Abstract: Call setup methods in a multi-domain network and a multi-domain network use dynamic link tagging and/or overbooking of External Network-Network Interface (ENNI) links. Thus, improved call setup systems and methods include two approaches to improve upon the responsiveness of the network for connection setups including bandwidth reservation in optical networks using “dynamic link tags” and link overbooking in optical networks based on a greedy approach. The bandwidth reservation and the link overbooking can be utilized together or separately to improve call setup. Advantageously, the improved call setup systems and methods can provide a generic bandwidth reservation mechanism, such as in Automatically Switched Optical Network (ASON) networks, to overcome the limitation of ENNI in concurrently updating the abstract link bandwidth and thereby improving the responsiveness of the network.

Abstract: An information processing method is disclosed according to the embodiments of the present invention. The method includes: A node receives a first message from overhead of a first dimension; the node searches for local configuration information, where the local configuration information includes the overhead of the first dimension of a protection path, a protection resource of the first dimension of the protection path, overhead of a second dimension of the protection path, and a protection resource of the second dimension of the protection path; according to the local configuration information and the first message, the node determines a protection path correlated with the first message and determines overhead of the second dimension correlated with the first message; and the node sends a second message to a node adjacent to the second dimension through the overhead of the second dimension correlated with the first message, according to the first message.

Abstract: An Optical Network Unit, ONU, and an Optical Line Terminal, OLT, as well as a respective method therein, are provided for enabling the ONU to communicate with the OLT. The ONU and at least one OLT are comprised in a passive fibre optic access network. The passive fibre optic access network comprises two fibre paths through the network, a main fibre path and a back-up fibre path, connecting the ONU with the OLT. When a fault is detected in the main fibre path is detected, transmission rate negotiation is performed between the ONU and the OLT over the back-up path. When a transmission rate is agreed upon between the ONU and the OLT during said transmission rate negotiation with regard to communication over the back-up path, the communication between the ONU and the OLT is executed using the agreed transmission rate over the back-up path.

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 OADM device without a transponder unit does not mount the transponder in charge of separating a fault between the OADM device and an external device and is difficult to perform fault separation and to identify a fault interval. To solve this problem, for the OADM device without the transponder unit, the optical loop back function is provided by using such a switch as, for example, 2×2 optical switch. By identifying a fault developing interval by the use of the optical loop back function, fault separation at the time of occurrence of a fault can be facilitated.

Abstract: In a communication line switching method for an optical communications system in which a station-side line terminal apparatus and user-side line terminal apparatuses are connected via a plurality of redundant physical lines, the discovery of the station-side optical line terminal registering the user-side line terminal apparatuses, wherein the registered user-side line terminal apparatuses monitoring a time stamp drift error that is generated when a difference between a time stamp included in a received signal and a local time measured by the own apparatus is larger than a value set in advance and, when the time stamp drift error occurs, shifting to a deregistered state and waiting for registration by the discovery. The station-side line terminal apparatus switches a physical line from a working physical line to a backup physical line of the physical lines.

Abstract: A PON ring system and a method for realizing primary and backup link protection in a passive optical network (PON) are provided. A PON ring is established between at least two optical line terminations (OLTs) through at least two user side edge nodes or network side edge nodes. Each of the OLTs is coupled to any other OLT through the at least two edge nodes. Two links respectively in a clockwise direction and a counterclockwise direction exist in the PON ring, in which one link is a primary link and the other is a backup link. Node of the links adopt the transmission mode of “multiple sending and selective receiving”. Therefore, the present invention reduces the impact on the PON caused by single link failure in the network.

Abstract: A network design apparatus includes: a first processing unit configured to select one or more paths between nodes in response to a request for a bandwidth between pairs of nodes in a network to determine working communication routes and protecting communication routes connecting the pairs of nodes, and estimate a number of communication lines in the selected path; and a second processing unit configured to allocate logical channels of the communication lines to the working communication routes and the protecting communication routes based on the requested bandwidth, wherein the first processing unit determines the protecting communication routes while permitting the sharing of the path, and the second processing unit allocates a common logical channel to one or more communication routes, out of the protecting communication routes, that share the path and are not simultaneously used when a failure occurs in the working communication routes.

