Abstract: A transmission apparatus includes a first storage configured to store data received from external into a write enable area, a second storage configured to store the data in accordance with a write request and output a retry request in response to occurring an error of writing a first data included in the data, and a controller configured to read the data from the first storage and send the write request to the second storage, set an area of the first storage storing the first data to a write disable area in combination with stop sending the retry request to external when receiving the retry request from the second storage, and send the first data reading from the write disable area of the first storage to external in response to a read request from external.

Abstract: A transmission apparatus includes a first storage configured to store data received from external into a write enable area, a second storage configured to store the data in accordance with a write request and output a retry request in response to occurring an error of writing a first data included in the data, and a controller configured to read the data from the first storage and send the write request to the second storage, set an area of the first storage storing the first data to a write disable area in combination with stop sending the retry request to external when receiving the retry request from the second storage, and send the first data reading from the write disable area of the first storage to external in response to a read request from external.

Abstract: A packet transmission device including plural queues for storing packets to be transmitted is provided. The device includes a token storage section for storing queue information for identifying a queue and an accumulated token value in which token values assigned to the queue are accumulated so as to obtain correspondence therebetween and a capture section for identifying one or both of an unused queue and a queue in which the accumulated token value exceeds a given upper limit value and capturing the queue information thereof. The device includes a selection section for selecting the queue information of the unidentified queue on the basis of the queue information captured using the capture section and an addition section for adding the accumulated token value of the token storage section on the basis of the queue information selected using the selection section.

Abstract: A method of communicating through a passive optical network (PON) that improves the efficiency of the network with low cost child apparatuses having only simple functions. A parent apparatus provides the child apparatuses with a multi-frame standard signal, and a child apparatus transfers asynchronous information as a frame of variable length, as it is, at a time delayed from the multi-frame standard signal by a time period designated by the parent apparatus. Since the asynchronous information does not need to be divided into pieces to which a frame header is attached, the efficiency of the uplink channel is increased.

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 frame transmission device which does not require a separate supervisory line and enables supervisory frames to efficiently enter subscriber traffic for transmission without securing a fixed bandwidth. A supervisory token computing section gives supervisory frames supervisory tokens as permission to transmit within a minimum bandwidth. Subscriber token computing sections give subscriber frames subscriber tokens as permission to transmit within respective set transmission bandwidths. A best-effort token computing section gives the frames best-effort tokens as permission to transmit by using an extra bandwidth. The supervisory or subscriber tokens are given to read frames from a supervisory queue or subscriber queues, and if a frame queue length is smaller than or equal to the best-effort tokens remains in the queue, a queue read control section reads and outputs the remaining frames from the queue by using the extra bandwidth of best-effort tokens.

Abstract: A communication system is provided for preventing delivery of unnecessary packets to a user terminal and thereby improving transmission efficiency. In the communication system, an OLT communication interface transfers packets between a local office and a subscriber or transmits filter-setting data and receives filter-state data. An ONU communication interface transfers packets between the local office and the subscriber or receives the filter-setting data and transmitting the filter-state data. A terminal address managing unit obtains and manages a terminal address from a connected terminal. A packet filter performs an operation of filtering packets transmitted from an optical line terminal with respect to the connected terminal on the basis of at least one of delivery information, registered information and the filter-setting data.

Abstract: A frame transmission device which does not require a separate supervisory line and enables supervisory frames to efficiently enter subscriber traffic for transmission without securing a fixed bandwidth. A supervisory token computing section gives supervisory frames supervisory tokens as permission to transmit within a minimum bandwidth. Subscriber token computing sections give subscriber frames subscriber tokens as permission to transmit within respective set transmission bandwidths. A best-effort token computing section gives the frames best-effort tokens as permission to transmit by using an extra bandwidth. The supervisory or subscriber tokens are given to read frames from a supervisory queue or subscriber queues, and if a frame queue length is smaller than or equal to the best-effort tokens remains in the queue, a queue read control section reads and outputs the remaining frames from the queue by using the extra bandwidth of best-effort tokens.

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 access system that sends packets in a given time slot more efficiently without wasting bandwidth. The uplink channel from slave devices to a master device is divided into time slots. The sending slave device reads out upstream packets from its send packet buffer when an assigned time slot comes. If the maximum frame size is reached in the middle of a packet, the slave device suspends further reading until a next assigned time slot comes. The packets are sent to the master device, each being set off by a start and end delimiters. Detection of a start delimiter causes the master device to begin writing each received data word into a receive packet buffer, which is terminated by the end delimiter of that packet. Received packets are retrieved from their memory locations specified by a read address that includes the sender's slave device number.

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.

Abstract: A method of communicating through a passive optical network (PON) that improves the efficiency of the network with low cost child apparatuses having only simple functions. A parent apparatus provides the child apparatuses with a multi-frame standard signal, and a child apparatus transfers asynchronous information as a frame of variable length, as it is, at a time delayed from the multi-frame standard signal by a time period designated by the parent apparatus. Since the asynchronous information does not need to be divided into pieces to which a frame header is attached, the efficiency of the uplink channel is increased.