Abstract: An optical switching device includes plural wavelength selective switches that respectively have a first port and a plurality of second ports; and an optical coupler that has a plurality of third ports on an input-side or an output-side, respectively optically coupled to the first ports of the wavelength selective switches.

Abstract: A wavelength selective switch according to the present invention includes at least one input port for inputting wavelength-multiplexed light, a dispersive element which receives the light from the input port, and disperses the received light, a light converging element which converges dispersed light which has been dispersed for each wavelength, a light deflecting member having a plurality of reflecting optical elements which are capable of independently deflecting each dispersed light from the light converging element, and at least one output port which receives light which has been deflected by the light deflecting member. An area having a reflectivity higher than a central area of the reflecting surface is formed in at least a part of an end portion of the reflecting surface in the dispersive direction by the dispersive element.

Abstract: A method includes determining a line rate selection for a flexible optical wavelength-division-multiplexing WDM network, determining a traffic routing in said network, and determining simultaneously a channel routing, wavelength assignment and spectrum allocation in said network based on an auxiliary graph.

Abstract: Scheduling methods and apparatus for use with optical switches with hybrid architectures are provided. An exemplary distributed scheduling process achieves 100% throughput for any admissible Bernoulli arrival traffic. The exemplary distributed scheduling process may be easily adapted to work for any finite round trip time, without sacrificing any throughput. Simulation results also showed that this distributed scheduling process can provide very good delay performance for different traffic patterns and for different round trip times associated with current switches.

Abstract: An optical de-multiplexer (de-MUX) that includes an optical device that images and diffracts an optical signal using a reflective geometry is described, where a free spectral range (FSR) of the optical device associated with a given diffraction order abuts FSRs associated with adjacent diffraction orders. Moreover, the channel spacings within diffraction orders and between adjacent diffraction orders are equal to the predefined channel spacing associated with the optical signal. As a consequence, the optical device has a comb-filter output spectrum, which reduces a tuning energy of the optical device by eliminating spectral gaps between diffraction orders of the optical device.

Abstract: A reconfigurable optical add/drop multiplexer and a reconfigurable optical add/drop multiplexing method are provided. The reconfigurable optical add/drop multiplexer comprises: an optical processing unit for receiving a first optical signal containing a plurality of optical channels, processing the first optical signal to generate a second optical signal which is a part of the first optical signal, and outputting the second optical signal; and a coherent detection unit for performing a coherent detection on the second optical signal so as to separate from the second optical signal an optical channel contained therein, and outputting the optical channel.

Abstract: An apparatus switches paths in a wavelength-multiplexing network in which a first number of wavelengths each used for a path to transmit an optical signal are multiplexed into an optical fiber. The apparatus includes an entire switching unit and a second number of individual switching units where the second number is smaller than the first number. The entire switching unit is configured to perform a path-switching process for switching a path, simultaneously on all the first number of wavelengths when failures have occurred for all the first number of wavelengths. The second number of individual switching units are each configured to perform the path-switching process individually on one of a third number of wavelengths included in the first number of wavelengths when at least one failure has occurred for the third number of wavelengths where the third numbers is smaller than the first number.

Abstract: Method and system for band blocking in an optical telecommunication network. According to an embodiment, the present invention provides a system for optical network. The system includes an input that is configured to receive an input signal through a first optical input. The system also includes a band splitting module that is coupled to the input. The band splitting module is configured to separate the input signal into a plurality of bands. The plurality of bands includes a first band and a second band. The first band includes a first plurality of wave channels. The first plurality of wave channels is characterized by a first channel spacing. The second band includes a second plurality of wave channels, which is characterized by a second channel spacing.

Abstract: There is provided an optical transmission apparatus including: a transmitter to output an optical signal to be transferred to other optical transmission apparatus; a first dummy light source to generate first dummy light having a wavelength which is not included in an optical signal received from other optical transmission apparatus; a first wavelength-multiplexer to wavelength-multiplex the optical signal received from other optical transmission apparatus, the optical signal output from the transmitter, and an optical signal with a wavelength, of the first dummy light, which is not included in the optical signal received from other optical transmission apparatus and in the optical signal output from the transmitter; and an optical amplifier to amplify an optical signal multiplexed by the first wavelength-multiplexer.

Abstract: The present disclosure provides a method and device for obtaining the routing information of an electro-optical multi-layer network. The ports on which an optical transmitter and an optical receiver are located are determined, and the electro-optical conversion information is added to the routing information on a port of the optical layer node side or the electro layer node side on which the optical transmitter and the optical receiver are located. The electro-optical conversion information includes but is not limited to the wavelength tuning capability and signal processing capability.

