• Title, Summary, Keyword: Fiber network

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The Development of Optical Fiber Line Operation and Monitor System (광선로 운용감시 시스팀 개발)

  • Kim, Seong-Il;Choi, Shin-Ho;Park, Kap-Seok;Jang, Eun-Sang;Lee, Byeong-Wook
    • Proceedings of the KIEE Conference
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    • pp.2492-2494
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    • 1998
  • Recently the optical fiber lines have been widely deployed in the trunk lines and digital data service network. The unexpected failures of optical fiber lines by natural disasters and road construction work have increased rear by rear and the number of damaged telecommunication lines per failures is on increasing. In the meantime, it takes long time to recover the optical fiber lines failures. So, it is important to maintain and monitor the status of optical fiber lines for prevention of optical fiber lines failures. Therefore, KT(Korea Telecom) needs efficient and automatic maintenance system to operate and monitor the optical fiber lines. FLOMS(Fiber Line Operation and Monitor System) had been developed in '96 and pilot system was installed at telephone offices in '97. This paper describes the FLOMS which carries out the functions of efficient maintenance and supports for monitoring optical fiber lines and managing facilities in optical fiber lines.

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Suggestion of an Fiber Channel-Embedded IPTV STB for Optical Fiber-based IPTV Networks (광섬유 기반 IPTV 네트워크를 위한 FC 내장형 IPTV STB 제안)

  • Chung, Sung-Wook
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.3
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    • pp.213-219
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    • 2017
  • Recently, the Internet Protocol Television (IPTV) services have become very common, enabling various Internet-based services as well as watching TV. In the IPTV system, a Set-Top box (STB) plays a key role as a network terminal device that transmits and receives realtime multimedia contents. In addition, the IPTV networks are usually supported by broadband optical fiber-base network such as fiber-to-the-home (FTTH), However, a general IPTV STB is regarded as one of the local area network (LAN)-attached devices while sharing the bandwidth of the LAN (e.g., Ethernet). In order to overcome the limited bandwidth utilization by fully facilitating the broadband bandwidth (e.g., 1 Gbps) of the optical fiber-based network, we propose a new FC (Fiber Channel)-embedded IPTV STB which can be directly attached to the optical fiber network. Then, we verify that the impacts of the proposed FC-embedded IPTV STB by organizing the the FC-AL (Fiber Channel-Arbitration Loop) network equipped with the FC-embedded IPTV We measures the average Start-up Delay, Average Reject Ratio and the Number of Concurrent Users through extensive simulations to investigate the performances of the suggested FC-AL-based IPTV network. Surprisingly, the IPTV network architecture with the proposed FC-embedded IPTV STBs has an excellent average start-up delay of less than 10 msec, an acceptable average reject ratio of less than 3 % as well as a linear increase of the number of concurrent users when extending the architecture. This reveals that the proposed FC embedded STB has a superior impacts on the performance of the entire IPTV network by effectively utilizing the broadband bandwidth of the fiber optic-based network.

Fabrication and Analysis of Chirped Fiber Bragg Gratings by Thermal Diffusion

  • Cho, Seung-Hyun;Park, Jae-Dong;Kim, Byoung-Whi;Kang, Min-Ho
    • ETRI Journal
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    • v.26 no.4
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    • pp.371-374
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    • 2004
  • We propose and demonstrate a fabrication method of chirped fiber gratings by a thermal diffusion process. The method could suggest a direction for a simple and cost-effective implementation of chirped fiber grating-based devices.

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Optical Super-highway Network Maintenance and System Trends (초고속통신망 광케이블의 유지보수 및 시스템 발전방향)

  • Choi, Shin-Ho;Lee, Byeong-Wook;Park, Kap-Seok;Jang, Eun-Sang;Kim, Seong-Il
    • Proceedings of the KIEE Conference
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    • pp.2495-2497
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    • 1998
  • Fiber optic facilities are increasingly being deployed in loop applications for both busines and residential areas. These facilities support a variety of communications services that include high speed data and video using leading technologies such as Synchronous Optical Network (SONET), Wavelength Division Multiplexing(WDM). This proliferation of fiber optic facilities combined with the increasing pressure on network operators to reduce costs are fostering increased automation to reduce labor costs associated with providing and maintaining communications services. Effective fiber management and accurate records can improve the reliability and integrity of the future telecommunications networks and the quality of customer services. This paper describes the trend forward and the need for the deployment of Fiber Administration System (FAS) into the operations enviroment of a typical network provider.

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국내가입자망에서의 광 전송 기술응용

  • 이종희
    • Information and Communications Magazine
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    • v.3 no.1
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    • pp.52-63
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    • 1986
  • This paper discusses the network evolution strategies, worldwide trends in fiber optics systems, fiber hub in KTA access network, positioning the access network for new digital services - DLC(Digital Loop Carrier), CSA(Carrier Serving Area), and fiber optics systems overlay in the existing access network and its evolution toward near term ISDN.

