Abstract: An optical module inspection circuit on an optical platform includes an optical module carrier for precisely aligning optical devices with optical interfaces of inspection equipment located at fixed positions in the optical module inspection circuit. The module-includes an apparatus for conveyance along a top surface of the optical platform. The module may be conveyed automatically to predetermined positions on the optical platform to automate alignment and positioning of optical devices with respect to optical inspection stations in the optical test circuit.

Abstract: A method, apparatus and network for transporting layer-2 frames, such as Ethernet MAC, ATM AAL5, and Frame Relay, over SONET, SDH, or OTN transport networks is disclosed. The method establishes “pseudo-wires” between, for example, SONET switches and directly on top of the SONET layer. The method may implement MPLS signaling protocols on traditional SONET switches for the purpose of aggregating layer-2 frames from the transport network edges, while the transport network itself is independent from IP and MPLS routing. This approach provides a number of advantages to the network carriers in terms of operation and equipment expense reduction. To enable the transport network to be independent from IP and MPLS, and avoid subsequent IP control message processing inside the networks, an edge-to-edge “tunneling” mechanism is designed to transmit control messages as a part of the SONET (or SDH or OTN) frame payload.

Abstract: According to one embodiment, a method is disclosed. The method comprises receiving a first set of clock signals from a first clock unit at a second clock unit whenever the first clock unit is operating. The method further includes receiving a signal indicating that the second clock unit is to enter into the operating mode; and entering a holdover mode at a protection timing unit within the second clock unit. In the holdover mode, the protection timing unit generates output clock signals based upon the first set of clock signals received from the first clock unit at the second clock unit.

Abstract: An exemplary embodiment of the invention is a method of managing test files among a plurality of test stations for testing products. The method includes obtaining a test file having a test file name and assigning a unique identifier to the test file. Enforcement criteria are also assigned to the test file. The test file, test file name, the unique identifier and the enforcement criteria are stored. The test file is then conditionally distributed to at least one of the plurality of test stations according to the enforcement criteria. An alternate embodiment is a system for implementing the method.

Abstract: The present invention is directed toward a laser wavelength locking scheme suitable for incorporation into WDM systems having channel spacings of 25 GHz or less. In a preferred embodiment, light output from the laser is supplied to a filtering element, such as an in-fiber Bragg grating or an etalon, and photodetectors are used to sense light transmitted through and either reflected by the filtering element or input to the filtering element. A measured ratio corresponding to a quotient of the photocurrents generated by the photodetectors is calculated and compared to a desired ratio corresponding to a measured temperature of the filtering element when the filtering element transmits the desired wavelength to be locked. Based on the comparison of the desired and measured ratios, a temperature error value is calculated which is used to adjust the laser temperature, as well as the laser wavelength.

Abstract: A method and apparatus are provided for flexible time-division multiplexing, and demultiplexing, of serial line data, from 1-n client lines, based on the SONET standard (e.g. OC-48 or OC-192) whereby a predetermined and reconfigurable number of STS-1s are allocated to each client. A multiplexer includes 1 to n mappers for mapping the data of 1 to n clients, according to a predetermined bandwidth allocation, to an N×STS-1 SONET payload, each mapper using y STS-1s where y is 0 to N, the y STS-1s being selected on a sequential or non-sequential concatenation basis from the N STS-1s. Each mapper maps the data of one client and each allocated STS-1 is allocated to one client and the total number of STS-1s allocated to the clients is less than or equal to N. An aggregator aggregates the mapped data into a composite STS payload comprising N STS-1s. A bandwidth allocation receiver receives the bandwidth allocation.

Abstract: A fiber bending apparatus for bending an optical fiber in a networking device and an optical fiber management system and method are provided. The fiber bender has an arcuate main body which is attached to the end of an optical fiber above the male connector and partially including the connector boot, bending the fiber substantially orthogonal to a direction from which the fiber is connected to a line module of the networking device, i.e., substantially parallel to the faceplate of the line module. In this way, the optical fibers are made to bend away from the chassis of the networking device, thereby preventing them from being crushed when the door of the chassis is closed. The optical fibers are also shielded from inadvertent impacts when a technician is working on the networking device. By enabling the optical fibers to be easily directed and managed, the overall fiber density of the networking device may be increased, thereby increasing its bandwidth and information processing capabilities.

Abstract: An apparatus and method for measuring optical signal to noise ratio (OSNR) in a node of an optical data network is disclosed. A peak power level and an average power level are measured for an optical input to an optical detector. The OSNR is determined by selecting an OSNR having the peak power level and the average power level associated with an optical signal traversing an optical path having attenuation and optical amplifier noise.

Abstract: A database architecture and method of using a database is disclosed. The database is intended for use with a product stress testing system in which a large number of different modules may be subjected to a variety of stressors including environmental stressors and functional load testing. The database also enables a wide variety of test and communication equipment to be used in an efficient manner to test and communicate with the module being tested. Stress test results may be associated with the various products, the results may be mapped against product-specific test criteria and generic commands may be translated to product-specific commands.

Abstract: One or more fiber optic cable management systems provided with an optical communications housing for managing and routing fiber optic cables. Each fiber optic cable management system includes a series of saddle brackets, and a channel for routing and separating matrix fiber optic cables from customer fiber optic cables. Each saddle bracket is capable of routing customer fiber optic cables in multiple directions without bending the customer cables beyond their minimum bend radii. As many saddle brackets as practical are provided in the fiber optic cable management system. Providing a multitude of saddle brackets allows the slack in the customer fiber optic cables to be distributed across more brackets, and allows each saddle bracket to be shorter. Shorter saddle brackets, in turn, increases hand space for a technician to manipulate and route the customer fiber optic cables.

