Telefonaktiebolaget Lm Ericsson (publ)

Ericsson Ab

Fabio Cavaliere

Luca Giorgi

Giulio Bottari

Stefano Stracca

Luca Poti

Stefano Ruffini

Ernesto Ciaramella

Paola Iovanna

Filippo Ponzini

Marco Secondini

Marco Presi

Francesco Testa

Paolo Debenedetti

Gianluca Meloni

Antonio D'Errico

Enrico Forestieri

Renato Grosso

Roberto Sabella

Pierpaolo Ghiggino

Francesco Fresi

Gianmarco Bruno

Alberto Bianchi

Antonio Malacarne

Vito Sorianello

Tommaso Catuogno

Roberto Magri

Stefan Dahlfort

Marzio Puleri

Marco Romagnoli

Roberto Proietti

Philip Nibbs

Giampiero Contestabile

Jacob Österling

Elmar Trojer

Kim Laraqui

Antonella Bogoni

Gianluca Berrettini

Tommaso Foggi

Stefano Chinnici

Emma Matarazzo

Daniele Ceccarelli

Gabriele De Angelis

Giovanni Fiaschi

Fabio Falconi

Peter Olanders

Erin Seder

Antony Thorley

Andrea Chiuchiarelli

Pallab Choudhury

Luca Banchi

Nicola Calabretta

Giancarlo Gaimari

Stefano Brugioni

Michele Midrio

Menelaos Ralli

Jacob ÖSterling

Methods and apparatus are provided for transmitting synchronization data over a FlexE communications link. In an example aspect, a method of transmitting synchronization data over a FlexE communications link includes, in response to a synchronization event, selecting a next slot of the FlexE communications link that is unallocated or is allocated to a FlexE client, and transmitting synchronization data associated with the synchronization event in the selected slot.

Transmitting and receiving synchronization data

There is provided a method comprising: detecting () a subset of protocol data units in an original stream of protocol data units to be transmitted over the network, wherein the original stream is associated with a first source port; generating () an updated transmitting-side stream of protocol data units based on the original stream, wherein the updated transmitting-side stream excludes the detected subset; merging () the subset of protocol data units with a subset of protocol data units associated with a second source port to form a merged stream; transmitting () the merged stream, as a first stream, over a first link of the network; transmitting () the updated transmitting-side stream associated with the first source port, as a second stream, over a second link; and transmitting () an updated transmitting-side stream associated with the second source port, as a third stream, over a third link.

Network traffic management

Methods and apparatus are provided for routing Flex Ethernet (FlexE) data in a network. In an example aspect, a method comprises receiving data on a first FlexE physical layer (PHY) group, determining, from first FlexE overhead on the first FlexE PHY group, that data in one or more time slots on the first FlexE PHY group is associated with a predetermined path in the network, determining a second FlexE PHY group for the data in the one or more time slots based on at least a portion of the predetermined path in the network, and sending the data on the second FlexE PHY group.

Routing flexe data in a network

An optical receiver () comprising: a polarisation controller () arranged to receive as its input a first modulated optical signal having a first polarisation and an unmodulated optical carrier signal polarisation aligned with the first modulated optical signal, the first modulated optical signal having negligible spectral power density within a predetermined bandwidth, BW, around an optical spectrum of the unmodulated optical carrier signal; optical filter apparatus () having a main polarisation mode; and coherent optical receiver apparatus (), wherein the polarisation controller is arranged to apply polarisation rotations to the first modulated optical signal and the unmodulated optical carrier signal such that their polarisation is aligned to the main polarisation mode of the optical filter apparatus, the optical filter apparatus is arranged to receive and separate the unmodulated optical carrier signal from the first modulated optical signal, and the coherent optical receiver apparatus is arranged to receive said separated signals and perform coherent detection of the first modulated optical signal using as a local oscillator, LO, signal the unmodulated optical carrier signal.

