Fujitsu Corporation

Tomoyoshi Fujimori

Satoru Saitoh

Hiroyuki Honma

Osamu Takeuchi

Yoshitaka Taki

Transmission equipment comprises: a measurement unit configured to measure respective transmission delays of the plurality of paths by using a frame transmitted between the transmission equipment and correspondent equipment; a detector configured to detect a priority of an input packet; a selector configured to select a path for transmitting the input packet from among the plurality of paths; and a frame processing unit configured to transmit a frame onto which the input packet is mapped to the correspondent equipment through a path selected by the selector. The selector selects an alternative path for transmitting the input packet from among the plurality of paths based on the priority of the input packet detected by the detector and respective transmission delays of the plurality of paths measured by the measurement unit when a failure occurs in a path that has been selected by the selector.

Transmission equipment and path selection method

A transmission characteristic adjustment device includes: a setting process portion that sets a setting value concerning each transmission characteristic of a plurality of electric signals to at least one of a sending device that sends the plurality of electric signals and a receiving device that receives the plurality of electric signals; a generation process portion that acquires each error rate calculated based on identification information included in each of the plurality of electric signals whenever the setting value is changed, and generates a table on which a plurality of sets of the setting value and the error rate are recorded; and an adjustment process portion that adjusts the setting value based on the table.

Transmission characteristic adjustment device, transmission device and method for adjusting transmission characteristic

There is provided an optical transmission system including: an optical transmitting apparatus including: a first processing circuit configured to process a transmission signal to be transmitted, a second processing circuit configured to process overhead data, the processed overhead data being multiplexed to the transmission signal, a retaining circuit configured to retain the overhead data, the retained overhead data being multiplexed to the transmission signal; and an insertion circuit configured to generate an identifier to be inserted into the retained overhead data; and an optical receiving apparatus including a detecting circuit configured to receive the transmission signal transmitted from the optical transmitting apparatus, and detect the identifier, wherein, when the overhead data is a predetermined state, the first processing circuit multiplexes the retained overhead data into which the identifier is inserted and the detecting circuit detects the identifier.

Optical transmission system

A redundancy control method is disclosed that controls a first redundancy function that switches between a working line and a protection line in response to a detection of a line error and a second redundancy function that performs a path switching in response to a detection of a path error in a ring network operating at a path rate lower than a line rate thereof. The method comprises a step of masking the path error detection within a period from a time of the detection of the line error to an expected time of the detection of the path error.

Method for controlling redundancy and transmission device using the same

In a path status monitoring method and device which can enhance or reduce a band more rapidly, for example, SONET frames FR serially connected over 32 frames to which frame Nos. FN ('0'-'31')) are assigned are cyclically generated respectively for paths P-Pin a cycle T(=64 ms). After output timing delays T-Tof the frames FR are shifted by an optimal delay interval D (=21 ms) between the paths P-Pbased on the number of the paths &#x201c;3&#x201d;, the output timing delays Tand Tare restored by preliminarily obtained transmission delays for the paths Pand Pto the path P. When the frames FR are transmitted through each of the paths P-P, statuses (path statuses MST) where a reception fault has occurred in each of the paths P-Pare collected to be stored in the frame whose frame No. FN=&#x201c;0&#x201d;.

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Kawasaki, Japan

Tomoyoshi Fujimori