Abstract: A joint switching method for an aggregation node, an aggregation node, and an optical network protection system including an aggregation node are provided. By monitoring information transferred between an active optical line terminal (OLT) and a broadband network gateway (BNG), the aggregation node finds a fault in time according to the monitored information and when a fault occurs, the aggregation node starts a local protection solution, enables a corresponding backup port connected to a backup OLT corresponding to the active OLT, and disables an active port connected to the active OLT. Through the method, when the active OLT is switched to the backup OLT, the aggregation node performs joint switching, which ensures normal communication.

Abstract: An apparatus serves as a node in a network on which plural working paths and plural protection paths for bypassing the plural working paths are set, where the plural protection paths share bandwidths allocated thereto. The apparatus includes a data plane unit functioning as an interface that transmits and receives data with a node in the network. The apparatus predicts a first working path having a highest probability that a failure is likely to occur, among the plural working paths, based on transmission qualities of the plural working paths. The apparatus beforehand sets, to the data plane unit, a setting value for a first protection path corresponding to the first working path, and validates the setting value set to the data plane unit, based on a request for activating the first protection path, when the first working path is switched to the first protection path.

Abstract: The invention relates to a distributed radio access network communicatively coupled to a core network, and a method for upholding a service in case of a failure in the distributed radio access network. The distributed radio access network comprises a main radio equipment controller communicatively coupled to at least one remote radio unit over a main optical path, a backup radio equipment controller communicatively coupled to the main radio equipment controller for synchronization, and a protection optical path for communicatively coupling the at least one remote radio unit to the backup radio equipment controller in case of a failure in communication between the main radio equipment controller and the at least one remote radio unit over the main optical path such that a service remains running when the failure occurs.

Abstract: The invention relates to a protection mechanism for a communications network. A node, a method, a computer program product and a communications network to provide protection for an optical communications network are disclosed. Communications traffic is selecting from a working path in the optical network. A first fault condition is determining on the working path. The communications traffic is selected from a protection path in the optical network in response to clearing of the first fault and determining a second fault condition on the working path within a first predetermined time period of determining the first fault condition.

Abstract: A node may determine a failure in a first path for routing first optical network traffic between a first set of networking devices, where the first path includes a first set of optical transport nodes. The node may determine a second path for routing the first optical network traffic between the first set of networking devices, where the second path includes a second set of optical transport nodes that route second optical network traffic between a second set of networking devices. The second set of optical transport nodes may include at least one node that is not included in the first set of optical transport nodes. The node may pre-empt routing of the second optical network traffic via the second path, and may route the first optical network traffic via the second path after pre-empting routing of the second optical network traffic via the second path.

Abstract: In a communication line switching method for an optical communications system in which a station-side line terminal apparatus and user-side line terminal apparatuses are connected via a plurality of redundant physical lines, the discovery of the station-side optical line terminal registering the user-side line terminal apparatuses, wherein the registered user-side line terminal apparatuses monitoring a time stamp drift error that is generated when a difference between a time stamp included in a received signal and a local time measured by the own apparatus is larger than a value set in advance and, when the time stamp drift error occurs, shifting to a deregistered state and waiting for registration by the discovery. The station-side line terminal apparatus switches a physical line from a working physical line to a backup physical line of the physical lines.

Abstract: An optical network system that performs transmission of N:1 protection includes a node that includes transmission-side operating muxponders that multiplex client signals for every M-channel signal bundle and convert multiplexed signals into optical signals having different wavelengths, transmission-side optical couplers that branch the client signals into two channels of operating and redundant, transmission-side optical switches each selecting one channel from redundant signals as a redundant client signal, and a transmission-side redundant muxponder that performs a predetermined transmission-side process according to an accommodation mode set on the redundant client signal and then multiplexes the redundant client signals, converts the multiplexed signal into an optical signal having a wavelength different from that of the operating signal, thereby making the accommodation mode settable for each channel in an independent manner.

Abstract: In one embodiment, notifications of upcoming maintenance activities are provided by network devices, such as to allow packet switching or other optical layer client devices to reroute traffic prior to the occurrence of the traffic affecting event. For example, one such network device includes optical interfaces for coupling with fibers for transporting information using dense wavelength-division multiplexing (DWDM); DWDM switching equipment for cross-connecting wavelengths of the fibers; and a controller configured to inform packet switching or other optical layer client devices whose traffic would be affected by an upcoming event that would disrupt communication on one or more wavelengths on one or more fibers so that the packet switching or other optical layer client devices can reroute traffic that would otherwise go over said one or more wavelengths onto a different path in a network prior to said disruption.

