Abstract: A communication network system including a connectionless type communication network and a connection type communication network, wherein a communication device forming the communication network comprises a unit which transfers in-band control information to be exchanged on an in-band of the connectionless type communication network to other communication device through a virtual control link generated on an IP control network for controlling the connection type communication network and exchanges the in-band control information with other communication device, a unit which determines whether to generate a new connection for the connection type communication network based on the in-band control information to be exchanged, and a unit which generates a new connection for the connection type communication network in response to an instruction from the determination unit.

Abstract: A Wavelength Division Multiplexing (WDM) multi-mode switching system and method and method provides concurrent switching in various switching modes. For example, WDM links may communicate data in various switching modes including, but not limited to, an electronic packet switching (EPS) mode, optical circuit switching (OCS) mode, and optical burst switching (OBS) mode. Edge routers and core routers in the WDM multi-mode switching systems and methods provide switching and processing necessary to handle data provided in the various switching modes. Further, the WDM multi-mode switching systems and methods can also provide dynamic reconfiguration between the various switching modes.

Abstract: A method for communicating optically between nodes of an optical network, including forming, between a first node and a second node of the network, a set of lightpaths, each of the set of lightpaths having a respective configuration, and transferring communication traffic between the first and second nodes via the set of lightpaths. The method also includes forming a determination for the set of lightpaths that a communication traffic level associated therewith is less than a predetermined threshold, and in response to the determination, removing a lightpath having a given configuration from the set of lightpaths to form a reduced set of lightpaths. The method further includes transferring the communication traffic between the first and second nodes via the reduced set of lightpaths, while reducing a level of power consumption in the removed lightpath and while maintaining the given configuration of the removed lightpath.

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: A method for optical network signaling processing of a signal from a first node to an end node through intermediate nodes is presented. The method comprises determining, in a first pass from the first node to the end node, available wavelengths and wavelength conversion at each node, the end node optimizing wavelengths using the available wavelengths and wavelength conversions, at each node, dropping a cross-connect command, in a second pass from the end node to the first node, choosing wavelengths for connection based on the optimizing step, in a third pass from the first node to the end node, receiving at each node a signal message and releasing unused cross-connect commands, the end node identifying the chosen wavelengths and releasing the unused resources, and transmitting the signal on the chosen wavelengths. Restoration paths can also be determined. Optimizing can include selecting and marking one or more backup wavelengths.

Abstract: In an optical communication network that includes a plurality of interconnected network nodes, a method includes storing in each network node one or more cross-talk margins of respective communication channels that traverse the node. A potential communication channel that traverses a subset of the nodes in the network is identified. A quality of the potential communication channel is evaluated by processing the cross-talk margins stored in the nodes in the subset.

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: The present disclosure provides bandwidth defragmentation systems and methods in optical networks such as Optical Transport Network (OTN), Synchronous Optical Network (SONET), Synchronous Digital Hierarchy (SDH), Ethernet, and the like. In particular, the present invention includes bandwidth defragmentation algorithms that may be used within the context of a signaling and routing protocol to avoid bandwidth defragmentation. As such, the present invention defines a mechanism for computing an end to end path for a connection in a manner that avoids bandwidth fragmentation and provides for better network utilization. For example, the present invention may include a path computation based upon administrative weight and upon fragmentation costs. This may be implemented in existing signaling and routing protocols without changes to existing protocol messages used in topology discovery.

Abstract: A method and apparatus for control and data burst routing in WDM photonic burst-switched network is disclosed. In one embodiment, only the control bursts and network management labels are going through optical-electrical-optical conversion inside the photonic burst switching (PBS) module. The building blocks of the control processing unit inside the PBS module may include input and output buffers, control burst parser, burst scheduler, PBS configuration and control, contention resolution, forwarding engine, network management controller, control burst generator, and queue manager. The contention resolution block may be used to resolve resource contention between multiple data bursts. Such contention resolution may take the form of adding additional delays to one of the data bursts, changing one of the data bursts to an alternate wavelength, or dropping some of the data bursts based on various criteria such as relative priority and wavelength.

