Ciena

About: Ciena is a company organization based out in Hanover, Maryland, United States. It is known for research contribution in the topics: Signal & Node (networking). The organization has 1259 authors who have published 1557 publications receiving 25989 citations.

Method and system for determining and suppressing sympathetic faults of a communications network

Abstract: A distributed method and system of controlling a communications network having a plurality of spans of interconnected network elements some of which include a network element processor distributes network topology information to respective span databases; stores original fault objects in the respective span databases; advertises fault objects to other network element processors in a local span when the original fault affects network elements other than a network element in which the fault occurred; advertises alarm objects to other network element processors that are respectively associated with a circuit affected by the original faults; stores the advertised fault and alarm objects in the respective span databases; and performs distributed processing of the advertised fault and alarm objects with the other network element processors and the respective span databases. Aggregation of other faults and alarms that may be occurring on the communications network due to other faults other than the received fault aids in determining causality of the fault. Causality may be determined by correlating other faults and alarms with the received fault. If not a root cause of another fault or alarm, the received fault is sympathetic to another fault or alarm. Sympathetic faults are suppressed while root cause faults are promoted to an alarm and reported to affected network elements. The number of alarms viewed by a network manager as well as the reporting of alarms and underlying faults are reduced by performing such distributed alarm correlation and fault reporting suppression.

System for clock synchronization

Abstract: A timing circuit for use with transport logic in a network element is provided. The network element forms part of a data network and the timing circuit includes a timing receiver having a timing input, a timing output, and a selection input, the timing receiver operable to receive one or more timing signals at the timing input and to select a selected timing signal for distribution to the transport logic via the timing output based on a selection signal received at the selection input. The timing circuit also includes a determination circuit that is operable to determine whether the timing circuit is one of a master timing circuit and slave timing circuit, and based on the determination, produce the selection signal. A sync transmitter is also included in the timing circuit. The sync transmitter is coupled to the timing output, the determination circuit, and a communication channel. The sync transmitter is operable to receive the selected timing signal and to transmit the selected timing signal on the communication channel when the determination circuit determines that the timing circuit is the master timing circuit.

Methods and systems of preserving client overhead bytes in optical transport network tunneling applications

Abstract: A method, a network, and a node each implement the transmission of Automatic Protection Switching (APS) switching coordination bytes across an OTN network. A working signal and a protection signal are received, one of which is designated as an active signal. The active signal is encapsulated in an Optical channel Data Unit (ODU) signal. APS switching coordination bytes from the working and protection signals are placed in an overhead segment of the ODU signal. The ODU signal is transmitted into and received from an Optical Transport Network (OTN) network. The working and protection signals are recreated based on the active signal encapsulated in the ODU signal and the APS switching coordination bytes in the overhead segment. The recreated working and protection signals are transmitted. In this manner, a single ODU signal may be used to transmit both the working and protection signals.

Methods and systems for reduced complexity nonlinear compensation

Abstract: Aspects of the present invention provide techniques for compensating nonlinear impairments of a signal traversing an optical communications system. A parallel array of linear convolutional filters are configured to process a selected set of samples of the signal to generate an estimate of a nonlinear interference field. The predetermined set of samples comprises a first sample and a plurality of second samples. A processor applies the estimated nonlinear interference field to the first sample to least partially compensate the nonlinear impairment.

Laser diode and heatsink quick connect/disconnect assembly

Abstract: A connect and disconnect assembly for connecting and disconnecting a laser diode having leads to a printed circuit board (PCB). The assembly includes a heatsink having a base plate portion and fins extending from and integral with the base plate portion. The heatsink further includes spacer sleeves extending from a side of the base plate portion opposing the fins. The heatsink connects to the printed circuit board by providing mount screws through the heatsink and spacer sleeves which are received in mount holes formed in the PCB. The laser diode connects to the base plate portion of the heatsink. Laser support blocks connect with the heatsink and support opposing sides of the laser diode. Each laser support block is provided with a dielectric gasket. When the heatsink is mounted onto the PCB, the laser diode leads are forced against corresponding pads provided on the PCB for electrically connecting the laser diode to the PCB. The dielectric gaskets provide pressure on the laser diode leads so that they adequately contact their corresponding pads on the PCB, and electrically isolate and insulate the leads to prevent lead frequencies from intermixing. The assembly provides a convenient mechanism for connecting/disconnecting the laser diode and heatsink to/from the PCB. Further, the laser diode and assembly can be easily disconnected from the PCB so that a modified, repaired, and/or updated laser diode or other component can be quickly and easily inserted into the circuit without damaging or destroying the laser diode or the PCB.