Telefonaktiebolaget Lm Ericsson (publ)

Ericsson Ab

Gianmarco Bruno

Daniele Ceccarelli

Jeroen Nijhof

Francesco Lazzeri

Fabio Cavaliere

Roberto Magri

Giulio Bottari

Paola Iovanna

Diego Caviglia

Luca Giorgi

Stefan Dahlfort

Filippo Ponzini

Ming Xia

Piero Castoldi

Francesco Fondelli

Filippo Cugini

Alberto Deho

Nicola Sambo

Riccardo Ceccatelli

Antonio Tartaglia

Edoardo Mongiardini

Marco Camera

Anna Soso

A method () of end-to-end path computation across a plurality of domains () in a communication network comprises receiving () a request for a path across the plurality of domains. The method comprises computing () in a network control entity () the end-to-end path across the plurality of domains as part of a hierarchical path computation. Computing the end-to-end path comprises determining if a stored path corresponding to at least a part of the end-to-end path matches one or more criteria of the end-to-end path, and if so, using the stored path for the end-to-end path computation. The method further comprises transmitting () information indicating at least part of the stored path to a domain control entity () configured to control a said one of the plurality of domains involved in the end-to-end path.

Determining a path in a communication network

A method in a physical network controller () for configuring physical resources to provide a physical layer connection in a communications network (). The physical layer connection provides physical connectivity for a higher layer network connection controlled by a higher layer network controller () in a hierarchical arrangement with the physical network controller (). The method comprising the physical network controller () receiving () an indication for a minimum traffic capacity for the physical layer connection. The physical network controller configuring () physical resources according to the received indication.

Physical path control in hierarchical networks

Apparatus and methods are provided for path computation for a service in a telecommunications network. In one aspect, a method comprises receiving a request to schedule the service utilizing the network in a time period determining that a path for the service is not available for the whole of the time period, and determining a plurality of paths for the service, each of the plurality of paths being available during a respective portion of the time period, such that at least one of the plurality of paths is available for the service at any time during the time period.

Methods and apparatus for path computation in a telecommunications network

Apparatus and methods are provided for scheduling services in a traffic-engineered communications network. In one aspect a method comprises: receiving a request to schedule a second service utilizing the network in a second time period, wherein the second time period overlaps a first time period in which a first service utilizing the network has already been scheduled; and computing a path for the second service through the network. The step of computing the path for the second service through the network comprises: responsive to a determination that the request is received less than the threshold period of time before the start of the first time period, disallowing the second service from pre-empting the first service.

Methods and apparatus for scheduling of services in a traffic-engineering network

Methods and apparatus are provided for locating a fault in an optical communication link. In one aspect, a method comprises determining a fault in a first optical link, and determining a fault in a second optical link. The method then determines that a first portion of the first optical link is co-located with a second portion of the second optical link and identifies, as a result of determining that the first portion is co-located with the second portion, that the fault in the first optical link is located in the first portion and/or the fault in the second optical link is located in the second portion.

Locating a fault in an optical communication link

A path computation method involves receiving () a request for computation of a new path in the network, the request indicating a future time interval when the path is desired. Subsequently a future network status is generated (), having a representation of availability of path resources at the future time interval, based on selected paths already reserved at that future time interval. Then there is a step of computing () which of the path resources to select for the new path according to the future network status. By generating this future network status when the future time interval is known, it can be generated in respect of a limited time interval rather than covering all possible future reservable times. Thus the benefits of time aware path computation can be achieved without the need for maintaining a huge database of availability at all future times, of all the path resources.

Time aware path computation

A path computation method for use by a control entity () of a tenant () in a multi-tenant communications network () receives a request for computation of a path in the communications network () and obtains a current virtual topology of the communications network from a shared topology store () which is shared by the tenants. The virtual topology is a topology of the communications network which is available for use by the tenant (). The virtual topology is used to service the request. The method may create the path. The path computation may be in respect of a future time interval.

