Abstract: The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is a slave station device that cannot perform communication via the normal path. If the first slave station device is detected, the master station device calculates a first backup path for the first slave station device based on a first RTT between the master station device and the loop path, a loop RTT required for one full lap on the loop path, and the first normal path RTT for the first slave station device.

Abstract: A signal forwarding system includes: a plurality of signal forwarding devices forming a plurality of communication routes between a slave station and a master station; and a route control device that determines a communication route, wherein the route control device includes at least: a communication route calculation unit that calculates a communication route in response to a route switching request; and a forward destination setting instruction unit that outputs forward destination setting information based on the communication route, the signal forwarding devices include at least: a forward destination setting instruction acquisition unit that acquires the forward destination setting information; a forward destination set unit that changes a forward destination based on the forward destination setting information; and a forward unit that outputs input traffic based on the forward destination, and any of the route control device and the signal forwarding devices includes: a traffic monitor unit; a non-signa

Abstract: A communication system includes a subscriber network unit and a communication device provided in an accommodating station. The subscriber network unit includes an acquisition unit that acquires uplink data from one or more lower-layer devices. The communication device includes: a data processing unit that acquires the uplink data from the subscriber network unit using a band of uplink communication and executes data processing on the acquired uplink data; a policy determination unit that determines a policy of band allocation of the uplink communication on the basis of the result of the data processing; and an allocation control unit that allocates the band of the uplink communication to the subscriber network unit on the basis of the policy.

Abstract: A wavelength multiplexing communication system includes a master station apparatus and a plurality of slave station apparatuses. The master station apparatus includes a wavelength multiplexing communication unit that performs wavelength multiplexing communication with the plurality of slave station apparatuses by wavelengths the number of which is equal to or less than the number of the plurality of slave station apparatuses using an optical signal of a wavelength in a first wavelength group and an optical signal of a wavelength in a second wavelength group.

Abstract: An optical sensor (3) is installed in an optical path control device (1) that controls an optical path (2) without using an electrical element. The optical sensor (3) detects an optical signal passing through the optical path (2). A communication state determination unit (5) determines a communication state of the optical path (2) based on detection of the optical signal by the optical sensor (3). A position information reception management unit (10) receives and stores position information of the optical path control device (1). An information arrangement unit (6) collectively converts a determination result of the communication state determination unit (5) and the position information into information. A transmission unit (7) transmits the information.

Abstract: A user terminal 12-1 can wirelessly or preferentially connect to a router 14 to communicate with an upper network 18, and can communicate with another network 20 via a mobile line. An ONU 16 generates a disconnection notification in a case where congestion exceeding a reference is recognized in the PON communicating with the upper network 18, and generates a connection notification when the congestion is resolved. The router 14 stores the user terminal 12-1 that can communicate with another network 20 among the user terminals 12-1 to 12-4 being connected. In addition, the router 14 disconnects the connection with the user terminal 12-1 that can communicate with another network 20 when the disconnection notification is generated, and attempts reconnection with the user terminal 12-1 that has been disconnected when the connection notification is generated.

Abstract: Provided are a communication control device, a communication control system, a communication control method, and a communication control program that make it difficult to reduce band utilization efficiency. In an OLT server 9b that is a communication control device, a transmission time storage unit 12 stores a transmission time of an optical signal between each ONU 3 and OLT 4. An optical transmission control unit 13 generates control information for controlling transmission start and transmission end of optical signals in each ONU 3. A failure detection suppression unit 15 calculates a first time at which the reception of the optical signal from an ONU 3p ends using control information and a transmission time.

Abstract: A bandwidth allocation apparatus includes an acquisition unit acquiring scheduling information related to transmission of uplink data from a first subscriber line termination apparatus corresponding to a subscriber line termination apparatus needing to transfer uplink data with low latency, a requested amount reception unit receiving, from second subscriber line termination apparatus corresponding to a subscriber line termination apparatus not needing to transfer uplink data with low latency, information representing a requested amount related to transmission of uplink data from the second subscriber line termination apparatus, in a requested amount reception cycle corresponding to a cycle equal to or longer than a predetermined maximum round-trip time, and an allocation unit allocating, in an allocation amount determination cycle shorter than the requested amount reception cycle, a bandwidth to the uplink data from the first subscriber line termination apparatus on a basis of the scheduling information, and

Abstract: An optical communication system includes a looped path in which an active trunk fiber and a standby trunk fiber are connected in a loop. A plurality of optical combining/splitting units is provided on an active trunk fiber in series, and a plurality of slave devices is connected the plurality of optical combining/splitting units, respectively. A master device performs optical communication with each slave device. Each optical combining/splitting unit includes an optical sensor configured to detect an optical signal passing through an optical fiber and a transmitter. The transmitter determines whether or not there is an abnormality in optical communication on the basis of a detection state of the optical signal and transmits an abnormality notification including identification information of the optical combining/splitting unit to a monitoring apparatus in a case where there is an abnormality.

Abstract: In an optical communication system, an optical communication device and a plurality of optical transmission devices are loop-connected via transmission line. An optical signal transmission unit of the optical communication device, when no communication interruption occurs in the transmission line, outputs an optical signal addressed to a communication destination device that communicates with the own device to a transmission line connected to either one of two neighboring optical transmission devices. The optical signal transmission unit outputs, at the time of communication interruption occurring in the transmission line, an optical signal addressed to the communication destination device to both of transmission lines connected to respective two neighboring optical transmission devices.

