Abstract: A monitoring control unit (22) of an OXC (20d) stores a management table (22a) in which pieces of information regarding a modulation mode, an FEC, and a frame mode of an optical signal are associated with each other, and sequentially changes the modulation mode, the FEC, and the frame mode according to the management table (22a) upon an LOS alert from a relay-side optical input/output unit (24) or an LOF alert from a DSP (25) being input thereto. Upon successfully receiving an appropriate optical signal according to the change, the monitoring control unit (22) acquires transmission source information included in the optical signal, and detects an occurrence of erroneous connection of an optical transmission line in an OXC (20g), which serves as a relay apparatus, when the acquired transmission source information indicates an optical cross-connect apparatus that is a transmission source different from an original transmission source.

Abstract: A transmission side transmission device (40) includes a first transmitter (20) including a first switch (21) and a second transmitter (30) including a second switch (31). When the first transmitter (20) detects a fault in the first main signal, the second transmitter (30) outputs a duplicated signal of the second main signal to the first transmitter (20). The first selector (22) of the first transmitter (20) selects and outputs a duplicated signal of the input second main signal. When the second transmitter (30) detects a fault in the first switch (21), the second transmitter (30) selects and outputs the second main signal.

Abstract: A transmission device (10) includes a flow table (11) that stores identification information about an uninterruptible target flow; a transmission-side identification unit (12) that identifies whether a received packet is from the target flow or a non-target flow based on whether the received packet matches the identification information about the target flow stored in the flow table (11); a tag application unit (13) that applies, to packets from the target flow, an uninterruptible identifier indicating that the packets are from the target flow and a sequence number for distinguishing the packets from other packets; and a branch unit (14) that branches the packets from the target flow processed by the tag application unit (13) into packets to be transferred to an active path (41) among redundant routes and packets to be transferred to a backup path (42) among the redundant routes.

Abstract: [Problem] whether optical input interruption detected by an OXC device is due to an external failure from an upstream side or an internal failure of the OXC device in a transponder device connected to the OXC device using an optical transmission line, and this determination is implemented at low cost. [Solution] An optical transmission system (10A) is configured by connecting a plurality of OXC devices (14A) using optical fibers (16) between transponder devices (15A1) that relay optical signals transmitted to/from terminals (19a, 19b). The OXC device (14A) includes an OSC part (4d1) and a monitoring control part (4e1). The OSC part (4d1) outputs wavelength information on an optical signal in which optical input interruption has occurred and path information on a path of an optical fiber (16) in which the optical input interruption has occurred, at the time of detecting the optical input interruption from the optical fiber (16).

Abstract: A communication system includes counter devices forming a pair and a plurality of switch devices, which are network relay devices connecting the counter devices. A traffic bypass unit of each of the switch devices transmits a part of traffic of a multi-chassis link-aggregation group to the other switch device via a bridge port when a traffic amount per effective communication port in the own device is larger than a traffic amount per effective communication port in the other switch device by a threshold or more in the multi-chassis link-aggregation group.

Abstract: [Problem] To deal with interference in cases where a plurality of business operators perform testing at the same time at different MEG levels. [Solution] A network device 2 includes a frame distinguishing unit 22a that, upon receiving a start instruction for a test from a control device 3, monitors whether or not an OAM frame of a preceding test of a different level from a MEG level of an own device has arrived at the own device, for a predetermined period, and a CPU 24 that, if the frame distinguishing unit 22a detects arrival of the OAM frame, and determination is made that its own test will affect the preceding test, notifies the result of the detection and determination.

Abstract: A part information management device (10) includes: a part setting information acquirement unit (111) that acquires, as part setting information, information for identifying parts set in apparatuses; a market data acquirement unit (112) that acquires, for each of the parts, market data related to a part change of the part; a risk estimation unit (114) that estimates a risk of a silent change by a predetermined estimation algorithm with use of the market data, the risk of the silent change indicating that the part is changed; and a part information generation unit (113) that generates part information with the part setting information acquired for each of the parts and the estimated risk of the silent change corresponding to each other and stores the part information in a storage unit (13).

Abstract: A transmission device (10) includes a flow table (11) that stores identification information about an uninterruptible target flow; a transmission-side identification unit (12) that identifies whether a received packet is from the target flow or a non-target flow based on whether the received packet matches the identification information about the target flow stored in the flow table (11); a tag application unit (13) that applies, to packets from the target flow, an uninterruptible identifier indicating that the packets are from the target flow and a sequence number for distinguishing the packets from other packets; and a branch unit (14) that branches the packets from the target flow processed by the tag application unit (13) into packets to be transferred to an active path (41) among redundant routes and packets to be transferred to a backup path (42) among the redundant routes.

Abstract: A monitoring control unit (22) of an OXC (20d) stores a management table (22a) in which pieces of information regarding a modulation mode, an FEC, and a frame mode of an optical signal are associated with each other, and sequentially changes the modulation mode, the FEC, and the frame mode according to the management table (22a) upon an LOS alert from a relay-side optical input/output unit (24) or an LOF alert from a DSP (25) being input thereto. Upon successfully receiving an appropriate optical signal according to the change, the monitoring control unit (22) acquires transmission source information included in the optical signal, and detects an occurrence of erroneous connection of an optical transmission line in an OXC (20g), which serves as a relay apparatus, when the acquired transmission source information indicates an optical cross-connect apparatus that is a transmission source different from an original transmission source.

