Submarine Optical Cable Research Articles

PLGR 작업을 위한 실시간 모니터링 시스템의 설계 및 구현

해저 광테이블 공사는 해양조사, PLGR(Pre Lay Grapnel Run), 천해부공사, 포설/매설 순서로 이루어진다. PLGR은 케이블의 해저면 안착을 용이하게 하고, Plough 및 ROV(Remotely-Operated Vehicle)매설작업의 성능을 향상시키며, 매설 장비를 보호하기 위한 작업이다. 본 논문은 해저 광테이블 건설 작업 중에서 PLGR 작업을 효율적으로 관리할 수 있는 실시간 모니터링 시스템의 설계 및 구현에 대해서 논한다. 본 논문에서는 이를 위하여 전체적인 실시간 모니터링 시스템을 설계하고, 시리얼 멀티포트 통신 모듈, 실시간 처리 모듈, 환경 설정 모듈, 그리고 그래프 및 프린터 출력 모듈을 설계 및 구현하였다. 끝으로 본 논문의 타당성 검토를 위하여 시리얼 멀티포트 통신, 실시간 데이터 추출, 그래프 출력을 실험하였다. Submarine optical fiber cable construction consists of marine survey, PLGR(Pre Lay Grapnel Run), shore-end-work, laying the submarine optical cable. This PLGR is work to ease the cable lay safely in seabed, improve the performance of Plough and ROV (Remotely-Operated Vehicle) laying work, and protect laying equipment. This paper presents the design and implementation of real-time monitoring system for PLGR work in submarine optical fiber cable construction enterprise. In this paper, we designe overall real-time monitoring system. For this purpose, the modules such as serial multiport communication module, real-time processing module, environment configuration module, real-time graph and a printout modules are designed and implemented. For the validity evaluation of this paper, serial multi port communication module, data parsing, realtime graph output are implemented and tested.

Low-loss submarine optical fibre cable for repeaterless submarine transmission system employing remotely pumped EDF and distributed Raman amplification

A low-loss submarine optical fibre cable for a long-distance repeaterless submarine transmission system employing remote pumping is described. The features of this system are an increased signal power budget and the provision of cost-effective submarine transmission systems that are easy to maintain. The relationship between the signal and pump losses of optical fibre needed to achieve a repeaterless submarine transmission system operating at 2.5 Gbit/s over a distance exceeding 370 km were investigated. A submarine optical fibre cable based on the results was manufactured and confirmed to have low-loss and stable transmission characteristics for practical applications in submarine repeaterless transmission systems.

Review on recent optical submarine cable network systems - 4. The latest technological trend of optical submarine cable.

Review on recent optical submarine cable network systems - 4. The latest technological trend of optical submarine cable.

Optical Submarine Cable System Technologies: Present and Future

Optical Submarine Cable System Technologies: Present and Future

Time evolution of polarisation mode dispersion in 120 km installed optical submarine cable

The timewise evolution of polarisation mode dispersion (PMD) is measured. PMD varies very slowly in a 120 km installed optical submarine cable. The measured timewise evolution of PMD suggests that compensation with a response time shorter than a few minutes can greatly reduce the system performance degradation caused by PMD.

Field demonstration of endless polarization control in 195-km installed optical fiber submarine cable at a sea depth of 2900 m

A low-insertion loss module with rotatable fractional wave plates was used to achieve endless polarization control at the output of a 195-km-long 2900-m deep-sea optical fiber submarine cable. The module could be compensated for state of polarization (SOP) fluctuations for frequencies up to 3 Hz. It was confirmed that a module with mechanical rotatable fractional wave plates could be used to control the real polarization variations that occur in installed optical submarine cables. >

Fiber Length Dependence of Polarization Mode Dispersion Measurements in Long-Length Optical Fibers and Installed Optical Submarine Cables

Fiber Length Dependence of Polarization Mode Dispersion Measurements in Long-Length Optical Fibers and Installed Optical Submarine Cables