Abstract: A method, a node, and a network include mesh restoration and bandwidth allocation systems and methods for shared risk connection groups for source-based routing control planes. The mesh restoration and bandwidth allocation systems and methods utilize signaling from a node closest to a point of failure to “advise” source nodes about protect paths to be taken for a particular unidirectional or bidirectional connection in the event of mesh restoration. Specifically, the systems and methods include an ability to correlate connection information as Shared Risk Connection Groups (SRCG) to optimally utilize network bandwidth in the event of failure. The systems and methods could also be used to optimally distribute connections in a mesh network as well, trying to utilize maximum bandwidth, in distributed or centralized environments. Effectively, the systems and method distributed path computation in the network away from solely being the responsibility of source nodes.

Abstract: N optical transceivers are each connected to a respective electronic module in one-to-one relation such that a respective one electronic module controls a respective one optical transceiver. An electronic switch matrix provides cross-connect capability between the P redundant electronic modules and N electronic modules to the N optical transceivers. A system controller determines when an active N electronic module has failed, and configures the electronic switch matrix to switch a P redundant electronic module into the optical transceiver to which the failed electronic module was connected. A system switch module redirects traffic and routing information, under the direction of the system controller, from the failed module to the newly activated redundant module so that the redundant module assumes the functionality of the failed module.

Abstract: Terminals of upstream and downstream sides of an in-service line and a detour line are connected by optical couplers. An optical oscilloscope is connected to one optical coupler, and a chirped pulse light source is connected to the other optical coupler to thereby form dualized lines. The detour line includes an optical line length adjuster for compensating for the phase difference of optical transmission signals that occurs because of the optical line length difference with the in-service line. Pulse light in which an optical frequency is chirped is transmitted from the chirped pulse light source. The pulse light is branched by the second optical coupler, passes through the in-service line and the detour line, is multiplexed again by the first optical coupler, and is measured by the optical oscilloscope.

Abstract: A transmission apparatus includes a processor configured to recognize a number of working failures and a number of protection failures on a network for transmission of wavelength-multiplexed signal light, the number of working failures being the number of failures in signal light in wavelengths at a working entity and the number of protection failures being the number of failures in signal light in wavelengths at a protection entity, configured to perform path switching for each group of signal light in wavelengths that are different from each other and configured to select, when multiple failures occur, restoration processing, on a basis of the number of working failures and the number of protection failures.

Abstract: The present invention discloses an optical line transmission protection system and method. In which, the optical line transmission protection system includes: at least one stage of optical line protection segment having a transmitting end provided with a Tunable Optical Divide Module (TOD), and a receiving end provided with an OSW; the transmitting end of a local Optical Line Protector (OLP) is connected to the receiving end of an opposite OLP to form main and standby optical lines; and the TOD is configured to set splitting ratios of the main and standby optical lines according to a difference between the optical fiber states of the current working channel and non-working channel, and tune optical power distributions at respective transmitting ends of the main and standby optical lines, according to the splitting ratios of the main and standby optical lines.

Abstract: The present invention embraces an optical wavelength division multiplex (WDM) transmission system, especially a WDM passive optical network, typically including a central node having a first and a second WDM port and a remote node having a first and a second WDM port and a plurality of channel ports, the central node first WDM port being connected to the remote node first WDM port via a bidirectional single-fiber optical working path and the central node second WDM port being connected to the remote node second WDM port via a single-fiber bidirectional optical protection path, and a group of basic optical node units (ONU's) each of which is connected to a respective remote node channel port via a bidirectional optical ONU path, each ONU including an optical receiver for receiving a downstream optical channel signal and an optical tunable transmitter for creating an upstream channel signal.

Abstract: Described is a light module interlock system comprising: an optical cable enabled to transmit light of a first wavelength and a second wavelength different than the first wavelength; a first light module enabled to provide the first wavelength to the optical cable; a second light module enabled to provide the second wavelength to the optical cable; a sensor enabled to detect the first wavelength transmitted by the optical cable, the sensor located at an opposite end of the optical cable as the first light module; and an interlock in communication with the sensor, the interlock enabled to: disable the second light module when the sensor fails to detect the first wavelength, such that the second wavelength is no longer provided to the optical cable.

