Abstract: Methods of operating an optical circuit switch and optical circuit switches are disclosed. An optical circuit switch may receive a first make command to make a first optical connection between a first port and a second port, the first port uniquely associated with a rotatable mirror element, determine a first baseline voltage to be applied to an electrode coupled to the mirror element to cause the mirror element to rotate about an axis to make the first optical connection, and apply the first baseline voltage to the electrode. The optical circuit switch may periodically adjust the voltage applied to the electrode to minimize an insertion loss of the first optical connection, and periodically store accumulated angular drift data in a memory, the accumulated angular drift data derived from a difference between the adjusted voltage applied to the first electrode and the first baseline voltage.

Abstract: A multi-chassis network device includes a plurality of nodes that operate as a single device within the network and a switch fabric that forwards data plane packets between the plurality of nodes. The switch fabric includes a set of multiplexed optical interconnects coupling the nodes. For example, a multi-chassis router includes a plurality of routing nodes that operate as a single router within a network and a switch fabric that forwards packets between the plurality of routing nodes. The switch fabric includes at least one multiplexed optical interconnect coupling the routing nodes. The nodes of the multi-chassis router may direct portions of the optical signal over the multiplexed optical interconnect to different each other using wave-division multiplexing.

Abstract: A method and a system for providing an external optical data packet to a destination node of a packet optical network are described. The packet optical network includes a plurality of nodes and a first optical data channel for optically communicating local optical data packets between the plurality of nodes. The external optical data packet is optically converted for a transmission to the destination node over a second optical data channel of the packet optical network, the first and second optical data channels being independent of each other, the converted external optical data packet is optically transferred to the packet optical network, and the converted external optical data packet is transmitted to the destination node over the second optical data channel.

Abstract: The method of placing regenerators along a trail connecting a source network node with a destination network node of an automatically switched optical network first identifies N tentative regeneration sites and n+1 optical paths along the trail. Wavelengths are assigned to each optical path, and the performance of the trail is assessed based on regenerator placement data and wavelength assignment data.

Abstract: A reconfigurable optical add/drop multiplexer (ROADM) with a multiplexer, demultiplexer, and a wavelength cross-connect unit provides directionless capabilities. The ROADM allows a signal not to be limited to a particular direction when added at an optical network node, for example. The signal can be sent to other directions of the optical network node. Furthermore, the ROADM allows the wavelengths of add and drop signals to be changed and hence is “colorless.

Abstract: Optical transmitter apparatus 10 comprising a reflective optical amplifier 12, a driver 14, an optical splitter 16, polarisation compensation apparatus 18 and an optical router 20. The reflective optical amplifier is arranged to receive an optical seed signal. The driver is arranged to generate a drive signal arranged to cause the reflective optical amplifier to amplify the optical seed signal to form an optical signal. The optical splitter is arranged to receive the optical signal and to split off a part of the optical signal to form a further optical signal. The polarisation compensation apparatus is arranged to receive the further optical signal and to rotate a polarisation of the further optical signal by a pre-determined amount, to form a further optical seed signal. The optical router is arranged to receive the further optical seed signal and to direct the further optical seed signal to the reflective optical amplifier for amplification thereby.

Abstract: A photonic-based distributed network switch and method where the switch is designed to reduce or filter optical data frames entering a port of the switch so that only data frames that are appropriate for the port are forwarded from the port. This reduces the amount of data that needs to be handled by the port interface, which is especially important where the port may be using legacy interface technology that may be incapable of handling the volume of data entering the port.

Abstract: A network component comprising at least one processor configured to implement a method comprising transmitting a request to compute a routing assignment, a wavelength assignment, or both, wherein the request comprises a lightpath constraint indicator is disclosed. Also disclosed is an apparatus comprising a Path Computation Client (PCC) configured to transmit a request to and receive a reply from a Path Computation Element (PCE), wherein the request comprises a lightpath constraint, and wherein the reply comprises a routing assignment, a wavelength assignment, an error message, a no-path indication, or combinations thereof. Included is a method comprising receiving a request comprising a request parameter (RP) object comprising a lightpath constraint, sending a reply comprising a routing assignment, a wavelength assignment, an error message, a no-path indicator, or combinations thereof, wherein the request is received and the reply is sent using path computation element protocol (PCEP).

