Abstract: There is provided a transmission apparatus, which includes: a filter configured to pass an optical signal having a predetermined wavelength received via an optical fiber, a variable optical attenuator configured to attenuate a power level of the optical signal passed by the filter, a first measuring circuit configured to measure a first power of the optical signal before being passed by the filter, a second measuring circuit configured to measure a second power of the optical signal attenuated by the variable optical attenuator, a detector configured to detect a difference between the first power and the second power, and a controller configured to increase an attenuation factor of the variable optical attenuator when the difference is equal to or larger than a first predetermined value.

Abstract: A control device for an optical channel monitor includes: at least one of a processor and a circuit configured to stop calibration of a measured wavelength when no peak intensity of a wavelength of incoming light is detected, the optical channel monitor measuring a light intensity at the measured wavelength, the at least one of processor and circuit configured to determine presence of a peak intensity in the incoming light when detecting the incoming light with a light intensity equal to or more than a given intensity, the at least one of processor and circuit configured to permit the calibration of the measured wavelength which has been stopped to be resumed when the wavelength peak is determined to be present.

Abstract: A SONET/SDH transmission apparatus comprises a plurality of interface units that accommodate a plurality of lines, and mesh wiring that interconnects the interface units in a mesh pattern. Each of the interface units includes a time slot interchange (TSI) unit to output a signal selected from among a plurality of signals through the TSI processing of a plurality of signals on the lines accommodated at all the interface units, a detection unit to detect alarm information on the lines accommodated at all the interface units, and a control unit to provide the TSI unit with control data reflecting protective switching operation calculated by computation of a logic circuit which virtually executes the protective switching operation to be as for the plurality of lines.

Abstract: A SONET/SDH transmission apparatus comprises a plurality of interface units that accommodate a plurality of lines, and mesh wiring that interconnects the interface units in a mesh pattern. Each of the interface units includes a time slot interchange (TSI) unit to output a signal selected from among a plurality of signals through the TSI processing of a plurality of signals on the lines accommodated at all the interface units, a detection unit to detect alarm information on the lines accommodated at all the interface units, and a control unit to provide the TSI unit with control data reflecting protective switching operation calculated by computation of a logic circuit which virtually executes the protective switching operation to be as for the plurality of lines.

Abstract: A transmission apparatus that receives data from a first external apparatus via a first network, and transmits the received data to a second external apparatus via a second network, the transmission apparatus includes a receiving unit that receives data from the first external apparatus, a storage unit that stores the data received by the receiving unit, a transmission unit that reads out the data stored in the storage unit and transmits the data to the second external apparatus at a predetermined transmission speed, a transmission-pause-time calculation unit that calculates the time that is needed to reduce an amount of data stored in the storage unit from a first threshold value to a second threshold value as a transmission-pause-time, and a pause-request-frame transmission unit that adds the transmission-pause-time to the pause request frame and transmits the pause request frame to the first external apparatus.

Abstract: An optical transmitting apparatus includes an unused-wavelength determining unit. The unused-wavelength determining unit monitors the wavelength of the optical signal transmitted by transmitting apparatuses to determine an unused wavelength currently not in use. The transmitting apparatuses contain a stopping unit that stops transmitting the optical signal when no signal is input, an unused-wavelength obtaining unit that obtains the unused wavelength determined by the unused-wavelength determining unit after the optical signal transmission is stopped and is then restarted, and a transmitting unit that converts a new signal to an optical signal of the unused wavelength obtained by the unused-wavelength obtaining unit to transmit the optical signal to the receiving apparatus.