Three Dimensional Dynamic Analysis for Laying and Recovery of Optical Submarine Cables

The author has developed two types of cable laying simulation programs based on three dimensional dynamic analysis method in order to analyze dynamic behavior of cables, repeaters and branching unit during laying and recovery.One is a computer simulation program for laying and recovery of submarine cables with repeaters. This program has following two new functions is addition to conventional cable laying simulation.(1) Slack control laying function. The cable pay-out speed is automatically calculated by internal feed back loop so as to make bottom cable slacks be constant. Using this function, the optimum cable pay -out speed history can be obtained by giving the bottom profile and cable ship speed profile.(2) Tension control laying function. The cable pay-out speed is automatically calculated by internal feed back loop so as to make shipboard tension be constant. The speed error of cable ship measured by 'taut wire' is discussed using this program. This error is exactly analyzed using this tension control laying simulation.The other is a computer program for laying and recovery submarine cables with a cable branching unit. The cable branching unit (BU) is newly installed to the optical submarine cable systems. This newly developed program can analyze dynamic behavior of BU and cables around it, and help to study how to lay BU with sufficient cable slacks and recover it safety.The sea trial was carried out in order to measure hydrodynamic constant of the submarine cable and verify this computer simulation method at the depth of 6000m by attaching sensors to the submarine cable at some intervals. According to the sea trial, the normal drag coefficient Cd was measured to 2.5, andd the cable configuration measured by this experiment was in good agreement with the result of the computer simulation.

Polarization mode dispersion measurements in an installed optical fiber submarine cable

Highly accurate polarization mode dispersion (PMD) measurement using an interferometric detection technique with AC modulation is discussed. This technique, which searches for the interference fringe signal, was used to measure PMD in a 60 km long installed optical submarine cabled fiber 2500 m sea depth and to determine the fiber-length dependence of PMD. PMD measurement in 60-km-long installed optical submarine cabled fibers was confirmed to be less than about 0.7 ps. It was found that the fiber length dependence of the PMD measurement in the less than approximately 20-km-long cascaded uncabled fibers was proportional to square root L; however, the PMD data in the long-length (over approximately 50 km long) fibers were slightly scattered. >

A 126 km unrepeatered optical fibre submarine cable between Ireland and the U.K.

A 126 km unrepeatered optical fibre submarine cable between Ireland and the U.K.

Sea trial of submarine optical amplifier repeater system using travelling-wave semiconductor laser amplifier

An optical amplifier repeater system consisting of semiconductor laser amplifiers was evaluated in 3000 m deep sea at 820Mbit/s in the 1.5μm wavelength region using 23.5 km of optical submarine cable. The repeater output power was stabilised by the APC system monitoring amplified optical signal power. We confirmed stable digital signal transmission and the reduction of variation in the repeater output power for changes in the polarisation of the input signal.

Design of world loop networks and effectiveness evaluation of dynamic routing

AbstractIntercontinental optical submarine cables with larger capacities than conventional coaxial cables are now being developed. In accordance with international communication demand evolution and digitalization, worldwide optical submarine cable networks will be constructed. A loop network around the world in an east‐west direction, composed of optical submarine cables is considered to be an international backbone trunk network due to the advantages in simplicity, efficiency and reliability. Since the proposed design method aims at making a macroscopic network planning outline rather than making a detailed network design, the stochastic process of traffic is neglected and the traffic is treated as stationary flow. We present the strategies to evolve the world loop network and the increased traffic demand that reflects the actual international communication traffic trend. In addition to the conventional routing scheme in which mainly direct routes are used, a dynamic routing scheme in which routes composed of up to two tandem links are used is studied, and its effectiveness through network evolution is quantitatively evaluated.

Reduction of high surge voltage on coiled optical fibre submarine cable

The induced high surge voltage caused by a sudden change of feed current on the long coiled optical fibre submarine cable has been measured. The reduction methods of the induced voltage have been examined and their effects are demonstrated.