Abstract: When separate service apparatuses that provide various communication services to users are connected by a wiring with communication functional units interposed, if there is a wiring abnormality, the location of the abnormality is easily identified. When a wiring connection is completed between separated service apparatuses X and Y that provide various communication services to user terminals 31 and 32 with communication functional units A1 and B2 interposed, a wiring management system 10A includes a transmission network management apparatus 14A that identifies a wiring abnormality. The transmission network management apparatus 14A associates endpoint names of the service apparatuses X and Y and of the functional units A1 and B2 with opposite endpoint names on the opposite sides, defines opposite endpoint IDs of the endpoints of the functional units A1 and B2 as expected values, and saves the end points in association with the opposite endpoint IDs in a DB 14b.

Abstract: [PROBLEM TO BE SOLVED] To uninterruptedly change a band of an optical transmission path in a line IF section, which relays a signal transmitted to an optical transmission path in a client IF section to which a communication terminal is connected, to the same band as a changed band in the client IF section without suspending the communication in the line IF section. [SOLUTION] An optical transmission system 10A performs processing for changing a band of an optical fiber 15 in a line IF section (L section) that relays a signal from an optical fiber 12 in a client IF section (C section) to the same band as that in the C section.

Abstract: [Problem] It is possible to cancel out beat noises in a WDM signal to obtain a high-quality signal component, and a configuration thereof is achieved with low mounting costs. [Solution] An optical reception device converts a WDM signal rs(t) of an optical signal to electrical signals d(t)1 to d(t)n expressed as complex numbers of orthogonal phases, cancels out beat noises from the electrical signals, and then demodulates the signals to obtain signals D1 to Dn of a transmission source.

Abstract: [Problem] whether optical input interruption detected by an OXC device is due to an external failure from an upstream side or an internal failure of the OXC device in a transponder device connected to the OXC device using an optical transmission line, and this determination is implemented at low cost. [Solution] An optical transmission system (10A) is configured by connecting a plurality of OXC devices (14A) using optical fibers (16) between transponder devices (15A1) that relay optical signals transmitted to/from terminals (19a, 19b). The OXC device (14A) includes an OSC part (4d1) and a monitoring control part (4e1). The OSC part (4d1) outputs wavelength information on an optical signal in which optical input interruption has occurred and path information on a path of an optical fiber (16) in which the optical input interruption has occurred, at the time of detecting the optical input interruption from the optical fiber (16).

Abstract: [PROBLEM TO BE SOLVED] To uninterruptedly change a band of an optical transmission path in a line IF section, which relays a signal transmitted to an optical transmission path in a client IF section to which a communication terminal is connected, to the same band as a changed band in the client IF section without suspending the communication in the line IF section. [SOLUTION] An optical transmission system 10A performs processing for changing a band of an optical fiber 15 in a line IF section (L section) that relays a signal from an optical fiber 12 in a client IF section (C section) to the same band as that in the C section.

Abstract: [Problem] It is possible to cancel out beat noises in a WDM signal to obtain a high-quality signal component, and a configuration thereof is achieved with low mounting costs. [Solution] An optical reception device converts a WDM signal rs(t) of an optical signal to electrical signals d(t)1 to d(t)n expressed as complex numbers of orthogonal phases, cancels out beat noises from the electrical signals, and then demodulates the signals to obtain signals D1 to Dn of a transmission source.

Abstract: [Problem] To improve the add/drop rates while suppressing the apparatus scale of the ROADM.

Abstract: [Problem] To deal with interference in cases where a plurality of business operators perform testing at the same time at different MEG levels. [Solution] A network device 2 includes a frame distinguishing unit 22a that, upon receiving a start instruction for a test from a control device 3, monitors whether or not an OAM frame of a preceding test of a different level from a MEG level of an own device has arrived at the own device, for a predetermined period, and a CPU 24 that, if the frame distinguishing unit 22a detects arrival of the OAM frame, and determination is made that its own test will affect the preceding test, notifies the result of the detection and determination.

Abstract: When separate service apparatuses that provide various communication services to users are connected by a wiring with communication functional units interposed, if there is a wiring abnormality, the location of the abnormality is easily identified. When a wiring connection is completed between separated service apparatuses X and Y that provide various communication services to user terminals 31 and 32 with communication functional units A1 and B2 interposed, a wiring management system 10A includes a transmission network management apparatus 14A that identifies a wiring abnormality. The transmission network management apparatus 14A associates endpoint names of the service apparatuses X and Y and of the functional units A1 and B2 with opposite endpoint names on the opposite sides, defines opposite endpoint IDs of the endpoints of the functional units A1 and B2 as expected values, and saves the end points in association with the opposite endpoint IDs in a DB 14b.

Abstract: Multi-wavelength light having a frequency band equal to or greater than the FSR of an AWG is demultiplexed into individual wavelength channels, and power level deviations between wavelength channels are suppressed. An optical demultiplexer includes a wavelength-group demultiplexer that demultiplexes multi-wavelength light into wavelength groups formed from wavelength channels, and channel demultiplexers that demultiplex each wavelength group into wavelength channels light. An optical multiplexer includes channel multiplexers that multiplex modulated signal light of each wavelength channel for each wavelength group, and a wavelength-group multiplexer that multiplexes, for each wavelength group, WDM signal light output from the channel multiplexers. The FSR of the wavelength-group multiplexer/demultiplexer is set to be equal to or greater than the frequency band of the multi-wavelength light.

Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.