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.

Abstract: A method and apparatus for automatic determination of a fiber type of at least one optical fiber span used in a link of an optical network, the method comprising the steps of measuring a length of said optical fiber span; measuring a chromatic dispersion of said optical fiber span; determining a fiber dispersion profile of said optical fiber span on the basis of the measured length and the measured fiber chromatic dispersion; and determining a fiber category and/or a specific fiber type of said optical fiber span depending on the determined fiber dispersion profile.

Abstract: A method and apparatus for logging transient events of an optical fiber span within a fiber optic system, the method comprising the steps of sampling measured values of at least one signal parameter of an optical signal transported through said optical fiber span, OFS; processing the sampled measurement values to detect an occurrence of a transient event during transport of the optical signal through said optical fiber span, OFS; and providing each detected transient event with a time stamp for correlation with other monitored events within said fiber optic system.

Abstract: A hybrid wavelength division multiplexing system wherein one or more intensity modulated signals generated by optical amplitude modulators are co-propagated with one or more phase modulated signals generated by optical phase modulators, wherein a drive voltage of said optical amplitude modulator is adapted to reduce an extinction ratio of the intensity modulated signal to minimize a cross-phase modulation impact on the co-propagating phase modulated signals.

Abstract: A holding device for holding cylindrical fiber optical components comprising at least one stackable body each having at least one recess adapted to receive cylindrical fiber optical components.

Abstract: A wavelength division multiplexing, WDM, network comprising an apparatus adapted to manage a frequency spectrum in the wavelength division multiplexing, WDM, network, the apparatus comprising an adjustment unit adapted to adjust a frequency offset between carriers for each individual carrier depending on performance characteristics of the individual carriers.

Abstract: The invention relates to an optical interference filter device which defines a first periodic filter frequency response between a first filter output port and a filter input port and a second periodic filter frequency response having the same free spectral range as the first periodic frequency response between a second filter output port and the filter input port. The first and second periodic filter frequency responses are shifted versus each other by a predetermined optical frequency distance.

Abstract: Disclosed is an optical multichannel transmission and/or reception module, in particular for high-bitrate digital optical signals, with a housing having multiple optical input ports and/or optical output ports and containing an electric assembly and an essentially flat opto-electric module connected electrically to the electric assembly. Multiple electro-optic transmission elements and/or multiple opto-electric reception elements are located on or in the opto-electric module. The opto-electric module has an optical coupling area on one of its surfaces that is connected to the respective first ends of multiple optical waveguides. The opto-electric module has multiple optic paths for optical connection of each first end of an optic waveguide with an associated electro-optic transmission element and/or an associated opto-electric reception element.

Abstract: A method for facilitating coordinated multipoint communication providing a plurality of network interface devices for measuring synchronization accuracy in the backhaul network; creating an actual coverage map for the coordinated multipoint communication analyzing the created actual coverage map to determine whether the backhaul network is sufficient for a selected coordinated multipoint technique; if the backhaul network is not sufficient determining one or more key performance indicators creating a conditional coverage map; comparing the actual coverage map with the conditional coverage map; reconfiguring the wireless communication network if the actual coverage map does not match the conditional coverage map.

Abstract: There are provided a system and method of assessing latency of forwarding data packets in virtual environment. The method comprises: generating packet signatures SGD and SGA respectively for departing and arriving data packets; maintaining a first data structure comprising records related to departing packets associated with a first virtual function (VF), each record informative of SGD and registered departure time TD of a given departing packet; responsive to registering arriving time TA of a given monitored arriving packet SGA associated with a second VF, searching the first data structure for a record matching a matching condition SGD=SGA; modifying the matching record to become informative of latency ?T=TA?TD and adding the modified record to a second data structure; and using data in the second data structure for assessing latency of forwarding packets from the ingress virtual port to the egress virtual port.