Self-coherent optical transmission system and receiver

A method of controlling transmission of an upstream packet traffic from a plurality of Optical Network Units to an Optical Line Terminal in a Passive Optical Network based fronthaul network. The Optical Network Units transmit packets in a time division multiplexed access scheme to the Optical Line Terminal and the method comprises obtaining mobile upstream scheduling information, scheduling the packet traffic from the plurality of Optical Network Units based on delay constraints of the PON-based front haul network and the obtained mobile upstream scheduling information. The method also comprises transmitting the scheduling of the packet traffic to the plurality of ONUs.

Method and apparatus for controlling transmission of an upstream packet traffic in a TDM PON-based fronthaul

Methods and apparatus are provided for transmitting data. In one aspect, a method of transmitting data comprises identifying a start of a Common Public Radio Interface (CPRI) frame, identifying CPRI data blocks of the CPRI frame, and transmitting the CPRI data blocks of the CPRI frame in slots of a FlexE calendar of a Flex Ethernet physical layer group (FlexE PHY group).

CPRI data block transmission method and apparatus

Device and method for processing an optical signal. The device includes a photonic device arranged between a first input/output and second input/output and optically communicating with the inputs/outputs by a signal path for transmission of an optical signal in a first or second direction between the first input/output and second input/output. The device includes an optical gain element for amplifying the optical signal. The device includes a path switching circuit including a first signal amplification path connectable between the first input/output and the photonic device for optically coupling the signal path to and from the optical gain element, and a second signal amplification path connectable between the photonic device and the second input/output for optically coupling the signal path to and from the optical gain element. The path switching circuit selectively connects the first or second signal amplification path into the signal path.

Device and method for processing an optical signal

A method () of controlling compensation of chromatic dispersion in an optical transport network. The method comprises determining () whether a residual dispersion, RD, of a first path () within the network is within a defined RD range and if the RD of the first path is outside the defined RD range the method comprises identifying () a first tuneable dispersion compensation module, TDCM, crossed by the first path (), configured to apply a respective value of dispersion compensation. The method also comprises determining () a different value of dispersion compensation to be applied by the first TDCM to bring the RD of the first path within the defined RD range; if () the first TDCM is crossed by at least one other path (), checking () that the respective RD of said at least one other path is within a respective defined RD range for said different value of dispersion compensation; and generating () a control signal comprising instructions configured to set the first TDCM to apply said different value of dispersion compensation.

Controlling compensation of chromatic dispersion in optical transport networks

A method in a first level aggregation node of a transport network is disclosed. The transport network comprises the first level aggregation node, a second level aggregation node and a Passive Optical Network. T the method comprises receiving, from the second level aggregation node, a plurality of wavelength division multiplexing (WDM) channels having wavelengths in a first spectrum section and generating at least one passive optical channel having a wavelength in a second spectrum section, different to the first spectrum section. The method further comprises combining at least some of the WDM channels received from the second level aggregation node with the at least one passive optical channel, and forwarding the combined WDM channels and passive optical channel to a termination node in the Passive Optical Network. Also disclosed are a method in a termination node of a transport network, a first level aggregation node, a termination node and a computer program.

Apparatus and methods for a transport network

An Optical Dispersion Compensator (ODC) is disclosed, the ODC being suitable for managing chromatic dispersion of an optical signal for transmission over an optical fiber. The ODC comprises a first ODC unit () arranged on a first optical bus (), a second ODC unit () arranged on a second optical bus (), parallel to the first optical bus (), and a switching element () interconnecting the first and second optical buses () between the first and second ODC units (). The first and second ODC units () are operable to provide a delay to the optical signal that varies with frequency. The switching element () is configured, in a first state, to switch an optical signal received on one of the first or second optical buses () to the other of the first or second optical buses () and, in a second state, to maintain an optical signal received on one of the first or second optical buses () on the optical bus on which it was received (). Reflective elements () may be included in the ODC, providing bidirectional propagation through one of more ODC units.

