Abstract: An optical cross-connect switch (12) includes and optical matrix 14 for passing optical communication data between an origination I/O port (20) and a destination I/O port (22). Control information is passes between the origination I/O port (20) and the destination I/O port (22) in transport frames 24. The transport frames include multiple framing bytes indicative of the start of a frame (24) and stuff bytes at regular intervals to ensure adequate bit transitions in the control information data stream. Payload bytes carrying control information are positioned between stuff bytes. The stuff bytes have different bit values from the framing bytes in multiple bit positions to allow false framing only if there are multiple bit errors in the stuff frame.

Abstract: A wavelength access server (WAS) architecture provides aggregation of traffic streams of diverse data communication protocols as well as provision of wavelength resources in an optical transport network. The WAS provides functions such as service traffic adaptation, traffic aggregation and segmentation, traffic classification, optical inter-working and system management. In particular, system management includes aspects such as signaling, connection management, resource co-ordination, protection prioritization and access policy management.

Abstract: A multi-dimensional optical cross-connect switching system. The system is capable of multi-dimensionally using wavelength resources, such as in the forms of optical fibers, optical wavelength bands and optical wavelengths. The system can three-dimensionally use the wavelength resources by being matched with an optical transport network through the optical fiber layer, optical wavelength band layer and optical wavelength layer. In addition, the multi-dimentional optical cross-connect switching system is constructed in such a way that two cross-connect switches are symmetrically arranged and an insertion/extraction switch is added to switch addition/dropping links between the two switches.

Abstract: A multi-grained network includes edge modules that switch high-variance multi-rate data traffic, and independent core modules that switch paths having different granularities. The core may include core modules that switch fixed-size data blocks, core modules that switch channels or bands of channels, core modules that switch entire links, and core modules that cross-connect channels or links. To simplify the control functions, the core modules operate independently from each other. Direct link, band or channel connections may be established for selected ingress-egress edge module pairs, if traffic volumes warrant. The use of graded granularity in the core simplifies the control function and reduces network cost.

Abstract: An optical switching system includes multiple layers for switching optical signals. A first layer is for switching optical channels. A second layer is for switching groups of optical channels. A third layer is for switching composite optical signals. Between layers demultiplexing and multiplexing of signals allows switching within a single switch core at any level from fiber to wavelength group to optical wavelengths. Optical amplifiers between layers compensate for losses within the switch and within demultiplexers and multiplexers. One configuration provided additional multiplexing and demultiplexing to allow direct connection between the first and third layers. Another configuration shares optical switching matrices between the first and third layers.

Abstract: A method for setting a cut-through optical path in an optical network system is proposed. At first, a destination side edge node device which confirmed,the transfer of a packet to a terminal accommodated by the present node device or to an access system network notifies the open resource information of the present node device to a transmission side edge node device. Then the transmission side edge node device determines the optimum allocation of an optical path to be set on the transfer route based on the open resource information notified by the destination side edge node device and the core node device. Then, according to the allocation optical path determined in the previous step, the transmission side edge node device, the core node device, and the destination side edge node device set the optical path which omits the packet transfer processing (layer 2 and layer 3 processing) in transit nodes.

Abstract: A method for setting a cut-through optical path in an optical network system is proposed. Each node device inquires of node devices adjacent to the present node device about connection information on the present node device and connection information on the node devices adjacent to the present node device each time a predetermined time elapses or each time a predetermined event is generated. When the inquiry is received from the node device adjacent to the present node device, the present node device responds with the connection information and/or traffic information on the present node device and the connection information on the node device adjacent to the present node device.

Abstract: An optical switch is equipped with a set of optical intensity controllers at its input, each intensity controller being driven to vary a corresponding WDM input traffic signal with a low power test signal. The switch is also equipped with optical splitters at its output and a path integrity analyzer connected to the splitters and to the intensity controllers. The path integrity analyzer generates or controls generation of the test signals applied by the intensity controllers. The path integrity analyzer also receives the tapped portions of the WDM output signals and separates them into their single-carrier components in order to recover a set of switched single-carrier optical signals. The path integrity analyzer is further provided with test signal detectors used to detect the presence of a test signal in each recovered switched single-carrier optical signal.