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Performance of Bipolar Optical Spectral Encoding CDMA with Modified PN Codes

  • Chang, Sun-Hyok;Kim, Bong-Kyu;Park, Heuk;Lee, Won-Kyoung;Kim, Kwang-Joon
    • ETRI Journal
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    • v.28 no.4
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    • pp.513-516
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    • 2006
  • Experimental demonstration of bipolar spectral encoding code-division multiple-access with modified pseudorandom noise codes is presented. Bipolar spectral encoding is achieved with an erbium-doped fiber amplifier amplified spontaneous emission source and arrayed waveguide gratings. The bit-error rate performance of 1.25 Gbps signal transmission over 80 km single mode fiber is measured in a multiple-user environment.

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Implementation of Fiber Optic and Wireless Complex Communication Network for Distribution Automation using IEEE 802.11a WLAN technology (IEEE 802.11a WLAN 기술의 사용에 의한 배전자동화용 광무선 복합통신망의 구현)

  • Hwang, Jin-Kwon;Choi, Tae-Il
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.10
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    • pp.49-57
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    • 2010
  • In order to provide electricity to users economically and safely, distribution automation systems (DASs) monitor and operate components of distribution systems remotely through communication networks. The fiber optic communication network has been mainly installed for the DAS of Korea Electric Power Corporation (KEPCO) because of its huge bandwidth and dielectric noise immunity. However, the fiber optic communication network has some shortcomings that its installation cost and communication fee are expensive. This paper proposes a complex network where WLANs are combined with conventional fiber optic communication networks in order to expand DAS easily and inexpensively. A fixed wireless bridge communication unit (FWB-CU) for the proposed complex network is implemented using IEEE 802.11a WLAN technology. The proposed complex network is built actually to verify its feasibility experimentally as a DAS communication network.

Paper Strength Mechanism Depending on Mixing Ratio of Softwood and Hardwood Fibers (침엽수, 활엽수 펄프섬유의 혼합비에 따른 종이의 강도발현 기작 구명)

  • 이진호;박종문
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.3
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    • pp.1-8
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    • 2001
  • Paper consists of fiber network and paper properties were highly affected by fiber characteristics. Many researchers have tried to relate fiber and paper properties. Softwood and hardwood fiber's are quite different in their properties. Generally, softwood fiber's are longer and more flexible than hardwood fibers. At present, many paper mills make mixed paper with softwood and hardwood fibers except for special grade. During fracture some fiber's are broken and others are pulled out. In this paper, the number of broken and pulled out fiber's during fracture is analyzed depending on the mixing ratio of softwood and hardwood fiber's. Fiber length, curl, kink, coarseness, WRV and formation index were measured. Double-edged strength samples were prepared to observe the number of broken and pulled out fiber's. Mixed paper strength was decreased with increasing hardwood fibers ratio. During fracture, softwood fiber's were more likely broken and hardwood fibers were more likely pulled out. The strength of paper which consists of softwood fibers was determined by fiber's broken strength and that of hardwood fibers by fiber's debonding strength. Paper strength was changed depending on the fiber's bonding capability. If the fiber is longer and more flexible, the fiber network becomes stronger and stiffer.

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A survey on the topological design models for fiberoptic subscriber loop networks (광가입자 선로망 구성을 위한 설계모형 조사연구)

  • 윤문길;백영호
    • Korean Management Science Review
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    • v.11 no.3
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    • pp.103-128
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    • 1994
  • Due to the trend of evolution toward a broadband communication network with fiber-optics, the design and operation of fiber-optic network have been received a great deal of research attention recently. Furthermore, even a single fiber link failure in the network may result in severe service loss. Thus, the network survivability becomes an importantissue in planning and designing the network. This survey is on modelling of various fiber-optic subscriber loop network(FSLN) design problems, which are essential ones for providing broadband communication services and B-ISDN services. Models are classified and investigated as either conventional decomposition-iteration approach or integrated design method. To build survivable networks, SHR models are also suggested by ring control schemes. The result of this study will be effectively applied to build a design model for FSLN in the practical applications.

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Development of Model of Shear Strength Estimative for Steel Fiber Reinforced Concrete Using Neural Network (신경망 기법을 이용한 강섬유 혼입 콘크리트의 전단강도 추정 모형 개발)

  • Kwak, Kae-Hwan;Hwang, Hae-Sung;Kim, Woo-Jong;Jang, Hwa-Sup;Kang, Shin-Muk
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.2
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    • pp.27-36
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    • 2007
  • This study, the present study wishes to develop a model that estimates shear strength characteristics of steel fiber reinforced concrete using artifical neural network models. Neural network models, developed as mathematical models, are being widely used not only in its original purpose of pattern recognition, but also in application fields by the function's nonlinear loaming and interpolar ability Neural network has a repetitive rotation algorithm that can cyclically and repeatedly estimate system conditions and parameter ideal values, and it can be used in the modeling of the nonlinear system by nonlinear characteristic functions that construct the system.