Telefonaktiebolaget Lm Ericsson (publ)

Ericsson Ab

Luca Giorgi

Fabio Cavaliere

Filippo Ponzini

Antonio D'Errico

Giulio Bottari

Ernesto Ciaramella

Renato Grosso

Francesco Testa

Luca Poti

Patryk Urban

Marco Presi

Stefano Ruffini

Boris Dortschy

Wei-Ping Huang

Antonio D'errico

Elmar Trojer

Antonella Bogoni

Stefan Dahlfort

Robert Frank Brunner

Gianmarco Bruno

Stefano Stracca

Marzio Puleri

Peter Öhlén

Björn Skubic

Jeroen Nijhof

David V Plant

Antonio Malacarne

Emma Matarazzo

Tommaso Catuogno

Francesco Giurlanda

Fabio Falconi

Gemma Vall-Ilosera

Roberto Proietti

Gabriele De Angelis

Giampiero Contestabile

Gianfranco Sfameni

Veronica Tinucci

Andrea Chiuchiarelli

Pallab Choudhury

Giancarlo Gaimari

Stefano Brugioni

Ramon Gutierrez Castrejon

Saber Md Ghulam

Gemma Vall-Llosera

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

Methods in an optical receiver, for decoding a received M-level pulse-amplitude-modulated, PAM-M, optical signal. An example method comprises, for a first interval, decoding () the received PAM-M optical signal using a standard PAM-M decoder with M-1 thresholds, using first sampling times, to obtain a first set of decoded bits, and decoding () the received PAM-M optical signal using a duobinary decoder with 2M-2 thresholds, at second sampling times offset from the first sampling times, to obtain second set of decoded bits. The method further comprises calculating () first and second error metrics corresponding to the first and second sets of decoded bits, respectively, and selecting () the standard PAM-M decoder or the duobinary decoder for subsequent decoding of the received PAM-M optical signal, based on the first and second error metrics.

Chromatic dispersion tolerant PAM-M transceiver for optical routing to extended paths

A communication signal multiplexing apparatus includes first and second optical receivers, with the second optical receiver configured to receive an optical analog radio signal and to convert it into a corresponding electrical analog radio signal having a carrier frequency and the first optical receiver configured to receive an optical digital communication signal and to convert it into a corresponding electrical digital communication signal having a frequency spectrum. Further, a first electrical filter apparatus is configured to receive the electrical digital communication signal, and comprises a low-pass filter having a cut-off frequency lower than the carrier frequency of the electrical analog radio signal, and applies the low-pass filter to the electrical digital communication signal. The apparatus also includes a signal combining apparatus configured to combine the low-pass filtered electrical digital communication signal with the electrical analog radio signal to form a combined electrical signal and an optical transmitter configured to generate an optical communication signal carrying a representation of the combined electrical communication signal.

Communication system multiplexing and demultiplexing apparatus and methods

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 for monitoring a passive optical network, the passive optical network comprising a plurality of network components, comprises receiving an alert message () from a fault detection system associated with the passive optical network, the alert message comprising an indication of one or more candidate locations for a detected fault in the passive optical network. The method further comprises accessing an inventory () of the plurality of network components, the inventory storing, for each of the plurality of network components, information comprising the network component location. The method further comprises identifying (), based on the one or more candidate locations and the network component locations, one or more network components of the plurality of network components as candidates for the cause of the detected fault.

Methods and apparatus for maintenance in an optical communication network

A data center network node () comprises one or more switch () configured to link an optical transceiver () to an optical connection comprising a multi-core optical fiber () having a plurality of cores (). For each core (), the one or more switch () is configurable between a first configuration in which an optical signal on a said core () of the multi-core optical fiber bypasses the optical transceiver and a second configuration in which the optical transceiver is optically linked to the said core () of the multi-core optical fiber ().

Data center network node

A radio over fibre system () comprises a base station () with a first base station node () and a second base station node () connected by an optical communication link (). At least one of the base station nodes () comprises an optical transmitter (). A method of determining an operating parameter for the optical transmitter () comprises receiving signal quality parameters for a plurality of user equipments (UE) served by the base station (). The method determines an operating parameter of the optical transmitter using the determined signal quality parameters of the plurality of user equipments (UE). The operating parameter of the optical transmitter can be a modulation parameter.

Control of an optical transmitter in a radio over fibre system

A data center network node comprising at least one server connection for connecting to a server, a connectionfor connecting the at least one serverto a first subnetwork. The first subnetwork is a conventional subnetwork which comprises at least one of a switch or a router. The node further comprises an optical receiver arrayfor connecting the node to an optical offload subnetwork, wherein the optical receiver arraycomprises a plurality of optical receivers. The array is configured such that each receiver is connectable to an optical path within a multi-path optical connection. The node further comprises an optical transmitter arrayfor connecting the node to an optical offload subnetwork. The optical transmitter array comprises a plurality of optical transmitters. The array is configured such that each receiver is connectable to an optical path within a multi-path optical connection. The node further comprises an electrical switching arrangementfor directing an incoming data stream from a receiver in the receiver arrayto at least one of the at least one server connection to serveror at least one transmitter in the transmitter array, and for directing an outgoing data stream from one of the at least one serverto at least one transmitter in the transmitter array. The electrical switching arrangementprovides for effective transport of data in a data center, e.g. transporting high bandwidth elephant flows on an optical offload network. The electrical switching arrangementenables the provision of point to multipoint connections for data streams by enabling a data stream to be passed to multiple transmitters or received at a node, sent to a server in the node, and transmitted to a subsequent node in the network. Once high bandwidth flow demands have been identified, a schedule of logical links between the nodes of the network is constructed so as to enable the high bandwidth flows to be transmitted on the offload network. The development of the schedule is implemented by an orchestratorand comprises constructing a booking list for high bandwidth flows, wherein a high bandwidth flow is a data stream which has a capacity requirement greater than a threshold.

