Protection switching for an optical network, and methods and apparatus therefor

Abstract

An optical communications network having at least one optical switch connected to a network access device. The optical switch includes a first line card disposed along a first communications path over which a first optical signal is transmitted. The first line card is connected to the network access device. A second line card is disposed along a second communications path over which a second optical signal is transmitted. An inter-card communication channel is provided for bridging the second path to the first line card. The system enables the rapid switching of traffic from the first optical path to the second optical path.

Description

BACKGROUND OF INVENTION[0001] Network service providers typically offer their customers varying types of service, often based on different quality of service guarantees. One parameter that may be negotiated between the service provider and its customers is service availability or permitted outage. Customers having demanding service requirements often necessitate the service provider to provide path protection or restoration features to its customers. Path protection is the provisioning of a predetermined redundant or pre-emptable communication path(s) that can be switched into operation whenever a problem is detected with a connection over a first communication path. Path restoration is the ability to automatically re-establish or re-signal a connection using a different path through the network.[0002] The advent of all-optical networks system which establish switched light paths without any optical to electrical conversion, such as the novel system described below, has increased th...

AI Technical Summary

Problems solved by technology

First, optical networks are intended for deployment in network backbones and as such will likely carry massive levels of communications traffic, the loss of which can be disruptive to many organizations.

Second, optical switches are likely to employ state-of-the-art optical devices such as switching fabrics.

The long-term performance characteristics and longevity of such devices are not yet fully understood.

Third, the new all-optical networks are likely to embody complex mesh topologies, unlike the linear and ring topologies of current SONET networks.

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