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.

Systems and methods for distance-proof n-pass auto negotiation for gigabit ethernet

Abstract: The present invention provides distance-proof N-pass Auto Negotiation systems and methods for Gigabit Ethernet. The present invention distance proofs Auto Negotiation. No matter the distance between two nodes configured according to the systems and methods of the present invention, the link at either end of the two nodes will only come up once each end has negotiated, resolved its link partner's capabilities, and received a similar success signal from the remote node.

G.8032 ethernet multiple fault recovery mechanisms

Abstract: A method, network element, and network provide detecting a failure on both ports of a major ring at a network element that has an interconnecting sub-ring terminating thereon; causing a block at an associated sub-ring termination port of the interconnecting sub-ring responsive to the failure on both the ports of the major ring; and monitoring the failure and clearing the block responsive to a recovery of one or both ports from the failure. The method, network, and network element include G.8032 multiple concurrent or simultaneous fault recovery mechanisms that traffic being transported between an interconnected major ring and a sub-ring to be successfully delivered in the event of dual concurrent faults on the major ring.

Wavelength locking scheme and algorithm for ultra-high density WDM system

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. Accordingly, the temperature of the filtering element, for example, influences the laser temperature, so that wavelength variations stemming from temperature induced changes in the filtering element and other components in the laser package can be compensated, and the output wavelength can remain substantially fixed.

Dispersion slope compensation and dispersion map management systems and methods

Abstract: The present disclosure relates to dispersion slope compensation and dispersion map management systems and methods in an optical network utilizing a reconfigurable optical add-drop multiplexer (ROADM) with a plurality of different values of dispersion compensation modules (DCMs). The DCMs form a dispersion compensation ladder at certain intermediate nodes in the optical network to provide dispersion slope compensation and dispersion map management. The reconfigurable routing structure of the ROADM enables these intermediate nodes to route individual wavelengths to any one of the DCMs as required for the particular path of the wavelength. Advantageously, the present invention removes the requirement for banded compensation at receiver nodes and allows for dispersion map management at intermediate points along a fiber route as opposed to bulk compensation at the receiver.

Optical filter having a quartz substrate

Abstract: An optical filter including a plurality of dielectric layers is provided on a quartz substrate. Quartz is advantageous as a substrate material because it has relatively low loss at wavelengths commonly used in telecommunication systems. Moreover, it is thermally and chemically stable, and has good adhesion to most dielectric films used as quarter and half wave layers. Further, quartz is mechanically tough, relatively inexpensive and readily available. The quartz substrate is cut from a crystal and has an orientation with reduced birefringence. In addition, the thickness of the quartz substrate is selected to reduce temperature-related shifts in the center wavelength of the filter.