Abstract: An optical network is configured to provide an optical reroute over a backup path (2139) during a failure in a signal path (2133). The network comprises a first node (B). A second node (C) is coupled to receive a signal from the first node (B) via the signal path (2133), and a backup signal via the backup path (2139). The network is adapted to transmit a signal and a corresponding backup signal from the first node to the second node even when there is no failure in the signal path (2133), wherein the backup signal is blocked at the second node (C) when there is no failure in the signal path (2133). Embodiments of the invention utilize the broadcast and blocking functionalities of a wavelength selective switch (WSS) device. Such WSS devices enable, in the case of a failure of a link, the fast switchover of optical traffic onto local detours within a reduced time.

Abstract: A wavelength selective switch includes a wavelength dispersing element, a wavelength converging element, multiple transmission control elements, and a controller. The wavelength dispersing element performs wavelength dispersion of input signal light. The transmission control element divides input signal light into wavelength bands within a channel band and transmits or cuts off the divided input signal light. The wavelength converging element converges signal light having respective wavelengths produced from the transmission control elements for output. The controller controls a transmittance of the transmission control element of at least one of the low and high frequency sides in a channel band.

Abstract: A compensator device may include a selection switch to receive a first optical signal and provide first and second groups of channels associated with the first optical signal; a polarization beam splitter to receive the first channels, and provide first and second components; a photodiode that provides an electrical signal indicative of an intensity of the first group of channels; a first modulator to receive the electrical signal and the first components and to modulate the first components to form first modulated channels; a second modulator to receive the electrical signal and the second components to modulate the second components to form second modulated channels; a polarization beam combiner to receive the first and second modulated channels to form combined modulated channels; and a coupler to receive the combined modulated channels and the second group of channels to form a second optical signal.

Abstract: Provided is a wavelength division multiplexing (WDM) optical transmission device which is suitable of performing splitting, wavelength multiplexing, switching, and routing on an optical WDM signal in which optical signals having a spectrum close to a rectangle are arranged with a high density, and efficiency of spectral usage is ultimately high in units of wavelengths. A WDM optical transmission device according to the present invention is configured to cause flat portions of adjacent transmission bands on a wavelength spectrum overlap each other.

Abstract: In an embodiment, a pluggable optical host and network I/O optoelectronic module (hereinafter “module”) includes a first optical-electrical-optical (OEO) converter and a second OEO converter. The first OEO converter is configured to convert N inbound optical signals to M inbound optical signals and includes N network-side optical receivers, first signal processing circuitry communicatively coupled to the N network-side optical receivers, and M host-side optical receivers communicatively coupled to the first signal processing circuitry. The second OEO converter is configured to convert M outbound optical signals to N outbound optical signals and includes M host-side optical receivers, second signal processing circuitry communicatively coupled to the M host-side optical receivers, and N network-side optical receivers communicatively coupled to the second signal processing circuitry.

Abstract: Optical equipment for 1G-EPON, 10G-EPON, and CWDM services are joined together using a novel combination of optical power splitters and multiplexers. This combination of splitters and multiplexers can be disposed in a single housing, which reduces the size of the combination and improves performance, since jumpers between multiple, separately packaged, optical components can be avoided. One example of the inventive techniques and circuits disclosed herein is a combiner/separator circuit for combining and separating 1G-EPON and 10G-EPON signals. In the example application detailed herein, where EPON equipment is combined with CWDM equipment, an important advantage of this optical circuit is its ability to provide return wavelength isolation for EPON systems that have separate ports for 1G and 10G services.

Abstract: Provided is a passive optical network (PON) providing system of an Ethernet-based packet transport layer (PTL) scheme, including: a connection management server to manage a unified PTL connection overall over the network by establishing a PTL connection between an optical network unit (ONU)/optical network terminal (ONT) of a customer termination of one party and an ONU/ONT of a customer termination of another party, and by applying a PTL-PON scheme to a PON section between the ONU/ONT and an optical line termination (OLT); an OLT to manage a connection of a received packet, and to convert a format of the packet according to a transmission direction of the packet and thereby transmit the packet; and an ONU/ONT becoming an end point of the PTL connection to convert the format of the packet according to the transmission direction of the received packet and to thereby transmit the packet to a customer terminal or the OLT.