Abstract: A system is provided for identifying signal propagation information. The system includes at least one component configured to receive an optical input signal and to emit an optical output signal. The emitted optical output signal is representative of the optical input signal, and is associated with characteristic information indicative of the component. A processor is also included, the processor being configured to sense the optical output signal and correlate the characteristic information with said component.

Abstract: A network component comprising a control plane controller configured to implement a method comprising transmitting routing and wavelength assignment (RWA) information to at least one adjacent control plane controller, wherein the RWA information is transmitted using an interior gateway protocol (IGP). Included is a method comprising communicating a message comprising RWA information to at least one adjacent control plane controller, wherein the message comprises an indication whether the RWA information is static or dynamic. Also included is an apparatus comprising a control plane controller configured to communicate data to at least one adjacent control plane controller, wherein the data comprises RWA information, and wherein the data comprises an indicator that indicates whether the RWA information is associated with a node, a link, or both.

Abstract: Servers attached to a data communications network, such as a wavelength division multiplexed network, are made aware of events on the network, such as a protection switch for scheduled maintenance to reduce latency and improve performance, etc. Switching data paths on the data communications network is no longer transparent to the server. A message from the network equipment is received and decoded by a holographic enterprise interface coupled to the server and to a virtual network operation centers. The network equipment reports network switch conditions to the holographic enterprise interface and other connected servers. In response to the network switch conditions, the holographic enterprise interface may automatically reprovision data traffic on the network quickly enough to prevent server timeouts and workload interruptions. The switching is then shown in real time in the virtual network operations center.

Abstract: The present invention provides reduced power dissipation and other benefits at the optical transport network layer by utilizing a digital subcarrier optical network comprising multiple digital subcarrier cross-connect switches. This offers several advantages for optical networks, including spectral efficiency and robustness against signal corruption and consumption of less energy than traditional TDM-based electric switches (OTN/SONET/SDH).

Abstract: An optical network includes multiple source, cross connect, and destination nodes. A traffic demand matrix is constructed for each possible pair of combinations of the source nodes and the destination nodes. A first energy reduction metric is determined for creating the bypass between the source node and any XC node based on the traffic demand matrix, and a second energy reduction metric is determined for creating the bypass between any XC node and the destination node using the traffic demand matrix. Then, a bypass that terminates at one of the XC nodes that has a largest energy reduction metric is created.

Abstract: In a Wavelength Division Multiplexed (WDM) all-optical network having optical nodes linked together by optical fibers carrying communication channels of separate wave-lengths, a method is applied in order to extend the size of the all-optical network. According to the method, a model is set up for the all-optical network in which a wavelength graph containing vertices and edges represents the physical effects of the nodes and links. After identifying a set of demand, an objective function is calculated expressing the total routing cost and total signal power demand of the channels. The minimum of the objective function returns the signal powers for each channel to be tuned.

Abstract: The present invention provides a method for establishing an inter-domain path that satisfies wavelength continuity constraint. The fPCE stores a virtual topology comprised by border nodes of all domains. The present invention uses parallel inter-domain path establishment method to decrease the influence from WCC. Compared with the sequential process way in prior art, it enhanced the resource utilization and decreased computation delay.

Abstract: A method, apparatus and system for advertising a routing protocol message and calculating a route are provided which solve the problems that the time of connection establishment or rerouting in wavelength routing is too long and that wavelength utilization efficiency is low. The method for advertising the routing protocol message includes: obtaining node information and link information of a node, in which the node information contains port cross-connection capability information of the node, and the link information contains wavelength restriction information and wavelength status information of each link connected to the node; carrying the obtained node information and link information in a Type-Length-Value object of a routing protocol message, and advertising the routing protocol message in the network.