Abstract: A plurality of transmission circuits transmit data over one or more output lines. A plurality of receiving circuits receive data over one or more of a set of input lines A plurality of parallel-serial conversion circuits coupled to the plurality of transmission circuits and to the plurality of receiving circuits, the plurality of conversion circuits to convert parallel signals to one or more sets of serial signals and to send the converted serial signals to one or more corresponding transmission circuits, and to receive one or more sets of serial signals from one or more of the receiving circuits and to convert the serial signals to parallel signals.

Abstract: An electrical circuit pack ejector system provides a preemptive warning to the circuit pack that allows redirection and disabling of circuit pack functionality prior to ejection and subsequent disconnection of power and input/output signal contacts. The ejector system is based on proximity detection that measures the distance between a Hall-effect sensor and a magnet affixed to an ejector arm. The magnetic field strength increases as the magnet approaches the sensor. Once the sensor threshold is reached, a logical bit from the sensor is flipped and a positive ejector engagement is surmised. As the ejector arm rotates away from the sensor, the magnetic field strength around the sensor is reduced. Once the sensor threshold is reached, a logical bit from the sensor is flipped and a negative ejector engagement is surmised. The circuit pack then redirects and disables functions prior to the power and signal connectors physical disengagement.

Abstract: System to optimize received power at an input to a component in a network element that forms part of an optical network. The system includes a graphical user interface (GUI) that guides an installer to allow optimal setting for a variable optical attenuator (VOA) to be determined, thereby using the VOA to optimize the received power at the component. Power parameters are determined for each card in a signal path from the VOA to the input, and as part of the GUI, the system provides a display of calculated and received power to the user, thereby allowing the user to determine the optimal power setting.

Abstract: An optical device including dynamic channel equalization is provided. In an exemplary multiplexer or line amplifier configuration the device includes a plurality of separate optical paths, each of which receiving a separate group of optical signals. Each group of optical signals is provided to an associated variable optical attenuator. Separate inputs of an optical combiner are each coupled to an output of an associated one of the variable optical attenuators. The optical combiner has an output providing the separate groups of optical signals in an aggregated form on an aggregate optical signal path. An optical performance monitor is coupled to the aggregate optical signal path, and is configured to detect an optical signal to noise ratio of each of the separate groups. The monitor supplied a feedback signal to corresponding ones of the variable optical attenuators for adjusting a respective attenuation associated with each of the attenuators in dependence of the detected optical signal to noise ratios.

Abstract: An optical fiber ring is provided carrying a plurality of WDM optical signals, each at a respective one of a plurality of wavelengths. Each optical signal carries data associated with a corresponding group of TDM add/drop multiplexers coupled to an optical path spaced from the optical fiber ring. The optical signals are extracted from the fiber ring with optical add/drop multiplexers, and the data carried by the optical signals is then supplied to the corresponding group of TDM add/drop multiplexers. Accordingly, instead of assigning an optical add/drop multiplexer to each TDM add/drop multiplexer, the optical add/drop multiplexers are assigned to respective groups of TDM add/drop multiplexers. As a result, optical loss as well as cost of the WDM ring are minimized.

Abstract: An interface receiver coupled among a plurality network elements of at least one network is provided, comprising at least one random access memory (RAM) and at least one comparator. Time slot network (TS net) data frames comprising switching event information are received from each of a number of channels of a backplane network. Compare operations are performed at prespecified intervals among at least one data frame stored in the RAM and at least one subsequently received data frame. Interrupt signals are generated in response to data changes determined by the compare operations.

Abstract: A network element (NE) in a communications network decodes a data stream received over a communication link. Upon synchronization with the data stream, the NE determines a performance metric for the link based on a number of transmission code violations. In response to the performance metric exceeding a predetermined threshold, the NE commands the selection of a different link to carry the data stream via a switch signal. The switching or rerouting of signals may occur between a single pair of NEs (e.g., point-to-point span) or in a more complex topology having a plurality of interconnected NEs.

Abstract: A user interface for managing connections across multiple cross connects of a communication network. The user interface provides for creating, viewing and removing connections in the cross connect. The user interface displays the relative position of cross connects along the communication network. Time slots for communicating ports are adjacently displayed so that mis-configured connections may be easily recognized.

Abstract: A system and method for optical power transient control and prevention in communication networks. An optical signal propagating on a network is demultiplexed into individual spectral bands, e.g. at an OADM, and an optical power monitor point is included into each band. A separate idler laser is provided for each OADM band. The power output of each laser is adjusted such that it compensates for the signal power lost from each band. The wavelength of each laser is chosen to fall within the associated OADM spectral band, but outside of the window of individual signal wavelengths, so that it may propagate through the network without causing deleterious interference at the receiver.

Abstract: System for providing distributed group-based protection switching at a network element in a communication network. The communication network includes a plurality of interconnected network elements, and wherein the network element includes first and second card logic coupled to the communication network to transmit and receive network traffic. The system comprises selector logic distributed between the first and second card logic that includes first and second switching engines that have associated activity states that indicate how the network traffic is routed at the network element. The switching engines generate new activity states based on selected fault indicators. A processing system operates to detect fault conditions, generate the selected fault indicators, and receive the new activity states from the switching engines to perform one or more switch reconfigurations at the network element based on the new activity states, and thereby implement the distributed group-based protection switching.