• Journal of Institute of Control, Robotics and Systems
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• v.6 no.8
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• pp.666-671
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• 2000

With the current advances in optical WDM (Wavelength Division Multiplexing) networking technologies and the increasing demand for network bandwidth the Next Generation Internet is expected to be a network that runs IP(Internet Protocol) directly over WDM-based optical networks. The network control architecture for the IP over WDM networks is different from that of traditional Internet since the underlying WDM devices have more constraints than electronic IP routers such as the lack of optical buffers and wavelength continuity property etc. In this paper we introduce several architectural models for implementing IP over WDM networks and propose an integrated network control framework for the IP over WDM networks. This framework leverages the traffic engineering control architecture for the MPLS (Multi-Protocol Label Switching) networks and is mainly developed for the IP over packet-switched WDM networks. We also report several preliminary simulation results of contention resolution schemes in the packet-switched WDM networks.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.394-401
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• 2007

High speed all optical network is a viable option to satisfy the exponential growth of internet usage in the recent years. Optical networks offer very high bit rates and, by employing technologies like internet protocol over wavelength division multiplexing(IP-over-WDM), these high bit rates can be effectively utilized. However, failure of a network component, carrying such high speed data traffic can result in enormous loss of data in a few seconds and persistence of a failure can severely degrade the performance of the entire network. Designing IP-over-WDM networks, which can withstand failures, has been subject of considerable interest in the research community recently. Most of the research is focused on the failure of optical links in the network. This paper addresses the problem of designing IP-over-WDM networks that do not suffer service degradation in case of a single link failure. The paper proposes an approach based on the framework provided by a recent paper by M. Kurant and P. Thiran. The proposed approach can be used to design large survivable IP-over-WDM networks.

• ETRI Journal
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• v.28 no.1
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• pp.99-102
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• 2006

In this letter, we study the protection problem in wavelength division multiplexing (WDM) optical networks, and propose a novel dynamic heuristic algorithm called differentiated reliable segment protection (DRSP). Differing from previous work, DRSP can effectively avoid the trap problem and is able to find a feasible solution for each connection request. Therefore, DRSP outperforms the previous work. Simulation results have shown to be promising.

• Journal of the Optical Society of Korea
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• v.20 no.5
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• pp.557-562
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• 2016

In this paper, for the first time, the transmission performances of long-haul 100-Gb/s direct detection optical OFDM (DDO-OFDM) and coherent optical OFDM (CO-OFDM) wavelength division multiplexing (WDM) systems are compared by simulation. It provides specific guides for system parameter selection to get a high-performance and cost-effective OFDM WDM system. Specifically, the comparison involves three aspects: launched power is investigated to achieve better system performance; laser linewidth is numerically investigated to choose cost-effective laser; system dispersion tolerances with different laser linewidths are analyzed to further reveal the advantages and disadvantages of these two detecting methods, direct detection and coherent detection, in long-haul OFDM WDM system.

• ETRI Journal
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• v.29 no.4
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• pp.524-526
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• 2007

In this letter, we study the multicast protection problem in sparse-splitting wavelength-division multiplexing (WDM) optical network, and propose a novel multicast protection algorithm called the shared source-leaf path-based protection (SLPP) algorithm. Unlike the proposals in previous studies, the backup paths derived by SLPP can share wavelength with the primary tree in sparse-splitting WDM networks. Simulations are used to evaluate the effectiveness of the SLPP algorithm.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.11-14
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• 2006

This paper reviews the optical link technologies which have been developed for gigabit-per-second wavelength-division-multiplexing passive optical networks (WDM-PONs). Similarly to the 100Mb/s WDM-PON systems which have been deployed for trial services by KT, the most important requirement for 1Gb/s WDM-PON is wavelength independence (colorless feature) of its ONU/ONTs, which makes possible convenient operation and cost-effective maintenance with minimum inventory cost. Among various methods to implement such colorless feature, four promising candidates for gigabit WDM-PON are analyzed with their own development issues and their expected performances are compared.

• ETRI Journal
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• v.28 no.4
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• pp.517-520
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• 2006

In this letter, a new sharing mechanism, SRLG sharing, is proposed, which allows the links of the same shared risk link group (SRLG) in a primary light tree to share protections in WDM optical networks. In previous studies, how to share spare resources with SRLG constraints has not been studied in multicast optical networks. In this letter, considering SRLG sharing, we propose a novel algorithm -multicast with SRLG sharing (MSS)- to establish a protection light tree. Finally, the algorithm MSS and the algorithm multicast with no SRLG sharing (MNSS) are compared through a simulation to show that our new sharing scheme of SRLG sharing is more efficient than that of no SRLG sharing in terms of spare resource utilization and blocking probability.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.441-446
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• 2006

In recent years, WDM networks have received much attention as the Internet backbone networks because of the explosive growth of the Internet IP-based traffic. The Optical Burst Switching (OBS) has been proposed as an effective optical switching technology in the WDM networks. The OBS has the advantages in 1) the high usage rate of the bandwidth, and 2) no necessity of optical buffer. However, the OBS has the burst-contention problem in the networks. The deflection routing is proposed as one of means to solve this problem. In this paper, we propose a new routing method to minimize burst loss in the deflection routing based networks. In addition, we propose a QoS control method using a new routing algorithm. Finally, we show the variety of the proposed methods by computer simulations.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.43-48
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• 2019

We design a reconfigurable optical node for metropolitan WDM networks, and numerically study the capability of the node in the optical signal level. Unlike a long-haul WDM system, major limitations of metropolitan WDM systems are power loss, fiber dispersion and optical signal-to-noise ratio(OSNR) degradation due to EDFAs. Therefore, we include the behaviors of transmitter and receiver, and fiber, EDFAs, and optical filters(MUX/DeMux) in numerical simulations with varying parameters over wide range. From simulation results, we can identify the maximum span numbers for OC-48 and OC-192 to achieve $BER<10^{-12}$ using the node structure at various received powers and residual dispersions.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.473-476
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• 2000

WDM is a very promisinig technique for the realization of future All-Optical networks. WDM gives an advantage of high rate transmission without delay for Electronic/optical conversion. But the available number of wavelengths is limited by technical restriction. so the efficient optical path routing and wavelength assignment is needed. this paper is concerned with the efficient design of WDM optical transport networks. RWA assumes that the connection demands between node pairs are given. the objective of RWA is to minimize the number of wavelengths. these design consider the static routing and wavelength assignment in the network of arbitrary topology. To solve these problems, this paper proposes some heuristic algorithms.