Abstract: A cross-connect device in an optical network which includes a demultiplexer for demultiplexing an input optical signal by channels; a plurality of arbitrary transmission optical receivers for converting the optical channel signals received from the demultiplexer to electrical signals and for recovering a clock signal and data according to a reference clock signal generated at the transmission rate of the electrical signals; a cross-connect switch for path-routing the electrical signals received from the arbitrary transmission optical receivers; a controller for controlling the path-routing of the cross-connect switch; a plurality of arbitrary transmission optical transmitters for converting the electrical signal received from each output port of the cross-connect switch to an optical signal; and, a multiplexer for multiplexing the optical signals received from the arbitrary transmission optical transmitters onto one stand of optical fiber.

Abstract: The present invention relates to an optical switching device for WDM systems based on multi-frequency lasers and optical couplers. A router/switch mapping of IP (or other protocols) subnets or addresses to an optical channel instead of a physical interface. Another embodiment of the invention implements the mapping directly at the source where the data transmission originates. The invention allows integration of WDM in the routers and switches, and ultimately in the information source. As a result, unnecessary opto-electrical conversion steps and physical interfaces are eliminated.

Abstract: An optical path cross-connect device includes a wavelength branching unit, an intra office signal input unit, “m” pieces of routing units, a wavelength combining unit and an intra-office signal output unit. The routing units input thereinto an optical signal outputted from either of the wavelength branching unit and the intra-office signal input unit via a first optical path group, and convert an input optical signal into a predetermined wavelength to thereby output a wavelength-converted optical signal to a second optical path group. The “m” (symbol being an integer and also being larger than 1)” pieces of routing units are subdivided into units of at least “n (symbol “n” being an integer and also being larger than 1)” wavelengths, as wavelength ranges to be processed by the respective routing unit are different from each other.

Abstract: An optical crossconnect apparatus which includes one terminal connected to a transmission path from one optical transmission terminal station and another terminal connected to a transmission path from another optical transmission terminal station, a first optical signal switch having “M1” ports and “N1” ports, through which the optical signal can pass, a second optical signal switch having “M2” ports and “N2” ports, through which the optical signal can pass, and “L” optical signal repeaters, one end connected to the “N1” ports of the first optical signal switch, and the other end connected to the “N2” ports of the second optical switch. The “N1” and the “N2” ports are equal to “L” optical signal repeaters.

Abstract: The invention relates to a time division and wavelength division multiplex optical switching node for use in an optical communications network (2), which node combines a set of time division multiplex packets (8-1, 8-2, . . . , 8-i) into a wavelength division multiplex packet (18) to form a composite wavelength division multiplex packet, in particular by conferring on each time division multiplex packet (8-1, 8-2, . . . , 8-I) a respective appropriate multiplexing wavelength (&lgr;1, &lgr;2, . . . , &lgr;i), for example a wavelength specific to each time division multiplex packet. The invention has applications in high bit rate optical networks in particular, in which it offers versatility and transparent use of the different multiplexing modes.

Abstract: Methods and apparatus for providing a time slot switch which performs switching in the optical domain without the need for O-E-O conversion is described. The time slot switching device of the present invention may be part of a large switching device capable of performing switching and other function on WDM, TDM and WDM signals which are time division multiplexed. An optical time slot switch implemented using a time slot demultiplexer, optical cross-connect, variable delay lines and time slot multiplexer are described. Frequency conversion may be performed on a per time slot basis in cases where time slot signals are switched between lines using different wavelengths. Wave division demultiplexers and multiplexers can be added to the basic time slot switch to provide support for WDM switching and switching of TDM signals which are transmitted using wave division multiplexing.

