Hitachi, Ltd.

Yukihisa Tamura

Masatoshi Shibasaki

Kenji Okamoto

Toshiyuki Atsumi

Takao Fukushima

Hidemasa Narita

Tetsuya Nakajima

Mitsuru Asayama

Tsutomu Kawaizumi

A transfer device according to an embodiment transfers blocks generated by dividing a frame into pieces of data and adding a synchronization header each of the pieces of data. The blocks comprise a first, second and third blocks in this order. The transfer device is configured to acquire a first synchronization header in the first block, a second synchronization header in the second block and a third synchronization header in the third block, judge, in a case where a value of the second synchronization header is incorrect, as to whether or not the value of the second synchronization header can be estimated based on the first and the third synchronization headers so that the second block is consistent with the first and third blocks, and correct the second synchronization header into the estimated value.

Data transfer device and data transfer system

A network system having duplicate lines of a primary system and a backup system between a transmitter apparatus and a receiver apparatus is provided. Each of the transmitter apparatus and the receiver apparatus includes an arithmetic operator for conducting a BIP-8 arithmetic operation and a CRC arithmetic operation on an input signal and thereby detecting a bit error. The transmitter apparatus transmits data to both lines. The receiver apparatus includes a switcher. When a bit error is detected in received data of the primary system. the switcher switches control of the primary system and the backup system. Hitless protection switching of a VC path is executed.

Network system

A circuit capable of processing signals of different signal types is provided for identifying the signal type by the signal type setting from an administrator or by the implementation of the optical module, thereby selecting a signal processor to be used. An OTN frame standardized by ITU is used in a fixed manner independent of the signal type to be accommodated, while a corresponding SDH/SONET frame standardized by ITU is used for signal accommodation.

Interface board and optical transmission equipment

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Yokohama, Japan

Yukihisa Tamura