s) (e.g. clock correction by the client clock node, etc.) are provided only subject to successful validation of the cycle by VE.

Abstract: The present disclosure relates to an optical time domain reflectometry method including the steps of feeding a plurality of unipolar optical probe signals to a near end of an optical path under test, receiving a corresponding plurality of reflected unipolar optical receive signals, creating a corresponding plurality of digital receive data signals, calculating at least one correlation signal by correlating the digital receive data signals with a bit sequence corresponding to a respective probe bit sequence, and determining the signal propagation delay between the near end of the optical path and a respective reflective position. The present disclosure also relates to an optical time domain reflectometry system in which this method is implemented and a computer program having instructions to cause the optical time domain reflectometer and to execute the method herein.

Abstract: There is provided a technique of establishing encryption keys for communication between 1st peer and 2nd peer via a data path. The technique comprises: by each peer, using input keying material to independently generate equivalent pairs of peer encryption keys (PEKs), verifying equivalence of the generated PEK pairs, and using by 1st peer and 2nd peer the verified PEK pairs to become in possession of equivalent pairs of session encryption keys (SEKs). Verifying comprises: generating by 1st peer a first handshake (HS) message encrypted by PEK Tx1 and sending the first HS message to the 2nd peer via the data path; decrypting by the 2nd peer the first HS message using the PEK Rx2, generating a second HS message encrypted by PEK Tx2, and sending the second HS message to the 1st peer via the data path; and decrypting the second HS message by the 1st peer using PEK Rx1.

Abstract: An apparatus adapted to perform spectrometric measurements, said apparatus comprising a tunable laser light source adapted to generate a laser light with an excitation wavelength supplied to an optical sensor which produces a sample specific response light signal; an optical reference filter adapted to measure laser light with the excitation wavelength fed back as a reference signal to provide wavelength calibration of the tunable laser light source; at least one optical measurement filter adapted to measure the sample specific response light signal produced by the optical sensor, wherein the optical reference filter and the at least one optical measurement filter are thermally coupled to maintain a constant wavelength relationship between the filter characteristics of the optical filters.

Abstract: Allowing a network function (such as a router, firewall or SD-WAN endpoint) or service chain of network functions to transparently access a network uplink, while also allowing a set of management entities to access the same link without interference or configuration. To the extent that a conflict arises between ports allocated to the management functions and to the network functions, the relevant port is automatically removed from use by management functions and allocated to network functions to end the conflict.

Abstract: An apparatus for management of a spectral capacity of a wavelength division multiplexing, WDM, system includes at least one pair of transmission fibers provided for transporting optical signals. Each transmission fiber of a transmission fiber pair is connected to a first port of an optical circulator having at least two additional ports and adapted to transmit an incoming optical signal entering one of its ports via its next port. WDM subsystems configured with counter-propagating assignable wavelengths are connected to associated ports of the optical circulator of the apparatus.

Abstract: A computer-implemented method for reducing service disruption times in a network functions virtualization, NFV, network infrastructure includes at least one universal customer premise equipment, uCPE, having hardware resources used for running virtual network functions, VNFs, on virtual machines, VMs. In response to a request for substituting an implemented virtual network function, VNF, linked to other virtual network functions, VNFs, in a VNF service chain by another substitution VNF resource allocation ratios of available hardware resources of the universal customer premise equipment, uCPE, are automatically increased from a default value by oversubscription to provide the hardware resources required by the substitution VNF.

Abstract: The present invention relates to a method for optimizing performance of a multi-span optical fiber network. Each span has an associated optical transmission fiber connected to an associated optical amplifier. Gain and output power of the associated optical amplifier are respectively controlled independently. An amplifier noise figure respectively depends on the gain of the associated optical amplifier, with each associated optical amplifier further connected to launch optical signals into a remainder of a corresponding optical transmission line. The method includes the steps of for each span, computing the amplifier noise figure and a non-linear noise generated in the span based on information about the span and using the computed amplifier noise figure and the computed non-linear noise to compute an optimum launch power, and optimizing performance of the multi-span optical fiber network based on the computed optimum launch powers of all spans.

Abstract: An optical endless phase shifting device includes a Mach-Zehnder structure operated in push-pull configuration and that creates a differential phase shift. The first stage outputs combined signals which are phase shifted by a phase shift of zero or ? in the second stage by phase shifters provided in both arms of the second stage or in a first arm only. These additionally phase-shifted signals are combined to at least one output signal. A control device controls the phase shifters such that endless shifting capability is provided by switching one of the phase shifters or the single phase shifter of the second stage to the respective other value when the differential phase shift reaches a given range of the differential phase shift of [0;?/2] in the configuration with two phase shifters in the second stage or [0;?/2] in the configuration with only one phase shifters in the second stage.

