Abstract: The present invention provides a method and apparatus for managing distributed statistical data retrieval in a network device. Periodically, statistical data is gathered by processes on one or more remote cards in a network device and transferred to a central process. The statistical data may comprise, for example, management/historical data including accounting, performance, security and fault logging data (or some portion thereof). In one embodiment, the central process may notify each process as to when gathered statistical data may be reported. This allows the central process to throttle the amount of data sent to the central process in accordance with any existing backlog of data to be processed by the central process.

Abstract: System and methods for upgrading an optical add-drop multiplexer (OADM) to higher degree wavelength selective router (WSR)/wavelength selective switch (WSS) are disclosed. For example, an OADM of degree-2 may be provisioned for upgrades to degree-3 and higher. The existing links power and signal-to-noise (SNR) budgets are not significantly affected when the node is upgraded to a higher degree WSS/WSR. Cascaded power dividers and combiners may be used in conjunction with optical amplifiers and reconfigurable blocking filters to increase the number of paths over which an optical signal can be routed/switched without affecting the paths already utilized. Prior to enabling service on either an input or output fiber, taps and combiners are pre-provisioned so as to ensure that at least one additional transmission path is always available.

Abstract: A method of reducing correlation between channels in an optical communication network. A transmission characteristic of first data on a first channel is altered to reduce correlation between the first data and second data on a second channel. The reduction in correlation reduces crosstalk. The transmission characteristic may be one or more of time delay, scrambling, inversion or modulation.

Abstract: The present invention provides an optical telecommunications network that includes at least one of a filter having equal group delay ripple and minimized phase non-linearity which is formed by the process including limiting at least one of the group delay ripple and the phase non-linearity of the filter between a predetermined upper boundary and a predetermined lower boundary, wherein such limiting includes selecting a baseline filter of a predetermined order having a given transmission at a given frequency from a center frequency of the baseline filter; deriving a scaling factor by, where the given transmission of the baseline filter is equal to a predetermined transmission of the filter, comparing the given frequency from the center frequency of the baseline filter to a predetermined frequency from a center frequency of the filter; applying the scaling factor to a denominator polynomial of the baseline filter to obtain a denominator polynomial of the filter; and performing simplex-type multi-parameter optim

Abstract: An optical attenuator with increased dynamic range and reduced temperature-dependence over the dynamic range. The optical attenuator has a Faraday rotational angle variable device which applies an external magnetic field to light polarized by a garnet crystal, and a polarizer and an analyzer disposed at the front and rear of the optical axis of the device. There is an angle x formed between the plane of polarization of the light incident to the garnet crystal and the magnetic field orthogonal to the optical axis, where an angle y is formed between the polarizer and the analyzer, and the angle x is set to satisfy {(?z/2)+90×n}?12<x<{(?z/2)+90×n}+12 (n=0, 1, 2 or 3), where z=y±90; z is the angle of rotation of the plane of polarization caused by the Faraday rotational angle variable device.

Abstract: A method and apparatus for controlling phase alignment in a modulator of a transmitter in an optical communications system utilizes an RF power signature to tune phase alignment. A portion of the optical signal is tapped and converted to an electrical signal. An electrical band-pass filter and RF detector examines a narrow slice of the RF spectrum and utilize the detected RF power to control phase alignment between the data modulator and pulse carver. Another portion of the optical signal is multiplied by the pulse carver clock, filtered and integrated in order to generate a second phase control signal for controlling the relative phase of a dual arm modulator being used as the pulse carver in one embodiment.

Abstract: A method of controlling phase alignment in a modulator of a transmitter in an optical communications system uses a narrowband optical filter to monitor changes in power spectral density of a modulated output at and around the optical carrier frequency. In one embodiment, a method controls alignment of a carrier-suppressed-return-to-zero (CSRZ) pulse train in accordance with changes in the power spectral density of the CSRZ modulated optical signal at and around the optical carrier frequency and generates phase adjustment control signals by executing a phase-control loop to maintain the power spectral density of the CSRZ modulated output at the optical carrier frequency at a desired level.

Abstract: A system and method for selecting optical amplifier placement in an optical network is disclosed. In one embodiment, a design tool is used to configure the optical add/drop multiplexers of each nose. For nodes with more than a small number of nodes there are a large number of possible optical amplifier configurations. Consequently, a subset of optical amplifier placement configurations is formed. In one embodiment an algorithm is used to eliminate from consideration optical amplifier configurations unlikely to have satisfactory minimum power characteristics. In one embodiment the quality of service of each configuration of the subset is analyzed to determine an optical amplifier placement configuration having a minimal number of amplifier and a desirable quality of service.

Abstract: Methods and apparatus implementing and using techniques for creating a permanent sub-network connection in a network of connected nodes. A route including a working path for a permanent sub-network connection is defined in the network from an ingress node to an egress node. A time out period to be associated with the permanent sub-network connection is defined. The time out period defines a time over which a failure in the permanent sub-network connection is permitted to be corrected prior to a tear down of the permanent sub-network connection. The route is provisioned. A route description is distributed to each node along the route and each node along the route is configured in accordance with the route description to provide data traffic services from the ingress node to the egress node. Methods and apparatus implementing and using techniques for deallocating resources in a network of connected nodes are also described.

