Fujitsu Corporation

Tateo Shimaru

Katsuhiko Hirashima

Toshiyuki Sakai

Tamotsu Matsuo

Kenji Miura

Yoshimi Toyoda

Toshinori Koyanagi

Mitsuharu Wakayoshi

Kazuhiro Uchida

Takashi Monzawa

Setsuo Abiru

Jun Asato

Kazuya Ryu

Shinichi Fujiyoshi

Hideki Shiono

Naoyuki Takeshita

Hiroaki Shiraishi

Masaru Nishida

Hisaya Urabe

Tsuneharu Suzuki

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.

Transmission apparatus and retry method

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

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Fukuoka, Japan

Tateo Shimaru