Abstract: Switching architectures for WDM mesh and ring network nodes are presented. In mesh networks, the switching architectures have multiple levels—a network level having wavelength routers for add, drop and pass-through functions, an intermediate level having device units which handle add and drop signals, and a local level having port units for receiving signals dropped from the network and transmitting signals to be added to the network. The intermediate level device units are selected and arranged for performance and cost considerations. The multilevel architecture also permits the design of reconfigurable optical add/drop multiplexers for ring network nodes, the easy expansion of ring networks into mesh networks, and the accommodation of protection mechanisms in ring networks.

Abstract: The present invention relates to a method for negotiating link capability information. The method includes: After a higher order optical channel data unit (ODU) link is established, a second node receives first higher order ODU link capability information supported by a first node at one end of the link, where the second node is located at the other end of the link; determines link capability information according to the first higher order ODU link capability information and second higher order ODU link capability information that is supported by the second node; and sends the link capability information to the first node; or sends the second higher order ODU link capability information to the first node, so that the first node determines the link capability information according to the first higher order ODU link capability information and the second higher order ODU link capability information.

Abstract: Optical network protection devices and protection methods including: a working line; a protection line; a determination module configured to determine the protection type of optical network; a first judgment module configured to judge whether the working line is normal according to performance parameter values of service signal in the working line and switching conditions configured for multiplexing section protection when the protection type of optical network is the multiplexing section protection; a second judgment module, configured to judge whether the working line is normal according to performance parameter values of service signal in the working line and switching conditions configured for channel section protection when the protection type of optical network is the channel section protection; a switching module, configured to take the service signal in the protection line as an output signal when working line is abnormal.

Abstract: An optical transceiver device is provided, including an O/E transceiver module, an optical switching module and a switching control module, for providing network communication services for a first and a second optical fiber network equipment. The O/E transceiver module is an integrated chip having multiple transceiver units integrated therein. The switching control module is connected to an in-line equipment and the optical switching module for controlling the optical switching module to execute corresponding optical path switching operation according to an optical path switching control signal output from the inline equipment. In comparison with conventional optical transceiver devices, the invention is advantageous of simple structure, smaller volume and more flexible optical path switching.

Abstract: A network apparatus used in an optical network is disclosed. The network apparatus includes one or more first tunable and temperature controlled (TTC) lasers, one or more transmitters each of which is connected to one of said one or more TTC lasers, one or more second TTC lasers, one or more digital signal processing (DSP) transponders (TPNDs) each of which is connected to one of said one or more second TTC lasers, one or more receivers, and a controller to control said one or more transmitters and said one or more DSP TPNDs, wherein said one or more transmitters defragment an optical access spectrum, and said one or more DSP TPNDs exploit a newly available spectrum. Other apparatuses, systems, and methods also are disclosed.

Abstract: At least one of a first device, a second device, and a relay device compensates for wavelength dispersion in a first optical wavelength path. The first or second device changes a wavelength dispersion compensation amount at the first or second device so that wavelength dispersion in a second optical wavelength path is compensated. The relay device changes a wavelength dispersion compensation amount at the relay device so that a total amount of wavelength dispersion of the signal light compensated in the first optical wavelength path does not change substantially with the change in the wavelength dispersion compensation amount at the first or second device. The first optical wavelength path is switched to the second optical wavelength path after the wavelength dispersion compensation amount at the first or second device is changed to a value that can compensate for the wavelength dispersion in the second optical wavelength path.

Abstract: A method for reallocating a wavelength in an optical wavelength multiplexer transmission system is disclosed. The method includes switching a supply of a first channel electric signal from a first optical transmitter device to a second optical transmitter device, the first optical transmitter device converting the first channel electric signal into an optical signal of a first wavelength, and the second optical transmitter device converting the first channel electric signal into an optical signal of a second wavelength differing from the first wavelength, and transmitting the optical signal of the second wavelength output from the second optical transmitter device.

Abstract: A hub node in a wavelength division multiplexed optical network automatically discovers at least one of new client-side optical ports and new edge-side optical ports. The hub node comprises a wavelength switch network, port discovery equipment, and a controller. The wavelength switch network routes any wavelength channel that does not support a matching pair of client-side and edge-side ports to port discovery equipment at the hub node. The port discovery equipment searches for new ports, and, responsive to finding a new port, automatically discovers a predefined set of one or more attributes of the new port. The controller determines that a client-side port and an edge-side port are a matching pair of ports if discovered sets of attributes of those ports match according to one or more predefined rules. The controller then controls the wavelength switch network to re-route the wavelength channel supporting that matching pair between those ports.