Abstract: A reconfigurable optical add-drop multiplexer (10) comprising an input (20), an output (22), drop outputs (30), add inputs (22), a demultiplexer (18), a cross-connect element (12), a drop element (34) and an add element (26). The cross-connect element (12) comprises cross-connect outputs (36), a by-pass output (38), and optical switches (14) connected together as a first switch array. The drop element (34) comprises optical switches (14) connected together as a second switch array. The add element (26) comprises optical switches (14) connected together as a third switch array. Each optical switch (14) comprises a first input (13), a second input (15), a first output (17) and a second output (19). Each optical switch is arranged to deliver a first optical signal received at the first input to the first output.

Abstract: A system for a re-configurable optical de-multiplexer, multiplexer or add/drop multiplexer is provided. A re-configurable de-multiplexer system comprises a wavelength selective switch having an input port, an output port and an internal port; a wavelength division de-multiplexer (WDM) optically coupled to the internal port and a plurality of dropped-channel ports optically coupled to the WDM. The wavelength selective switch receives a plurality of input wavelength-division multiplexed channels from the input port and routes a first subset of the channels to the output port and a second subset of channels to the internal port and then to the WDM. The WDM separates each of the dropped channels to a different respective one of the channel ports.

Abstract: An optimal resource utilization method and system is disclosed. The method includes monitoring an optical network comprising optical cross connect (OXC) nodes comprising regenerators and connected by links. Communication paths each comprising a group of OXC nodes connected by links of said links are selected. Routing demands, working communication paths, and protection communication paths are selected. A computer processor assigns successive links a wave length and allocates regenerators to multiple successive links. The computer processor positions a first group of the regenerators along the working communication paths and positioning a second group of regenerators along the protection communication paths.

Abstract: A system includes a laser array that receives a plurality of electrical signals and generates a plurality of optical signals driven from a corresponding member of the plurality of electrical signals, wherein the plurality of optical signals are arranged in a plurality of different groups. A coplanar router routes the plurality of optical signals to an array of optical multiplexers, such that each multiplexer receives optical signals from each of the plurality of different groups.

Abstract: A method for generating a frame signal includes monitoring a first frame signal and obtaining a first parameter based on the monitoring result; setting a second parameter based on the type of the first frame signal; when the first frame signal is being input, generating a second frame signal with a bit rate different from that of the first frame signal by determining data and stuff byte positions based on the first parameter and performing frame processing on data and stuff bytes corresponding to the first frame signal based on the determined data and stuff byte positions; and when the first frame signal is not being input, generating the second frame signal by determining the data and stuff byte positions based on the second parameter and performing the frame processing on data and stuff bytes corresponding to a maintenance signal based on the determined data and stuff byte positions.

Abstract: A switched wireless system is used to increase the range of peer-to-peer communications. The optically-switched fiber optic communication system includes a head-end unit (HEU) having a switch bank. Cables couple the HEU to one or more remote access points in different coverage areas. The switch bank in the HEU provides a link between the remote access points in the different coverage areas such that devices in the different cellular coverage areas communicate with each other. By using the switched communication system, the range and coverage of communication between devices may be extended such that devices in different coverage areas and devices using different communication protocols can communicate.

Abstract: Wavelength-based optical power provisioning is provided by multiplexing a plurality of continuous wave light beams at different wavelengths onto a single optical fiber as a multiplexed light source and demultiplexing the multiplexed light source based on wavelength at a photonic unit coupled to the optical fiber to recover the continuous wave light beams. The recovered continuous wave light beams are split into a plurality of light beams by the photonic unit, each light beam having the same wavelength and the same or lower power as one of the recovered continuous wave light beams so that at least one of the light beams generated by the photonic unit has a higher power than the other light beams generated by the photonic unit.

Abstract: An apparatus, comprising a first node configured to communicate with a second node to generate a wavelength assignment, wherein the first node is configured to send a wavelength availability information to the second node. Included is a network component comprising at least one processor configured to implement a method, comprising receiving a wavelength availability information, and updating the wavelength availability information using a local wavelength availability information. Also included is a method, comprising acquiring a local wavelength assignment information, calculating a local wavelength availability information, and transmitting the local wavelength availability information to a subsequent network element on a lightpath.

