Abstract: A rework re-timer with forward error correction handling is disclosed. An example first intermediate transceiver includes a first interface to communicatively couple the first intermediate transceiver with a first computing device, a second interface to communicatively couple the first intermediate transceiver to a second intermediate transceiver configured to be communicatively coupled with a second computing device, an auto-negotiation controller to: terminate a first auto-negotiation with the first computing device before the first auto-negotiation is completed, transmit, to the second transceiver, first capabilities of the first computing device determined during the first auto-negotiation, and perform a second auto-negotiation with the first computing device utilizing the first capabilities of the first computing device and second capabilities of the second computing device received from the second transceiver.

Abstract: A communication apparatus configured to communicate with a router included in a first network and a multiplexer that multiplexes a plurality of optical signals having different wavelengths transmitted from the communication apparatus, the communication apparatus comprising a memory, and a processor coupled to the memory and configured to transmit and receive a first signal to and from the router, transmit and receive a second signal to and from another communication apparatus in a second network through the multiplexer, the second signal having a transmission scheme different from the first signal, mutually convert the first signal and the second signal with each other, detect a first communication disabled state between the another communication apparatus and the communication apparatus, and transmit, to the router, a first detection signal for detecting adjacency relationship between the communication apparatus and the router when the first communication disabled state is detected.

Abstract: Embodiments herein relate to optoelectronic transceivers with power management. An optoelectronic device may include a photodetector, a loss of signal (LOS) detector coupled with the photodetector, and a re-timer coupled with the LOS detector, wherein a component of the re-timer is to be disabled in response to a detection by the LOS detector that an optical signal has not been received for a predetermined time period. In some embodiments, the LOS detector is coupled with a driver disable input of the re-timer and a driver component of the re-timer is to be disabled. In some embodiments, a clock data recovery circuit, a transmit module re-timer and modulator, and/or a laser may be disabled. In various embodiments, components may be re-enabled in response to detection that an optical signal is being received and/or an electrical signal is received for optical transmission. Other embodiments may be described and/or claimed.

Abstract: Radio-frequency (RF) integrated circuit (RFIC) chip(s) allow for the integration of multiple electronic circuits on a chip to provide distributed antenna system functionalities. RFIC chips are employed in central unit and remote unit components, reducing component cost and size, increasing performance and reliability, while reducing power consumption. The components are also easier to manufacture. The RFIC chip(s) can be employed in distributed antenna systems and components that support RF communications services and/or digital data services.

Abstract: A method of local path protection in a node on a shared alternative path of a network. The method comprising receiving a signal switched on a primary label switched path (LSP). The signal is switched by lambda-switching or time-division multiplex TDM switching. The method further comprises receiving identification information arranged to identify the signal, and forwarding the signal on the alternative path based on the identification information.

Abstract: A network design device includes a processor. The processor determines a second wavelength allocation based on a first wavelength allocation that indicates a wavelength allocation for a plurality of optical lines established in a wavelength division multiplexing optical network. The processor searches for a disconnection target optical line that is requested to be disconnected in order to realize a transition from the first wavelength allocation to the second wavelength allocation from among the plurality of optical lines. The processor generates procedure information that indicates a procedure of the transition from the first wavelength allocation to the second wavelength allocation based on a difference between the first wavelength allocation and the second wavelength allocation and a searched disconnection target optical line.

Abstract: Embodiments relate to providing simultaneous digital and analog services in optical fiber-based distributed radio frequency (RF) antenna systems (DASs), and related components and methods. A multiplex switch unit associated with a head-end unit of a DAS can be configured to receive a plurality of analog and digital downlink signals from one or more sources, such as a service matrix unit, and to assign each downlink signal to be transmitted to one or more remote units of the DAS. In one example, when two or more downlink signals are assigned to be transmitted to the same remote unit, a wave division multiplexer/demultiplexer associated with the multiplex switch unit can be configured to wave division multiplex the component downlink signals into a combined downlink signal for remote side transmission and to demultiplex received combined uplink signals into their component uplink signals for head-end side transmission.

Abstract: The present invention provides a protection switching method for a passive optical network. The method includes receiving, by an optical network unit ONU through each of two uplink passive optical network PON interfaces, an optical network terminal management and control interface OMCI message delivered by an OLT, where the OMCI message includes: configuration information on a work side and configuration information on a protect side; and processing, by the ONU by using each of two independent OMCI MIBs of the ONU, the OMCI message received by each of the two uplink PON interfaces, updating each of the two independent OMCI MIBs according to the OMCI message, and independently responding to the OMCI message.

