Fujitsu Corporation

Kanji Naito

Koji Takeguchi

Toru Katagiri

Takashi Honda

Junichi Moriyama

Kazunari Shiota

Toshihiro Togo

Mineshi Nakashima

Isao Takata

Hidetoshi Kawamura

Osamu Takeuchi

Taku Saito

Katsuhiro Shirai

Katsumi Fukumitsu

Ryoichi Mutoh

Hirofumi Araki

Hiroyuki Homma

Fumihiro Ikawa

Hatsumi Iino

Shoichi Murakami

Hiroshi Kanzawa

Hisashi Taketomi

Masumi Kurokawa

Kumiko Uematsu

Seiji Miyahara

Yukie Yoshihara

Kazuhiko Taniguchi

An optimization unit in an optical receiver divides a symbol region out of a plurality of symbol regions into which signal points that specifies symbol information included in an optical signal are classified, into a plurality of division regions from the symbol center coordinate of the symbol region. Moreover, the optimization unit accumulates the signal points of the symbol information for every division region in the symbol region. Furthermore, based on the accumulated number of signal points for every division region, the optimization unit controls the average length of a phase estimation unit when the phase noise of the optical signal is calculated.

Optical signal processing device, optical signal processing method and recording medium

A transmission device that is coupled to a mesh network includes a memory, and a processor coupled to the memory, configured to detect an another transmission device in the mesh network, which receives a first data signal that is same as a second data signal requested to the transmission device, and branch the first data signal to the transmission device from the detected another transmission device.

Transmission device, transmission system, and transmission method

A network setup method used in a ring network including a plurality of transmission equipments. The method includes: transmitting a frame in the ring network; causing each of the transmission equipments to write an identifier to the frame according to a specified rule; determining whether or not a plurality of identifiers written to the frame by the plurality of transmission equipments satisfy a specified condition; and causing each of the transmission equipments to obtain a corresponding identifier according to the specified rule from among the plurality of identifiers, when the plurality of identifiers satisfy the specified condition.

Ring network setup method

A failure protection method of a network connecting between nodes by multiple working paths and a protection path is disclosed. An allocation bandwidth is determined to allocate to a detected path where a failure is detected in multiple paths being set to the multiple working paths, depending on the detected path. The detected path is switched from one of the multiple working paths to the protection path. Data to be transmitted by the detected path is transmitted by using the allocation bandwidth determined within an entire bandwidth of the protection path.

Failure protection method and node apparatus

A communication apparatus operable to set a path based on path setting information used to set a communication path over a communication network formed by a plurality of the communication apparatuses, the communication apparatus including a first storage medium operable to store first path setting information formatted with a first format, a second storage medium operable to store second path setting information formatted with a second format, and a controller operable to control to convert control information of the communication apparatus in which the first path setting information stored in the first storage medium is set, to the second path setting information formatted with the second format.

Communication apparatus and path setting control method

Data arriving from a plurality of channels asynchronously to each other are respectively stored in separate FIFOs (). A controller () monitors the status of the FIFOs (), retrieves the stored data in a predetermined order, and multiplexes the data, together with timing data indicating the presence or absence of the data, into a serial signal having a frame structure in which time slots are fixedly assigned to the respective channels. On the serial data, the same value appears successively as data, and when the data is valid, the corresponding timing data changes from a 0 to a 1. When the data is invalid, the value of the corresponding timing data does not change.

Multiplexing method and apparatus suitable for transmission of overhead data arriving from many communication lines

A ring configuring method configures a network in which a plurality of nodes are connected linearly, and performs topology construction for the ring by circulating topology data through the respective nodes and collecting connection information of the respective nodes. The method includes the steps of providing in the topology data a flag indicating whether the connection information is collected in each node; inverting the flag at a terminal station which is an end node of the open ring, and turning the topology data there; causing the topology data to passing through a node other than any terminal station as it is; and adding the connection information to the topology data in each node according to the flag, and performing topology construction.

Ring configuring method and node apparatus used in the ring

Disclosed is an optical transmission system for transmitting data via an optical transmission line in accordance with a frame format having overhead which includes a K1 byte used for a switching request and a K2 byte used to respond to the K1 byte. The optical transmission system includes N sets of working terminal stations, one set of protection terminal stations, N-number of optical transmission lines for interconnecting respective ones of the N sets of working terminal stations one optical protection transmission line for interconnecting the one set of protection terminal stations, repeater stations, which are provided in the optical transmission lines between the N sets of working terminal stations, for demultiplexing and outputting data extracted from the transmission lines or for multiplexing data and inserting the data in the transmission lines, protection transmission line connecting units, which are provided at positions in a protection transmission line corresponding to positions at which the repeater stations are disposed, for switching a failed transmission line to the protection transmission line in every section demarcated by the repeater stations. A working terminal station or repeater station that has detected occurrence of failure in a transmission line of a prescribed section sends K1 byte to and receives K2 byte from an opposing working terminal station or repeater station of the section via a protection terminal station or protection transmission line connecting unit and switches the failed transmission line section to the protection transmission line.

Optical transmission system and transmission line switching control

Code data of input type and output type low-speed interface units installed in one and other optical data transmission apparatus, placed opposite to and operatively connected to each other, are compared automatically in the one and the other optical data transmission apparatus respectively with code data of input type and output interface units in the other optical data transmission apparatus, sent from the other to the one optical data transmission apparatus and with code data of input type and output interface units in the one optical data transmission apparatus, sent from the one to the other optical data transmission apparatus.

Method for automatically discriminating low-speed interface units

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Kawasaki, Japan

Kanji Naito