Abstract: An access subnetwork node herein comprises one or more add-drop modules, each module including one or more passive optical filters. The one or more add-drop modules are configured to selectively drop a fixed band of wavelength channels from an access subnetwork, via a passive directional coupler, to each of multiple client nodes that actively select to receive client-specific channels within the fixed band. The one or more add-drop modules are also configured to selectively add the fixed band of wavelength channels to the access subnetwork, as received via a passive directional coupler from the multiple client nodes that actively select to transmit client-specific channels within the fixed band. With an access subnetwork node and a client node configured in this way, embodiments herein reduce the complexity and accompanying cost of nodes in an optical network, while also maintaining flexibility for assigning wavelength channels in the network.

Abstract: A wavelength selective switch includes a substrate. On the substrate, the wavelength selective switch includes at least one input port, a dispersive element, a light converging element, a light deflecting member, an output port, and a driving mechanism which drives at least one of the dispersive element, the light condenser element, and the light deflecting member, and drive by the driving mechanism is a rotational drive around an axis perpendicular to the substrate, for the dispersive element, and is a translational drive in a direction of dispersion of wavelength with respect to the substrate, for the light condenser element or the light deflecting member.

Abstract: In a multi-chip module (MCM), integrated circuits are coupled by optical waveguides. These integrated circuits receive optical signals from a set of tunable light sources. Moreover, a given integrated circuit includes: a transmitter that modulates at least one of the optical signals when transmitting information to at least another of the integrated circuits; and a receiver that receives at least one modulated optical signal having a given carrier wavelength associated with the given integrated circuit when receiving information from at least the other of the integrated circuits. Furthermore, control logic in the MCM provides a control signal to the set of tunable light sources to specify carrier wavelengths in the optical signals output by the set of tunable light sources, thereby defining routing of at least the one of the optical signals in the MCM during communication between at least a pair of the integrated circuits.

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 includes novel techniques, apparatus, and systems for optical WDM communications. Tunable lasers are employed to generate subcarrier frequencies representing subchannels of an ITU channel to which client signals can be mapped. Client circuits can be divided and combined before being mapped, independent of one another, to individual subchannels within and across ITU channels. Subchannels may be independently routed to a single subchannel receiver filter, such that each subchannel detected at the receiver may come from a different source location. Network architectures and subchannel transponders, muxponders and crossponders are disclosed, and techniques are employed (at the subchannel level/layer), to facilitate the desired optical routing, switching, concatenation and protection of client circuits mapped to these subchannels across the nodes of a WDM network. Subchannel hopping may also be used to increase the optical network security.

Abstract: In an automatically switched optical network, the wavelengths are assigned to optical path based on their intrinsic physical performance and on the current network operating parameters. The wavelength performance information is organized in binning tables, based primarily on the wavelength reach capabilities. A network topology database provides the distance between the nodes of the network, which is used to determine the length of the optical path. Other network operating parameters needed for wavelength selection are also available in this database. Once a bin corresponding to the path length is identified in the binning table, the wavelength for that path is selected based on length only, or based on the length and one or more additional parameters. The optical path performance is estimated for the selected wavelength, and the search continues if the estimated path performance is not satisfactory.

Abstract: An optical node includes an optical routing apparatus including N ports, N is an integer greater than 2, the optical routing apparatus configured to direct light that is input to each of the N ports to all of the other N ports, and a configurable optical blocking element located in line with at least one of the N ports. A method includes broadcasting a plurality of optical signals over a plurality of ports using a broadcast element, selectively receiving a desired signal from all of the plurality of optical signals at one of the plurality of ports, and blocking the plurality of signals via a blocking element in line with one of the plurality of ports thereby preventing a multiple path of the broadcast plurality of optical signals.

