Accommodation design for wavelength and sub- paths in a communication network is performed. If sub- path accommodation is possible according to search for a wavelength path present in a single-hop logical route, the accommodation in the wavelength path is executed. If sub- path accommodation is possible according to search for a wavelength path present in a multi-hop logical route, a logical route is selected based on the wavelength path and the sub- path is accommodated in the wavelength path. Additionally, each physical route suitable for the sub- path accommodation is searched for. If the route can accommodate a wavelength path set in a single-hop logical route by available wavelength allocation, the sub- path is accommodated in the wavelength path. Furthermore, routes in consideration of overlapping of nodes, pipelines, and links and operation rate are selected based on information about the start and end nodes of each of redundant routes.

In the elastic optical network, there has been the problem that processing steps increase that are required to re-optimize client signals to be concentrated; therefore, an optical network controller according to an exemplary aspect of the present invention includes reallocation detection means for monitoring an operation status of at least one of an optical communication channel and an optical node device that constitute an optical network, and determining, based on the operation status, whether or not to reallocate a client signal accommodated in an optical path set in the optical network; design-candidate exclusion means for designating, as a design exclusion object, at least one of the optical communication channel and the optical node device that are associated with an optical path targeted for reallocation that accommodates the client signal that the reallocation detection means has determined to reallocate; optical path design means for determining an alternative route for the optical path targeted for reallocation from among routes with the exception of the design exclusion object; traffic reference means for determining the client signal to be reaccommodated in an optical path on the alternative route, referring to demand traffic accommodated in the optical path targeted for reallocation; and line concentration design means for constituting line-concentration traffic in which traffic having been allocated to the alternative route and the demand traffic are concentrated, wherein the traffic reference means determines a reallocation optical path in which an optical path candidate with number of occupied wavelength slots increasing is excluded from optical path candidates on the alternative route, and the optical path design means determines wavelength allocation of the reallocation optical path so as to accommodate the line-concentration traffic.

This disclosure describes devices and methods related to multiplexing optical data signals. A method may be disclosed for multiplexing one or more optical data signals. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to one or more wave division multiplexer (WDM). The method may comprise combining, by the one or more WDM, the combined one or more optical data signals and one or more second optical data signals, and outputting an egress optical data signal comprising the combined one or more optical data signals and one or more second optical data signals.

Devices and methods for bypassing a defective component in a combining network relaying respective upstream and downstream signals between a head end and a plurality of subscribers. The devices and methods may preferably redirect the upstream signal without redirecting the downstream signal using a wavelength-dependent filter.

A communication system of a passive optical communication network includes an optical line terminal (OLT) system including a first OLT, a second OLT, and an OLT control device that controls the first OLT and the second OLT, a plurality of splitters that connect the first OLT and the second OLT with an optical communication path, and an ONU that is connected to each of the splitters with an optical communication path. The splitter distributes and outputs an optical signal transmitted from the OLT system to the ONU connected to the splitter and a succeeding device that is another splitter or the OLT system, and the OLT control device determines a distribution ratio at the splitter, the distribution ratio indicating a ratio between the intensity of the optical signal distributed to the succeeding device and the intensity of the optical signal distributed to the ONU.

An optical transmission apparatus of an embodiment is an apparatus for redundantly transmitting a multiplexed signal obtained by multiplexing N (N is an integer of 2 or greater) optical signals having different wavelengths, the apparatus including: a first demultiplexing unit to which a first multiplexed signal is input, the first demultiplexing unit configured to demultiplex the input first multiplexed signal into the N optical signals; N first detection units to which the N optical signals demultiplexed by the first demultiplexing unit are respectively input, each of the N first detection units configured to detect presence or absence of deterioration of a corresponding input optical signals of the input optical signals based on a signal level of the corresponding input optical signal; a second demultiplexing unit to which a second multiplexed signal is input, the second demultiplexing unit configured to demultiplex the input second multiplexed signal into the N optical signals; N second detection units to which the N optical signals demultiplexed by the second demultiplexing unit are respectively input, each of the N second detection units configured to detect presence or absence of deterioration of a corresponding input optical signal of the input optical signals based on a signal level of the corresponding input optical signal; and a selection unit configured to select, based on the detection result of presence or absence of deterioration of each of the optical signals by the first detection units and the second detection units, N optical signals having different wavelengths from either the optical signals demultiplexed by the first demultiplexing unit or the optical signals demultiplexed by the second demultiplexing unit.

A transmission apparatus includes a first communication unit, a second communication unit, a detection unit, a control unit, and a selection unit. The first communication unit uses a first path for communication, when electric power is supplied. The second communication unit uses a second path for communication, when electric power is supplied. The detection unit detects a fault predictive sign. The control unit supplies no electric power to the second communication unit when the detection unit does not detect the fault predictive sign. The control unit starts supplying electric power to the second communication unit and performs normality confirmation of the second path when the detection unit detects the fault predictive sign, before switching from the first path to the second path. The selection unit selects and outputs, when the first communication unit and the second communication unit have received signals, either the signal received by the first communication unit or the signal received by the second communication unit.

An example system includes a first network device having first circuitry. The first network device is configured to perform operations including receiving data to be transmitted to a second network device over an optical communications network, and transmitting first information and second information to the second device. The first information is indicative of the data, and is transmitted using a first communications link of the optical communications network and using a first subset of optical subcarriers. The second information is indicative of the data, and is transmitted using a second communications link of the optical communications network and using a second subset of optical subcarriers. The first subset of optical subcarriers is different from the second subset of optical subcarriers.

An optical interface includes circuitry configured to operate the optical interface at a first rate, subsequent to a requirement to subrate the optical interface to a second rate, determine which services are affected, signal a partial failure for the one or more affected services, and operate the optical interface at a second rate that is less than the first rate. The optical interface can be a Flexible Optical (FlexO) or ZR interface.

An apparatus includes a first reconfigurable optical add/drop multiplexer (ROADM) to receive a first optical signal and a second ROADM to receive a second optical signal. The apparatus also includes a reconfigurable optical switch that includes a first switch, switchable between a first state and a second state, to transmit the first optical signal at the first state and block the first optical signal at the second state. The reconfigurable optical switch also includes a second switch, switchable between the first state and the second state, to transmit the second optical signal at the first state and block the second optical signal at the second state. The reconfigurable optical switch also includes an output port to transmit an output signal that is a sum of possible optical signals transmitted through the first switch and the second switch.