Abstract: The invention relates to an optical switch fabric comprising at least one micro mirror array with tilting micro mirrors for individually switching optical paths for optical signals between input and output ports, especially fibers or waveguides gathered in at least one fiber arrays, comprising a beam splitter and a detector array, wherein the beam splitter is adjusted to partly reflect the optical signals reflecting from the mirrors of said at least one micro mirror array to said detector array and micro mirror control means, that are realised such, that a control signal is generated out of a feedback signal of said a detector array to correct the angular positions of the micro mirror and a method therefore.

Abstract: A device and method for detecting rotational drift of mirror elements in a MEMS tilt mirror array used in an optical crossconnect. The optical crossconnect directs optical signals from an input fiber to an output fiber along an optical path by rotatably positioning mirror elements in desired positions. A monitoring device disposed outside of the optical path is used to obtain images of the MEMS array or to transmit and receive a test signal through the crossconnect for detecting the presence of mirror element drift.

Abstract: One embodiment of the present invention provides a system that facilitates optical switching. The system starts by receiving a plurality of optical input signals. The system then divides each of the plurality of optical input signals into a plurality of wavebands that can be carried on a single optical fiber, wherein each waveband includes a predetermined subset of the wavelengths in the optical signal. Once the optical input signals have been divided into wavebands, the wavebands are then routed through a waveband switch. After being routed through the waveband switch, the wavebands are combined to form a plurality of optical output signals, where each optical output signal can possible include wavebands from different optical input signals. Additionally, some of the wavebands can be divided into wavelengths, and the wavelengths can be routed through a wavelength switch or a traffic grooming switch.

Abstract: An optical wavelength-division-multiplexing (WDM) network has at least one transit node, where a majority of received channels are destined for a remote node, and at least one hub node, where a majority of received channels are switched to a local destination. The network follows a channel-level protection scheme, and at least one of the nodes has a cross-connect switch of a tandem design with a wavelength switch portion optically positioned in a feedback path of a space switch portion. Alternatively, the transit node has a tandem switch design, where the space switch interfaces with the network fibers, and the hub node has at least a wavelength switch that interfaces with the network fibers. The capacities of the respective wavelength and space switch portions of the tandem cross-connect are configured according to the expected ratio of local traffic to passthrough traffic.

Abstract: A method and device for optical add/drop is disclosed. The add/drop splits an input signal into two portions. The first portion is optically filtered to remove the channels, leaving an unmodulated carrier which is modulated with the newly added information. The second portion is split again into the through channels and a channel to be dropped. The dropped channel is detected or terminated and the through channels are recombined with the newly added channel to form an output optical signal. If desired, multiple channels may be dropped at the add/drop node. A dense wavelength division multiplexed (DWDM) optical communication system incorporating the add/drop node is also disclosed.

Abstract: Disclosed is a WDM network which has: a lightwave path which connects between clients and each of which is provided with an overhead, and a sub-network which is defined by dividing the WDM network. In this WDM network, the sub-network has a partial lightwave path to go through the sub-network, the overhead has a partial lightwave path supervisory control information region which is terminated at both nodes of the partial lightwave path, and when a fault occurs on a lightwave path, the fault information of partial lightwave path including the position information of fault occurred is added to the partial lightwave path supervisory control information region of the overhead.

Abstract: A four fiber ring network optical switching circuit capable of realizing the bridge function at times of the span switching and the ring switching economically by a very compact structure is disclosed. A four fiber ring network optical switching circuit is formed by a 10×8 optical matrix switch having ten input ports and eight output ports, and two branching elements adapted to branch each one of two optical signals among eight optical signals that are inputs of the four fiber ring network optical switching circuit, into two identical optical signals, and to enter the two identical optical signals into two input ports of the 10×8 optical matrix switch such that the eight optical signals are entered into the ten input ports of the 10×8 optical matrix switch as ten optical signals.

Abstract: To solve a problem of modularity favoring under-equipping and a problem of energy losses in an all-optical distribution frame for optical lines, a primary converter block includes a redundancy circuit which can emit an optical signal with a wavelength different from any of the other wavelengths broadcast by the other converter circuits of the primary block. In this case a star coupler responsible for frequency domain cross-connection of the signals preferably includes P+1 input channels for P output channels.

