Fujitsu Corporation

Hiroyuki Kitajima

Hiromichi Makishima

Toru Katagiri

Hidetaka Kawahara

Shingo Hotta

Takashi Kuwabara

Hiroyuki Honma

Ryoichi Mutoh

Hiroyuki Homma

Yuji Obana

Wataru Odashima

Kazumasa Mikami

Toshiharu Sakai

Ryoji Azumi

Kiyomasa Nishisaka

Daisuke Hirata

Toshiaki Ohkubo

A transmission apparatus includes: a generator configured to generate position information indicating a position of header information of each of a plurality of first signals from a second signal nesting the plurality of first signals; a storage configured to store the position information generated by the generator and the plurality of first signals; a monitor configured to read the position information and the plurality of first signals stored in the storage, and to monitor the header information of each of the plurality of first signals based on the position information; and an output unit configured to output the plurality of first signals after monitoring the contents of the header information.

Transmission apparatus and transmission method

A transmission device to multiplex in a first signal a plurality of second signals each having a low rate as compared with the first signal, the transmission device includes: a plurality of memories to store the plurality of second signals; a selector to select one of the second signals read from the plurality of memories; and a controller to control read timing to read the plurality of second signals from the plurality of memories and signal selection timing to select the one of the second signals by the selector so as to execute rearrangement processing of the plurality of second signals read from the plurality of memories in accordance with cross-connect setting information for the plurality of second signals and shift processing of the plurality of second signals read from the plurality of memories in accordance with multiplexing positions of the plurality of second signals for the first signal.

Transmission device

An optical receiver includes a reception module, a first detector, a second detector, a shift module, a first extraction module, and a second extraction module. The reception module receives a frame. The first detector detects a head position of a first layer, the head position being included in the frame. The second detector detects a head position of a second layer, the head position being included in the frame. The shift module shifts the frame so that the head position of the first layer and the head position of the second layer are located at respective predetermined positions. The first extraction module extracts a header of the first layer from the frame after the frame is shifted. The second extraction module extracts a header of the second layer from the frame after the frame is shifted.

Optical receiver and method of optical reception

A frame transmitting apparatus includes a transmitting unit which transmits, when a change is made to a value in a predetermined field of a frame, the frame including the predetermined field with the changed value a predetermined number of times in succession. A frame receiving apparatus includes a receiving unit which receives the frame and an acceptance processing unit which recognizes the value in the predetermined field of the received frame and conducts acceptance processing. The acceptance processing unit compares, when the value is different from a currently accepted value, the value with an expected value; accepts the value when the value matches the expected value; and accepts, when the value does not match the expected value, the value after receiving the same value the predetermined number of times in succession.

Communication system and method therefor

A frame transmitting unit divides a payload area of an upper-layer frame into a plurality of slots, maps a lower-layer frame to one or more of the slots, and transmits the upper-layer frame including connection information that indicates which one or more of the slots the lower-layer frame of a same type is mapped to. The frame synchronization detection unit identifies, as one or more allocated slots, the one or more slots to which the lower-layer frame of the same type is mapped, on the basis of the connection information, and detects the frame synchronization by identifying a frame head signal of the lower-layer frame of the same type that is mapped to the one or more allocated slots.

Communication system, frame synchronization detection apparatus, and frame synchronization detection method

An error correction processing circuit, includes: a division circuit that divides input data into a plurality of pieces of a predetermined data length; a plurality of operation circuits that are provided in parallel, and that perform operations of error correction for the plurality of pieces of data divided by the division circuit, respectively; a multiplexing circuit that multiplexes the plurality of pieces of data for which the operations have been performed by the plurality of operation circuits; and an output circuit that outputs the data multiplexed by the multiplexing circuit.

Error correction processing circuit and error correction processing method

A transmission apparatus exercises insertion control for inserting a client signal and a stuff byte into a payload area in a frame into which the client signal is to be mapped, and sends the frame after the insertion control. In addition, the transmission apparatus inserts the client signal or the stuff byte in columns of the frame into the payload area except a leading column.

Transmission apparatus and signal mapping method

An apparatus for mapping multiple lower-speed signal transmission frames to a higher-speed signal transmission frame. The apparatus includes buffers configured to buffer the lower-speed signal transmission frames, determination units configured to determine frequency justification information for the lower-speed signal transmission frames, a barrel shifter configured to receive signals output from the buffers, and a controller configured to control the barrel shifter to map the lower-speed signal transmission frames to the higher-speed signal transmission frame based on external settings for the respective lower-speed signal transmission frames and the frequency justification information determined by the determination units. When the minimum unit of the lower-speed signal transmission frames is a channel, the number of the buffers and the number of the determination units correspond to the maximum number of channels that can be multiplexed in the higher-speed signal transmission frame.

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Oyama, Japan

Hiroyuki Kitajima