Abstract: An optical communications system includes a MSAP and an optical transceiver mounted at the MSAP that communicates over an optical network to at least one optical network terminal (ONT). A first electronic module is operatively connected to the optical transceiver and configured to control the optical transceiver and mounted at the MSAP separate from the optical transceiver. A redundant second electronic module is supported within the MSAP and mounted separate from the optical transceiver. A Mux/Demux module interconnects and supports the first and second electronic modules to form an integral unit and mounted at the MSAP separate from the optical transceiver. The Mux/Demux module is configured to switch the second electronic module into communication with the optical transceiver upon failure of the first electronic module.

Abstract: Embodiments of the present invention disclose a troubleshooting method. The method includes: determining, by an aggregation node when a link fault or a device fault occurs on an OLT side, an active logical port used by the active OLT to forward a data packet; searching, by the aggregation node, a locally stored logical port mapping table according to the active logical port to obtain a standby logical port corresponding to the active logical port, where the standby logical port supports a same user service as the active logical port; and triggering, by the aggregation node, the standby OLT to enable the standby logical port to receive a data packet that is sent by the standby OLT through the standby logical port. The implementation of the present invention can provide utmost compatibility with the live network and enable a communication link to recover from a fault quickly.

Abstract: A wavelength path communication node apparatus includes a wavelength path demultiplexer (321) which demultiplexes branched optical signals input to wavelength multiplexing ports into wavelength path signals, and outputs the wavelength path signals from wavelength demultiplexing ports corresponding to the respective wavelengths, a wavelength path multiplexer (322) which outputs wavelength path signals input to wavelength demultiplexing ports from wavelength multiplexing ports corresponding to the wavelengths of the wavelength path signals, a plurality of transponders (331) each of which converts a wavelength path signal input to a wavelength path transmission port into a client transmission signal to transmit the client transmission signal, and converts a received client reception signal into a wavelength path signal of a wavelength to output the wavelength path signal from a wavelength path reception port, a demultiplexing system optical matrix switch (323) which switches and connects the wavelength demultipl

Abstract: A method for routing and wavelength assignment (RWA) in an optical network with improved heuristics for reducing the computational times required for the RWA. The method minimizes the number of wavelengths by packing the lightpaths using a minimum number of bins in a bin packing problem. Computational efficiency is enhanced by using several novel methods to determine shortest paths and eliminate arcs in a graph that represents the network topology.

Abstract: An Optical Line Termination (OLT) system in a multi-wavelength Passive Optical Network (PON) includes a protection port for protecting a set of OLT ports without the use of a physical switch. The protection port has a tunable transceiver. The OLT system detects a failure of one of the OLT ports, which was originally adapted to transmit downstream traffic to a subset of ONUs on a downstream wavelength and to receive upstream traffic from the subset of ONUs on an upstream wavelength. In response to the detection, the OLT system tunes the protection port to the downstream wavelength for transmission and to the upstream wavelength for reception, and resumes communication between the OLT system and the subset of ONUs through the protection port instead of the OLT port.

Abstract: Systems and methods are described that provide a distributed restoration signaling protocol for shared mesh restoration with standbys for transparent optical networks.

Abstract: A transmission apparatus includes a package that has a plurality of slots into each of which a board can be freely detachably inserted; at least one control board; a PWE interface communication unit that is connected to the control board, converts an input SDH or PDH signal to a packet signal, and outputs the converted signal to the control board; a radio transmission communication unit that is connected to the control board, converts the packet signal to a radio signal, and outputs the converted signal; and an optical transmission communication unit that is connected to the control board, converts the packet signal to an optical transmission signal, and outputs the converted signal. The units are separately inserted in the slots.

Abstract: An optical communication system includes an optical transmission terminal including a first transmitter for transmitting an optical signal, and a second transmitter for transmitting information that indicates the first transmitter transmitting the optical signal; and an optical receiving terminal including an optical receiver for receiving the optical signal and the information transmitted from the first and second transmitter, respectively, a storage device for storing a power value of the optical signal monitored in response to receipt of the information transmitted from the second transmitter, and a fault detector for detecting fault of the optical signal by continuously monitoring a power value of the optical signal received by the optical receiver in comparison with the power value stored in the storage device.

Abstract: In a normal operation, line cards LCm1 and LCm2 set transmit ports TXu of user ports UPm1 and UPm2 into an open state, and line cards LCs1 and LCs2 set transmit ports TXu of user ports UPs1 and UPs2 into a blocking state. Here, for example, if a failure occurs in a communication line LNa1, the line card LCm2 detects the failure through a transmission port HPm2, and then changes the transmit port TXu in the user port UPm2 from the open state to the blocking state, and notifies the line card LCs2 of failure detection through a backplane. The line card LCs2 receives the notification of the failure detection, and changes the transmit port TXu in the user port UPs2 from the blocking state to the open state.

