Restoration systems for an optical telecommunications network
First Claim
1. In an optical communication network having a plurality of nodes interconnected by a plurality of transmission links and an operation support system communicatively connected to said nodes, a method of selecting an alternate signal path for bypassing a failed link in the network, comprising the steps of:
- a) detecting an alarm in said network indicative of a failed transmission link;
b) using wavelength information stored in said system for determining an alternate signal path to bypass said failed transmission link;
c) selecting from among said plurality of nodes a number of nodes to form said alternate signal path in said network;
d) downloading a routing map to each of said selected number of nodes in said alternate signal path;
e) commanding said selected number of nodes to set up said alternate signal path; and
f) forwarding status information from said selected nodes to said operation support system upon completion of said alternate signal path.
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Accused Products
Abstract
An optical telecommunication network has a plurality of optical cross-connect switching nodes linked together by optical cables to form transmission paths for traffic between sending and destination stations. A centralized operation support system (OSS) is coupled to each node for receiving failure alarms and port status messages for failed cables from the switching nodes and terminal sites. The collected data is used to select alternate routes through the network using the spare capacity of the optical cross-connect switches and available wavelengths within the network. Any connection(s) to put into effect an alternate routing plan is broadcast to the affected nodes or terminal sites. A Real-Time Multiple Wavelength Routing (RMWR) algorithm is used by the OSS or by decentralized switching nodes to select, coordinate and route traffic among selected paths to bypass the failed cable such that wavelength collisions or adjacent cross-talk do not degrade the network performance. The OSS is updated when network restoration is performed by a switching node in the path of the failed cable.
102 Citations
19 Claims
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1. In an optical communication network having a plurality of nodes interconnected by a plurality of transmission links and an operation support system communicatively connected to said nodes, a method of selecting an alternate signal path for bypassing a failed link in the network, comprising the steps of:
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a) detecting an alarm in said network indicative of a failed transmission link; b) using wavelength information stored in said system for determining an alternate signal path to bypass said failed transmission link; c) selecting from among said plurality of nodes a number of nodes to form said alternate signal path in said network; d) downloading a routing map to each of said selected number of nodes in said alternate signal path; e) commanding said selected number of nodes to set up said alternate signal path; and f) forwarding status information from said selected nodes to said operation support system upon completion of said alternate signal path.
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2. An optical restoration system for use in an optical communication network formed from a plurality of nodes interconnected by a plurality of transmission links, said system comprising:
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a) means for detecting failed links in a signal path in the network and generating an alarm; b) means for receiving link failure alarms and port status messages from the nodes; c) means for determining an alternate signal path between a sending station and a receiving station in the network bypassing a failed link and restoring communication between said sending and said receiving station; and d) means installed at each node for building an alternate routing table defining a restoration path for a failed path, the identity of nodes in such restoration path, and a restoration wave length at each node of the alternate path. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. In an optical restoration system for use in an optical communication network formed from a plurality of nodes interconnected by a plurality of transmission links, a method of selecting an alternate signal path bypassing a failed link in the network, comprising the steps of:
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a) detecting a failed link in a signal path by a node at the origin of the failed link; b) requesting alternating routing information from adjacent nodes by the originating node; c) determining at the originating node an alternate signal path bypassing the failed link in the network; d) sending coordinating messages to selected nodes in the alternate signal path; e) commanding the selected nodes to implement the alternate signal path; f) advising a centralized support center of the status of the nodes in the alternate signal path; and g) uploading to the support center a routing map indicating the status of the nodes in the network.
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16. In an optical telecommunications network having a plurality of nodes and links, said nodes comprising optical cross-connect switches using a combination of space and wavelength division multiplexing, a method of reconfiguring said optical network upon failure of a node or link comprising the steps of:
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a) identifying the location of failure of said node or link; b) analyzing the network configuration to determine an alternative network configuration that optimizes for space and wavelength division multiplexing while avoiding the location of failure of said node or link; c) effecting network reconfiguration according to said alternative network configuration by building an alternate routing table at each node of an alternate route, the table including the identification of each node in the alternate path and a restoration wavelength for each optical fiber connected to said each node. - View Dependent Claims (17, 18, 19)
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Specification