Abstract: There is provided an optical transmission control device includes a memory, and a processor coupled to the memory and the processor configured to aggregate information of candidacy sections having a possibility that communication is discontinued among wavelength-multiplexed transmission sections, classify, based on the aggregated information, optical paths set between optical transmission devices into a first optical path on which, when communication in the candidacy sections is discontinued, an optical signal is not transmitted, and a second optical path on which, when the communication in the candidacy sections is discontinued, an optical signal is transmitted, and determine a wavelength allocation in a first wavelength group of the first optical path and a second wavelength group of the second optical path so that a difference in gain wavelength characteristics of the first optical path and the second optical path is equal to or less than a predetermined level.

Abstract: Individualized gain control of uplink paths in remote units in a wireless communication system based on individual remote unit contribution to combined uplink power is disclosed. The gain level is reduced for uplink paths of individual remote units that provide higher power contribution to the combined uplink power of a combined uplink communications signal received in the central unit. This allows the initial uplink gain of all remote units to be set higher to increase sensitivity, because the gain of the remote units that provide higher power contributions to the combined uplink power in the central unit can be reduced if the combined uplink power exceeds the desired threshold power level. The gain of the remote units that provide higher power contributions to the combined uplink power in the central unit can be reduced without reducing the gain in the other remote units that would otherwise reduce their sensitivity.

Abstract: Aspects of the subject disclosure may include, for example, a network device that accesses internet protocol addresses associated with a group of end point devices where the network device is a closest network device to the group of end point devices, and transmitting data to another network device responsive to a determination that an internet protocol address associated with the data from an end point device is one of the internet protocol addresses associated with the group of end point devices. Other embodiments are disclosed.

Abstract: An optical line terminal (OLT) coupled to a plurality of optical network units (ONUs) through a passive optical network (PON). The OLT includes a transceiver configured to communicate via a management channel of a communication network with a plurality of OLTs. The communication includes sending or receiving a notification, wherein the notification includes the following: a source OLT identifier associated with a source OLT sending the notification, wherein the source OLT is configured to communicate over a first channel at a first wavelength of the PON; a destination OLT identifier associated with a destination OLT receiving the notification, wherein the destination OLT is configured to communicate over a second channel at a second wavelength of the PON; and an ONU identifier associated with a first ONU associated with the notification.

Abstract: According to an aspect of an embodiment, a method may include receiving a digital data signal at an optical receiver. The method may further include measuring an eye quality of the received digital data signal. In addition, the method may include adjusting a decision threshold of the optical receiver based on the measured eye quality.

Abstract: A method is provided for establishing a communication path in an optical network, the communication path comprising a plurality of sections, wherein the power level of a section is controlled by a respective power control unit of a network node. The method comprises the steps of, in response to a request to establish a communication path, step 201, controlling at least one power control unit to perform a first power-up mode of operation. The first power-up mode of operation comprises the step of setting a power control factor of a respective section of the communication path directly to a value estimated to provide a target power level, step 203.

Abstract: A monitoring and troubleshooting system to determine whether or not an antenna that is used for receiving wireless weak signals, like base station for cellular wireless communication, is operational. The antenna status condition is signaled over the Fiber Optic (FO) link without interfering the signal during normal operation. When a fault is detected the status at the FO receiver is determined. Then, an indication using special signaling allows a service technician to distinguish if the status fault is antenna failure or antenna disconnect. The present invention will also allow a service technician to determine if there is a FO link failure by use of light intensity monitoring.

Abstract: A monitoring apparatus and method for an optical signal-to-noise ratio and a receiver, where the apparatus includes: a processing unit configured to perform nonlinear processing on a pilot signal in received signals, or on a pilot signal in received signals and data signals in a predefined range neighboring the pilot signal; and a calculating unit configured to calculate an optical signal-to-noise ratio of the received signals according to a result of the nonlinear processing. Complexity of calculation may be lowered and accuracy of calculation of an optical signal-to-noise ratio may be improved, thereby efficiently improving the performance of the system.

