Abstract: A master device includes: a light emission circuit configured to emit first laser light; an amplitude control circuit configured to control a scanning amplitude of a micro electro mechanical system (MEMS) mirror that scans the first laser light in a raster scan method; a timing data generation circuit configured to generate timing data that indicates a timing when a scanning angle of the MEMS mirror becomes zero, based on an operation of the MEMS mirror; a buffer configured to store the timing data in one frame of the scanning of the MEMS mirror; a light emission control circuit configured to control light emission of the first laser light by the light emission circuit, based on the timing data generated by the timing data generation circuit; and a data output circuit configured to output data to a slave device that operates dependent on an own device.

Abstract: A measurement device includes: a memory; and a processor coupled to the memory and configured to: generate a drive signal with a sine wave, according to a clock signal; control a reflection direction of output light of a light emitting device, by utilizing a resonance frequency, according to the drive signal; control a timing at which the drive signal is generated; and add or remove a pulse of a reference clock signal configured to generate the clock signal, according to a phase difference between a desired control signal and the control signal.

Abstract: A scanning-type distance measurement apparatus that includes a two-dimensional micro electro mechanical system (MEMS) mirror that reflects a laser beam includes: a memory; and a processor coupled to the memory and configured to: drive, on an axis that controls an angle of view out of two axes orthogonal to each other of the two-dimensional MEMS mirror, the axis of the two-dimensional MEMS mirror with a drive signal; and control a scanning angle range of the laser beam when a drive waveform of the drive signal is offset by an offset amount to shift a center angle of the scanning angle range, on the basis of the offset amount according to a shift direction from the center angle.

Abstract: A mirror control device configured to output a signal that indicates a first frame immediately after the angle-of-view change and a shift change amount, generate a shift correction amount and a scanning angle range correction amount that correspond to an expected deviation amount in the first frame using the shift change amount, output a corrected angle-of-view parameter and a corrected scanning angle range, drive the scanning mirror in the first direction to drive the scanning mirror, based on output of the angle-of-view parameter correction means, drive the scanning mirror in the second direction to drive the scanning mirror through a low-pass filter.

Abstract: A laser sensor includes: a micro electro mechanical systems (MEMS) mirror that performs scanning in a reflection direction of laser light of a light emitting device on a first axis in a resonance direction and a second axis in a non-resonant direction; and a processor that performs control that synchronizes a drive cycle of the second axis with the drive cycle of the second axis of the MEMS mirror mounted on another laser sensor, using a timing designated based on the drive cycle of the first axis.

Abstract: A first relay device included in a plurality of relay devices each of which configured to forward a frame to another relay device, the first relay device includes a memory, and a processor coupled to the memory and configured to receive a frame which includes a count value which is reduced by another relay device according to forwarding by the another relay device, set a second value in the count value of the received frame, wherein the second value is specified in accordance to a destination device of the frame, and after setting the second value in the count value, transmit the frame to another relay device of the plurality of relay devices.

Abstract: A transmission method executed by a transmission apparatus including a plurality of reception modules that receive packets and a plurality of transmission modules that receive the packets and transmit the packets to destinations of the packets, the transmission method includes extracting, by each of the plurality of reception modules, the amounts of data for respective priority levels of the received packets; transmitting, to one of the plurality of transmission modules, information regarding the extracted amounts of data for the respective priority levels; determining, by the one of the plurality of transmission modules, the amounts of discard data to be discarded for the plurality of respective reception modules, based on the extracted amounts of data for the respective priority levels and the amount of packet data that is able to be output; and notifying the plurality of reception modules of feedback information related to the determined amounts of discard data.

Abstract: A transmission device includes: one or more processors; and a memory configured to store a program which is executed by the one or more processors, wherein the one or more processors is configured to: measure a communication traffic amount on a line; calculate a degree of change in the communication traffic amount; compare the degree of change in the communication traffic amount with a threshold; and measure, in accordance with a comparison result, the communication traffic amount on the line in accordance with one of a first measurement cycle and a second measurement cycle that is shorter than the first measurement cycle.

Abstract: A communication system capable of communicating control information without decreasing the bandwidth available to users. A coder encodes a primary signal to generate encoded data such that the polarity of the encoded data alternates between positive and negative polarities. A polarity-reversed data generator reverses the polarity of part of the encoded data to generate polarity-reversed data. A transmitter transmits, as communication data, the encoded data including the polarity-reversed data. A receiver receives the communication data, and a polarity-reversed data detector determines whether or not the polarity of the received communication data alternates between positive and negative polarities, and detects, as the polarity-reversed data, data of which the polarity differs from an expected polarity. A polarity recognizer recognizes the polarity of the polarity-reversed data and treats the recognized polarity as control information.