Abstract: Embodiments of the present invention include a single fiber bi-directional optical module, and a transport system and method based thereon. The single fiber bi-directional optical module includes a self-search circuit respectively connected to a transmission selection circuit and a receiving selection circuit. The self-search circuit is configured to search for channels, and instruct, the transmission selection circuit to transmit optical signals through one of at least two transmitting channels, where optical wavelengths of the at least two channels are different; and instruct the receiving selection circuit to receive optical signals through one of at least two receiving channels, where optical wavelengths of the at least two receiving channels correspond to the optical wavelengths of the at least two transmitting channels. The single fiber bi-directional optical module does not need to be used in pairs, so that device numbers and maintenance costs are reduced.

Abstract: The present invention provides a method for processing a switch control command for solving the problem that consistency of data of the network device and the network management is unable to be kept in the process of processing the switch control command in the prior art. This method includes: when a priority of obtained trigger information is higher than a priority of a switch control command, discarding the switch control command (103); and reporting the discarded switch control command to a control system which manages the network device (104). The present invention further provides an device for processing a switch control command.

Abstract: In an OTN (Optical Transport Network), an OTN interface of a network element may receive a BDI (Backwards Defect Indicator) signal from a far end network element to which OTN frames are being transmitted. A BDI signal indicates the occurrence of a unidirectional failure in the transmission of OTN frames to which the far end network element responds by switching its routing to the network element. The OTN interface generates an AIS (Alarm Indication Signal) for its network element so that the network element switches network communication channels to the far end network element to ensure bidirectional switching upon a unidirectional failure.

Abstract: In accordance with embodiments of the present disclosure, a method is provided for communicating multicast traffic. The method may include in response to receipt of multicast control traffic at a network element to be communicated to a protection switching group, communicating the multicast control traffic to each of a working path and a protection path of the protection switching group. The method may also include in response to receipt of multicast control traffic via either of the working path and the protection path, processing the multicast control traffic as if the multicast control traffic was received via both the working path and the protection path.

Abstract: Disclosed herein are a combined communication and broadcasting dual switching system and method. The system includes broadcasting transmission means, an Optical Line Terminal (OLT), an optical detection unit, an active path determination unit, an optical switch unit, and a combining unit. The broadcasting transmission means converts a Radio Frequency (RF) broadcast signal into an optical signal. The OLT includes dual lines and selectively outputs an Internet data signal. The optical detection unit detects a line from which the Internet data signal is being output. The active path determination unit determines that the line is an active path. The optical switch unit receives the optical signal from the broadcasting transmission means, and switches to the active path. The combining unit receives the optical signal output after having been switched, receives the Internet data signal from the OLT, and multiplexes the received optical signal and the received Internet data signal.

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: The procedure comprises using a pre-planned path restoration scheme for computing in advance, or pre-calculating, recovery paths for recovering failed working paths, and particularly comprises pre-calculating a set of recovery paths for each working path linking an origin node with a destination node, and simultaneously using the recovery paths of the set of recovery paths to try to communicate the origin node with the destination node, in case of one or more failures have been produced in the working path. The system is arranged for pre-calculating a set of recovery paths for each working path and simultaneously using them to recover a working path failure, and is apt for implementing the procedure.

Abstract: An existing path in a connection-oriented network requires resizing from a first size to a second size. Nodes exchange control plane signalling with other nodes which advertises available resources on links between nodes. A node on the existing path receives a request to establish a path capable of being resized to the second size. The node determines, using information acquired by the control plane signalling with other nodes, a new path between nodes capable of supporting the second size. The node signals to establish the new path and switches traffic from the existing path to the new path. The node causes the new path to be resized to the second size. Nodes exchange control plane signalling with other nodes which advertises whether a link supports resizing, such as OSPF-TE advertisements.

Abstract: A visible light communication (VLC) device is provided for use in a VLC system. The VLC device detect a trigger condition indicating a failure of a VLC link associated with first allocated resources used to communicate with a second VLC device. In response to the detection, the VLC device terminates on the first allocated resources transmission of data to the second VLC device and transmits a fast link recovery (FLR) signal using the first allocated resources. The VLC device receives a fast link recovery response (FLR RSP) signal indicating the second VLC device received the FLR signal and, in response, the VLC device resumes transmission of data to the second VLC device.

