Abstract: A transmitter used in a transmission system in which a first network is connected, via a second network, to a third network, the transmitter being arranged between the first network and the second network, the transmitter includes: a generator configured to specify an identifier of data area in which communication data affected by a failure occurred in the first network are stored, in a frame transmitted from the second network, and to generate failure information associated with the identifier specified; and a transmitter configured to transmit the failure information generated by the generator, via the second network, to another transmitter arranged between the second network and the third network.

Abstract: An information processing apparatus that includes a housing provided with a dust filter, the information processing apparatus includes a first temperature sensor that measures an internal temperature of the housing; a second temperature sensor that measures an external temperature of the housing; and a processor configured to acquire an amount of information processing of the information processing apparatus, identify a first amount of temperature change resulting from information processing of the information processing apparatus based on the amount of information processing, acquire the internal and external temperatures, calculate a second amount of temperature change resulting from an air intake fault of the dust filter by subtracting the first amount of temperature change from a temperature difference between the internal temperature and the external temperature, calculate a rate of increase in the second amount of temperature change, and output a fault notification according to the calculated rate of in

Abstract: A transmission method includes notifying, by a first transmission device, a number of packets transmitted from the first transmission device to the second transmission device via the first communication line, of the second transmission device; storing the number of the transmitted packets; notifying, by a second transmission device, a number of packets received from the first transmission device via the first communication line, of the first transmission device; storing the number of the received packets; and when an operation system is switched from the first communication line to the second communication line, initiating, by the first transmission device, counting of a number of packets transmitted from the first transmission device to the second transmission device using the number of transmitted packets; and initiating, by the second transmission device, counting of a number of packets received from the first transmission device using the number of received packets.

Abstract: A transmitter used in a transmission system in which a first network is connected, via a second network, to a third network, the transmitter being arranged between the first network and the second network, the transmitter includes: a generator configured to specify an identifier of data area in which communication data affected by a failure occurred in the first network are stored, in a frame transmitted from the second network, and to generate failure information associated with the identifier specified; and a transmitter configured to transmit the failure information generated by the generator, via the second network, to another transmitter arranged between the second network and the third network.

Abstract: A transmission device includes a receiver which receives a wavelength multiplex optical signal having a plurality of optical signals different in terms of wavelength multiplexed, a generator which generates notification signals, which notify another device of a failure in reception of the wavelength multiplex optical signal, for optical signals which are separated from the wavelength multiplex optical signal and which are transmitted to the other device, out of the plurality of optical signals, in accordance with frame types of the optical signals, and one or more transmitters which respectively convert the notification signals into wavelength optical signals having the same wavelengths as the optical signals out of the plurality of optical signals have and which respectively transmit the wavelength optical signals in place of the optical signals to the other device when the wavelength multiplex optical signal is not received in the receiver.

Abstract: A frame counter correction apparatus connected to an Ethernet network, including transmission counter for counting a number of frames to be transmitted; inspection frame generator for generating an inspection frame for measuring a frame loss; and transmission counter correction unit for calculating a difference between a counter value of the transmission counter at a time of generation of the inspection frame and the counter value of the transmission counter at a time of transmission of the inspection frame, and adding a calculated difference value and information for specifying the inspection frame as a correction target to another inspection frame.

Abstract: A frame counter correction apparatus connected to an Ethernet network, including transmission counter for counting a number of frames to be transmitted; inspection frame generator for generating an inspection frame for measuring a frame loss; and transmission counter correction unit for calculating a difference between a counter value of the transmission counter at a time of generation of the inspection frame and the counter value of the transmission counter at a time of transmission of the inspection frame, and adding a calculated difference value and information for specifying the inspection frame as a correction target to another inspection frame.

Abstract: An optical receiver including a variable optical attenuator for controlling an optical loss value for each optical transmission line based on a predetermined optical loss value; a variable dispersion compensation module for controlling a wavelength dispersion value for each optical transmission line based on a predetermined dispersion value; an optical loss/dispersion controller for measuring the optical loss value and the wavelength dispersion value of every optical transmission line, outputting these values so that they are equal in all the optical transmission lines, and controlling the attenuator and the module based on the outputted predetermined values; a receive amplifier for receiving the optical signal whose light level is kept constant and amplifying the signal; and, a transmission line switch control module is provided for switching a working transmission line into a protection line if the optical signal level of the working line is lower than a threshold value.

Abstract: The present invention is to provide a control method for an information network connecting a plurality of telecommunication nodes by a ring transmission path and giving a plurality of priorities to frames which are exchanged among the telecommunication nodes, comprising the processes of: recognizing a bandwidth assurance value set up for each of the telecommunication nodes on the ring transmission path for each layer of the priorities; and judging whether or not a sum of the total of the bandwidth assurance value at the present and a newly allocated value of the bandwidth assurance value exceeds a physical transmission bandwidth of the ring transmission path when a discretionary one of the telecommunication nodes accepts an allocation of the bandwidth assurance value anew.

Abstract: An optical receiver is provided for reducing in scale the overall system for wavelength division multiplex transmission lines configured redundantly and improving the quality of transmission when the line is switched. The optical receiver includes a variable optical attenuator for controlling an optical loss value for each optical transmission line based on a predetermined optical loss value. A variable dispersion compensation module is also provided for controlling a wavelength dispersion value for each optical transmission line based on a predetermined dispersion value.

Abstract: A synchronous digital multiplex transmission apparatus judges whether a received signal is a SONET AU-3 mapping signal or a SDH AU-4 mapping signal, based on values of H1, H2 and H3 bytes which form H bytes, and carries out an AU-3 pointer process in the case of the AU-3 mapping signal and an AU-4 pointer process in the case of the AU-4 mapping signal, with respect to the received signal. A pointer value is inserted in each of the H1, H2 and H3 bytes in the case of the AU-3 mapping signal and a pointer value is inserted in the H1 bytes in the case of the AU-4 mapping signal, with respect to a transmitting signal.