Abstract: An object of the present invention is to provide an optical communication system and an optical communication method capable of achieving a long transmission distance with a passive element and obtaining redundancy of a ring topology. The optical communication system according to the present invention is a PON system having a ring configuration, in which an unequal branch optical splitter having a left-right symmetrical configuration is disposed in a trunk fiber wired in a loop shape. An OLT and an ONU have a configuration in which two sets of Tx (transmitter) and Rx (receiver) are mounted. Two sets of Tx (transmitters) and Rx (receivers) in each of a plurality of ONUs are respectively connected to left and right symmetrical ports of one unequally branched light beam SP.

Abstract: An objective is to provide a terminal device, a communication method, and a communication system in which the time taken by connection operations/authentication operations does not increase proportionally with the pattern length, even if the transmitting side and the receiving side are not synchronized. A terminal device, a communication method, and a communication system according to the present invention create n pieces of signal information (n-bit patterns) by sequentially shifting each bit of a single piece of received signal information (n-bit pattern) one bit at a time. Through the above, signal information time-shifted by one bit each is obtained. Thus, even if the transmitting side and the receiving side are not synchronized, one of the n pieces of signal information is a signal synchronized with the transmitting side. Thereafter, the signal synchronized with the transmitting side can be detected by a brute-force calculation with the patterns (ID information) in the list.

Abstract: An optical switch having a plurality of ports outputs an optical signal, which is input from one of the plurality of ports, from another port. A quality compensator perform quality compensation of the optical signal output from the optical switch, and input the quality-compensated optical signal to the optical switch. A controller selects, among the plurality of quality compensators, a quality compensator that performs quality compensation according to the degree of quality deterioration of the optical signal when the optical signal input from a predetermined port of the optical switch is transmitted through a transmission path. The controller controls the optical switch so that the optical signal, in which quality is compensated by the selected quality compensator through the optical signal input from the predetermined port being output to the selected quality compensator, is output from the port corresponding to a transmission destination of the optical signal.

Abstract: An object is to provide a communication system, a base station, and a communication method that can avoid a state in which an RF wireless communication cannot be started due to the quality of optical wireless communication. In an optical communication system according to the present invention, a base station device repeatedly transmits an authentication information frame addressed to a terminal device at a predetermined cycle by the optical wireless communication, the frame including authentication information for connection to the terminal device by the RF wireless communication. Even if the terminal fails to acquire the authentication information at a certain timing due to the quality of optical wireless communication, the communication system has a mechanism that acquires the same authentication information at regular time intervals, so that terminal authentication processing can be performed at the time when the terminal acquires the authentication information.

Abstract: An optical communication device that communicates with another optical communication device using at least a time division multiplexing method, the optical communication device includes: a band request unit that requests a band for transmitting a management control signal used for management and control; and a transmitting unit that transmits the management control signal as a burst signal using a band assigned to be able to transmit data having a data length or more obtained based on a transmission rate of the management control signal, a transmission rate of a main signal, and a data length of the management control signal.

Abstract: An optical communication system according to the present invention cancels waveform distortion due to wavelength dispersion by extracting the spectrum of a transmitted optical signal and passing the optical signal to a fiber having a dispersion value opposite to a dispersion amount corresponding to a transmission distance received by the spectrum component and compensates for a transmission path loss due to the fiber having the opposite dispersion value using optical splitters having different split ratios. With this configuration, the present invention can compensate for waveform distortion due to wavelength dispersion by a simple method in an access network and achieve an increase in the reachable transmission distance of the farthest user or an increase in the number of connectable users.

Abstract: An optical communication system configured with a station-side apparatus and a plurality of subscriber-side apparatuses in a bus network topology includes an optical amplification unit installed on a station side, and a drop unit configured to branch an optical signal and excitation light, wherein the optical amplification unit includes an amplifier configured to amplify a downlink signal, and an excitation light output unit configured to output the excitation light for amplifying an uplink signal to a communication path, and the drop unit changes a branching ratio in accordance with a wavelength of the optical signal so that a transmission loss of the excitation light with respect to a trunk fiber is reduced.

Abstract: An optical line terminal includes a communication unit configured to communicate with a plurality of optical network units, and a control unit configured to dynamically change at least one of a time width of a specific period and a cycle of the specific period, the specific period being a period in which an authentication request signal is received from the new optical network unit via the communication unit.

Abstract: An object of the present invention is to provide a light irradiation system capable of securing economic efficiency, flexibility, reliability, and safety, and further capable of reducing a transmission loss between a center side and a remote side. The present light irradiation system can secure economic efficiency by sharing a single light source installed on the center side with a plurality of irradiation places. The present light irradiation system can irradiate a place to be sterilized with ultraviolet light output by moving the optical fiber tip end on the remote side in a pinpoint manner, and can also secure flexibility. In addition, the present light irradiation system can secure reliability and safety by performing output control of the light source on the center side.

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and a decontamination method that are economical and easy to operate, and that can perform decontamination without any input from a user. In the present invention, an optical fiber or an optical waveguide that radiates ultraviolet light in a lateral direction, the optical fiber or the optical waveguide is built in a sheet shape, and irradiates a surface with the ultraviolet light. Specifically, a material in which a material having a high scattering coefficient is added to the optical fiber is used, a grating is formed in the optical fiber, the optical fiber is given a minute bending with a minute ruggedness, and an arbitrary bending is given on the optical fiber, or the like, thereby achieving side radiation. By such a feature, it has the effect that ultraviolet light decontamination can be performed at all times or at necessary timing for an object touched by an unspecified number of people.

