Telefonaktiebolaget Lm Ericsson (publ)

Annamaria Fulignoli

Roberto Magri

Sergio Lanzone

Andrea Corti

Riccardo Ceccatelli

Stefano Orsi

Antonio Tartaglia

Marcello Morchio

Stefano Parodi

Marina Valeri

Alfredo Palagi

A communications network remote node having a downstream optical circuit configured to receive downstream, DS, optical signals from an active main node and from a standby main node, the downstream optical circuit switchable between a working mode and a protection mode. Optical receivers are configured to receive the demultiplexed downstream optical signals and output encapsulated downstream client signals. Optical transmitters are configured to receive encapsulated upstream client signals and to transmit upstream, US, optical signals at upstream wavelengths carrying the encapsulated upstream client signals. An upstream optical circuit is configured to multiplex the upstream optical signals carrying the encapsulated upstream client signals and to send the upstream optical signals to both main nodes. Processing circuitry is configured to extract downstream client signals and alignment data from encapsulated downstream client signals and form encapsulated upstream client signals by encapsulating upstream client signals and alignment data.

Optical transport network protection architecture, nodes and method

For protecting traffic on paths extending from a source client entity (CE) to a destination client entity (CE) via an optical transport network and attachment circuits at ingress (A,B) and egress (C,D) nodes, there are multiple paths within the OTN network, and the attachment circuits are dual homed. By sending () an indication of operational status of the dual homed attachment circuits within overhead associated with the traffic and sent with the traffic through the network, a selection can be made () of which of the provided paths and attachment circuits to use for the traffic, based on the indicated operational status, and on OTN fault detection, to protect against a fault in the attachment circuit or in the OTN network. Thus protection can extend across the edge nodes without the complexity and delays involved in interworking of separate protection schemes and without a control plane.

Protection for optical transport network with dual homed attachment circuits

For protecting traffic from a source client entity (CE) to a destination client entity (CE) via an optical transport network and attachment circuits at ingress (A,B) and egress (C,D) nodes, there are multiple paths within the OTN, and the attachment circuits are dual homed. By sending () an indication of operational status of the dual homed attachment circuits within overhead associated with the traffic and sent with the traffic through the network, a selection can be made () of which of the provided paths and attachment circuits to use for the traffic, based on the indicated operational status, and on OTN fault detection, to protect against a fault. Thus protection can extend across the edge nodes without interworking of separate protection schemes and without a control plane. Traffic flows can be multiplexed at the ingress, with the indication in the overhead having separate indications for each of the traffic flows.

Protection for optical transport network using operational status of dual homed attachment circuits

In an optical transport network a traffic flow comprises data grouped into a number of resizable data units, encapsulated by optical transport frames, each having a frame overhead. A rate of the traffic flow is changed by changing the data unit overhead and changing at the source node the frame overhead to indicate a change in rate of an optical signal carrying the traffic flow. An optical transmission part is tuned to transmit at the new rate, and at any intermediate nodes along the route the indication of the change in rate is detected in the frame overhead so that the traffic flow on a next optical link is transmitted at the new rate. Thus optical bandwidth allowed for enlarging the data units, can be saved, and electrical processing of data units at the nodes can be simplified, reducing power consumption.

Resizing existing traffic flow in optical transport network

Growing community of inventors

Latina, Italy

Annamaria Fulignoli