Abstract: A Maintenance Entity Group, MEG, End Point, MEP, of a subnetwork within a multi-domain network, said MEP comprising an encapsulation unit configured to encapsulate SOAM frames received by a passive Service Access Point, SAP, of the MEP and a decapsulation unit configured to decapsulate encapsulated SOAM frames received by an active Service Access Point, SAP, of the MEP.

Abstract: Disclosed is an optical coupler device, especially for monitoring purposes in an optical point-to-point transmission link, which includes a first, a second and a third optical port and is configured to transmit a first optical signal received at the first optical port to the second optical port and to transmit a second optical signal received at the second optical port to the first and third optical port according to a monitoring split ratio with respect to the optical power of the second optical signal, the first and second optical signal having a wavelength lying in a first optical band. The device is further configured to transmit a third and a fourth optical signal received at the third and the second optical port to the respective other optical port, the third and fourth optical signal having a wavelength lying in a second optical band. The device is controllable with respect to the monitoring split ratio and includes a control means adapted to receive a control signal.

Abstract: There are provided a clock node, a controller, a method of operating the clock node and a method of operating the controller in a time distribution network (TDN) comprising the controller being in data communication with the clock nodes via a control path. The method of operating the clock node comprises: sending, from the clock node via the control path to the controller, a first timestamp-related data; receiving, by the clock node via the control path from the controller, clock-recovery control data generated by the controller using the first timestamp-related data received from the clock node; processing the received clock-recovery control data to extract data usable for phase and frequency recovery; and using the extracted data to steer frequency and phase characterizing the clock node.

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: The invention relates to a method for establishing a communication channel, preferably an embedded control channel, between a central network node and at least one network unit to be integrated in a communication network including the central network node and an arbitrary but limited number of network units. The central network node is adapted to create and output a wavelength-division multiplex (WDM) downstream signal including downstream channel signals to be transmitted to the network units and to receive a WDM upstream signal including upstream channel signals created by the network units.

Abstract: The invention relates to a method for creating a control channel in an optical transmission signal, wherein the optical transmission signal (SDS,i, SUS,i) includes an optical carrier frequency component, a higher frequency modulation component carrying user information to be transported from a first end to a second end of an optical transmission link and a lower frequency modulation component carrying control information, the higher frequency modulation component realizing a user channel and the lower frequency modulation component realizing the control channel, and wherein the lower frequency modulation component is created by amplitude modulation. According to the invention, the lower frequency modulation component includes a binary digital pilot tone signal component which corresponds to a pilot tone signal having a predetermined pilot tone frequency (fi).

Abstract: The invention relates to an optical WDM transmission network including at least one optical line terminal, a remote node and a plurality of optical network units. The at least one optical line terminal is connected to the optical remote node via an optical WDM path. Each optical network unit is connected to the optical remote node via an optical distribution path.

Abstract: A pair of brackets to allow a component with a chassis of width W to be installed in one of three standardized racks, a wide gap rack, a narrow gap rack, or an intermediate gap rack. Each bracket having a corner between a short leg and a long leg, longer than the short leg. The brackets may also be used to mount the component to a wall instead of installed in a standardized rack.

Abstract: A fiber temperature control assembly comprising a spool holding element adapted to hold a fiber spool and a compression element adapted to press fiber windings of a doped optical fiber wound around the fiber spool against said spool holding element being in thermal contact with a heating and/or cooling element of said fiber temperature control assembly.

Abstract: A transmitter with at least one optical modulator adapted to modulate the optical signal output by a laser source to generate a modulated optical signal, wherein the optical signal output by the laser source is tapped and supplied to a monitoring circuit comprising an optical front end configured to select signal components of the tapped modulated optical signal and to convert the selected signal components of the tapped modulated optical signal into analog signals, and comprising at least one analog-to-digital converter, ADC, adapted to perform equivalent-time sampling of the analog signals to provide digital signals processed by a processing unit to monitor signal quality of the modulated optical signal.