Abstract: Provided is a passive optical network system, wherein the electric power to be consumed is reduced on the basis of the quantity of signal to be transmitted downstream in a WDM-PON where signals having different transmission rates for wavelengths are mixed. In the passive optical network system, an OLT (200) and a plurality of ONUes (300) are connected by an optical fiber network including an optical splitter (100) and a plurality of optical fibers (110 and 120). The OLT (200) indicates to the ONUes (300) the wavelength to be used, in addition to the timing for transmission to the ONUes (300). A format for signal transmission from the OLT (200) to the ONUes (300) comprises both the region, in which the timing for transmission to the ONUes (300) indicated by the OLT (200) to the ONUes (300) is stored, and the region, by which the wavelength to be used in the communication in the direction from the OLT (200) to the ONUes (300) is indicated.

Abstract: Restrictions, due to wavelength paths which are non-alternative combinations of wavelengths and paths, are solved.

Abstract: An optical path switching type optical signal transmission/reception apparatus includes a one-to-seven compatible optically controlled optical path switching apparatus 100 that is connected to a host optical signal transmission/reception apparatus 1 via an optical fiber, a total of seven subordinate optical communication adapters 110 connected via optical fibers, user side devices 160 connected to respective subordinate optical communication adapters via an electric circuit, an optical transmission/reception control circuit provided in each of the total of seven subordinate user side optical communication adapters 110, and including an uplink optical signal transmission mechanism, a downlink optical signal reception mechanism, a control light source that can generate control light to drive the optical path switching apparatus 100, in which a wavelength of the generated control light is different from a wavelength of signal light, and an optical communication oriented transmission/reception mechanism using the

Abstract: A wavelength selective optical switch device includes an incidence and exit part where a signal beam made of light of a multiplicity of wavelengths enters and a signal beam of a selected wavelength exits, a wavelength dispersion element that spatially disperses a signal beam according to the wavelength thereof and multiplexes reflected light, a condensing element that condenses the light dispersed by the wavelength dispersion element onto a two-dimensional plane, and a wavelength selection element that uses a multilevel optical phased array arranged in a position to receive incident light developed on an xy-plane made of an x-axis direction and a y-axis direction perpendicular thereto developed according to a wavelength, having a multiplicity of pixels arrayed in a lattice on the xy-plane, and that cyclically changes the phase shift amount in the y-axis direction to a sawtooth wave pattern for each pixel on the x-axis.

Abstract: One embodiment of the present invention provides a system that facilitates automatic adjustment of logical channels in a Fibre Channel (FC) network. During operation, the system receives FC data frames. A respective data frame is associated with a logical channel. The bandwidth on an FC link can be allocated into a plurality of logical channels, and a respective logical channel is associated with a dedicated buffer and can transport a plurality of data flows with data frames of variable length. The system then identifies a slow data flow in a first logical channel. Next, the system assigns the slow data flow to a second logical channel, thereby preventing the slow data flow from slowing down other data flows in the first logical channel. The system subsequently forwards the data frames in the slow data flow on the second logical channel onto an outgoing link.

Abstract: Data locality constraints are alleviated by a data processing system and method of reorganizing data. Multiple electronic components are configured to modulate a light beam on a shared photonic interconnect and to detect the data according to a global schedule to reorganize data across the multiple electronic components. By constructing data transfer patterns in a shared photonic interconnect, rather than in dedicated reorganization hardware, data is reorganized while in transit, greatly accelerating the reorganization of data, and reducing the amount of power-consuming hardware necessary to achieve the task.

Abstract: A packet switch/router including a first stage switch fabric receiving an electrical signal, a mid-stage buffer receiving and storing the electrical signal from the first stage switch fabric, and a second stage switch fabric receiving the electrical signal from the mid-stage buffer. Each switch fabric includes N layers of N×N arrayed waveguide gratings (AWGs), and each AWG has ingress ports and egress ports. A wavelength tunable device, such as a tunable laser, communicates with a source ingress port of an AWG and converts the received electrical signal to an optical signal having a wavelength selected for routing a packet from the source ingress port to a target egress port of the arrayed waveguide grating. A photoreceiver, such as a burst-mode photoreceiver, receives the propagated optical signal from the target egress port and converts the optical signal to the electrical signal.

Abstract: A packet switching system includes a plurality of switch fabrics connected in cascade and a plurality of buffers respectively connected to the plurality of switch fabrics. In the event of packet competition, the plurality of switch fabrics buffer the competing packets to the corresponding buffers through buffer connection ports, and forward the competing packets in excess of the number of buffer connection ports to an adjacent switch fabric through switch connection ports.