Optical dispersion compensator

A method () of encoding communications traffic bits onto an optical carrier signal in a pulse amplitude modulation, PAM, format. The method comprises: receiving () bits to be transmitted; receiving () an optical carrier signal comprising optical pulses having an amplitude and respective phases; performing () PAM of the optical pulses to encode at least one respective bit in one of a pre-set plurality of amplitudes of a said optical pulse; and performing () phase modulation of the optical pulses to encode at least one further respective bit in a phase difference between a said optical pulse and a consecutive optical pulse.

Encoding and decoding communications traffic in a pulse amplitude modulation format and optical apparatus for same

A path computation engine, PCE, () for an optical communications network comprising a plurality of nodes and a plurality of links. The PCE comprises a processor and memory comprising instructions executable by the processor whereby the PCE is operative to: receive a request to configure a quantum key, Qkey, path from a first node to a second node in the optical communications network for a quantum key distribution, QKD, signal for a quantum key for a secure data transmission signal; calculate a feasible Qkey path from the first node to the second node that is logically different to a traffic path from the first node to the second node for the secure data transmission signal, wherein the Qkey path is feasible if an optical signal power originating from the secure data transmission signal within the Qkey path, caused by optical interference of the secure data transmission signal with the QKD signal, is below a predetermined threshold value; and generate a control signal comprising instructions arranged to configure said feasible Qkey path.

Path computation engine and method of configuring an optical path for quantum key distribution

A method for scheduling resources for a Wavelength Division Multiplexed, WDM, Passive Optical Network, PON. The WDM PON comprises a central hub () and a plurality of remote Optical Network Terminals, ONTs, () handling different types of communications traffic. The method () comprises receiving () a notification message from the plurality of remote Optical Network Terminals, ONTs, indicating a loading status of the ONT, and allocating () one or more slots to a plurality of the ONTs based on the received notification messages from the ONTs, wherein the plurality of ONTs () handle different types of communications traffic. The slots () are allocated based on the received notification messages as a time slot which is time division multiplexed with further time slots, and the slots are further allocated based on the received notification messages as an optical wavelength of a plurality of optical wavelengths of the WDM PON.

Time and wavelength division multiplexing

A receiver module () is disclosed for receiving an optical input signal and generating an electrical output signal from the optical input signal. The receiver module comprises an input () for receiving an optical input signal and a polarising beam splitter () for splitting one of the optical input signal and a local recovery optical signal. The receiver module also comprises a multiport optical coupler () for coupling the outputs of the polarisation beam splitter and the other of the optical input signal and local recovery optical signal and outputting a plurality of outputs. The receiver module further comprises a first photodetector unit () for individually photodetecting the outputs of the multiport optical coupler and an optical modulation unit () for using each of the photodetected outputs to modulate a respective local conversion optical signal, where each local conversion optical signal has a different frequency from the other local conversion optical signals. The receiver module also comprises an optical coupler () for coupling the modulated local conversion optical signals to generate an optical output signal and a second photodetector unit () for photodetecting the optical output signal to generate an electrical output signal. Also disclosed are a method () and a multichannel receiver ().

Optical receiver and method of operation

An optical link for a communication network, the optical link having an optical fibre link, a downstream transmitter, a downstream receiver, an upstream transmitter and an upstream receiver. The upstream and downstream transmitters are configured to transmit a respective pilot tone on a respective optical carrier and are configured to tune a frequency of the pilot tone within a preselected frequency range. The upstream and downstream receivers are configured respectively to determine an upstream notch frequency, f, and a downstream notch frequency, f, of respective detected photocurrents from at least one respective pilot tone frequency at which the respective detected photocurrent is equal to or lower than a photocurrent threshold. The optical link also includes processing circuitry configured to receive the upstream and downstream notch frequencies and configured to estimate a propagation delay difference of the optical link depending on the upstream and downstream notch frequencies.

Method of estimating a propagation delay difference of an optical link and apparatus for same

Growing community of inventors

Pisa, Italy

Fabio Cavaliere