Abstract: A plurality of optical sensors (3) are installed in an optical path control device (1) configured to control a plurality of optical paths (2) without using an electrical element. The plurality of optical sensors (3) detect optical signals each passing through at least one of the plurality of optical paths (2). A transmitter (4) simultaneously determines communication states of the plurality of optical paths (2) based on detection of the optical signals by the plurality of optical sensors (3), and transmits information on the determined communication states.

Abstract: Provided is a communication monitoring system capable of monitoring a state of a connection device that forms an optical path by using an optical passive component. A communication monitoring system (1) includes a plurality of photodetectors (9) provided in a connection device (6), a plurality of recognition units (13), a processing unit (14), a light emitting unit (15), a mixing unit (12), a separation unit (16), a collection unit (17), and a management unit (18). The photodetector (9) detects an optical signal passing through a corresponding optical path. The recognition unit (13) recognizes a state of detection by the corresponding photodetector (9). The processing unit (14) generates information regarding a communication state of the connection device (6) on the basis of the recognition by each recognition unit (13). The light emitting unit (15) converts the generated information into a monitoring signal that is an optical signal and transmits the monitoring signal.

Abstract: Provided is a communication monitoring device and a communication monitoring system capable of monitoring a state of a connection device that forms an optical path by using an optical passive component. A communication management device (8) of a communication monitoring system (1) includes a plurality of photodetectors (11), a plurality of recognition units (14), a processing unit (15), and a transmission unit (16). The photodetectors (11) are provided in a connection device (6). The connection device (6) connects a plurality of optical communication lines (3) by using an optical passive component to form a plurality of optical paths through which optical signals pass. Each photodetector (11) detects an optical signal passing through the corresponding optical path. Each recognition unit (14) recognizes a state of detection of the optical signal by the corresponding photodetector (11).

Abstract: A communication device that is connected to a wavelength-multiplexed optical ring network and conducts communication by performing time-division multiplexing on an optical signal for each wavelength includes: a communication unit that transmits a requested transmission amount for requesting a transmission band to a master communication device, and receives an allowed transmission amount for allocating a transmission band from the master communication device; and a control unit that estimates a band utilization rate of each wavelength on the basis of the requested transmission amount and the allowed transmission amount, and allocates data to the respective wavelengths so as to equalize the band utilization rates among the wavelengths. Thus, it is possible to equalize band utilization rates among wavelengths, and enhance communication efficiency of the entire system.

Abstract: An optical communication system includes a plurality of optical combining/splitting units provided on a trunk fiber in series, a plurality of slave devices connected to the plurality of optical combining/splitting units, respectively, a master device connected to the trunk fiber and configured to perform optical communication with each slave device, and a monitoring apparatus. Each optical combining/splitting unit includes an optical sensor configured to detect an optical signal passing through an optical fiber and a transmitter. The transmitter determines whether or not there is an abnormality in optical communication on the basis of a detection state of the optical signal and transmits an abnormality notification including identification information of the optical combining/splitting unit to the monitoring apparatus in a case where there is an abnormality in optical communication.

Abstract: A communication device includes: a communication unit that is connected to an optical ring network, conducts optical signal communication by time-division multiplexing, and receives a control signal for controlling an optical signal transmission timing from a master communication device; and a determination unit that determines the master communication device not to be operating properly and causes the subject communication device to operate as a new master communication device, in a case where the control signal is not received in a predetermined period. Thus, even in a case where the master device cannot operate properly, a slave device operates as the master device, so that the system operation can be continued.

Abstract: The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is one of the slave station devices, and a second slave station device is a slave station device that cannot perform communication via the normal path.

Abstract: A communication device is connected to a wavelength-multiplexed optical ring network, and performs communication by performing time-division multiplexing on optical signals at each wavelength. In a case where a control signal transmitted from the master communication device is not received in a predetermined period, the communication device instructs a scheduler unit to suspend transmission of data at a failure wavelength that is the wavelength at which the host communication device has been determined not to be operating properly, also instructs the scheduler unit to transmit the data stored in the buffer of the failure wavelength at another wavelength, and suspends allocation of new data to the buffer of the failure wavelength. Thus, the delay in transmission of data at the failure wavelength can be shortened.

Abstract: A plurality of optical sensors (3) are each installed in an optical path control device (1) that controls a corresponding one of the plurality of optical paths (2) without using an electrical element. Each of the plurality of optical sensors (3) detects an optical signal passing through the corresponding one of the plurality of optical paths (2). A transmitter (4) determines a communication state of the corresponding one of the plurality of optical paths (2) based on detection of the optical signal by the corresponding one of the plurality of optical sensors (3), and transmits information on the determined communication state. A power supplying optical signal generation unit (11) generates a power supplying optical signal. An optical signal synthesizing device (12) synthesizes the power supplying optical signal with the optical signal and transmits a signal obtained by the synthesis to the optical path control device (1). A storage battery (13) supplies electric power to the transmitter (1).

Abstract: The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is a slave station device that cannot perform communication via the normal path. If the first slave station device is detected, the master station device calculates a first backup path for the first slave station device based on a first RTT between the master station device and the loop path, a loop RTT required for one full lap on the loop path, and the first normal path RTT for the first slave station device.