Abstract: The optical systems of the present invention include optical switching device generally configured to control signal characteristic profiles over the pluralities of signal channels, or wavelengths, to provide desired signal characteristic profiles at the output ports of the device. Various signal characteristics that can be controlled include power level, cross-talk, optical signal to noise ratio, etc. The optical switching devices can include balanced demultiplexer/multiplexer combinations and switches that provide for uniform optical loss through the devices. In addition, low extinction ratio switches can be configured to provide higher extinction ratios.

Abstract: An optical router integrated in an InP-based substrate bonded to a single thermo-electric cooler for packet-based networks utilizing wavelength-division multiplexing (WDM) on silica fibers. Input and output arrayed waveguide gratings (AWGs) respectively demultiplex and multiplex the WDM signals to and from multiple transmission fibers. Input and output wavelength converters are connected between the input and outputs AWGs and a switching AWG. The output converts may include a tunable laser and interferometer formed in the same substrate. The header information is preferably carried out-of-channel from the WDM data signals, either in the same fiber band or a different one. Photodetectors and laser diodes are formed in the same substrate.

Abstract: A modular optical router/switch construction system and method are described. In one aspect of the present invention, the modules provided are basic 1×N optical components and/or pass-through 1×N optical components, both of which have input/output (I/O) ports which are capable of detachably interconnecting. Pass-through 1×N optical components are like the basic 1×N optical components but include extra ports so that input light may “pass through” the component. In another aspect of the present invention, a bi-directional optical component capable of modular construction is provided. The bi-directional optical component has the same I/O ports as the basic 1×N optical component, but the bi-directional I/O ports are built to engage a duplex optical link (i.e., a link comprised of two optical fibers with signals going in two opposite directions).

Abstract: A time-division multiplexed optical signal is routed to several input ports of a MEMS-mirror Optical Cross connect (OXC). Advantageously, a single optical signal can be routed through fiber delay coils of varying lengths to introduce precise delay to an optical pulse such that the optical pulse is fed to the input ports of the OXC at various timeslots. After switching the optical pulses through the OXC, the switched optical pulse at different timeslots is combined (multiplexed) and thereafter detected. The amount of optical energy in the (combined) received (output) enables the calibration or training of the OXC. The circuit may be reconfigured to measure the amount of cross talk (signal leakage), insertion loss, and time delay that the OXC introduces in the system.

Abstract: A SONET framer with multiple clock-crossing capability for use in an optical cross-connect system. The input stage of the cross-connect includes a framer ASIC that performs both frame alignment of multiple data streams and retimes them with a system clock at a same frequency. The ASIC processes multiple clocks from PLL's and retimes the data with the system clock at the same frequency. The present invention nests the clock crossing function in the frame alignment function in order to align all the incoming data streams with the system clock. Advantages include reduced chip area and reduced power consumption.

Abstract: A switch is provided that receives user information through a plurality of framer circuits, which group the user information into frames. The frames are fed to a switch fabric including an array of switch elements, each having a switch matrix for routing each frame to a desired output in accordance with configuration data stored in a first table coupled to the switch matrix. If different outputs are desired, i.e., the switch matrix is to be reconfigured, a switch control circuit supplies additional switch configuration data to the frames through the inputs along with additional user information to be routed through the switch. While the additional switch configuration data is stored in a second table, data flow remains uninterrupted through the switch matrix.

Abstract: An optical apparatus comprises a phase grating, an input-ring array, an output-ring array and an optical interconnect. The phase grating produces a modulated light beam for each of a plurality of processing elements. The modulated light beams have a plurality of light wavelengths. An input-ring array receives the plurality of data modulated light beams. An output-ring array outputs a light beam to each processing element. An optical interconnect transfers light from the input-ring array to the output ring array and uniquely rotates each wavelength of the transferred light.