Abstract: A protocol identifies and configures rings in a network topology automatically in order to simplify and quicken the actions that need to be performed in response to addition, deletion and shuffle of network nodes in that topology. Such rings do not need to be identified and configured manually. The protocol involves two separate sequentially performed phases. In the first phase, the protocol can automatically identify all rings that are present within a Virtual Local Area Network (VLAN) topology. In the second phase, the protocol can automatically configure each node of each such ring in conformity with the Ethernet Ring Protection (ERP) protocol. After this ERP configuration has been performed, the failure of a link within the network will not require every network node to re-learn paths through the network; instead, the nodes that are required to re-learn such paths can be limited to those within the particular ring that contained the failed link.

Abstract: Proposed is a method of equalizing an optical signal that has an overall bandwidth formed on a number of adjacent spectral slots, wherein the signal comprises a set of non-overlapping subcarrier signals. A distribution of the subcarrier signals onto the slots is such, that at least one slot is occupied by more than one subcarrier signal. The signal is received and amplified. Respective power levels are measured for the subcarrier signals. Distribution data is provided, which indicates the distribution of the subcarrier signals onto the spectral slots. Power level data is provided, which indicates for the spectral slots respective desired power levels. For the spectral slots respective attenuation values are derived, using the measured power levels, the distribution data and the power level data. Finally, the optical transmission signal is attenuated within the spectral slots individually, using the derived attenuation values.

Abstract: Techniques are described for providing managed virtual computer networks that have a configured logical network topology with virtual networking devices, such as by a network-accessible configurable network service, with corresponding networking functionality provided for communications between multiple computing nodes of the virtual computer network by emulating functionality that would be provided by the virtual networking devices if they were physically present.

Abstract: A network switch having one or more multi-endpoint (MEP) optical transceivers configured to provide an interface for optical data transport through the corresponding network. The use of MEP optical transceivers advantageously enables the network switch to be compatible with multiple network topologies. As a result, various embodiments of the disclosed network switch may be used to provide a builder and/or an operator of the corresponding network with a great deal of flexibility in choosing a network topology and/or degree of redundancy better suitable for the network's intended purpose and/or application without having to change some of the underlying hardware.

Abstract: Mechanisms are provided for tracing a route taken by a packet in a Software Defined Network (SDN). Each switch in the SDN is assigned a first color label, from a set of color labels, such that such that adjacent switches have different color labels. Rules are installed in each switch to forward a received data packet to the SDN controller in response to a second color label of the received data packet not matching the first color label assigned to the switch. A second color label, from the set of color labels, is assigned to a trace data packet. A route of the trace data packet is traced through the SDN based on the second color label and application of the one or more rules to the trace data packet at each of the switches in the SDN as the trace data packet is received by each of the switches in the SDN.

Abstract: The present applies to digital wavelength converters that convert, independently of the format in which optical data may be encoded, an input waveform at a first wavelength to an output waveform at a second wavelength. When operating in an environment where an input waveform has a pilot tone associated thereto, the method and system of the present disclosure allows for the removal of the pilot tone from the input waveform, and also allows for the addition of another pilot to the output waveform.

Abstract: Optimizing ripple reductions in equalizers shared between multiple interface ports in a distributed antenna system (DAS). In one aspect, a downlink equalizer is shared between a downlink simplex port and a duplex port in a radio interface module(s) (RIM(s)) in the DAS. In another aspect, to optimize ripple reduction in the downlink equalizer, the downlink equalizer is configured to go through a plurality of downlink equalizer states that each can generate a downlink equalizer frequency response affecting downlink ripple of the RIM(s). At each of the downlink equalizer states, a test signal is provided to the downlink equalizer and a corresponding downlink ripple of the RIM(s) is recorded. When all of the downlink equalizer states are evaluated based on the test signal, the downlink equalizer is configured to function based on the downlink equalizer state associated with the smallest downlink ripple of the RIM(s).

Abstract: A transmission apparatus includes: a first input-output unit; a second input-output unit; a third input-output unit located in a first direction that is a transmission direction from the first input output unit and the second input-output unit; and a switch coupled to the first input-output unit, the second input-output unit, and the third input-output unit, wherein the first input-output unit requests the third input-output unit via the switch to notify in a second direction opposite to the first direction of a defect upon detecting the defect, wherein the third input-output unit transmits defect information indicating the defect to one of the first input-output unit and the second input-output unit via the switch in response to a requesting from the first input-output unit.