Abstract: A method and system of correcting a packet delay variation, PDV, of express traffic comprising high-priority express packets interspersed at a transmitter (2) by a preemption mechanism with a best-effort traffic comprising low-priority best-effort packets, wherein the method comprises the steps of: calculating (S1) at the transmitter (2) a preemption delay value, PRDV, which indicates a preemption delay, PD, introduced by the preemption mechanism; writing (S2) the calculated preemption delay value, PRDV, into a delay header field of a header of a high-priority express packet transmitted by said transmitter (2) via a signal line (4) to a receiver (3); extracting (S3) the preemption delay value, PRDV, from the delay header field of the header of the high-priority express packet received by the receiver (3) via the signal line (4) from the transmitter (2); calculating (S4) at the receiver (3) a variation compensation delay, VCD, value by subtracting the extracted preemption delay value, PRDV, from a predetermine

Abstract: The invention relates to a method for optically sensing a parameter of the group of temperature, humidity or mechanical stress using at least one optical sensor which includes a chirped Bragg grating and an optical reference reflector.

Abstract: An apparatus for automatic amplifier gain setting of an optical amplifier, said apparatus comprising an optical channel counter, OCC, unit configured to detect a number of channels present in an optical transmission spectrum; a determination unit configured to determine an average power per channel calculated by dividing a measured total power of a signal input and/or signal output of the optical amplifier by the number of channels detected by said optical channel counter, OCC, unit and a gain adjustment unit configured to adjust the amplifier gain of said optical amplifier automatically depending on a calculated power difference between a predetermined desired power per channel and the determined average power per channel provided by said determination unit.

Abstract: The invention relates to a method for migrating data traffic from an existing optical WDM transmission system to a new optical WDM transmission system, the existing optical WDM transmission system using a first optical transmission band and the new optical WDM transmission system being capable of using a second optical transmission band. The second optical transmission band at least partially includes the first optical transmission band and a further extension band that does not overlap with the first optical transmission band, the method including the steps of. According to the invention, a migration filter device is used in order to connect, during a migration phase, the network nodes of the existing system and the network nodes of the new system to the network paths that have been used by the existing system. During the migration phase, both systems are operated in parallel, with the new system using the extension band only.

Abstract: A system 1 for remote sensing of information to be transmitted, said system 1 comprising; an optical time-domain reflectometer, OTDR, 2 adapted to transmit an optical probe signal OPS into an optical fiber 3 and to measure a backscattered signal power; and at least one electro-optical signaling unit 4 connected to said optical fiber 3, wherein the electro-optical signaling unit 4 is configured to change an attenuation and/or a reflection of the optical probe signal OPS depending on at least one signal provided by one or more signal sources 5 in response to the information to be transmitted.

Abstract: The invention relates to a storage tray for protecting one or more optical fibers mechanically coupled to an optoelectronic device, characterized in that it is configured to be capable of coupling with the optoelectronic device, and comprising a fiber storage portion which is configured to receive and store the one or more optical fibers. The present invention also relates to an assembly comprising a storage tray according to the invention, and an optoelectronic device, wherein one or more optical fibers are coupled to the optoelectronic device, and wherein the one or more optical fibers are stored in the fiber storage portion of the storage tray.

Abstract: An electro-optical assembly comprises a substrate having a support-surface, and a photonic integrated circuit (PIC) mounted with a contact surface on the support-surface. The (PIC) comprises an integrated optical waveguide structure defining at least two waveguide end faces, at an edge surface of the PIC, perpendicular to its contact surface, and forming optical ports. An optical coupling device, mounted with a contact surface on the support-surface, optically connects at least two optical fibers to the PIC and comprises an optical waveguide structure-defining at least two front waveguide end faces provided at a front edge surface thereof, perpendicular to its contact surface. The number of front waveguide end faces corresponds to the number of the waveguide end faces. The optical coupling device is positionable during an active positioning process to align the respective waveguide end faces. A method of manufacturing such an electro-optical assembly is also provided.

Abstract: There is provided a technique of clock managing in a packet data network implementing a time-transfer protocol. The technique comprises: modifying, by the timing-server, a timestamp record to enable a controllable access to data informative of the least significant part of clock-informative data (CLSP data), wherein modifying the timestamp record comprises modifying the least significant part of the timestamp record (RLSP) to comprise the CLSP data in an encrypted form or to comprise values substituting, in a predefined manner, the CLSP data; transferring the modified timestamp record to all timing-clients, wherein CLSP data are transferred in a controllable access manner; enabling access to the CLSP data merely to authorized timing-clients among the plurality of timing-clients; and enabling the authorized timing-clients to obtain the CLSP data and synchronize the respective clocks using the CLSP data together with data informative of the most significant part of the clock-informative data.

Abstract: Dynamically allocating workloads to a fixed number of CPU resources within a compute platform. Determining whether a workload should be in a Dedicated Class of workloads and assigned to a dedicated CPU resource or in a Shared Class of workloads that is handled by a set of at least one shared CPU resource, wherein a shared CPU resource may service more than one workload. The determination may be made based on a comparison of a parameter from two samples of a parameter taken at different times. The determination may be made using metadata associated with the workload. The determination may be made repeatedly so that some workloads may change from being in the Dedicated Class to the Shared Class or from the Shared Class to the Dedicated Class. High availability virtual network functions may be handled economically by deeming the failover workloads to be in the Shared Class.