Abstract: A peer network node, along with other peer network nodes, forms a higher-tiered optical network that transports wavelength division multiplexed traffic for multiple lower-tiered optical networks. The node comprises a plurality of dedicated bidirectional optical ports, including two or more lower-tiered ports and one or more peer ports. The node also comprises one or more hub-side bidirectional optical ports, and a switching circuit. The switching circuit is configured to distribute traffic received at the one or more hub-side ports to respective dedicated ports, for dedicated transport to one or more of the lower-tiered networks and peer network nodes. The switching circuit is also configured to direct any traffic received at the dedicated ports to the one or more hub-side ports for transport to a hub node, even if that traffic is actually destined for one of the lower-tiered networks to which a lower-tiered port is connected.

Abstract: An optical waveguide router device with feedback control that uses the fringe frequencies of an optical data signal to derive a wavelength (e.g., temperature) control signal in order to compensate for wavelength variations due to temperature fluctuations and/or other wavelength shifting factors without the need for a reference laser. A monitoring circuit converts an output of at least one output monitoring port to an electrical signal and comparing the output of said at least one output monitoring port against 1) a reference signal, or 2) at least one output from another output monitoring port having a higher or lower frequency fringe of an optical data signal of at least one data port, or 3) at least one output from another output monitoring port having light from diffraction pattern(s), and outputting a control signal reflecting a result of the comparison to control at least one center wavelength of the waveguide router.

Abstract: New designs of optical devices, particularly for dropping a selected wavelength or a group of wavelengths as well as demultiplexing a multiplexed signal into several signals, are disclosed. An optical device employs thin film filters with reflectors to reassemble as a fiber Bragg grating. Depending on implementation, a reflector may be a mirror or a coated substrate disposed in a unique way to reflect a light beam from a filter back to a common port of a device. The reflector may also be coated accordingly to bypass a certain portion of the light beam for other purposes. As a result, the optical devices so designed in accordance with the present invention are amenable to small footprint, enhanced impact performance, lower cost, and easier manufacturing process.

Abstract: An apparatus comprising a network element (NE) configured to communicate at least one of signal constraints and processing capabilities for a plurality of resource blocks (RBs) associated with a network node in a wavelength switched optical network (WSON) node Type-Length-Value (TLV) and signal constraints and processing capabilities associated with a link in a WSON link TLV, wherein the WSON node TLV comprises a node identifier (ID), one or more Generalized Multi-Protocol Label Switching (GMPLS) TLVs, a connectivity matrix TLV, and a resource pool TLV, and wherein the WSON link TLV comprises a link ID, one or more GMPLS TLVs, and a port wavelength restriction TLV.

Abstract: Optical networks occasionally experience a fault along a communications path. Service providers prefer to have an alternative communications path available to enable users to still communicate in a seamless manner. Accordingly, a method and corresponding apparatus for providing path protection for dedicated paths in an optical network is provided.

Abstract: A multi-chassis network device includes a plurality of nodes that operate as a single device within the network and a switch fabric that forwards data plane packets between the plurality of nodes. The switch fabric includes a set of multiplexed optical interconnects coupling the nodes. For example, a multi-chassis router includes a plurality of routing nodes that operate as a single router within a network and a switch fabric that forwards packets between the plurality of routing nodes. The switch fabric includes at least one multiplexed optical interconnect coupling the routing nodes. The nodes of the multi-chassis router may direct portions of the optical signal over the multiplexed optical interconnect to different each other using wave-division multiplexing.

Abstract: A ROADM device generates link information including a virtual link in which a first link that is used by a node apparatus for transmitting a signal and a second link of a ROADM device that is capable of branching a signal transmitted via the first link when the signal is transmitted via a WDM network are virtually connected each other, and transmits the generated link information.

Abstract: An example embodiment of the present invention is a non-blocking wavelength switching architecture that enables graceful scaling of a network wavelength switching node from small to large fiber counts using fixed size bidirectional 1×N Wavelength Selective Switches (WSS). The architecture uses an intermediate broadcast and select layer implemented using optical splitters and WSSs to eliminate wavelength blocking.

Abstract: A joint-optimization method addresses the generalized routing and wavelength assignment problem with variable number of combined 1+1 dedicated and shared connections. The inventive method enables a solution in time that is polynomial of the input size. Thus, the time complexity of the joint-optimization method is significantly less than that of existing methods.