Abstract: Techniques are provided for receiving a connection request at a first network node configured to request a connection from the first network node to a second network node. At the first network node, it is determined if a path to the second network node without an optical regenerator is available for the connection. In response to determining that a path without an optical regenerator is not available, a path to the second network node is determined that has a minimum number of optical regenerators. The connection is set up using the path with the minimum number of optical regenerators.

Abstract: The present disclosure provides systems and methods for administrative boundaries in a single domain optical network such as emulation of an External network-network interface (ENNI) using an Internal-Network to Network Interface (INNI). For example, in a single monolithic domain, a network and associated network elements may discover network elements, build topology, compute paths, establish new calls, etc. A user may identify/mark specific links as emulated “ENNI” links with the specific links actually being INNI links. As a call traverses this emulated link, a new call is initiated (much in the same way a new call segment would be created for a call). Signaling proceeds as normal. When the call set-up is fully complete, instead of a single call segment, many call segments exists. Advantageously, this allows use of INNI control plane features while allowing a network operator to future-proof their network by installing call segments at future boundary points.

Abstract: The present disclosure provides methods and systems for automatic carving of Optical channel Data Unit k (ODUk) levels on connection creation as well as the enforcement of an OTN hierarchy policy. In an exemplary embodiment, the present invention provides several methods of automatically carving Optical channel Data Tributary Unit Group (ODTUG) structures down to a desired ODUk layer during end-to-end circuit setup. These methods may include a recursively descending algorithm, an iterative array algorithm, and an ordered linked list algorithm. Additionally, to interoperate with network elements which may have a fixed ODTUG structure within an Optical channel Transport Unit (OTU), a method of policy enforcement describing each ODUk layer mapped into ODTUG structures is used to select a best match of the currently provisioned ODUk layers.

Abstract: A system, device, and method for supporting cut-through pats in an optical communication system involves obtaining hop count and quality of service information by an initiating device and using the hop count and quality of service information by the initiating device to make decisions relating to a cut-through path. The hop count and quality of service information is provided in a reply message that is sent by a terminating device and modified by intermediate devices between the initiating device and the terminating device. The terminating device sends the reply with a hop count equal to one and quality of service information for a first link (hop) toward the initiating device. Each intermediate device increments the hop count in the reply and adds quality of service information for a next link (hop) into the reply.

Abstract: A wavelength is selected for use in transmitting optical data along a path in an optical network. Wavelengths that are available for use end-to-end along the path are found, the wavelengths that are available on each link attached to each node on the path are found and a wavelength that is available end-to-end and that is more available on the links attached to the nodes is selected.

Abstract: A method of providing routes through heterogeneous subsystems in an optical network is disclosed, which includes generating, using a processing device, a reachability matrix based on subnetwork information; and generating, using the processing device, a topology associated with the optical network using the reachability matrix. The method also includes determining, using the processing device, a shortest path through the optical network using the reachability matrix and a cost model graph; and displaying, using a graphical user interface, subsystems associated with the shortest path, regeneration locations associated with the shortest path, wavelengths associated with the shortest path, the topology, and the shortest path. Corresponding apparatus and computer-readable storage media are also disclosed.

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: 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 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: Systems and methods are described that provide a two-step, physically-diverse optical routing. A diverse routing is formulated using Integer Linear Programming (ILP) to find feasible routes having a minimum estimated cost, and post-processing the feasible routes on an auxiliary cost graph to optimize regenerator and terminal Optical Transponder (OT) placement and wavelength assignment.

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: The present invention provides a system, apparatus and method to compute a route through a network having both digital nodes and optical express-thru nodes. According to various embodiments of the invention, a network topology is generated in which both digital nodes, optical express-thru nodes, and optical nodes are identified, and both physical and virtual links between these nodes are mapped. The network connectivity is identified, at least in part, by broadcasting a local link state advertisement and optical carrier group binding information to neighboring nodes, which enables both physical and virtual neighboring nodes to be identified. Once a topology is generated, both physical and virtual link characteristics are analyzed to ensure link diversity for traffic through the network and load balancing functionality across the network.

