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 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: 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: A source node 11 obtains from a destination node 12 quality information on routes 31 and 32 to the node 12, and adaptively changes data distribution ratios for the multiple routes based on the quality information.

Abstract: In a trunk transmission network for transmitting information signals between nodes via paths, flexible path operation is achieved by setting up paths between source nodes and destination nodes after pre-classifying paths into a higher service class in which any loss of information occurring in that path is made good restored; and a lower service class which permits loss of information to occur in the path. The flexible operation is further achieved by arranging for each node, when it acts as a source node, to recognize the service class of the information signal it is sending to a destination node, and to select a path corresponding to that service class.

Abstract: A source node 11 obtains from a destination node 12 quality information on routes 31 and 32 to the node 12, and adaptively changes data distribution ratios for the multiple routes based on the quality information.

Abstract: In a trunk transmission network for transmitting information signals between nodes via paths, flexible path operation is achieved by setting up paths between source nodes and destination nodes after pre-classifying paths into a higher service class in which any loss of information occurring in that path is made good, and a lower service class which permits loss of information to occur in the path, and by arranging for each node, when it acts as a source node, to recognize the service class of the information signal it is sending to a destination node, and to select a path corresponding to that service class.

Abstract: In a trunk transmission network for transmitting information signals between nodes via paths, flexible path operation is achieved by setting up paths between source nodes and destination nodes after pre-classifying paths into a higher service class in which any loss of information occurring in that path is restored, and a lower service class which permits loss of information to occur in the path. The flexible operation is further achieved by arranging for each node, when it acts as a source node, to recognize the service class of the information signal it is sending to a destination node, and to select a path corresponding to that service class.

Abstract: The invention has the object of offering a channel-selection-type demultiplexing circuit which is capable of interchanging the time slots of demultiplexed signals when demultiplexing ultra-high-speed multi-channel multiplexed signal stream without expanding the scale of the circuits, and does not require the scale of the circuits to be expanded even if the speed of the transmission path increases. The invention is a channel-selection-type demultiplexing circuit capable of demultiplexing signals to a desired output port during bit demultiplexing, instead of simply demultiplexing the bits as in conventional devices, which performs bit demultiplexing based on a frequency division clock after selecting the bit signals to be demultiplexed to the desired output port from the N-channel multiplexed signal stream based on channel selection information.

Abstract: A pointer processor for use in an SDH/SONET transmission system, realizing a proper VC path management. A pointer interpreter constantly monitors 3X pairs of H1 and H2 bytes to contain a prescribed maximum size pointer AU-4-Xc that can possibly be received by the pointer processor, to obtain and hold an inside AU-size map indicating an occupation state of AU pointers on 3X pairs of H1 and H2 bytes, while generating and holding an assigned AU-size map indicating an assigned state of AU pointers on 3X pairs of H1 and H2 bytes according to an externally set AU pointer size, and compares these two AU-size maps.

Abstract: A hitless path switching method without a bit loss. The same digital line signals on a working path and a protection path are continuously monitored independently for bit errors. If a bit error occurs in the working path and no bit error occurs in the protection path, a switching trigger is produced and a switching operation from the working path to the protection path is performed on a data block basis. Only correct data are transferred to downstream apparatuses. Reliable hitless switching is achieved not only in response to a failure in a path, but also in response to a bit error. Using data blocks of one frame length with an indicator for bit error checking placed at its beginning or top makes effective switching possible.