Abstract: According to one embodiment, there is provided a communications system that conducts multiplex communications of main signals and at least one sub-signal via redundant routes between a transmission apparatus and a reception apparatus. The transmission apparatus includes a main signal duplication unit configured to duplicate each of the main signals to be communicated via a main signal channel, according to the number of the redundant routes, and a delay unit configured to adjust sending timings of copies of the main signal on the respective redundant routes based on the at least one sub-signal to be communicated via a sub-signal channel and transmit the copies of the main signal to the respective redundant routes.

Abstract: According to one aspect of the disclosure, in a communication apparatus at a transmission end, a packet train that is input is grouped to generate a duplicate packet for each packet group. For each packet group, encoded packets are generated using some packets in a group of duplication source packets and other packets in a group of duplicate packets that do not correspond to the some packets in the group of duplication source packets, and above-described other packets in the duplication source, some packets in the group of duplicate packets that are not used to generate the encoded packets, and the above-described encoded packets are transmitted.

Abstract: A communication apparatus according to an aspect of the present invention is a communication apparatus that is able to be connected to a different communication apparatus via a network including three or more paths, the communication apparatus including a processing circuitry configured to measure a network state for each of the three or more paths, calculate an evaluation value based on a result of measuring the network state for each of the three or more paths, select at least two paths to be used for communication from among the three or more paths based on the calculated evaluation value, generate a packet for transmission through duplication of an input packet, and transmit the generated packet to the different communication apparatus through the selected paths.

Abstract: An object of the present invention is to provide a communication system and a communication method that can suppress an increase in the total fiber distance even if the number of secondary devices increases and that can make complex processing for band allocation for uplink optical signals unnecessary. The configuration of the communication system according to the present invention is a mixture of a ring type and a branch type, in which an optical fiber cable (primary path) from a communication station to each user's home is arranged in a ring (loop) shape, and the primary path is branched and laid to the user's home. Furthermore, unidirectional communication is enabled by a ring-type primary path, and the transmittable amount can be made uniform by further combining time division multiplexing.

Abstract: A network design apparatus, a network design method, and a network design processing program design a network configuration for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs, and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of the network configuration, the optimal path candidates of each of the lines minimizing a total cost value in the overall network is calculated. In the calculation of the optimal path candidates of each of the lines, only a path candidate of each of the lines can be selected, and a combination candidate of link portion apparatuses for each of the links is derived uniquely from the selected path candidate of each of the lines.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, a threshold value of an inter-end delay and the number of redundant paths are calculated for each line on the basis of topology information, line information, and design parameter information. A path candidate set is calculated for each line on the basis of the threshold value of the inter-end delay and the number of redundant paths.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, an optimal combination candidate of a link portion apparatus for each link for minimizing a total cost value in an overall network is calculated on the basis of a combination candidate set of link portion apparatuses. The combination candidate set of the link portion apparatuses is configured using only combination candidates with a cost-effectiveness indicating a ratio of a total capacity to a total cost value of the link portion apparatus higher than a predetermined reference.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, a threshold value of an inter-end delay and the number of redundant paths are calculated for each line on the basis of topology information, line information, and design parameter information. A path candidate set is calculated for each line on the basis of the threshold value of the inter-end delay and the number of redundant paths.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, an optimal combination candidate of a link portion apparatus for each link for minimizing a total cost value in an overall network is calculated on the basis of a combination candidate set of link portion apparatuses. The combination candidate set of the link portion apparatuses is configured using only combination candidates with a cost-effectiveness indicating a ratio of a total capacity to a total cost value of the link portion apparatus higher than a predetermined reference.

Abstract: A network design apparatus, a network design method, and a network design processing program design a network configuration for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs, and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of the network configuration, the optimal path candidates of each of the lines minimizing a total cost value in the overall network is calculated. In the calculation of the optimal path candidates of each of the lines, only a path candidate of each of the lines can be selected, and a combination candidate of link portion apparatuses for each of the links is derived uniquely from the selected path candidate of each of the lines.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed for each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, a maximum total capacity of a link portion apparatus is calculated, and a combination candidate set of the link portion apparatus including only combination candidates of which a total capacity is equal to or smaller than the maximum total capacity is calculated.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed for each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, an optimal path candidate of each of the lines, an optimal link portion apparatus combination candidate of each link, and an optimal transfer apparatus combination candidate at each of the communication hubs minimizing a total cost value in an overall network are calculated on the basis of a path candidate set, an interface combination candidate set, and a combination candidate set of a transfer apparatus.

Abstract: In order to prevent stator windings and power amplification semiconductor devices from being damaged by heat when a rotor is locked, a current feed term setting circuit that maintains an output signal circuit of a logical circuit in “OFF” state to completely cut off currents to the stator windings, when the number of repetitions of “ON” and “OFF” states of the output signal circuit reaches a predetermined value, is added to a driving IC of a control circuit for a brushless DC motor equipped with a protective circuit.

Abstract: In order to prevent stator windings and power amplification semiconductor devices from being damaged by heat when a rotor is locked, a current feed term setting circuit that maintains an output signal circuit of a logical circuit in “OFF” state to completely cut off currents to the stator windings, when the number of repetitions of “ON” and “OFF” states of the output signal circuit reaches a predetermined value, is added to a driving IC of a control circuit for a brushless DC motor equipped with a protective circuit.