Kokusai Denshin Denwa Kabushiki Kaisha

Kokusai Denshin Denwa Co., Ltd.

Masanori Sato

Yoshihiro Ejiri

Taiichiro Nakai

Hitoshi Yamamoto

Hiroharu Wakabayashi

Yasuhiko Niiro

Makoto Nunokawa

Kahei Furusawa

Kitsutaro Amano

Yoshihiko Yamazaki

An optical fiber submarine cable, which is provided with at least one coated optical fiber, a power supplying, pressure resisting layer of a pipe-like configuration, a tension resisting wire layer formed of a conductive material of relatively low conductivity and disposed in close contact with the power supplying, pressure resisting layer of the pipe-like configuration, and an insulator layer disposed around the tension resisting wire layer. The power supplying, pressure resisting layer is formed as at least one inner layer and an outer layer. The inner layer is formed as a single layer or composite layers by forming a tape-like good conductor material into a pipe-like configuration with its joint made a mere butt, or by assembling together a plurality of pressure resisting material segments equally divided in the circumference direction for at least one layer of the inner layer and having housed the above-mentioned at least one coated optical fiber in an optical fiber housing space defined centrally of the inner layer. The outer layer is formed by winding a metal tape on the inner layer.

Optical fiber submarine cable

An optical fiber submarine cable comprising at least one optical fiber. A pipe-like pressure resisting layer is produced by forming a tape-like pressure resisting material into a pipe-like configuration with the optical fiber inserted therein. The pressure resisting layer has butt ends in its cross section, and a waterproof insulator layer is disposed closely around the pipe-like pressure resisting layer for maintaining the pipe-like configuration of the pipe-like pressure resisting layer and for preventing seawater from entering into a gap between the butt ends.

An optical fiber introducing equipment for an optical submerged repeater, in which for introducing an optical fiber for optical communication into an optical submerged repeater housing through an introducing hole, the coating of the portion of the optical fiber to be disposed in the introducing part is entirely removed for a suitable length; the coated optical fiber having the exposed fiber portion is inserted into a small-diametered metal cylinder having an insertion hole which has an inner diameter more than several times as large as the outer diameter of the coated optical fiber; an adhesive whose volume remains substantially unchanged even if hardened is filled between the optical fiber and the insertion hole to unite the optical fiber and the metal cylinder; seawater preventing means is provided on the outside of the adhesive for preventing the adhesive from making direct contact with seawater; and the metal cylinder is disposed in the introducing hole provided at a part of the repeater housing.

Optical fiber introducing equipment for optical submerged repeater

The error rate and the operation of repeaters inserted in an optical transmission line are monitored at the terminal station on land by transmitting the test signal and monitoring the response signal of repeaters through the optical data transmission line without utilizing interstitial copper pair. Each repeater has the particular identification code, and the transmission terminal transmits the test code having the repeater identification code and an acknowledgement block with an empty bit position on the time divisional basis with the data to be transmitted. The repeater which finds his identification code in the test code, inserts the response in the acknowledgement block, and repeats the signal including both said test code and the data to be transmitted. The reception terminal analyzes the response signal of each repeater to determine the error rate of each repeaters.

Monitoring system for optical transmission line repeaters

A digital signal repeater selecting system for a digital signal transmission system equipped with a plurality of digital signal repeaters disposed on a transmission line at desired intervals, in which there are provided in each of the repeaters a delay circuit having a particular delay time corresponding to an integral multiple of the unit code length of a digital signal and assigned to the repeater and having its input terminal connected to the transmission line, and a code comparator for comparing the input signal to and the output signal from the delay circuit with each other to produce a predetermined output signal when the both signals are decided to be substantially identical with each other, and in which when a repeater selecting code train repeating in synchronism with the delay time is applied to the transmission line, the repeater to which the delay time is assigned produces the predetermined output signal from the code comparator to allow an operation of selecting the repeater. The above principle can be applied to monitor the condition of the transmission line.

Growing community of inventors

Machida, Japan

Masanori Sato