Apparatus and method for an optical network

摘要

An optical network is configured to provide an optical reroute over a backup path (2139) during a failure in a signal path (2133). The network comprises a first node (B). A second node (C) is coupled to receive a signal from the first node (B) via the signal path (2133), and a backup signal via the backup path (2139). The network is adapted to transmit a signal and a corresponding backup signal from the first node to the second node even when there is no failure in the signal path (2133), wherein the backup signal is blocked at the second node (C) when there is no failure in the signal path (2133). Embodiments of the invention utilize the broadcast and blocking functionalities of a wavelength selective switch (WSS) device. Such WSS devices enable, in the case of a failure of a link, the fast switchover of optical traffic onto local detours within a reduced time.

主权项

1. A first node of an optical network, the first node comprising:
a first port comprising a first blocking unit (BU) for receiving a primary optical signal via a first working signal path, said primary optical signal being transmitted by a second node to the first node via the first working signal path; a second port comprising a second BU for receiving a backup optical signal via a first backup signal path while the first BU receives the primary optical signal via the first working signal path, said backup optical signal being transmitted by a third node to the first node via the first backup signal path, the third node being separate and distinct from the second node; and a third port, the third port being connected to the first BU via a first internal link and further being connected to the second BU via second internal link, wherein the first BU is configured to provide to the third port via the first internal link the primary optical signal during a first mode of operation in which the primary optical signal is being received at the first BU, the second BU is adapted to block the backup optical signal received at the second BU during said first mode of operation in which the primary optical signal is being received at the first BU, the second BU is further adapted to provide to the third port via the second internal link the backup optical signal during a second mode of operation in which the primary optical signal is not being received at the first BU, the third port is configured such that, during the first mode of operation, the third port provides the primary optical signal to a fourth node via a second working signal path, the third port is further configured such that, during the second mode of operation, the third port provides the backup optical signal to said fourth node via said second working signal path, and the backup optical signal is a duplicate of the primary optical signal.