Data center network

A data center network node () comprising a first data connection () for connecting at least one server to a conventional subnetwork comprising at least one of a switch or a router, an optical transceiver () comprising a transmitter () and a receiver (), a second data connection () for connecting the at least one server to the optical transceiver, a switching arrangement () for linking the optical transceiver () to an offload subnetwork (), the switching arrangement configurable between a first configuration () in which the offload subnetwork bypasses the optical transceiver and a second configuration () in which the optical transceiver is optically linked to the offload subnetwork.

A hybrid multiplexing apparatus is provided for multiplexing a digital communication signal from an electrical domain with one or more analog subcarrier communication signals from the electrical domain into a multiplexed optical signal for transmission over a common optical communication link. The apparatus comprises a laser module configured to modulate a laser source with the one or more analog subcarrier communication signals to be multiplexed, and output an intermediate optical modulated signal. An electro-optical modulator is coupled to receive the intermediate optical modulated signal and the digital communication signal to be multiplexed, and configured to modulate the intermediate optical modulated signal with the digital communication signal to form the multiplexed optical signal.

Methods and apparatus for multiplexing signals

An optical source comprises a first laser arranged to generate a first optical signal having a first state of polarization (SOP) and a first optical frequency; a second laser arranged to generate a second optical signal having a second SOP, substantially orthogonal to the first SOP, and having a second optical frequency, different from the first optical frequency by a preselected frequency difference; a polarisation beam coupler arranged to combine the first optical signal and the second optical signal into a composite optical signal comprising both the first optical signal and the second optical signal having said substantially orthogonal SOPs; and an output arranged to output the composite optical signal.

Optical source, communications network optical apparatus and method of providing an optical signal

A method in a node of a telecommunication network comprises receiving a digital communication signal from a first signal source, source, wherein the digital communication signal comprises a wherein the digital communication signal comprises a plurality of low amplitude windows, step, and receiving one or more analog subcarrier signals from a second signal source, step. The method further comprises multiplexing the one or more analog subcarrier signals into one or more of the plurality of low amplitude windows of the digital communication signal, step

Methods and apparatus for multiplexing and demultiplexing signals

The present invention provides an optical source comprising a laser, a first optical power splitter, phase changing equipment, polarisation state setting equipment, a polarisation beam coupler and an output. The laser is configured to generate an optical signal. The first optical power splitter is configured to split the optical signal into a first optical signal and a second optical signal. The phase changing equipment is configured to change the phase of at least one of the first optical signal and the second optical signal such that the first optical signal has a first phase and the second optical signal has a second phase different from the first phase by a preselected phase difference. The polarisation state setting equipment is configured to set the polarisation state of at least one of the first optical signal and the second optical signal such that the first optical signal has a first state of polarisation and the second optical signal has a second state of polarisation substantially orthogonal from the first state of polarisation. The polarisation beam coupler is configured to combine the first optical signal and the second optical signal into a composite optical signal comprising both the first optical signal and the second optical signal having said orthogonal states of polarisation. The output is arranged to output at least a portion of the composite optical signal.

Optical source

The invention provides a free space optical (FSO) communications terminal for a first telecommunications card or a backplane. The FSO terminal comprises a plurality of transmission interfaces. The FSO terminal further comprises a light signal generating unit adapted to generate a plurality of light signals. Each of the plurality of light signals carries the same information as the other one or more of the plurality of light signals and is arranged for transmission through a respective one of the plurality of transmission interfaces. Each of the plurality of light signals is at a different orthogonal mode from the other one or more of the plurality of light signals. The invention further provides a free space optical (FSO) communications terminal for a second telecommunications card or a backplane. The FSO terminal comprises a plurality of receive interfaces. Each of the plurality of receive interfaces adapted to receive a light signal carrying information. The light signal may be at any one of a plurality of orthogonal modes. The FSO terminal further comprises a plurality of optical-to-electrical signal convertors. The invention further provides an optical backplane, a router and an optical node.

FSO communications terminals for connecting telecommunications cards

A wireless communications network radio unit () comprising: an input () arranged to receive a radio over fiber, RoF input optical signal () carrying digital radio communications traffic for transmission from a plurality of antenna elements, synchronization traffic and control and management traffic; a digital receiver () arranged to receive and terminate the RoF input optical signal to obtain the digital radio communications traffic; a framer () arranged to frame the digital radio communications traffic into at least one digital traffic stream consisting of the digital radio communications traffic for transmission from a plurality of the antenna elements and clock recovery information; and at least one optical transmitter () arranged to generate an RoF output optical signal () carrying the digital traffic stream.

Wireless communication network apparatus and method of transmitting communications traffic in simple format

Growing community of inventors

Pisa, Italy

Luca Giorgi