• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1048-1058
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• 1999

This paper compares some architectures to achieve the optimized WDM architecture for all optical transport network, the comparison is presented in terms of the number of required wavelength and LT. These architecture types are PPWDM, SHWDM, DHWDM and fully optical WDM. Topology is a static ring network where the routing pattern is fixed and traffic pattern has uniform demand. This paper also proposes an algorithm for the wavelength assignment for a folly optical WDM ring network which has full mesh traffic pattern. The algorithm is based on heuristic algorithm which assigns traffic connections according to their respective shortest path. Traffic described here that is to be passed through can be routed directly within the optical layer instead of having the higher layer to handle it.

• The Transactions of the Korea Information Processing Society
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• v.7 no.9
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• pp.2958-2968
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• 2000

To effectively supervise WDM systems requires that the alarm signals for each optical transport network layer is considered. The related recommendations and studies for alarm signals are defining fundamental functions without specifying the structure and configuration of the supervisory channel. In this paper, we propose the detailed alarm signals and propagation flows for each optical transport network layer. We also describe the structure of overhead and the configuration of supervisory channel. Our proposals are based on the ITU T requirements of optical transport network and the supervisory schemes of terminal & add-drop systems. We show that our proposed schemes effectively performs supervisory functions for various fault conditions which will occur in terminal & add-drop typed WDM systems.

• Convergence Security Journal
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• v.12 no.1
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• pp.35-42
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• 2012

Increase of data traffic and the advent of new real-time services require to change from the traditional TDM-based (Time Division Multiplexing) networks to the optical networks that soft and dynamic configuration. Voice and lease line services are main service area of the traditional TDM-based networks. This optical network became main infrastructure that offer many channel that can convey data, video, and voice. To provide high resilience against failures, Packet-optical networks must have an ability to maintain an acceptable level of service during network failures. Fast and resource optimized lightpath restoration strategies are urgent requirements for the near future Packet-optical networks with a Generalized Multi-Protocol Label Switching(GMPLS) control plane. The goal of this paper is to provide packet-optical network with a hierarchical multi-layer recovery in order to fast and coordinated restoration in packet-optical network/GMPLS, focusing on new implementation information. The proposed schemes do not need an extension of optical network signaling (routing) protocols for support.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.17-20
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• 1999

In these days, wavelength division multiplexing(WDM) all-optical network are being deployed to support various multimedia communication services. In this paper, various WDM all-optical network are discussed, and a design of an all-optical backbone network has been proposed by using multiple self-healing ring technology. The proposed multiple self-healing ring network improves network expandability and efficiency of bandwidth, while it retains simplicity and ease of network control, which are from the nature self-healing ring. Using PDI traffic modeling technique, a well-balanced all-optical backbone network using multiple self-healing ring is designed for the 2010s in Korea.

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.59-62
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• 2004

차세대 지능형 광 전달망의 구축, 확산에 따라 새로운 개념의 L1 VPN인 Optical VPN에 대한 많은 연구가 이루어지고 있다. 현재까지의 Optical VPN은 OXC 시스템 제조업체가 제공하는 EMS/NMS의 부가 기능으로 구현되고 있으며 따라서 멀티 벤더 환경의 광 전달망 구조에서는 적용할 수 없는 문제점 있다. 본 논문에서는 표준화된 시그널링 인터페이스를 활용하여 이러한 문제점을 극복하고 CNM 및 bandwidth-on-demand 기능을 제공하는 새로운 Optical VPN 서비스 플랫폼의 개념 및 개발 현황을 소개한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.2964-2985
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• 2019

Global data center IP traffic is expected to reach 20.6 zettabytes (ZB) by the end of 2021. Intra-data center networks (Intra-DCN) will account for 71.5% of the data center traffic flow and will be the largest portion of the traffic. The understanding of traffic distribution in IntraDCN is still sketchy. It causes significant amount of bandwidth to go unutilized, and creates avoidable choke points. Conventional transport protocols such as Optical Packet Switching (OPS) and Optical Burst Switching (OBS) allow a one-sided view of the traffic flow in the network. This therefore causes disjointed and uncoordinated decision-making at each node. For effective resource planning, there is the need to consider joining the distributed with centralized management which anticipates the system's needs and regulates the entire network. Methods derived from Kalman filters have proved effective in planning road networks. Considering the network available bandwidth as data transport highways, we propose an intelligent enhanced SDN concept applied to OBS architecture. A management plane (MP) is added to conventional control (CP) and data planes (DP). The MP assembles the traffic spatio-temporal parameters from ingress nodes, uses Kalman filtering prediction-based algorithm to estimate traffic demand. Prior to packets arrival at edges nodes, it regularly forwards updates of resources allocation to CPs. Simulations were done on a hybrid scheme (1+1) and on the centralized OBS. The results demonstrated that the proposition decreases the packet loss ratio. It also improves network latency and throughput-up to 84 and 51%, respectively, versus the traditional scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.10
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• pp.2687-2702
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• 1996

It is desirable that the implementation of next generation information infrastructure is the Integrated Network combining the satellite and the terrestrial network. The application of the ATM network being the dominant infrastrure of terrestrial network to the satellite network is being studied variously. Considering these concepts, this paper analyzes due to ATM transport via satellite, evaluates the degradation of QoS and proposes reliable method of ATM cell transport via satellite. Because ATM is investigated with the optical fiber which is almost error free characteristics, the practical application of ATM transport via satellite essentially need the channel coding(FEC:Forward Error Correction) to enhance BER performance. But using the FEC coding, satellite link has burst error characteristics which evoke severe performance degradation fo ATM QoS. Therefore in satellite link, we analyze burst error characteristics using experimental results of computer simulation. Then to compensate these characteristics, based on this analysis and HEC dual mode algorithm we propose various interleaver structures(Block interleaver, Intra interlever, and Inter-Intra interleaver) to improve cell transmission QoS. We execute performance evaluations of iterleaver structures by computer simulation.

• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.47-54
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• 2013

In this paper, the structural design of optical Internet is analyzed and by using UNI (User Network Interface) signaling protocol an optical transmission experiment was performed. The hierarchical structure of the basic optical Internet consists of the backbone network, the service network and the access network. The necessary functions for each layer were described as follows: Control structure of the optical transport layer, network operation and management structure, internetworking technology of sub networks, routing and signaling technology. By using UNI signaling protocol from OIF (Optical Internetworking Forum), the optical transmission in the proposed structure of the optical Internet network was experimented. By the traffic generation of LSP (Label Switched Path) data packets along the route-configuration was delivered to UNI. Finally, by showing the value of TCP (Transmission Control Protocol) packets the optical transmission was completely and successfully demonstrated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1832-1840
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• 1999

This paper proposed a network to implement all optical bidirectional BLSR/4 WDM/SHR allowing restoration in the event of a failure. The proposed network can provide a high degree of transparency using all-optical components with no electric implementation and effective failure restoration due to BLSR/4 WDM/SHR architecture. This paper also presented a genetic simulation model for the survivability analysis of the proposed BLSR/4 WDM/SHR under failure scenarios, the restoration performance of the proposed network is analyzed in terms of performance parameters such as propagation time, processing time, optical switch time.

• TTA Journal
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• s.96
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• pp.69-77
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• 2004

We developed QoS based Optical Transport System for premium packet transport network.. Our system will reduce capital cost and operation cost. And also It generate QoS guaranteed L2 VPN service for enterprise. The key technologies are packet emulation for