Path computation in a multi-tenant network

A method of path computation in a segment routing network, the network comprising a set of nodes. The method comprises receiving a request for computation of a path between end nodes in the network, the request including a constraint. The method further comprises determining a segment identifier-optimised path defined by a stack of one or more segment identifiers, wherein the segment identifier-optimised path meets the constraint. The determining of the segment identifier-optimised path comprises analyzing a topology of the network comprising: at least a sub-set of the nodes, links between adjacent nodes indicative of possible paths between the nodes, and virtual links between pairs of nodes indicative of possible paths between the pairs of nodes. The method further comprises outputting at least one segment identifier which defines the determined path.

Path computation in a segment routing network

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 method () of bi-directional optical communication, the method comprising: generating () a first optical communication signal for transmission in one direction through an optical fibre, generating the first optical communication signal comprising: receiving information for transmission and generating () a baseband signal comprising a representation of the information; performing digital upconversion () of the baseband signal to form an upconverted baseband signal; performing optical modulation () of an optical carrier signal with the upconverted baseband signal; and restricting an optical spectrum of the first optical communication signal to a first portion of an optical channel frequency slot by performing one of digital filtering () in addition to digital upconversion and optical filtering () after optical modulation; and receiving () a second optical communication signal transmitted in an opposite direction through the optical fibre, the second optical communication signal having an optical spectrum occupying a second portion of the optical channel frequency slot, separate to the first portion.

Methods of bi-directional optical communication and optical transceiver

A method of determining a path in an optical server network () comprises obtaining an indication of an amount of premium traffic from a client network (). The method further comprises considering paths () utilising an elastic capability of one or more network elements () of the optical server network, and selecting a path from the considered paths, wherein the path is selected based at least partially on having at least a capacity to carry the amount of premium traffic.

Method and apparatus for elastic optical networking

A method of optimizing optical signal quality in an optical communications link comprising a plurality of sections each comprising an optical amplification apparatus and an optical fiber span, the method comprising: for each section, determining a respective optimal optical channel power which minimizes a sum of an indication of a respective linear optical noise and an indication of a respective nonlinear optical noise; and generating and transmitting at least one control signal arranged to cause a target optical channel power of each section to be set to the respective optimal optical channel power.

Method of optimizing optical signal quality in an optical communications link, optical network element and optical communications link

A communications network element comprises a network element input, a network element output and a monitoring port. An optical splitting device taps a portion of an input optical signal or an output optical signal to form a first signal. An optical signal transforming apparatus applies an optical transfer function to the first signal to form the optical monitoring signal applied to the monitoring port. The optical transfer function preserves the spectral property of the first signal and applies a time-domain obfuscation to the tapped signal. The optical signal transforming apparatus comprises an optical through signal path, an optical splitting device positioned in the optical through signal path and an optical combining device positioned in the optical through signal path. An optical feedback path is connected to the optical splitting device and the optical combining device. The optical splitting device is arranged to tap off a portion of a signal passing along the through signal path and apply it to the feedback path, and the optical combining device is arranged to recombine at least part of the tapped portion of the signal with the signal passing along the through signal path.

Optical monitoring in an optical communications network

A communication network element () comprising: an optical path () for an optical communication signal (); a monitoring port () arranged to output an optical monitoring signal; an optical splitter () provided in the optical path, the optical splitter arranged to receive the optical communication signal and to split off a part of the optical communication signal to form the optical monitoring signal; and optical isolation apparatus () connected between the optical splitter and the monitoring port, the optical isolation apparatus arranged to transmit the optical monitoring signal propagating towards the monitoring port and arranged to apply an attenuation, IA, to an attacking optical signal () propagating from the monitoring port towards the optical splitter to thereby prevent a substantial part of the attacking optical signal being transmitted to the optical path.

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Genoa, Italy

Gianmarco Bruno