Abstract: The inventive 2-step-optimization procedure that addresses the generalized routing and wavelength assignment problem with variable number of combined 1+1 dedicated and shared connections for the first time. The proposed procedure results a solution in time that is polynomial of the input size. Thus, the time complexity of the 2-step-optimization procedure is significantly less than that of existing methods.

Abstract: A photonic network includes a plurality of nodes each supporting add and drop of at least Y wavelengths, a plurality of optical links interconnecting the plurality of nodes, the plurality of optical links support up to X wavelengths and Y?X, an optical routing protocol configured to compute a loop-free path through the plurality of nodes on the plurality of links, the loop-free path is computed for one of the X wavelengths or a group of the X wavelengths using routing constructs adapted to a photonic domain, and optical components at each of the plurality of nodes configured to selectively block at least one of the X wavelengths based on the computed loop-free path. A photonic routing method and photonic node are also disclosed.

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 multicast optical switch includes a free-space optical assembly of discrete splitters, cylindrical optics, and a linear array of reflective switching devices, such as microelectromechanical systems (MEMS) mirrors, to provide low-loss, high-performance multicast switching in a compact configuration. The assembly of optical splitters may include multiple planar lightwave circuit splitters or a multi-reflection beam splitter that includes a linear array of partially reflecting mirrors, each of a different reflectivity.

Abstract: Each of a plurality of data flows is classified as having a respective data flow type, and each data flow is assigned to one of a plurality of subcarrier groups, based on the data flow's type, wherein each subcarrier group comprises a respective plurality of subcarriers. First data flows assigned to a first subcarrier group are transmitted exclusively on respective subcarriers in the first subcarrier group, and second data flows assigned to a second subcarrier group are transmitted together on all of the subcarriers in the second subcarrier group.

Abstract: In one aspect, a system includes one or more electrical switches to transfer data in a data network; one or more optical switching groups coupled to each electrical switch, each switching group having one or more server racks, each server rack coupled to a top of rack (TOR) switch and an optical transceiver coupled to the TOR switch; and an optical switching unit (OSU) coupled to the one or more optical switching groups.

Abstract: An apparatus comprising a processor, wherein the processor is configured to split an optical signal into a first optical signal and a second optical signal, wherein the first optical signal comprises a plurality of encoded wavelengths, receive a selection signal, wherein the selection signal selects a plurality of active wavelengths, wherein the active wavelengths are a subset of the encoded wavelengths, compute the routing information for the second optical signal using the active wavelengths, and switch the second optical signal using the routing information.

Abstract: A method and system for energy-efficient routing of IP packets in which ingress traffic is forward from ingress nodes directly to source dominator nodes without address destination processing such that related address processing elements may be avoided in the ingress nodes. The source dominator nodes perform address destination processing and forward the packets to destination dominator nodes proximate the destination node.

Abstract: Systems and methods are described that that dynamically configure high-speed data link lightpaths between access routers and backbone routers at geographically dispersed locations to reassign traffic when a backbone router fails or is removed from service. Embodiments reduce the quantity of backbone router ports used in dual backbone router-homed networks.

Abstract: This disclosure is directed to optical data path systems that enable unidirectional and bidirectional transmission of optical signals between nodes of a multi-node system such as a multiprocessor system. In one aspect, an optical data path system includes an optical device layer connected to nodes of a multi-node system and a controller. The optical device layer includes a waveguide network of waveguide branches optically connecting each node of the multi-node system to every other node of the multi-node system, resonators disposed adjacent to the waveguide branches, and detectors disposed adjacent to waveguide branches of the waveguide network. Each detector is electronically connected to a node of the multi-node system. The resonators are operated by the controller to control the path of optical signals sent between the nodes of the multi-node system.

Abstract: An electro-optical switch (170) for receiving N data streams optically, each of said N data streams having an amplitude and a phase and each being located at an optical centre frequency FO1+RFM, where FO1 is a first optical modulation frequency and RFM is a signal centre frequency. The electro-optical switch is arranged to convert the N data streams to electrical data signals at the data stream's signal centre frequency RFM, the electrical data signals having the amplitude and phase of the optical data stream. The electro-optical switch is further arranged to convert electrical data signals to optical output signals at optical centre frequency FO2+RFOut with the amplitude and phase of the first electrical data signal maintained, and to transmit the optical output signals, with RFM and RFOut, being equal to or different from each other, and FO1 and FO2 also being equal to or different from each other.

