Fujitsu Corporation

Hideki Shiono

Tamotsu Matsuo

Kenji Miura

Yoshimi Toyoda

Takashi Monzawa

Jun Asato

Toshiyuki Sakai

Toshinori Koyanagi

Mitsuharu Wakayoshi

Kazuhiro Uchida

Setsuo Abiru

Katsuhiko Hirashima

Kazuya Ryu

Shinichi Fujiyoshi

Tateo Shimaru

Kenji Fukunaga

Satoshi Tomie

Takanori Yasui

Hirofumi Fujiyama

In a communication apparatus, a write controller writes received data in a temporary memory which serves as short-time storage. A read controller reads data out of the temporary memory. A discard controller controls discard operation of the data read out of the temporary memory.

Communication apparatus with data discard functions and control method therefor

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.

Optical network unit and optical line terminal

In an ATM cell multiplexer which multiplexes ATM cells outputted from a plurality of cards, sequential cell arrival numbers common to the ATM cells outputted from a plurality of cards are added to each of the cells to be written in memories, and the read side checks a sequentiality of the cell arrival numbers whereby the ATM cells are read in the order of arrival and the cell arrival number at that time is used as the cell arrival number to be checked at the next read time. Also, when any of the cards is pulled out, a card not pulled out is operated normally and an address counter of only the pulled-out card is cleared. Even when non-sequentiality of the cell arrival numbers occurs due to the clearance of the address counter, the maximum cell arrival number is set to the value which enables the oldest cells to be read first. Furthermore, by the division of storing memories according to priority degrees, a read control identifying the ATM cells for a real time system as well as the ATM cells for a data system can be performed.

ATM cell multiplexer

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Osaka, Japan

Hideki Shiono