Abstract: A protection switch is configured for an input optical signal using an n×n optical switch. Furthermore, a signal to be added and dropped is also configured using an n×n optical switch. Especially, the n×n optical switch uses a complete group switch. Thus, a signal can be output from any input port to any output port. Therefore, a more extensible NPE can be configured at an optical signal level, and a switch is simple and less expensive. As a result, unlike the conventional technology, an NPE itself can be simple and less expensive.

Abstract: An optical crossconnect constructed of micro -electromechanical systems (MEMS) tilt mirror arrays for selectively routing optical signals to optic fibers. The crossconnect includes a lens array for directing optical signals from a fiber array to the MEMS mirror array. Individual mirror elements in the mirror array reflect the optic signals to additional optic elements such as a planar mirror, a transmissive/reflective optical element or a second MEMS mirror array for routing the optical signals to output optic fibers.

Abstract: The present invention provides a cross-connect switching device and a method of cross-connect switching of Nf * N1 channels to one of a plurality of output lines of the switching device, Nf * N1 being equal or greater than four. The device and method includes three basic elements: 1) a partial demultiplexer for partially demultiplexing the channels on its input lines into groups of channels and individual channels; 2) a space switch for switching groups of channels en bloc; and 3) a combiner unit for combining individual channels onto one of the output lines of the cross-connect switching device. The cross-connect switching device according to the present invention may be combined with similar or dissimilar switching devices to form a larger switching device.

Abstract: The present invention combines several features to create a novel type of optical telecommunications switching component using microwave waveguides as opposed to the usual methods employing light deflection or digital signal processing. Some of the components of the device include: (1) an optical crossconnect (OXC) which allows any combination of wavelengths to be added or dropped from an element to an optical network, (2) an optical add/drop multiplexer (OADM) which allows any wavelength to be converted to any other, (3) a microwave crossbar switch array optimized for this purpose, and (4) a means for reshaping the exiting signal from the microwave crosspoint switch array without regard to signal format and without need for complex and expensive digital signal processing. The minimal architecture for this functionality is shown to be three N×N microwave crossbar switch arrays.

Abstract: Each piece of WDM light transmitted via the first and second line is demultiplexed for each wavelength by the first and second optical demultiplexer, and is selected by n optical selectors. Each selected optical signal is split by n optical splitters and is input to one set of optical switches. Each one of optical signals from the set of optical switches is selected by n optical selectors. Furthermore, each selected optical signal is regenerated by n wavelength converters. Each regenerated optical signal is split by n optical splitters, and is multiplexed by the first and second optical multiplexers.

Abstract: The present invention relates to telecommunication system/systems and is intended to make possible to implement in optical transmission networks. It provides a simple possibility to check the quality of channels after they having been put into operation, maintenance or after reconfigurations in the network.

Abstract: An optical cross connect with simultaneous correction of multiple mirror angles to achieve desired output power. In one embodiment beam offset and pointing angle are changed and output power is measured to determine changes to mirror angles.

Abstract: An optical network includes links and nodes. In each node, a control section sets an optical path to be used for optical transport. A switching section performs switching of the optical path. In the control section, a link observation section observes the wavelength of signal light that is being transmitted through a link connected to the node as the utilization of the link. A flooding section notifies each of the remaining nodes of the link utilization and acquires a link utilization observed by each of the remaining nodes so as to share the link utilization between the nodes. An optical path calculation section selects the optical path to be used for optical transport by calculation using the link utilization observed by the link observation section and the link utilization observed by each of the remaining nodes. An optical path setting section sets the optical path selected by the optical path calculation section to the optical path to be used for optical transport.

Abstract: An optical communication network is provided for reducing a required number of transmitters and receivers. A management device gives the amount of traffic passing through optical cross-connect devices along a route as an evaluation value for the route (step S6), and selects the route which has the largest evaluation value (step S7). The management device determines whether or not the evaluation value given to the selected candidate route is larger than a predefined reference value (step S8). When larger than the reference value, the management device outputs the route as an optical transmission path which includes at least one or more optical add-drop multiplexers (step S9).