Abstract: Provided is a method for reducing the impact of transient effects in an optical network. The optical network includes at least one span, and an optical signal having a plurality of sub-bands travels through at least one span of the at least one span of the optical network. Each of the at least one span has associated amplifiers and the associated amplifiers are connected to launch optical signals into a remainder of a corresponding optical transmission line. Respectively one of the sub-bands of the optical signal traveling through the span is amplified by one of these associated amplifiers. Each of the associated amplifiers includes at least one control element for controlling gain and tilt of the corresponding amplifier.

Abstract: A method for automatic detection of antenna site conditions, ASC, at an antenna site, AS, of an antenna, A, the method comprising the steps of providing (S1) signal source observations, SSO, derived from signals received by the antenna, A, from at least one signal source, SS, and transforming (S2) the signal source observations, SSO, into images fed to a trained image-processing artificial intelligence, AI, model which calculates antenna site conditions, ASC, at an antenna site, AS, of the respective antenna, A.

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: 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: 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: 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: 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: 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.

Abstract: There are provided a method and system for assessing latency of ciphering end point of secure communication channel. The method comprises: generating a test traffic comprising a series of original data packets, wherein, for each original data packet, size of a given packet is uniquely indicative of the packet's place in a sequence of data packets in the series and enables unique correspondence with a size of the given packet upon its encryption; successively transmitting the original packets to the ciphering end point, whilst associating with respective departure time stamps; receiving encrypted packets from the ciphering end point and associating them with respective arrival time stamps; using a size of a given encrypted packet with a timestamp TSa to identify a size of a matching original packet, its place in the sequence of original packets and, thereby, its departure timestamp TSd, thus giving rise to a plurality of timestamp pairs (TSd; TSa).

Abstract: A process for using a boot loader to load a set of boot commands to a device such as an embedded system before loading a system application. The process may use a combination of a read-only boot source and a pair of upgradable boot sources. Process also includes a power cycle to put system into a known state. An alternative process may simply use a pair of upgradable boot sources. The processes are resilient to failed updates of an upgradable boot source. After a successful update of an upgradable boot source, a request for a power cycle causes the device to immediately enter a known state and use the updated upgradable boot source.

Abstract: Disclosed is a method for determining the link latency of an optical transmission link which includes an end node at each end and one or more pass-through nodes. Each pair of neighboring nodes is connected, at a connection port of each node, by an optical connecting path. Each pass-through node includes an optical pass-through path between its connection ports. The optical connecting paths and optical pass-through paths form an optical link path. A delimiter device includes a delimiter element provided at each connection port of each node. The delimiter element forms a demarcation within the optical link path.

Abstract: A photonic chip includes a connecting means, a substrate, and a waveguide layer. The photonic integrated waveguide and the optical fiber each have a front end portion. The connecting means includes a groove configured to receive the front end portion of the optical fiber. The groove is essentially U-shaped in its cross section, and the groove has a bottom surface and two inner side surfaces. A least one of both inner side surfaces of the U-shaped groove has a coating of an elastic material configured to hold in place the optical fiber after it is inserted into the groove. The invention further relates to an optical device which includes a photonic chip and an optical fiber, as well as a method or production of such a photonic chip.

Abstract: There is provided a method of clock management in a packet data network (PDN) implementing a time-transfer protocol and a clock controller configured to operate therein. The clock controller is configured to: obtain topology data informative of a master clock node and a slave clock node constituting end points of a PTP path in the PDN and further informative of at least part of transit nodes of said PTP path; periodically obtain data informative of queue size and link rate characterizing, during a collection period, the at least part of transit nodes in master-slave (MS) and slave-master (SM) directions; for each collection period, use the obtained queue-related data to estimate queue-induced delay asymmetry of the PTP path; and send the estimated value of queue-induced delay asymmetry to the slave node, the estimated value to be used by a clock residing on the slave node as delay asymmetry correction parameter.