Abstract: In order to improve a measuring precision in case of measuring properties of the optical fiber to be measured, in accordance with returned lights which have wavelengths different from each other, detection is carried out with respect to the returned lights of the wavelengths different from each other, at a timing based on difference of propagation rates between the returned lights in the optical fiber to be measured, and error between the returning points is compensated with respect to each returned light, in the optical pulse testing device for inputting the optical pulse to the optical fiber to be measured, to detect returned lights which have wavelengths different from each other and which are returned back from passing points in the optical fiber to be measured, respectively, in order to measure the properties of the optical fiber to be measured, in accordance with detection results of the returned lights.

Abstract: An optical pulse ?0 from a light source section 10 is incident upon an optical fiber 1 through an optical demultiplexer section 20, and its return light is supplied to an optical/electrical processing section 30 as the light of a plurality of different wavelengths ?1 to ?n by the optical demultiplexer section 20, and is respectively converted into electrical signals. Signals of the converted return light are respectively sampled and are averaged by respective processing circuits 402 to 40n of a signal processing section 40 so as to be formed as desired measurement waveforms. In the measurement waveforms, which are the results, data for corresponding sampling points are expressed as measurement data at an identical distance in the optical fiber.

Abstract: In order to improve a measuring precision in case of measuring properties of the optical fiber to be measured, in accordance with returned lights which have wavelengths different from each other, detection is carried out with respect to the returned lights of the wavelengths different from each other, at a timing based on difference of propagation rates between the returned lights in the optical fiber to be measured, and error between the returning points is compensated with respect to each returned light, in the optical pulse testing device for inputting the optical pulse to the optical fiber to be measured, to detect returned lights which have wavelengths different from each other and which are returned back from passing points in the optical fiber to be measured, respectively, in order to measure the properties of the optical fiber to be measured, in accordance with detection results of the returned lights.

Abstract: In order to improve a measuring precision in case of measuring properties of the optical fiber to be measured, in accordance with returned lights which have wavelengths different from each other, detection is carried out with respect to the returned lights of the wavelengths different from each other, at a timing based on difference of propagation rates between the returned lights in the optical fiber to be measured, and error between the returning points is compensated with respect to each returned light, in the optical pulse testing device for inputting the optical pulse to the optical fiber to be measured, to detect returned lights which have wavelengths different from each other and which are returned back from passing points in the optical fiber to be measured, respectively, in order to measure the properties of the optical fiber to be measured, in accordance with detection results of the returned lights.

Abstract: In order to improve a measuring precision in case of measuring properties of the optical fiber to be measured, in accordance with returned lights which have wavelengths different from each other, detection is carried out with respect to the returned lights of the wavelengths different from each other, at a timing based on difference of propagation rates between the returned lights in the optical fiber to be measured, and error between the returning points is compensated with respect to each returned light, in the optical pulse testing device for inputting the optical pulse to the optical fiber to be measured, to detect returned lights which have wavelengths different from each other and which are returned back from passing points in the optical fiber to be measured, respectively, in order to measure the properties of the optical fiber to be measured, in accordance with detection results of the returned lights.

Abstract: An optical pulse &lgr;0 from a light source section 10 is incident upon an optical fiber 1 through an optical demultiplexer section 20, and its return light is supplied to an optical/electrical processing section 30 as the light of a plurality of different wavelengths &lgr;1 to &lgr;n by the optical demultiplexer section 20, and is respectively converted into electrical signals. Signals of the converted return light are respectively sampled and are averaged by respective processing circuits 402 to 40n of a signal processing section 40 so as to be formed as desired measurement waveforms. In the measurement waveforms, which are the results, data for corresponding sampling points are expressed as measurement data at an identical distance in the optical fiber.

Abstract: A client, when desiring to multicast the data, transmits the data and destination information on a plurality of transmission destinations to a center system. The center system generates a multicast group containing the plurality of transmission destinations on the basis of the destination information, and multicasts the data to the generated multicast group.

Abstract: A satellite communication system capable of notifying an user in speaking that a connection request is transmitted and capable of being implemented at low cost. A satellite communication system in accordance with the SCPC method using a voice activation is structured with a center station. The center station, when receiving a connection request to an user in speaking, measures a level of a carrier assigned to a reception line for the user with a demodulator. In this center station, when the level is not more than a predetermined level, the modulator transmits a signal notifying the user that the connection request is received.

Abstract: An automatic hot water supply apparatus produces and supplies hot water by mixing, with a hot water/cold water mixing valve, hot water supplied from an instantaneous water heater unit through a hot water supply pipe and cold water supplied through a cold water supply pipe. The automatic hot water supply apparatus includes a flow rate control valve actuatable by an electric actuator, and a flow rate limiting unit responsive to a hot water temperature setting, or a season setting, or a detected hot water temperature, for varying the flow rate of mixed hot water. The electric actuator is controlled by a signal from the flow rate limiting unit to operate the flow rate control valve in order to solve the problems of a low water temperature during the winter, an excessive hot water flow rate, and a low instantaneous water heater unit capability, so that the automatic hot water supply apparatus can supply hot water at a desired temperature.