Abstract: A method for optimizing an optical transmitter is provided. According to one exemplary method, the optical transmitter is optimized by varying three transmitter parameters including the bias voltage, the crossing level and the peak-to-peak voltage. Once the respective optimal levels for the bias voltage, the crossing level and the peak-to-peak voltage are obtained, the optical transmitter is further checked to ensure that the optical transmitter is able to function properly within certain predetermined system parameters. The optical transmitter is also checked under two limiting scenarios to ensure that the optical transmitter is optimized against two predetermined lengths of optical fiber.

Abstract: Phantoms and discrete spatial and frequency methods for quantitatively measuring the alignment of radiographic imaging systems are described. One embodiment comprises phantoms for use in mechanically aligning radiographic imaging systems. These phantoms comprise: a radio-opaque material capable of holding a well-defined edge that allows quantitative image resolution measurements to be obtained thereof; wherein once the quantitative image resolution measurements are obtained, the spatial frequency response of the radiographic imaging system at a given focal plane can be calculated therefrom, thereby defining the mechanical alignment, resolution, and resolution uniformity of the radiographic imaging system. Systems and methods for mechanically aligning radiographic imaging systems, and methods for obtaining a quantitative measurement of the mechanical alignment, resolution and resolution uniformity of radiographic imaging systems, are also disclosed.

Abstract: An exemplary embodiment of the invention is a method of detecting network elements in an optical communications network. The method includes an initiating network element generating a neighbor discovery message including a requested hierarchy level at which neighbor discovery is requested and transmitting the neighbor discovery message downstream along the optical communications network. A downstream network element receives the neighbor discovery message, determines if the downstream network element operates at the requested hierarchy level. The downstream network element generates a responding neighbor discovery message if the downstream network element operates at the requested hierarchy level and transmits the responding neighbor discovery message to the initiating network element. Alternate embodiments include a system and storage medium for implementing the method.

Abstract: An interface transmitter coupled among a number of network elements of at least one network is provided, wherein a number of data frames of a first type are received from at least one processor and stored in at least one random access memory (RAM). Data is read from the RAM to at least one data serializer in response to a number of signals received from the processor and over at least one backplane network. A number of data frames of a second type corresponding to the data frames of a first type are generated and serially transferred among the network elements using the backplane network.

Abstract: The present invention provides an upper layer network device with one or more physical layer data test ports. The data supplied to the test ports reflects the data received by the network device with minimal modification and no upper layer translation or processing, and supplying the data to the test ports does not impact or disrupt the service provided by the network device. Only a small portion of the network device need be operable to send data to the test ports. In addition, the test ports are programmable while the network device is operating and without impacting its operation. Moreover, because the test ports are programmable—that is, they are not dedicated—they may be re-programmed for normal device operation.

Abstract: A method and apparatus for assigning channel bands to a wavelength division multiplexed (WDM) system is disclosed. The WDM system includes an arrangement of optical amplifiers, banded optical add-drop multiplexers (OADMs) having blocking filters, and a tunable edge filter. The channel band assignment method suppresses amplified stimulated emissions (ASE) in a partially populated system in which at least one of the blocking filters is not in the transmission path. Channel bands are assigned from one edge of an amplified transmission window to the other in a sequential order and the tunable edge filter is adjusted to attenuate ASE wavelengths not blocked by the blocking filters as channels are assigned. A channel decommissioning method is also disclosed which employs similar techniques and the tunable edge filter to suppress ASE as blocking filters are removed or otherwise deselected from the transmission path.

Abstract: Network data is received in a first format. The data is converted to a synchronous optical network (SONET) format. Switching functions are performed on the SONET formatted data. The SONET formatted data is converted to a second format. In one embodiment, the switching functions on the SONET formatted data contains performing time switching and space switching.

Abstract: The present invention provides a network device having an internal configuration database process for managing configuration of internal resources within the network device in response to configuration input provided by an external Network Management System (NMS) process. In one aspect, the invention provides a communications system having a network device, and a computer system. The network device includes an internal configuration database process for managing configuration of internal resources within the device. The computer system includes an input mechanism for receiving configuration input data from a network manager, and an NMS process for responding to the configuration input data and for sending configuration data to the configuration database process within the network device, where the configuration database process within the network device configures internal resources of the network device in response to the configuration data received from the NMS.

Abstract: An apparatus and method for fault detection and isolation in an optical network is disclosed in which each node determines an appropriate response to a line fault or an equipment fault, obviating the need for a central computer to coordinate the actions of each node in response to a fault. Each network node includes a local controller and restoration elements for detecting and responding to faults. Each local controller correllates a first set of optical characteristics measured by optical detectors with the local node with a second set of optical characteristics for the channels reported to the local node from an upstream optical element, such as a neighboring upstream node, to determine if a line switch or equipment switch is required. In a preferred embodiment, each node is communicatively coupled to its neighboring node via an optical supervisory channel, with the neighboring nodes communicating status messages and data on channel characteristics via the optical supervisory channel.

Abstract: A system for use in a bi-directional path switched ring network for detecting a failed optical path and establishing a protection path so as to allow signals from the failed optical path to be re-routed via the protection path is provided. According to one aspect of the system, upon detecting a failure relating to an optical path, the destination node generates a connection request message for transmission to the source node. The connection request message is passed to the source node via one or more intermediate nodes, if any. Each intermediate node examines the connection request message accordingly reserves the requisite wavelength from the protection capacity so as to allow signals from the failed optical path to be re-routed. Upon receiving the connection request message, the source node readies its switching equipment to re-route signals from the failed optical path and generates an acknowledgment message and propagates it back to the destination node via the intermediate nodes.