Abstract: It is determined that service is to be disconnected for at least a first subscriber of a video content network employing at least one fiber optic cable. The service to the at least first subscriber is provided from a cross-connect cabinet, over the at least one fiber optic cable, to a premises of the at least first subscriber. Sufficient macro-bending loss is induced in the at least one fiber optic cable so as to cause a signal-to-noise ratio at the premises to degrade such that the service is disconnected. The macro-bending loss is induced in a portion of the at least one fiber optic cable which services only the first subscriber. The macro-bending loss can be induced, for example, by winding about a single mandrel, two mandrels in a figure eight pattern, in a tortuous groove in a tray, and so on.

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: The present disclosure provides hybrid packet-optical private network systems and methods for a private and dedicated multi-point Ethernet Private Local Area Network (EPLAN). The network systems and methods include a Layer 1 infrastructure service with the inclusion of reserved, dedicated packet switch capacity upon which clients can build their personal, private packet networks. In the systems and methods described herein, packet networking methods are not used to partition the isolated LAN connectivity. Instead, dedicated Ethernet Private LANs (EPLs) are defined between dedicated virtual switching instances (VSIs) that are defined, as necessary, within larger packet-optical switches. Each VSI is partitioned from the remainder of its packet switch fabric as a dedicated, private resource for a specific EPLAN. A packet network is then built by the customer on top of the private EPLAN bandwidth and operated as an isolated, private network with no influence by other carrier's network resources.

Abstract: This invention discloses methods to reconfigure highly scalable and modular automated optical cross connect switch devices comprised of large numbers of densely packed fiber strands suspended within a common volume. In particular, methods enabling programmable interconnection of large numbers of optical fibers (100's-1000's) are provided, whereby a two-dimensional input array of fiber optic connections is mapped in an ordered and rule-based fashion into a one-dimensional array. A particular algorithmic implementation for a system reconfigured by a three-axis robotic gripper as well as lateral translation of each row in the input port array is 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: 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: Methods and apparatus for determining transmission power of a plurality of optical channels for transmission of the channels along respective paths obtained through an optical transmission system. Information is obtained indicative of the path of each channel through the optical transmission system, and each channel is allocated to a group of channels in dependence upon the obtained information. A quality metric is determined for each group of channels, and a total transmission power for each group is determined in dependence upon the determined quality metric.

Abstract: A method of providing routes through heterogeneous subsystems in an optical network is disclosed, which includes generating, using a processing device, a reachability matrix based on subnetwork information; and generating, using the processing device, a topology associated with the optical network using the reachability matrix. The method also includes determining, using the processing device, a shortest path through the optical network using the reachability matrix and a cost model graph; and displaying, using a graphical user interface, subsystems associated with the shortest path, regeneration locations associated with the shortest path, wavelengths associated with the shortest path, the topology, and the shortest path. Corresponding apparatus and computer-readable storage media are also disclosed.

Abstract: Due to demand for more network bandwidth, a need for multi-user optical network topologies has, and will continue to, increase. A method or corresponding apparatus in embodiments of the present invention provide for an availability determination tool for determining and displaying wavelength and subrate availabilities within a network. Benefits of embodiments of a tool include allowing a user to identify the availability and capacity of any wavelength on any network, via an interactive graphical user interface, such as by using three-dimensional representations. In one embodiment, the disclosed availability determination tool allows users to locate and view any combination of available wavelengths between nodes in an optical network topology, and generate graphical and tabular reports of the availability in order to maintain an efficient and organized method or apparatus for determining and controlling wavelengths in a network.