Abstract: An optical cross-connect apparatus optical nodes in an optical network, the optical nodes being mutually connected through internode connection optical fibers, the optical cross-connect apparatus having: optical cross-connect portions having internode connection input ports and internode connection output ports respectively connected to the internode connection optical fibers, and internal connection input and output ports, the optical cross-connect portions being connected such that an internal connection output port of a predetermined optical cross-connect portion is directly connected to an internal connection input port of another optical cross-connect portion and is indirectly connected via the another optical cross-connect portion to an internal connection output port of a further optical cross-connect portion, at least one optical cross-connect portion of the optical cross-connect portions including an internal connection input port and an internal connection output port for connecting to an optical cr

Abstract: A method, in a node operating in a network with a control plane, to optimize wavelength retuning on service redials, includes detecting a failure on a link associated with the node; and, for each affected connections on the link, sending a respective release message to an associated originating node via the control plane, the release message including a protect path and a wavelength, wherein the release message is utilized by the associated originating node to redial the affected connections with the protect path and the wavelength determined by the node, to minimize wavelength retuning on the affected connections.

Abstract: Methods and systems for periodic optical filtering to identify tone modulated optical signals may enable relatively rapid scanning of an optical signal to identify individual optical channels. The optical signal having tone modulated optical channels may be scanned over a free spectral range of a periodic optical filter, such as a comb filter, to generate a filtered signal. Then, center optical frequencies for each of the optical channels in the filtered signal may be determined by demodulation and digital signal processing.

Abstract: The present invention provides a node apparatus, where two N×N wavelength selective switches are used to form a parallel-connected structure, and two ends of each power splitter are separately connected to input ends of the N×N wavelength selective switches, and two ends of each power combiner are separately connected to output ends of the N×N wavelength selective switches, thereby transferring route switching selection work originally performed between multiple 1×M wavelength selective switches to the inside of the N×N wavelength selective switch for implementation. Compared with an original structure using discrete components, the node apparatus is simplified, and when a traffic volume expands, the number of module slots on a line side does not need to be increased, thereby reducing usage costs eventually. The present invention is used for signal transmission in a node.

Abstract: Methods and systems for bias control in an optical switch fabric include monitoring optical power at outputs of a plurality of switch elements in an N×N switch fabric that has N inputs, N outputs, and M?2 stages. A bias control of a first of the plurality of switch elements is adjusted. It is determined whether the optical power at the outputs of the first switch element after bias control adjustment conform more closely to a predetermined criterion relative to the monitored optical power at the outputs of the first switch element prior to adjustment. The adjusting and determining steps are repeated for each of the remainder of the plurality of switch elements.

Abstract: The present applies to digital wavelength converters that convert, independently of the format in which optical data may be encoded, an input waveform at a first wavelength to an output waveform at a second wavelength. When operating in an environment where an input waveform has a pilot tone associated thereto, the method and system of the present disclosure allows for the removal of the pilot tone from the input waveform, and also allows for the addition of another pilot to the output waveform.

Abstract: Method and arrangement for protecting optical network systems, the arrangement (20) is based on an optical electrical optical GPON repeater structure. The repeater structure contains two optical modules—a regular ONU transceiver module and a reset-less OLT transceiver module which are working back-to-back. For management purposes, an ONU MAC module comprised in the repeater structure is intercepting the electrical signals from the ONU transceiver. The arrangement comprising the two repeater structures can be used to relay data between two passive optical network (PON) systems thereby opening a way to implement dual homing via the PON domain. Moreover, the arrangement is configured to enabling switch-over of functionality from one PON to the other PON at a communication failure in the former PON.

Abstract: An exemplary method and apparatus are provided for high efficiency wavelength division multiplexing (WDM) optical communication systems. An optical transmitter adapted to transmit an optical signal on an optical WDM transmission channel to a corresponding optical receiver is described. The optical transmitter comprises a symbol generation unit adapted to convert input data into a sequence of data symbols at a symbol rate B; with B being a real number greater zero; an amplitude modulation unit adapted to modulate an amplitude of every Nth data symbol in a sequence derived from the sequence of data symbols, thereby creating a modulated sequence of data symbols; wherein N is an integer; wherein N>2; and a digital-to-optical converter adapted to convert a sequence derived from the modulated sequence of data symbols into an optical signal to be transmitted to the optical receiver.