Abstract: The discloser provides a multi-input and multi-output optical switch capable of switching over all WDM wavelengths. An optical switch according to one embodiment includes: an optical demultiplexing element (3) that demultiplexes an optical signal from at least one input port into individual wavelengths; a first optical deflection element (5), which deflects an incident optical signal, that deflects the wavelength-separated optical signal incoming from the optical demultiplexing element to change a traveling direction for each wavelength to a switch axis direction perpendicular to a wavelength dispersion axis direction; a second optical deflection element (8) that deflects the optical signal incoming from the first optical deflection element to change the traveling direction to the switch axis direction for output to at least one of the output ports; and an optical multiplexing element (10) that multiplexes the optical signal with the different wavelengths incoming from the second optical deflection element.

Abstract: A method of establishing a data connection between terminal switching nodes in a network and switching nodes for implementing the method. The method involves switching nodes participating in a network layer wavelength routing (WR) protocol to determine the next hop switching node for every possible combination of terminal nodes based on the network topology. The method also involves the switching nodes participating in a network layer wavelength distribution (WD) once the data connection is to be established. The WR protocol determines the path used through the network, while the WD protocol assigns wavelengths on each link between switching nodes. The wavelengths may be different on different optical links. The switching nodes include wavelength converters with an optical switch or optoelectronic converters with a digital electronic switch. A digital electronic switch can also provide signal reformatting.

Abstract: A wave division multiplexing (WDM) system is disclosed which accommodates shifts in the resonant frequency of optical modulators by using at least two carriers per optical communications channel and at least two resonant modulator circuits respectively associated with the carriers within each optical modulator. A first resonant modulator circuit resonates with a first carrier and a second resonates with a second carrier when there is a shift in resonance frequency of the at least two resonant optical modulator circuits. A switch circuit controls which carrier is being modulated by its respective resonant modulator circuit.

Abstract: The method updating the status of a network by means of a protocol of the control plane of said network and in response to a path request from at least a path computation client (PCC) pre-reserving during a reserved period of time (Tres), by at least one path computation element (PCE), a plurality of network resources in at least one traffic engineering database (TED) of the at least one PCE. The method dynamically modifying by a timer policy said reserved period of time (Tres) by at least using information data regarding the delay of said control plane. The system of the invention is adapted to implement the method of the invention.

Abstract: A determination device for a wavelength division multiplex communication system, configured to set each of different paths each of which is formed by connection of spans each of which is a zone between two adjacent transmission devices, among transmission devices forming a communication network, in the communication network, or a single span in the communication network, for the corresponding one of different wavelengths, and configured to transmit an optical signal of each of the wavelengths via the corresponding path set to the wavelength, the device includes: a determination section configured to determine whether an optical signal of at least one of the wavelengths is transmittable only to a path, among newly formed paths, for which the number of spans forming the path is equal to or less than a predetermined upper-limit number, in order to transmit one or more optical signals of one or more wavelengths among the wavelengths.

Abstract: An optical repeater formed in an optical passive component passively relays an incoming multiplexed optical signal. The repeater has an optical decoder decoding the multiplexed optical signal, and an optical encoder encoding an optical signal from a termination unit connected to the repeater. The repeater further includes a first optical path switch outputting an incoming multiplexed optical signal to the optical decoder and outputting the optical signal delivered from the optical decoder, a second optical path switch outputting the optical signal coming from the first optical path switch to the termination unit, and a third optical path switch outputting the optical signal coming from the second optical path switch to the encoder and outputting the optical signal delivered from the encoder.

Abstract: A packet transport layer passive optical network providing method controls an optical line termination device and an optical network terminal or an optical network unit of the subscriber end to transport packet transport layer passive optical network packets between the optical network terminals or the optical network units and the optical line termination device, and the optical network terminals or the optical network unit of the subscriber end becomes an end point of a packet transport layer connection.

Abstract: Embodiments of the present invention are directed to implementing high-radix switch topologies on relatively lower-radix physical networks. In one embodiment, the method comprises constructing the physical network (702) composed of one or more optical switches connected via one or more waveguides. A desired switch topology (704) is then designed for implementation on the physical network. The switch topology is then overlain on the switch network by configuring the optical switches and waveguides (706) to implement the switch topology on the physical network. The optical switches can be reconfigured following a transmission over the physical network and can be configured to implement circuit switching or packet switch.