Abstract: A method of telecommunication network switch port polling enables very highly channelized ports to be polled. A polling engine reads information from at least one of a plurality of poll registers, and each of the plurality of poll registers is associated with a unique identifier. Depending on the information read from the at least one poll register, the polling engine reads a channel number representing the channel to be polled from a location in channel memory. The polling engine determines the location from the unique identifier associated with the at least one poll register from which the information is read. The polling engine polls channel represented by the read channel number.

Abstract: The present invention is directed to systems and methods for automated detection of one or more wireless network policy violations and/or enforcement of such policies. A wireless network policy violation is detected. Associated with the detected violation are one or more wireless network attributes. A responsive corrective action is triggered which is based at least in part upon the detected violation, the associated wireless network attributes or combinations thereof. The corrective action can in some instances include a notification to a user or further system. In addition to, or instead of, a notification, the corrective action can include an attempt to configure one or more devices in the wireless network to correct, in whole or in part, the detected violation.

Abstract: At least one protection line is shared among SONET rings. Identification and availability information of the shared protection line is distributed among the switches of the SONET rings using K-byte data in the SONET overhead.

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.

Abstract: A method of modeling or constructing a switch element uses an ingress stage with input sorters and input routers; an egress stage with output routers and output sorters; and a center stage interconnecting the ingress and egress stages. Routers are partitioned such that each partition is assigned to only one data line. A switch controller and method may use such modeling to advantage. For example, during initial configuration of the switch element, a subset of connections are excluded from a control algorithm that initially configures the switch with the subset being subjected to post processing. Furthermore, a fast rearrangement of the switch rearranges only part of the existing connections and then adds/deletes cross connects as necessary to complete the connections.

Abstract: A optical communications network including at least one optical phase conjugator for compensating for non-linear effects. The optical communications network includes at least one dispersion compensation module before the optical phase conjugator and at least one dispersion compensation module after the optical phase conjugator. The dispersion compensation modules compensate for linear effects of the transmission path such as dispersion and dispersion slope. This allows the optical phase conjugator to be designed to compensate for non-linear effects such as self-phase modulation and cross-phase modulation. The separate compensation of linear and non-linear effects provides enhanced control of these effects.

Abstract: A relative address protocol for communicating message packets along a linear chain network or quasi-linear chain network is disclosed. The protocol includes a relative destination address field that includes a counter having a preselected initial value at a source node. The initial value is a function of the desired number of node hops that the message packet should travel from the source node. The counter is adjusted in value at each subsequent node by a preselected step in value. When the counter value reaches a trigger value the message packet is accepted by a destination node. In a preferred embodiment, a relative source address field stores the initial value so that the destination node may return a status message to the source node.

Abstract: The invention is a granular media filter for in-line liquid applications that allows media as fine as 44 micron to be used to increase the removal of contaminants from the liquid with adequate flows consisting of a specific arrangement. A flow distributor has a non-woven fiber web welded to it; followed by a mixture of fine particle media (finer than 20×50 mesh); followed by a compressible chlorine resistant open cell polyurethane foam, then a 5 micron rated meltblown fiber tube attached to the outlet end by melt adhesive on one end and closed with a plastic plug on the other end. The foam can be either polyurethane or polyolefin, and it can be either open cell foam, or reticulated and open cell foam. A preferred embodiment includes within the fine particle media 10% by weight of flow-enhancing antimicrobial plastic pellets, about 4-5 mm in diameter and having an aspect ratio of 2-3, the pellets encapsulating an antimicrobial additive.

Abstract: A small-scale positioning device employing a platform, a levering mechanism and a floating actuator device. The platform is movably attached to a fixed frame by a lever, a pair of levers, or more. The floating actuator device is coupled between at least one lever and the platform. When the actuator device is activated, it generates a force on the platform and an equal but opposite force on the levering mechanism, causing one or more levers to rotate around their respective fulcrums, thereby controlling the position of the movable platform relative to the fixed frame. The amount of displacement of the platform is dependent upon the effective expansion or contraction of the actuator device and the lever ratio. If the pair of levers are symmetrical, then motion is created in only a single degree of motion. Flexures may be included to prevent motion in unwanted directions.

Abstract: Consistent with the present invention, tunable demultiplexers are provided in WSS-based add/drop multiplexer. The tunable demultiplexers are modular and thus allow the add/drop multiplexer to be readily expandable, and facilitate flexible add/drop capabilities whereby a channel present on any input line to the WSS can be dropped and supplied to one or more desired outputs of the tunable demultiplexer. Similar flexibility can be achieved on the add-side of the WSS. Moreover, the demultiplexers and the WSS are remotely configurable, thus obviating the need to manually disconnect and connect demultiplexers to a router. In a particular embodiment, multicast switches are provided that permit the same channel, for example, to be provided to one or more outputs of the add/drop multiplexer, such that copy of the channel can carry working traffic while the other copy carries protection traffic. As a result, 1+1 and 1:N optical layer protection can be achieved.