Abstract: A transmission apparatus for receiving frames from one transmission path, storing the frames in plural buffers, and transmitting the frames to another transmission path in which an estimated discard time determination part configured to determine an estimated discard time of the frames stored in the plural buffers, a transmission order determination part configured to determine a transmission order of the frames, an estimated transmission time calculation part configured to calculate an estimated transmission time of each of the frames based on the transmission order, and a discard control part configured to discard a target frame from the frames stored in the plural buffers based on the estimated transmission time and the estimated discard time in a case where the estimated discard time of the target frame is the same as or earlier than the estimated transmission time of the target frame, are provided.

Abstract: An optical network unit and an optical line terminal which efficiently control the data receiving and dechurning processes in a passive optical network. In a churning parameter memory subsystem, a first memory bank stores churning parameters that are currently used, while a second memory bank stores updates made to the churning parameters. Under the control of the churning parameter memory subsystem, those first and second memory banks change their roles with each other at a churning key updating time point. A data dechurning unit receives a data stream consisting of a plurality of frames and dechurns the information contained in the data stream, according to the stored churning parameters. When an update is done to the parameters in a certain frame, the data dechurning unit makes the update effective at the next frame, thus starting data dechurning operations from the next frame.

Abstract: A communication system capable of communicating control information without decreasing the bandwidth available to users. A coder encodes a primary signal to generate encoded data such that the polarity of the encoded data alternates between positive and negative polarities. A polarity-reversed data generator reverses the polarity of part of the encoded data to generate polarity-reversed data. A transmitter transmits, as communication data, the encoded data including the polarity-reversed data. A receiver receives the communication data, and a polarity-reversed data detector determines whether or not the polarity of the received communication data alternates between positive and negative polarities, and detects, as the polarity-reversed data, data of which the polarity differs from an expected polarity. A polarity recognizer recognizes the polarity of the polarity-reversed data and treats the recognized polarity as control information.

Abstract: An optical network unit and an optical line terminal which efficiently control the data receiving and dechurning processes in a passive optical network. In a churning parameter memory subsystem, a first memory bank stores churning parameters that are currently used, while a second memory bank stores updates made to the churning parameters. Under the control of the churning parameter memory subsystem, those first and second memory banks change their roles with each other at a churning key updating time point. A data dechurning unit receives a data stream consisting of a plurality of frames and dechurns the information contained in the data stream, according to the stored churning parameters. When an update is done to the parameters in a certain frame, the data dechurning unit makes the update effective at the next frame, thus starting data dechurning operations from the next frame.

Abstract: An optical network unit and an optical line terminal which efficiently control the data receiving and dechurning processes in a passive optical network. In a churning parameter memory subsystem, a first memory bank stores churning parameters that are currently used, while a second memory bank stores updates made to the churning parameters. Under the control of the churning parameter memory subsystem, those first and second memory banks change their roles with each other at a churning key updating time point. A data dechurning unit receives a data stream consisting of a plurality of frames and dechurns the information contained in the data stream, according to the stored churning parameters. When an update is done to the parameters in a certain frame, the data dechurning unit makes the update effective at the next frame, thus starting data dechurning operations from the next frame.

Abstract: An optical line terminal which sends and receives messages or data to/from optical network units (ONUs) connected thereto. A cyclic message monitor produces a trigger signal, for use in a PLOAM grant generator, at certain intervals in harmonization with upstream messages that a specific optical network unit regularly transmits. A downstream message monitor watches outgoing downstream messages to detect a certain message requesting an ONU to return a response, and it triggers the PLOAM grant generator if such a message is detected. An upstream message monitor detects an upstream message whose identification code indicates that the sending ONU has no information to return. If such an upstream message is found, it limits the issuance of PLOAM grants to that optical network unit. The PLOAM grant generator produces PLOAM grants which permit ONUs to transmit their messages, and sends them out through a PLOAM cell transmitter.

Abstract: In a homo-code continuity proof testing device for testing with test data including a predetermined homo-code continuity proof test pattern, a testing device on a transmitting side synchronizes the test data in the form of a frame, including a predetermined test pattern, a data synchronous pattern, an error detecting pattern, and preferably a frame synchronous pattern for testing a homo-code continuity proof strength, with a predetermined clock, to be transmitted. A tested device on a receiving side extracts a clock included in the test data, detects the data synchronous pattern, the error detecting pattern, and the frame synchronous pattern in synchronization with the extracted clock, and determines a homo-code continuity proof test by the detection/undetection of each pattern.