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: A method (10) of selecting an optical signal power for an optical signal carrying traffic encoded on the optical signal in a modulation format. The optical signal is for transmission across an optical path in an optical communications system. The method (10) comprises: a. providing a probe optical signal at a probe signal power (12). The probe optical signal carries test traffic encoded on the probe optical signal in said modulation format (14). b. transmitting the probe optical signal across the optical path (16); and c. receiving the probe optical signal at an end of the optical path (18) and measuring an indicator of the quality of the received probe optical signal (20). The method comprises implementing steps a. to c. for each of a plurality of different probe signal powers (22, 26).

Abstract: A method of configuring an optical path, comprising: selecting a path from a first to a second node in an optical communications network; identifying each wavelength that may be used continuously across the path and selecting a transmission wavelength for the optical path one of the identified wavelengths for which: a fixed wavelength direction-bound add/drop transponder add operable at said wavelength is available at each node; if that first requirement is not met, a fixed wavelength direction-bound add/drop transponder or a fixed wavelength directionless add/drop transponder operable at said wavelength is available at each node; and if that second requirement is not met, a tunable wavelength direction-bound add/drop transponder or a tunable wavelength directionless add/drop transponder operable at said wavelength is available at each node.

Abstract: Apparatus for enabling recovery from failures in up to M working paths of a set of N working paths that are allocated N frequency slots of L different slot widths, where M, N and L are positive integers, N?L>1, and N>M>1. The apparatus includes a processor and a control plane interface. The processor is operative to allocate protection frequency slots to M protection paths in different manners depending on whether M is greater than L, equal to L or less than L. The control plane interface is operatively associated with the processor and is operative to effect provisioning of the M protection paths for supporting recovery from the failures. Related network, apparatus and methods are also disclosed.

Abstract: An electrical circuit and method includes a transmitter in a first power domain with a first supply voltage referenced to a first voltage reference. The transmitter has an oscillator generating a first carrier signal, and an analog modulator receiving an input sensor signal and the first carrier signal and generating a modulated carrier signal. A receiver is in a second power domain with a second supply voltage referenced to a second voltage reference. The second voltage reference is different from the first voltage reference. The receiver includes a demodulator that receives and demodulates the modulated carrier signal and generates an output sensor signal. At least one coupler includes a pair of galvanically isolated elements with one galvanically isolated element in each of the first and second power domains. The modulated carrier signal couples from the first power domain to the second power domain through the at least one coupler.

Abstract: A highly reliable optical switching device and optical switching method ensure restoration of the failure in the large-capacity high density wiring of the multicore fiber with the general number of cores (7 cores, 19 cores and the like). An optical transmission system which transmits a supervisory control signal concerning a transmission path switching to one or more cores of a single or multiple multicore fibers, an active signal to one or more cores, and a standby signal to one or more cores includes optical switching devices connected to respective ends of the optical transmission system. Upon detection of the transmission failure of the active signal based on the signal transmission condition and information from the supervisory control signal, it is switched to the standby signal. The supervisory control signal is transmitted to the center core of the multicore fiber.

Abstract: There is provided a method for resizing a network connection in an optical transport network that supports protection switching and receives a flexible Optical channel Data (ODUflex(GFP)) signal. In addition, Hitless Adjustment of ODUflex(GFP) (HAO) procedure includes Suppress Bandwidth Resize (SBR) information that prevents a Bandwidth Resize (BWR) protocol from being initiated. Based on the SBR information, only the LCR protocol is executed at nodes located on a protection path for protection switching, except for the BWR protocol. On the other hand, both the LCR protocol and the BWR protocol are executed at nodes located on a working path.

Abstract: There is provided a method for resizing a network connection in an optical transport network that supports protection switching and receives a flexible Optical channel Data Unit (ODUflex(GFP)) signal. In addition, at nodes located on a protection path for protection switching, only a Link Connection Resize (LCR) protocol, except for a Bandwidth Resize (BWR) protocol, of Hitless Adjustment of ODUflex(GFP) (HAO) procedure is executed. On the other hand, both the LCR protocol and the BWR protocol are executed at nodes located on a working path for protection switching.

Abstract: A reconfigurable electrical add/drop multiplexing node, a network, and optoelectronic integrated circuit form a novel high capacity fiber-optic integrated transmission and switching system with a baseline target capacity in excess of 1 Tbps. The node, network, and circuit can leverage optoelectronic integration of transmission and switching components along with using the full “transparency” window of modern optical fibers from about 1270 nm to about 1670 nm for a large number of relatively low-rate wavelengths. The electrical switching fabric can be part of a Reconfigurable Electrical Add/Drop Multiplexer (READM) with similar functionality as a Reconfigurable Optical Add/Drop Multiplexer (ROADM) except in a highly integrated fashion with the transmission components. The electrical switching fabric can implement flow switching on a composite signal to provide comparable functionality to optical components in electrical circuitry such as in Complementary metal-oxide-semiconductors.