Water propagation blocking properties of submarine optical fiber cables

AbstractA transit transmission system for a long‐distance digital transmission line using a submarine optical fiber cable is expected to be used at water depth of 8000 m and transit distance of 40 km. This paper introduces a fundamental design for a submarine optical‐fiber cable for deep‐sea use, which can block water propagation within the cable if it is cut accidentally on the sea bed. Evaluations of the water‐blocking properties and signal transmission characteristics of the cable are presented also. The water propagation in the cable can be approximated by the stationary laminar flow of viscous fluid in a capillary tube. The distance of the water propagated is proportional to 0.5 power of the water pressure and 0.3 to 0.5 power of time. The transmission loss of the prototype submarine optical cable (with the water propagation blocking properties) is less than 0.04 dB/km. The propagation of water within the cable is estimated to be less than 800 m per month at water depth of 8000 m. This shows that the cable has practical application.

Arc fusion splicer with profile alignment system for high-strength low-loss optical submarine cable

In order to obtain a high-strength low-loss splice for an optical submarine cable, a new arc fusion splicer and a splice recoater with a prooftester have been developed. This splicer utilizes a profile alignment system (PAS) with a programmable discharge method for the alignment of the core axis. An average splice loss of 0.11 dB and strength of 2.95 GPa were achieved. The splicing is finished in about a half of the time of a conventional splicing system because the PAS system can simplify the loss measuring process and aligning procedure than using the conventional optical power monitoring method. The reliability of the recoated splice portion has been tested and confirmed. The splicing system can be sufficiently used for making an optical submarine cable.

Submarine optical cables: a phenomenon of resonance in suspended lengths

The advent of submarine optical cables has highlighted a problem which did not seriously affect coaxial systems. The letter discusses a resonance problem which affects safe cable design for deep-water use.

Water propagation blocking properties of submarine optical fibre cable

A submarine optical fibre cable is developed which has excellent water propagation blocking properties. Propagation is estimated to be less than 750 m/month at a depth of 8000 m. It also has low-loss properties of 0.40 dB/km at a wavelength of 1.3 μm.

The submarine optical cable of the SUBMARCOM S 280 system

Submarine optical telecommunication cables must satisfy a large number of specific items. To comply with specifications. CDL has developed a cable structure based on high-performance optical fibers placed with slack in the grooves of a plastic rod put in the center of a very strong cable. The deep-sea cable is the basic structure for armored cables or land cables. Armor transitions are designed to minimize cable twist. The couplings are designed to give a good optical electrical and mechanical continuity between the cable and the repeaters. The deep-sea repair is designed to be achievable on a cable ship. The cables, repairs, and couplings have successfully sustained several sea trials and two experimental links are now operating. No increase of the attenuation of the optical fibers in the cable have been noticed on the 19-month old first link. The development of the S 280 cable is proceeding on the right track.

The Submarine Optical Cable of the Submarcom S 280 System

Submarine optical telecommunication cables must satisfy a large number of specific items. To comply with specifications, CDL has developed a cable structure based on high-performance optical fibers placed with slack in the grooves of a plastic rod put in the center of a very strong cable. The deep-sea cable is the basic structure for armored cables or land cables. Armor transitions are designed to minimize cable twist. The couplings are designed to give a good optical electrical and mechanical continuity between the cable and the repeaters. The deep-sea repair is designed to be achievable on a cable ship. The cables, repairs, and couplings have successfully sustained several sea trials and two experimental links are now operating. No increase of the attenuation of the optical fibers in the cable have been noticed on the 19-month old first link. The development of the S 280 cable is proceeding on the right track.

Optical loss measurement results on an experimental optical fibre submarine cable of 30 km length

A continuous length of 30 km optical fibre submarine cable was successfully manufactured and laid on the sea bed about 1000 m deep. After the sea trial of 17 months, the cable was recovered from the sea bed. No significant degradation was observed in the optical loss of the recovered cable.