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: A large communication network suitable for nationwide or worldwide utilization. The present invention overthrows the conventional packet switching technologies with an all-optical network. The invention uses tunable laser sources to generate large number of highly stable narrow-band optical signals, each serving as a communication channel. With packet processing replaced by all-optical channels, the network become highly secure and scalable while harnessing the virtually unlimited capacity of fiber-optic. A large number of nodes (called area code nodes) are connected with all-fiber-optic links with all-optical switches. A routing algorithm provides one or more communication links from each area code node to every other area code node so that information never has to change carrier wavelength as it travels the network. Each area code node contains circuits that are provided to connect individual users to the network.

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: A network including nodes configured to provide auto-discovery and those that do not are provided in a network. The nodes that do not provide auto-discovery may be provided as end points or terminating nodes in the network. A path or circuit identifier is entered into a database at those nodes and communicated to a network management system. The network management system compares the path identifiers, and, if the two match, the network management system designates the nodes associated with the path identifiers as terminating nodes. A path through the network connecting these nodes can then be determined and monitored. In addition, fiber connection information may further be stored at each node and communicated to the network management system, such that links along the path can also be identified by the network management system. Thus, path determination and monitoring in a network including non-auto-discovering nodes can thus be obtained.

Abstract: A communication network management system including a node apparatus 10 provided with a wavelength detecting part 110 which detects the wavelength of an optical wave transmitted through a path, a destination node detecting part which detects a node apparatus connected to a transmission path, a connection information storage part 112 which stores connection information, a connection information sending part 113 which sends connection information to an NMS terminal, and a path setting part 114 which sets path based on path setting data received from the NMS terminal 20; and an NMS terminal provided with a connection information detecting part 220 which receives connection information from the node apparatus 10, a path setting data generating part 221 which generates path setting data of the node apparatus 10 based on the connection information and a path setting data sending part 222 which sends path setting data to the node apparatus 10.

Abstract: In a transmission apparatus, unlike in the conventional transmission apparatus, a protection switch is not arranged on the signal path, but a TSI having only the basic function performs the function of the protection switch as a substitute, a processing unit to perform the switching function at a low rate is artificially constructed on a TSI, the switch process of SONET protection type is artificially executed by the TSI, and a signal for controlling the TSI function is further controlled thereby to realize the protection switch function. The logic of switching at the main signal rate in addition to the conventional TSI function is deleted.

Abstract: The OSS provides unique and automated provisioning, activation, fallout management and monitoring of SONET and WDM networks comprising control plane mesh and traditional SONET/WDM Rings/Chains. Resource discovery and dynamic provisioning provides for increased use of network bandwidth. It is possible both all control plane networks and mixed control plane and traditional networks. Network connections or the network topology may be accomplished in a hop-by-hop manner.

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). The PCEP comprises at least one operation selected from the group consisting of a new RWA path request operation and a path re-optimization request operation. 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, and establishing impairment aware RWA (IA-RWA) based on the path computation information and a private impairment information for a vendor's equipment.

Abstract: An optical network is disclosed comprising one or more photonic switching nodes is disclosed. Each of the switching nodes comprises a plurality of input ports; at least one output port; and a switch configured to route messages between the plurality of input ports and the at least one output port and provide bufferless resolution of contention between messages for a common output port.

Abstract: For each path in a first plurality of paths in said communication network, a respective first weighted path length is determined based at least in part on a number of pure wireless links in the path. From among the first plurality of paths, a second plurality of paths having first weighted path lengths less than a threshold value is selected. For each path in the second plurality, a respective second weighted path length is determined based at least in part on a number of pure optical links in the path, and from among the second plurality of paths, a transmission path is selected having a highest second weighted path length. Information is transmitted via the transmission path.

Abstract: In asynchronous optical packet switches, scheduling packets from a buffer randomly will cause less efficient utilization of the buffer. Additionally, reordering of packets may cause problems for service quality demanding applications. According to the present invention a new electronic buffer scheduling algorithm is proposed and a switch utilizing this algorithm is disclosed. The algorithm is designed for utilizing the buffer resources efficiently, still avoiding serious packet reordering.