Abstract: Electrically conducting ceramic bearings are described. All components of these bearings preferably comprise TSC, and may not require any conductive coating, or any lubricating coating. These bearings may comprise at least one rolling element such as a bearing ball, a roller, a needle, or the like. These bearings may be ideal for use in x-ray tube bearing assemblies in x-ray imaging systems, or in any other systems that require electrically conductive bearings.

Abstract: A system for determining the position of an object, comprising a reference transmitter device (202) disposed in a fixed position, the reference transmitter device (202) having a reference time supplying means for supplying a reference time signal that indicates a reference time, at least two transmitter/receiver devices (302) disposed in fixed positions with respect to each other and to the reference transmitter device (202), each transmitter/receiver device (302) having a time supplying means for supplying a time signal indicating a time, a receiver means for receiving the reference time signal from the reference transmitter device (202) and a synchronization means for processing the time signal and the reference time signal, as well as a position determining device (502) on the object for determining the position of the object.

Abstract: An optical fiber ring network includes a plurality of interconnected nodes, each pair of neighboring nodes being interconnected by a pair of optical links. Using coarse wavelength division multiplexing, data is transmitted in both directions over each link, using a first wavelength ?1 to transmit data in a first direction over the link and a second wavelength ?2 to transmit data in a second, opposite direction over the link. The two wavelengths ?1 and ?2 differ by at least 10 nm. Each of the data streams transmitted over the optical link has a bandwidth of at least 2.5 Gbps. Further, each data stream has at least two logical streams embedded therein. A link multiplexer at each node of the network includes one or more link cards for coupling the link multiplexer to client devices, and one or more multiplexer units for coupling the link multiplexer to the optical links.

Abstract: A personal air filtration device has a cylindrical exhalation tube, with a one-way valve thereon. Concentric around the periphery of the exhalation tube and integrally connected to the exhalation tube rearward (proximate the user's mouth) of the one-way valve is a filter media housing. Filter media is contained between the housing and the tube. A plurality of perforations in the exhalation tube, rearward of the one way valve but forward from the housing connection ring, provide inhaled air ingress to the exhalation tube. Inhaled air forces the one-way valve closed, so that air is directed through the filter media, passes through the perforations and into the exhalation tube where the user can take in the cleansed air. The pressure of the exhaled air through the exhalation tube causes the one-way valve to open, so that exertion by the user is minimized.

Abstract: An embodiment of the invention provides an ejector latch that advantageously maximizes the use of face plate space in a circuit pack. An embodiment of the invention also provides an ejector latch, where sufficient force or leverage can now be provided by the user by grabbing a movable handle portion of the ejector latch in order to disengage the ejector latch from a portion or component of a carrier. Therefore, the movable handle portion of the ejector latch advantageously permits the application of more force to the ejector latch, in order to permit easier disengagement of the latch from the carrier.

Abstract: The invention relates to a device for applying pieces of material to a workpiece. Said device comprises a plurality of capillaries which respectively bring a piece of material (6) to a work station (3) in one working cycle. The piece of material is placed on the work station. A filling station fills a circular conveyer with a number of pieces of material (6) corresponding to the number of capillaries (4). An extracting station (19) is arranged in the transport path from the filling station (18) to the machining station (4?), said extracting station (19) extracting individual fragments of material (6) in a selective manner.

Abstract: The present invention provides a network device that fully utilizes the available space in a standard telco rack through the use of multiple mid-planes. Full utilization of available space allows a high switching capacity network device including both physical layer switch/router subsystems and upper layer switch/router subsystems to be fit in one telco rack. Inter-mid-plane connections may be provided by connecting switch fabric cards and/or control processor cards to each of the mid-planes. Providing a multi-layer network device in one telco rack allows for intelligent layer 1 switching (for example, dynamic network connection set up), allows for one network management system to control both layer 1 and upper layer networks and eliminates grooming fees.

Abstract: Lines within an aggregated link extending between network elements in a communications system are monitored for faults. Once a fault is detected on a particular line carrying a control channel, an alternative line is selected and control channel is transmitted on the alternative line. Once a control channel is received at a remote end on a new line, the control channel is reassigned to that line. In an alternative embodiment, the control channel is split into separate channels carrying routing and signaling information, respectively. The separate routing and signaling channels are carried by separate lines, but can be reassigned to other lines in response to a fault. Further, the routing information can be carried by multiple lines in an alternating pattern such as a round robin fashion.

Abstract: A switch is provided that includes three stages. The first stages has a plurality of switch circuits. The second stage has a plurality of switch circuits equal to N, where N is any integer other than a power of 2 and where the switch circuits can be logically configured into a logical configuration of a power of 2. The third stages includes a plurality of switch circuits.

Abstract: A high availability communication system is disclosed having multiple layers of redundancy, including network interface redundancy, network switching mechanism redundancy, and functional redundancy. To minimize the effect of the redundancy on other parts of an overall system, virtual addresses are implemented. These virtual addresses enable other parts of the overall system to interact with the communication system without knowing the details of the redundancy. By implementing multiple layers of redundancy with virtual addresses in this manner, high availability is achieved without causing inefficiencies to be suffered by other parts of the overall system.