• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.331-337
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• 2022

The length of optical fiber in dispersion-managed link combined with optical phase conjugation to compensate for signal distortion caused by chromatic dispersion and nonlinear Kerr effect is a major factor determining the compensation effectiveness. The dispersion-managed link consists of several fiber spans in which standard single mode fiber and dispersion compensating fiber are arranged. In this paper, the compensation effect in the link that changes residual dispersion per span only by adjusting the length of one type of optical fiber, which is different in the first half link and the second half link with respect to optical phase conjugator (OPC), has been investigated. It was confirmed that the best compensation for 960 Gb/s wavelength division multiplexed signal could be obtained in the dispersion-managed link, in which the cumulative dispersion profile is symmetric around the OPC, and the cumulative dispersion amount is all positive in the first half, and all the cumulative dispersion amount is distributed negatively in the second half.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.2
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• pp.1-5
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• 2007

Wavelength-division multiplexed (WDM) networks are emerging to be the right choice for the future transport networks. In WDM networks, the optical layer provides circuit-switched lightpath services to the client layer such as IP, SONET and ATM. The set of lightpaths in the optical layer defines the virtual topology. Since the optical switches are reconfigurable, the virtual topology can be reconfigured in accordance with the changing traffic demand pattern at theclient layer in order to optimize the network performance. We present a new approach to the virtual topology reconfiguration and loadbalancing problem for wavelength-routed, optical wide-area networks under dynamic traffic demand. By utilizing the measured Internet backbone traffic characteristics, our approach follows the changes in traffic without assuming that the future traffic pattern is known. For the simulation traffic modeling, we collected the data from real backbone traffic. Experiments show that the standard deviation compared to previous technique is reduced.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.35-44
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• 2006

Reflective semiconductor optical amplifiers(R-SOAs) were designed with high gain, wide optical bandwidth, high thermal reliability and wide modulation bandwidth in TO-can package for the transmitter of wavelength division multiplexed-passive optical network(WDM-PON) application. Double trench structure and current block layer were introduced in designing the active layer of R-SOA to enable high speed modulation. The injection power requirement and the viable temperature range of WDM-PON system are experimentally analysed in based on Amplified Spontaneous Emission(ASE)-injected R-SOAs. The effect of the different injection spectrum in the gain-saturated R-SOA was experimentally characterized based on the measurements of excessive intensity noise, Q factor, and BER. The proposed spectral pre-composition method reduces the bandwidth of injection source below the AWG bandwidth and thereby avoids spectrum distortion impeding the intensity noise reduction originated from the amplitude squeezing.

• The KIPS Transactions:PartC
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• v.10C no.4
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• pp.447-454
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• 2003

Optical burst switching (OBS) has been proposed to reduce the use of fiber delay lines (FDLs) and to realize the optical switching paradigm of the next-generation ail optical networks. The OBS can provide improvements over wavelength routing in terms of bandwidth efficiency and core network scalability via statistical multiplexing of bursts. Recently, another challenging issue is how to upport quality of service (QoS) in the optical burst switching networks. In this paper, we propose a deflection routing scheme to guarantee the QoS for the OBS networks to detour lower priority burst forward to the deflection routing path when congested. A big advantage of the proposed scheme is the simplicity of QoS provision, that comes from the simple QoS provisioning algorithm. Also, the QoS provisioning scheme be able to make efficient networks by fairly traffic distributing with the reduce of the use of FDLs at core routers. The QoS provisioning scheme has been verified to reliably guarantee the QoS of priority 0, 1, 2 burst and to efficiently utilize network resources by computer simulations using OPNET As results, the end-to-end delay of high priority burst is improved, and the network efficiency is also improved.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.56-62
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• 2006

Currently, Most of the Backhual and Submarine's networks are being installed using DWDM and EDFA to deal with dramatically increasing internet traffic. In a conventional type optical system, the so-called 3R repeater, fiber non- linearity was not significant factor but it is one of the most important consideration when designing new DWDM network based on the EDFAs. To minimize the signal pulse distortion in long-haul optical network, Zero-dispersion fiber is indispensable but causes the fiber non-linearity. Therefore this conflicting problems should be managed to transmit a high-speed capacity traffic. In this paper, key technologies in DWDM submarine optic network were found out for a high capacity traffic and introduced the dispersion management way for solving the conflicting problems between Zero-dispersion and non-linearity. Lastly designed a dispersion map in section between Korea and Hong-kong.