Abstract: A protection path reservation method which reserves protection paths to avoid a node failure for each transmission path on a network formed of a plurality of nodes, comprising assuming the nodes as an imaginary failure node in turn in a condition in which the node failure is not present in the network, and selecting N neighbor nodes connected to the imaginary failure node through N links, wherein the imaginary failure nodes sequentially transmit protection path reservation request messages to neighbor nodes, and the nodes which have received the protection path reservation request messages sequentially, one by one, reserve N?1 protection paths starting from the nodes.

Abstract: A method and system for protecting integrated optoelectronic devices are disclosed. The method includes (1) providing standby light source links of fixed wavelength and their corresponding standby data channel in a transmitting-end integrated optoelectronic device; (2) detecting whether there is failure in each active light source link in the transmitting-end integrated optoelectronic device; and (3) selecting a standby light source link having a fixed wavelength and its corresponding standby data channel for accomplishing service transmission of failed active light source link and its corresponding active data channel when detecting failure of an active light source link. The system includes a transmitting-end integrated optoelectronic device and a receiving-end integrated optoelectronic device.

Abstract: An optical ring network has one or more working wavelengths and multiple protection wavelengths adapted to support the working wavelength(s). Routing tables may be used in network nodes to assign traffic of a failed working wavelength to a protection wavelength. The protection technique may be applied to networks employing, for example, Dense Wave Division Multiplexing (DWDM).

Abstract: A wavelength division multiplexing (WDM)-time division multiplexing (TDM) passive optical network (PON) remote terminal (RT) is provided. The wavelength division multiplexing (WDM)-time division multiplexing (TDM) passive optical network (PON) remote terminal (RT), includes: a WDM-TDM converter configured to convert a WDM downstream optical signal that is received from a central office terminal (COT) into a TDM downstream optical signal or to convert a TDM upstream optical signal that is received from an optical network terminal (ONT) into a WDM upstream optical signal; an error detector configured to detect an error; and a controller configured to, in response to an error being detected, transmit the WDM upstream optical signal to the COT via a first standby link or transmit the TDM downstream optical signal to the ONT via a second standby link.

Abstract: A protected passive optical communications system includes terminals, a main head end, and a back up head end allowing communication with the terminals when a fault occurs. The main and back up head ends transmit frames that include header and payload portions to the terminals. The main head end normally transmits control instructions in the header and user data in the payload. The back up head end, in response to a fault, transmits control instructions in the payload, and a control message in the header. The control message indicates control instructions in the payload. If a control message is in the header, each terminal interprets the payload as control instructions for changing operational attribute(s) of a terminal. If a control message is not in the header, each terminal interprets the payload as user data that it forwards to external user(s) external based on an address from the user data.

Abstract: A network includes a plurality of interconnected nodes utilizing an all-broadcast architecture for a plurality of wavelengths therebetween; a routing protocol configured to compute a loop-free path through the plurality of interconnected nodes, wherein the loop-free path is computed for at least one wavelength of the plurality of wavelengths using routing constructs adapted to a photonic domain; and at least one blocking element configured to selectively block the at least one wavelength based on the computed loop-free path. A routing method photonic node are also disclosed.

Abstract: An approach for detecting an error associated with a routing network coupled to a transport network comprising a plurality of optical communication nodes, switching, by an optical communication node, to a troubleshooting channel associated with the transport network using one or more router counterpart cards, and troubleshooting the error using the one or more router counterpart cards.

Abstract: Systems and methods for performing protection switching in a passive optical network are provided. When a fiber cut is detected, control and management plane applications are not immediately informed. A rapid re-registration procedure is instigated upon detection of a fiber cut event. This allows multiple optical network units to re-register quickly without restarting control and management applications.

Abstract: A method and system for protecting against communication loss or disruption in an optical network system includes a signal state detector, which can measure received optical signals and determine if their strength is sufficient to support reliable communications. If the signal state detector informs the control circuit that the received optical signal is too low to support communications with the data service hub (or if there is no signal at all, such as in a severance of an optical waveguide), then the control circuit can instruct the data switch to re-route communications from the primary communication path to a secondary or back up communication path. This switching or re-routing of communications from a primary communication path which is non-functional or inoperative to an operational and fully functional communication path (a back up or secondary communication path) can be completed in a very short time, such as within fifty milliseconds or less.