Abstract: The invention provides for a method for using a computer network (10) comprising a number of switches (18, 20) each having ports for receiving and sending streams, wherein the streams are sent from a router (14) via the ports of switches (18, 20), that have shown interest, to at least one receiver (24, 26), whereby in case of a link failure at least one of the at least one receiver (24, 26) sends back a message to the router.

Abstract: Apparatus for enabling recovery from failures in up to M working paths of a set of N working paths that are allocated N frequency slots of L different slot widths, where M, N and L are positive integers, N?L>1, and N>M>1. The apparatus includes a processor and a control plane interface. The processor is operative to allocate protection frequency slots to M protection paths in different manners depending on whether M is greater than L, equal to L or less than L. The control plane interface is operatively associated with the processor and is operative to effect provisioning of the M protection paths for supporting recovery from the failures. Related network, apparatus and methods are also disclosed.

Abstract: A method and system of determining a new path through an optical network from a source node to a destination node when a link in an original path fails are disclosed. When a fault on a link is detected, adjoint weights are assigned to each operational link for each node on the original path. A connection cost is determined for each node based on the adjoint weights of the links connected to the node. A new path through the optical network is determined based at least in part on the adjoint weights and the connection costs.

Abstract: A data transmission system using an optical fiber includes an optical fiber, a first light-emitting device, a second light-emitting device, a first photo-detecting device and a second photo-detecting device. Each of the first light-emitting device and the second light-emitting device is optically coupled to the input facet of the optical fiber, respectively. Each of the first photo-detecting device and the second photo-detecting device is optically coupled to the output facet of the optical fiber, respectively. In particular, the first light-emitting device and the second light-emitting device are packaged into a first optical subassembly, and the first photo-detecting device and the second photo-detecting device are packaged into a second optical subassembly.

Abstract: The invention provides a method of simulcasting data fragments sent over a first packet-switched computer network to a trunk network and redistributed over a second packet-switched computer network. A method is provided comprising the steps of providing a trunk network including multiple links including an RF link and a fiber link, wherein all the transmission links transmit data packets to a receiver which will redistribute the earliest data packets with a matching frame check sequence (FCS) over the second packet switched computer network. The method provides for a sender for adding an incremental sender sequence number and sender FCS to the data packets, creating a sender data packet.

Abstract: A multi-channel optoelectronic device is configured to establish a redundant status link with a remote device. The optoelectronic device can transmit N transmit optical signals to the remote device over a plurality of transmit channels and receive N receive optical signals from the remote device over a plurality of receive channels. The optoelectronic device includes one or more spare transmit and receive channels. When used with a remote device having spare transmit and receive channels, each device can establish a status link with the other and use the status link to switch out transmit and/or receive channels to identify and permanently switch out the worst transmit and/or receive channels. Alternately, the device can interoperate with a non-status-link enabled remote device by determining that the remote device is not status-link enabled, transitioning to a low transmit power mode, and transmitting and receiving over a plurality of default transmit and receive channels.

Abstract: A procedure for transferring wavelengths, and a system that operates in accordance with the procedure. The system comprises at least one network terminal, each including a switch and a controller. A plurality of wavelength sets are applied to the switch. The controller is arranged to operate the switch such that the switch (a) selects at least one wavelength from at least one of the plurality of wavelength sets, based on electrical monitoring at a port module external to the network terminal, and (b) outputs the at least one wavelength to an output of the at least one network terminal.

Abstract: A light source package is disclosed for a Raman amplifier node having a primary optical fiber for carrying an optical signal and a secondary optical fiber for carrying the optical signal when the signal is rerouted from the primary optical fiber. The light source package includes a primary light source for emitting light into the primary optical fiber when the optical signal is carried by the primary optical fiber to induce Raman gain of the optical signal, and a secondary light source for emitting light into the secondary optical fiber when the optical signal is carried by the secondary optical fiber to induce Raman gain of the optical signal.

Abstract: A cross connecting unit outputs an including frame whose type matches a type of an including frame stored in a storage unit in association with identification information of a multiplexing unit having a problem among including frames generated by an including unit to a backup multiplexing unit when any one of multiplexing units has a problem.