Dynamic Method Enterprises Limited

Intellambda Systems, Inc.

Dynamic Method Enterprise Limited

Santosh Kumar Sadananda

Khoi Nhu Hoang

Christopher Michael Look

Jeffery J Maki

Adisorn Ermongkonchai

A method and apparatus for performing a path based quality check for a specified bit rate in a wavelength division multiplexing optical network is described. According to one embodiment of the invention, a method selects from a database one of the available paths as a currently selected path. The database stores a representation of the available paths from an access node of the optical network to other access nodes of the optical network. The method further determines a cumulative noise, cumulative chromatic dispersion, and a maximum allowable chromatic dispersion for the currently selected path. In addition, the method determines whether the currently selected path passes the path based quality check based on whether the cumulative noise is less than the maximum allowable noise at a specific bit rate and whether the chromatic dispersion is less than the maximum allowable chromatic dispersion at the specified bit rate.

Quality of service in an optical network

A method and apparatus for implementing optical network quality using bit error rate and chromatic dispersion. According to one embodiment of the invention, a method includes the provision of quality of service in a wavelength division multiplexing optical network that supports a plurality of bit rates. As part of this method, the cumulative noise and cumulative chromatic dispersion for each available path as a whole is determined, where an available path is a series of two or more nodes each connected by an optical link on which a set of wavelengths is available for establishing a lightpath. In addition, different grades of path quality are distinguished based on bit error rate (BER), where BER is based on cumulative noise and bit rate. Furthermore, a minimum path quality is required based on chromatic dispersion decibel penalty, where chromatic dispersion decibel penalty is based on cumulative chromatic dispersion and bit rate.

A set of one or more connectivity constraints imposed on the building/maintaining of network topology databases.

Optical network topology databases based on a set of connectivity constraints

A selective distribution messaging scheme for an optical network. According to one embodiment of the invention, a wavelength division multiplexing optical network includes a number of nodes each having an optical cross connect and each having stored therein a database representing conversion free connectivity from that node to others of the nodes. In addition, each of the nodes employs a messaging scheme to propagate notification of changes in the optical network to others of the nodes to maintain their databases. The messaging scheme in each of the nodes transmits messages to only selected ones of the other nodes based at least in part on the conversion free connectivity to minimize the number of communications between nodes.

Selective distribution messaging scheme for an optical network

A source based scheme to establish communication paths in an optical network. According to one embodiment of the invention, a number of wavelength division multiplexing access nodes of an optical network employ a source based scheme to establish communication paths. Each of these access nodes stores a set of one or more network topology databases based on a set of one or more connectivity constraints.

Source based scheme to establish communication paths in an optical network

Methods and apparatuses for handling multiple failures in an optical network are described herein. In one embodiment, an exemplary method includes receiving a demand for allocating a protection path that meets a set of disjointness constraints with respect to a working path, the protection path suitable to be shared with one or more other working paths, each of the working paths associated with a priority for obtaining the shared protection path, and in response to the demand, selecting a protection path that meets the set of disjointness constraints with respect to the working path and has not been shared with another working path having the same priority as the working path associated with the protection path in demand. Other methods and apparatuses are also described.

Methods and apparatuses for handling multiple failures in an optical network

Reroutable protection schemes of an optical network are described herein. In one embodiment, an access node detects that at least a portion of a first path of an optical circuit fails based on a loss of a light of the at least a portion of the first path. In response to the detection, the access node provisions a second path leading to a destination node of the first path without waiting for an update of a routing database regarding the failure of the first path, where the second path satisfies a set of disjointness requirements with respect to the first path. Other methods and apparatuses are also described.

Reroutable protection schemes of an optical network

A method and apparatus for an optical reroutable redundancy scheme. According to one embodiment of the invention, a wavelength division multiplexing optical network includes a number of nodes each having an optical cross connect and each having stored therein a database representing conversion free connectivity from that node to others of the nodes. In addition, each of the nodes employs a source based scheme with the database to provision optical circuits in real time and an optical reroutable redundancy scheme.

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Mountain View, CA, United States of America

Santosh Kumar Sadananda