Abstract: An apparatus comprising a path computation element (PCE) configured for at least partial impairment aware routing and wavelength assignment (RWA) and to communicate with a path computation client (PCC) based on a PCE protocol (PCEP) that supports path routing, wavelength assignment (WA), and impairment validation (IV). Also disclosed is a network component comprising at least one processor configured to implement a method comprising establishing a PCEP session with a PCC, receiving path computation information comprising RWA information and constraints from the PCC, establishing impairment aware RWA (IA-RWA) based on the path computation information and a private impairment information for a vendor's equipment, and sending a path and an assigned wavelength based on the IA-RWA to the PCC. Disclosed is a method comprising establishing impairment aware routing and wavelength assignment for a plurality of network elements (NEs) in an optical network using routing and combined WA and IV.

Abstract: An apparatus comprising a path computation element (PCE) configured to perform a path computation using signal compatibility constraints information for a network element (NE) in a wavelength switched optical network (WSON), wherein the signal constraints information are communicated at a Generalized Multi-Protocol Label Switching (GMPLS) control plane layer and comprise a plurality of signal attributes and a plurality of NE compatibility constraints. A network component comprising a transmitter unit configured to transmit signal compatibility constraints via GMPLS signaling, wherein the signal compatibility constraints define the signal compatibility constraints for a NE in a WSON. A method comprising receiving signal compatibility constraints for a NE in a WSON, performing a path calculation based on the signal compatibility constraints for the NE, and sending signal compatibility constraints associated with a computed path.

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: Various example embodiments are disclosed. According to an example embodiment, a method may include determining that a transmission of a data signal over a path of a wavelength division multiplexed (WDM) optical network using a group of optical subcarriers is not optically feasible; determining that the transmission of the data signal over the path using a subset of the group of optical subcarriers is optically feasible; activating subcarriers for the subset of optical carriers while deactivating one or more optical subcarriers of the group, at least one deactivated subcarrier provided between at least two activated subcarriers of the group; and transmitting the data signal over at least a portion of the path using the activated subcarriers of the group.

Abstract: An optical signal switching device comprises a plurality of broadcast couplers (125), a plurality of wavelength selective modules (126), and optical connection means linking outputs of broadcast couplers to inputs of wavelength selective modules in order to route incoming optical signals received by said broadcast couplers to said wavelength selective modules. The wavelength selective modules are arranged in a plurality of groups (117, 118, 119), the wavelength selective modules of one group being connected at the output to a common neighboring node. The optical connection means (127, 41, 40, 42) are configured in such a way as to enable, for each of said broadcast couplers, the broadcasting of the incoming optical signal received by said coupler to at least one wavelength selective module of each group simultaneously.

Abstract: An optical access network comprises L wavelength division multiplexed access sub-networks. Each of the wavelength division multiplexed access sub-networks is arranged to use a set of wavelength channels. M optical line termination apparatus, each receive traffic from a respective operator network and output traffic on the wavelength channels. A wavelength routing apparatus comprises M sets of first ports and L second ports. Each set of first ports connects to a respective one of the optical line termination apparatus and each second port connects to an optical link of a respective one of the wavelength division multiplexed access sub-networks. The wavelength routing apparatus is arranged to route the set of wavelength channels between the sets of first ports and the second ports and to route different wavelength channels of the same wavelength to different ones of the second ports.

Abstract: An apparatus comprising a network element (NE) configured to support routing-associated signal compatibility constraint information that is associated with the NE using Generalized Multi-Protocol Label Switching (GMPLS) and an open shortest path first (OSPF) routing protocol, wherein the signal compatibility constraint information comprises a modulation type list, a Forward Error Correction (FEC) type list, a bit rate range list, and an acceptable client signal list, and wherein the signal compatibility constraint information is associated with a resource block (RB) pool for a plurality of NEs. Also disclosed is a network component comprising a transmitter unit configured to transmit signal compatibility constraints via GMPLS OSPF routing, wherein the signal compatibility constraints comprise a modulation type list, a FEC type list, a bit rate range list, and an acceptable client signal list.