Abstract: A non-blocking telecommunications node comprising a plurality of ports. Each port adapted to pass telecommunications traffic comprising multiplexed signals. Each port is adapted to receive an incoming multiplexed signal comprising a plurality of component signals each having a predetermined wavelength. The node includes a plurality of transponders each arranged to receive a component signal. The plurality of transponders are arranged and connected to the ports such that each instance of a component signal having a specific wavelength received by each of the ports can be received simultaneously by the transponders. A node for adding component signals to an outgoing multiplexed signal is also disclosed.

Abstract: A network component comprising at least one processor configured to implement a method comprising obtaining a wavelength availability information for a path, determining whether to implement a wavelength assignment based on the wavelength availability information, updating the wavelength availability information when the wavelength assignment is to be implemented, and forwarding the wavelength availability information. Also included is a method comprising obtaining a wavelength availability information, comparing a number of wavelengths in the wavelength availability information to a threshold, determining whether to implement wavelength conversion along a path when the number of available wavelengths is less than or about equal to the threshold, and resetting the wavelength availability information when wavelength conversion is to be implemented.

Abstract: A method of establishing a data connection between terminal switching nodes in a network and switching nodes for implementing the method. The method involves switching nodes participating in a network layer wavelength routing (WR) protocol to determine the next hop switching node for every possible combination of terminal nodes based on the network topology. The method also involves the switching nodes participating in a network layer wavelength distribution (WD) once the data connection is to be established. The WR protocol determines the path used through the network, while the WD protocol assigns wavelengths on each link between switching nodes. The wavelengths may be different on different optical links. The switching nodes include wavelength converters with an optical switch or optoelectronic converters with a digital electronic switch. A digital electronic switch can also provide signal reformatting.

Abstract: A single step routing and wavelength assignment method and system for automated provisioning of services on DWDM networks is presented. This novel single step solution automates design and assignment of services in DWDM networks. For an automated provisioning platform that can handle the routing and wavelength assignment in a single step, the solution avoids reconfiguration of existing services. It also takes into consideration practical aspects of DWDM transponder availability at termination sites and regeneration sites along the selected route. The methodology includes iterative computation of common channel sets to avoid multiple shortest path computations for each of the wavelengths.

Abstract: An apparatus includes a wavelength-selective optical switch able to route light between a first optical port and a plurality of second optical ports. The wavelength-selective optical switch includes a bank of optical wavelength-converters. Each wavelength converter of the bank is able to selectively optically couple an optical data stream on a wavelength-channel between the first optical port and individual ones of the second optical ports.

Abstract: In one embodiment, a cloud radio access network (C-RAN) includes a first plurality of antennas and a first plurality of radio remote units (RRUs) coupled to the plurality of antennas. The C-RAN also includes a first plurality of broadband base units (BBUs) and a first photonic switch optically coupled between the first plurality of RRUs and the first plurality of BBUs.

Abstract: A transmission device includes: a wavelength detector configured to detect a first wavelength of a first optical signal; a wavelength selective switch to which the first optical signal is input; and a controller configured to detect a direction toward which a central wavelength of a passband of the wavelength selective switch is shifted from the first wavelength detected by the wavelength detector and to control the wavelength selective switch so as to increase a width of the passband toward an opposite direction of the direction toward which the central wavelength of the passband is shifted from the first wavelength.

Abstract: A network element of an optical communications network. The network element comprises an electronic router for forwarding traffic between a set of client access ports and a plurality of I/O ports. A respective EO interface is coupled to each one of the plurality of I/O ports. Each EO interface terminates a respective optical channel. A directionally independent access (DIA) node is configured to selectively route each optical channel between its respective EO interface and a selected one of at least two optical fiber links of the optical communications network.

Abstract: Optical networks are increasingly employing optical network nodes having multiple interfaces to allow a node to direct optical signals received at any interface to any other interface connected to the node. Constructing a larger wavelength selective switching (WSS) module used in such a node can be complex and expensive. A method an apparatus for constructing a large WSS using parallelism is provided. In example embodiments, a larger WSS may include multiple parallel non-cascaded smaller WSSs and an optical coupler configured to optically couple the multiple parallel, non-cascaded smaller WSSs. This technique may be used to construct both N×1 and 1×N WSSs. Because the technique employs multiple parallel, non-cascaded WSSs, all inputs of a larger N×1 WSS and all outputs of a larger 1×N WSS are available receive or transmit external signals rather than being rather than being unavailable due to, for example, cascading smaller WSS devices together.