Abstract: A method and apparatus of managing remote third party OTN & WDM transceiver equipment using the same fibers used for end user data exchange is described. A network device collects management instructions for the OTN & WDM transceiver equipment, assembles this management information into the overhead of a data frame and transmits on an optical link directly coupled to the network device. The WDM transceiver function converts the optical signal to an electrical one and the OTN function extracts the management instructions from the OTN overhead. A processor associated with the OTN framer function acts on that information. The management instructions includes the instruction to periodically and continuously, load certain performance, alarm or informational data into its OTN overhead and transmit that to a similar transceiver at the remote end of the communications link.

Abstract: 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.

Abstract: 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.

Abstract: Modular WSS-based Communications system with colorless and network-port transparent add/drop interfaces is described herein. According to certain aspects of the invention, equipment architecture is provided that enables a linear, ring, and mesh optical network. The embodiments of the invention are primarily on how to add and drop signals at a node of the network. The embodiments of the invention are based on the use a wavelength selective switch (WSS), which is an emerging component technology. Other methods and apparatuses are also described.

Abstract: According to one aspect of the invention, an optical network including multiple optical network devices, or nodes, is provided. At each node, an optical performance monitor analyzes dispersion while a dispersion compensation module reduces the amount of dispersion in the signals. Information about the dispersion and the amount of compensation performed by the dispersion compensation module is generated by the optical performance monitor and stored in a memory. If the bit error rate of a particular path between nodes becomes too high, a new path is used. A monitoring computer then accesses the information about the dispersion stored in at least one node of the old path. The information allows a user to determine where along the path the greatest amount of dispersion is occurring.

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

Abstract: A method and an apparatus to provide optical equipment protection have been disclosed. In one embodiment, the method includes splitting an incoming optical signal into a first and a second optical signals, sending the first and the second optical signals to a first and a second equipments in an optical network node, respectively, the second equipment being a protection module for the first equipment, monitoring a first and a second outgoing optical signals from the first and second equipments, and declaring a failure of the optical network node if only one of the first and the second outgoing optical signals has failed. Other embodiments have been claimed and described.

Abstract: 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.

Abstract: A method and apparatus for fault notification in an optical network are described herein. In one embodiment, an exemplary process includes detecting at a node that at least a portion of a first unidirectional path of an optical circuit is down, where the first unidirectional path is originated from a first terminating node. In response to the detection, the node signals the first terminating node by removing at least a portion of light of a second unidirectional path in an opposite direction of the first unidirectional path of the optical circuit, to indicate a path between the node and the first terminating node is down. Other methods and apparatuses are also described.

Abstract: Error detection and recovery of an optical network element are described herein. In one embodiment, an exemplary process includes, but is not limited to, transmitting from a transmitting module of the optical network element a first packet of data to a receiving module of the optical network element, and the transmitting module transmitting a first value representing a number of bits of the first packet having a predetermined logical value to the receiving module, wherein the first value is used by the receiving module to verify an integrity of the first packet in order to determine whether the packet has been transmitted successfully. Other methods and apparatuses are also described.

Abstract: Methods and apparatuses for multiple redundancy schemes in an optical network are described herein. In one embodiment, an exemplary method includes receiving a demand for allocating a first protection path that meets a first set of disjointness constraints with respect to a first working path according to a first protection scheme having a first priority, in response to the demand, locating a second protection path that meets a second set of disjointness constraints with respect to a second working path according to a second protection scheme having a second priority, and assigning the second protection path as a protection path to the first working path if the first priority of the first protection scheme is higher than the second priority of the second protection scheme. Other methods and apparatuses are also described.

Abstract: 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.

Abstract: 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.

Abstract: Optical switches are described herein. In one embodiment, an exemplary optical switch includes, but is not limited to, a first waveguide, a second waveguide across with the first waveguide in an angle to form an intersection, and a pair of electrodes placed within a proximity of the intersection to switch a light traveling from the first waveguide to the second waveguide, where the intersection includes a geometry that supports single and multimode propagation. Other methods and apparatuses are also described.

Abstract: A method and apparatus for fault notification in an optical network are described herein. In one embodiment, an exemplary process includes detecting at a node that at least a portion of a first unidirectional path of an optical circuit is down, where the first unidirectional path is originated from a first terminating node. In response to the detection, the node signals the first terminating node by removing at least a portion of light of a second unidirectional path in an opposite direction of the first unidirectional path of the optical circuit, to indicate a path between the node and the first terminating node is down. Other methods and apparatuses are also described.

Abstract: 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.

Abstract: An optical switch matrix is described herein. In one embodiment, an exemplary optical switch matrix includes, but is not limited to, multiple input waveguides, multiple output waveguides, for each of the input waveguides and each of the output waveguides, a switching node coupling the respective input waveguide and the respective output waveguide. The switching node includes a first switch coupling the respective input waveguide to an intermediate waveguide and a second switch coupling the intermediate waveguide to the respective output waveguide. The second switch is an X switch having first and second input ports and first and second output ports, the first input port receiving the intermediate waveguide and the first output port coupling to the respective output waveguide. Other methods and apparatuses are also described.

Abstract: Inter-module communications of an optical network element are described herein. In one embodiment, an exemplary optical network element includes multiple functional modules arranged in multiple shelves and multiple management modules for coordinating the functional modules. Each of the management modules corresponds to each of the shelves respectively. Each of the management modules includes a memory having multiple memory regions, where each memory region corresponds to each of the functional modules of a respective shelf to allow each of the functional modules of the respective shelf to communicate with the management module by accessing a respective memory region. Other methods and apparatuses are also described.

Abstract: Optical switches are described herein. In one embodiment, an exemplary optical switch includes, but is not limited to, a first waveguide, a second waveguide across with the first waveguide in an angle to form an intersection, and a pair of electrodes placed within a proximity of the intersection to switch a light traveling from the first waveguide to the second waveguide, where at least one of the electrodes includes a non-uniform edge to deflect a light remained after switching from the first waveguide to the second waveguide to a direction other than a direction associated with the first waveguide. Other methods and apparatuses are also described.