Abstract: A communication device capable of restraining the packet transmission efficiency from lowering. An address storing unit extracts, from uplink packets, the addresses of terminals connected to sub-units and registers the addresses in an address management table. An address extracting unit extracts the address of a destination terminal included in a downlink packet output from a layer 2 switch, and an address determining unit determines whether or not the address of the destination terminal is registered in the address management table. In accordance with the result of the determination, a packet output unit outputs the downlink packet to a corresponding coupler.

Abstract: In an optical transmission method and device of a point-multipoint type, whether or not identification information of an optical network unit designated is received within a fixed phase tolerance for a transmission enabling phase designated to optical network units on multipoint sides is determined. When it is determined that no identification information of the optical network unit designated is received and identification information of any optical network unit is received up to a transmission enabling phase subsequently designated, a transmission stop command is transmitted to the optical network unit whose identification information is received.

Abstract: In an optical transmission method and device of a point-multipoint type, whether or not identification information of an optical network unit designated is received within a fixed phase tolerance for a transmission enabling phase designated to optical network units on multipoint sides is determined. When it is determined that no identification information of the optical network unit designated is received and identification information of any optical network unit is received up to a transmission enabling phase subsequently designated, a transmission stop command is transmitted to the optical network unit whose identification information is received.

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: In a communication system comprising a network unit and a plurality of subscriber units connected to the network unit, the network unit generates a message in which validity of transmission grant information is set for the subscriber units, and suspends a transmission of polling information to allocate a transmission grant to the subscriber units by using the transmission grant information for a fixed time in consideration of a processing time of the subscriber units from a time when the message has been completely transmitted. Also, when a disconnection state of an inputted cell from the subscriber units is detected, the network unit may suspend an input disconnection detecting operation for a fixed time from a time when the message and the polling information have been completely transmitted. Furthermore, a switchover of an input disconnection detection/transmission grant information may be suspended by mutually exchanging messages.

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 communication device capable of restraining the packet transmission efficiency from lowering. An address storing unit extracts, from uplink packets, the addresses of terminals connected to sub-units and registers the addresses in an address management table. An address extracting unit extracts the address of a destination terminal included in a downlink packet output from a layer 2 switch, and an address determining unit determines whether or not the address of the destination terminal is registered in the address management table. In accordance with the result of the determination, a packet output unit outputs the downlink packet to a corresponding coupler.

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 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.

Abstract: In a communication system comprising a network unit and a plurality of subscriber units connected to the network unit, the network unit generates a message in which validity of transmission grant information is set for the subscriber units, and suspends a transmission of polling information to allocate a transmission grant to the subscriber units by using the transmission grant information for a fixed time in consideration of a processing time of the subscriber units from a time when the message has been completely transmitted. Also, when a disconnection state of an inputted cell from the subscriber units is detected, the network unit may suspend an input disconnection detecting operation for a fixed time from a time when the message and the polling information have been completely transmitted. Furthermore, a switchover of an input disconnection detection/transmission grant information may be suspended by mutually exchanging messages.

Abstract: An unsaturated polyester resin composition having excellent vibration-damping properties, comprising an unsaturated polyester resin (A) having a glass transition temperature (Tg) of 0° C. or more and less than 60° C. In the composition, the unsaturated polyester resin (A) may be blended with an unsaturated polyester resin (B) having a glass transition temperature (Tg) of 150° C. or more and less than 200° C. or an unsaturated polyester resin (C) having a glass transition temperature (Tg) of 200° C. or more. Further, the composition may contain an elastomer (D) having a glass transition temperature (Tg) of −50° C. or more and less than 100° C.

Abstract: A method of storage control of component works in an automated storehouse, including a plurality of shelf equipment for storage/delivery of component works conveyed by a plurality of transporters, and an apparatus therefor are provided. The control method comprising the steps in that the shelf-array equipment storage status is confirmed in step S11, a shelf-array containing an empty shelf is extracted in S12, the specification information is entered in S13, and the stored work having the same specification information as that to be stored is retrieved, and a shelf containing the minimum number of works is decided as the target location (in S14 to 17).

Abstract: An information signal comprised of a video component and a tracking information component which has been recorded in parallel oblique tracks on a record medium is reproduced by plural transducers which scan successive tracks. The tracking information component is separated from the reproduced information signal to derive error detection signals representing scanning errors of the transducers. Plural ones of the error detection signals are averaged to produce tracking control signals.