Abstract: An object of the present invention is to provide an ultraviolet light irradiation system and a decontamination method that can perform decontamination economically without any input from a user. The ultraviolet light irradiation system forms a linear or planar ultraviolet light irradiation space by spatially bundling a plurality of ultraviolet light beams with high energy density or moving the ultraviolet light with high energy density at high speed. The ultraviolet light irradiation system can decontaminate a human body and clothing simply by passing through the space. Further, since the ultraviolet light irradiation system performs decontamination in the space, bacteria and viruses emitted from a carrier are not passed through the space.

Abstract: In the present disclosure, a wireless base station apparatus sends out continuous light having a predetermined characteristic to a wireless terminal apparatus, and the wireless terminal apparatus selects authentication information corresponding to the predetermined characteristic, and transmits the authentication information to the wireless base station apparatus by RF wireless. When confirming that the received authentication information matches authentication information corresponding to the predetermined characteristic, the wireless base station apparatus permits information communication between the wireless terminal apparatus and an upper network.

Abstract: An object is to provide an optical communication system and an optical communication method that are capable of, when assigning wavelengths on a per-service basis and providing services on a per-area basis, preventing degradation of signal quality due to linear crosstalk and preventing an increase in cost and size. An optical communication system according to the present invention includes an optical splitter 300 connecting N first ports and M second ports by a combination of 2×2 fiber optical splitters, N and M each being an integer of two or more, where wavelengths of optical signals to be received are limited for each group of optical receivers 106, by using a correlation between a fused extension length of at least one 2×2 fiber optical splitter directly connected to the first port, among the 2×2 fiber optical splitters, and wavelength output characteristics of the second port of the optical splitter 300.

Abstract: The present disclosure aims to enable communication to be performed with stable quality even when a user uses a terminal while moving. In the wireless communication system according to the present disclose, a switching control unit 15 sets switching illuminance pth for maintaining illuminance of an optical signal received by a terminal 91 at requested illuminance corresponding to throughput or higher during the time until connection switching between the communication with an optical wireless access point 92 and the communication with an RF wireless access point 93 is completed, and when the received illuminance p becomes lower than the switching illuminance pth during connection with the optical wireless access point 92, the switching control unit 15 performs connection switching from the optical wireless communication to the RF wireless communication.

Abstract: The present disclosure provides a monitoring system including an edge processing apparatus including a space distinct ID management database, a space distinct ID control unit, a storage unit, an analysis unit, and an abnormality determination unit, and a controller, a transmitter, and a camera with sensor that are installed in a location to be monitored, in which the space distinct ID management database stores a space distinct ID and a transmission time of the space distinct ID in association with the location to be monitored, the space distinct ID control unit acquires the space distinct ID associated with the location to be monitored from the space distinct ID management database and transmits the space distinct ID that is acquired to the controller in the associated location to be monitored, the controller transmits the space distinct ID acquired from the space distinct ID control unit to the transmitter, the transmitter generates a signal based on the space distinct ID acquired from the controller and di

Abstract: An object is to provide an optical communication system capable of controlling the output ratio by port and by wavelength for incident light of different wavelengths, a method of determining the split ratio of an uneven-split optical splitter for controlling the output ratio by port and by wavelength, and a transmission range determination method for the optical communication system. The split ratio determination method for an uneven-split optical splitter according to the present invention uses the melt-draw distance to adjust the split ratio of each fiber-optic splitter included in the uneven-split optical splitter such that the light output from the farthest ONUs among each of the ports connected under the ports B to M of the uneven-split optical splitter arrives with the minimum reception sensitivity at OLT receivers in a PON system.

Abstract: It is an object of the present invention to provide a position measuring system, a position measuring device, and a method for measuring a position that can accurately measure the position of an object to be measured without being limited by an environment or an optical axis. A position measuring device 20 according to the present invention is characterized by including a light receiving unit 21 configured to receive scattered light Lsc emitted from a side surface of an optical fiber 50, a database 22 configured to store a correspondence between information on the scattered light and a position of the object to be measured, and a determination unit 23 configured to determine, based on the correspondence stored in the database, a position of the object to be measured from information on the scattered light received by the light receiving unit.

Abstract: In response to the above issue, an object of the present invention is to provide a diagnostic apparatus and a diagnostic method capable of accurately recognizing whether to use a long extension function at the time of relocation of an accommodation station of an OLT. The diagnostic apparatus according to an aspect of the present invention has an allowable line length list that is a relationship between a center wavelength and an allowable line distance that satisfies a selected spectrum width in an optical fiber used in an optical communication system, measures a center wavelength and a spectrum width of a spectrum for each ONU, matches the allowable line length list, and obtains an allowable line distance of each ONU.

Abstract: An object of the present disclosure is to make already installed smart lightings available as optical base stations as they are without modifying them, and perform connection/authentication control for RF communication using an optical signal sent out from the optical base stations.

Abstract: An object of the present disclosure is to inform a user of a safe evacuation guidance route in real time using smart lightings without deploying dedicated evacuation guidance facilities. The present disclosure is a wireless communication system including: one or more wireless base stations that wirelessly communicate with a terminal; a plurality of optical base stations that transmit an optical signal to the terminal; and a base station control device that controls the optical signal transmitted by the optical base stations, wherein the base station control device collects environment information around the optical base stations, detects a disaster around the optical base stations using the collected environment information, and when detecting a disaster, causes the optical base station installed at a position close to a disaster occurrence location and the optical base station installed at a position far from the disaster occurrence location to output light of different colors.