• 한국정보통신설비학회:학술대회논문집
• /
• 2003.08a
• /
• pp.159-162
• /
• 2003

This paper presents a novel heuristic mechanism, Dynamic-network Adapted Cost selection (DAC-selection), which has higher backup path sharing rate, lower number of blocked channel requests and number of used wavelengths fer reservation of working path and backup path by using unique cost function than that of widely used random selection (R-selection) mechanism and Combined Min-cost selection (CMC-selection) mechanism proposed by Lo, while maintaining 100% restoration capability.

• Journal of the Optical Society of Korea
• /
• v.11 no.3
• /
• pp.101-107
• /
• 2007

In this paper, we have presented the results of Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) based fiber-to-the-home (FTTH) field trial test which was held in the city of Gwangju. We have implemented an injection locked Fabry-Perot Laser Diode (FP-LD) based WDM-PON system and reliably delivered Internet Protocol TV (IP-TV), networked Personal Video Recorder (N-PVR), High-Definition Video on Demand (HD-VoD), Education on Demand (EoD) and Internet service as FTTH service through the system during the field trial test. We have also verified that the WDM-PON system worked well to provide quality of service (QoS) guaranteed 100Mbps bandwidth per subscriber. Furthermore, we have presented network designing issues in Outside Plant (OSP) and Customer Premises Network (CPN) that should be overcome to efficiently deploy FTTH service. Finally, based on the field trial test results, we proposed FTTH service deployment strategies.

• International Journal of Internet, Broadcasting and Communication
• /
• v.4 no.2
• /
• pp.22-27
• /
• 2012

The design characteristics of circular vertical-cavity surface-emitting lasers are studied by using a newly developed equivalent network. Optical parameters, such as the stop-band or the reflectivity of periodic mirrors and the resonance wavelength, are explored for the design of these structures. To evaluate the differential quantum efficiency and the threshold current density, a transverse resonance condition of modal transmission-line theory is also utilized. This approach dramatically reduces the computational time as well as gives an explicit insight to explore the optical characteristics of circular vertical-cavity surface-emitting lasers (VCSELs).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.05a
• /
• pp.550-555
• /
• 2001

최근 Internet의 가장 보편적이고 저렴한 Backbone Network 기술이다. 이러한 Internet의 전달 능력은 그대로 이용하면서 보안이 우수한 가상 사설망(VPN)을 구축하는 기술에 대한 수요가 증가하고 있다. 본 논문에서는 MPLS 기반의 터널링을 이용한 VPN망 구축 방안과 광 경로(Lightpath)를 갖는 Optical VPN에서 고려해야할 사항에 대해 제시하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.5
• /
• pp.119-123
• /
• 2015

This paper presents a theoretical study of transmission performance for an optical NRZ (nonreturn-to-zero) transmitter employed a Mach-Zehnder modulator. Especially, we have investigated the effects of the ${\alpha}$-parameters that represents the chirps and the driving voltage ratios(=driving voltage/switching voltage) of Mach-Zehnder modulators for transmitting 25Gbps optical NRZ signals at a wavelength of 1550nm without any dispersion compensation methods over single mode fiber. By optimizing the negative values of ${\alpha}$-parameters for the dispersion tolerance with the change of driving voltage ratios, it has been tested whether the transmission performance has improved. We have verified the improvement by the BERs and the optical eye diagrams.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.2
• /
• pp.89-94
• /
• 2017

This paper presents a theoretical study of transmission performance for optical duobinary transmitters employed a Mach-Zehnder modulator. Especially, we have investigated the performance of the various transmitters for transmitting 25Gbps optical duobinary signals at a wavelength of 1550nm without any dispersion compensation methods over single mode fiber. Due to the characteristics of generating their duobinary signals, each transmitter has a distinct optical power spectrum and an eye opening shape. By these, there was a difference in the dispersion tolerance. We could find a suitable transmitter for 25Gbps transmission considering the structure complexities and the restricted conditions with the simulation results.

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.07a
• /
• pp.10-11
• /
• 2003

완전 광 레이블 스위칭 기술은 차세대 광 인터넷에서 요구되는 투명성과 낮은 latency를 주기 위한 핵심기술이다. 패킷 스위칭 시스템은 각 노드에서 레이블을 이용해 패킷을 교환하는 방식으로 각 라우터에서는 이전 라우터에서 전달해 은 레이블을 분석하고 그 레이블 신호에 따라서 목적지로 포워딩 시키게 된다. 레이블을 교환하는 기술은 MLS 또는 완전 광 레이블 스위칭 (Optical label Switching： OLS) 네트웍에서 scalability를 구현하기 위한 핵심 기술이 된다. (중략)

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.9B
• /
• pp.760-773
• /
• 2003

The Internet is evolving from best-effort service toward an integrated or differentiated service framework with quality-of-service (QoS) assurances that are required for new multimedia service applications. Given this increasing demand for high bandwidth Internet with QoS assurances in the coming years, an IP/MPLS-based control plane combined. with a wavelength-routed dense-wavelength division multiplexing (DWDM) optical network is seen as a very promising approach for the realization of future re-configurable transport networks. This paper proposes a differentiated lambda establishment process for QoS guarantees based on the differentiated MPLS service (DMS) model. According to the QoS characteristics of wavelength in optical links and the type of used Optical Cross-Connect (OXC) nodes in DWDM next generation optical Internet backbone network, a differentiated wavelength assignment strategy that considers QoS recovery capability is also suggested.

• Journal of KIISE:Information Networking
• /
• v.29 no.4
• /
• pp.405-411
• /
• 2002

Open interfaces in the optica] Internet have been progressed by OIF's ISI, ITU-T ASTN's CCI and IETF's GSMP extensions with optical switching. These open interfaces enable the separation between the control plane and the optical transport plane. This separation allows flexibility in the network, but it suffers more setup delay than the traditional switch-by-switch connection setup. We propose the parallel interworking model, which will reduce the connection setup delay in the open interface of optical Internet. Based on the switch controller's caching capability about networks states, the parallel interworking procedures between signaling protocol and GSMP protocol are performed in the switch controller. We simulated and evaluated our proposed parallel interworking model and the existing sequential interworking model in terms of a connection setup delay and a completion ratio. We observed that the completion ratios of the two interworking models were quite close. However the connection setup delay of parallel interworking model is improved by about 30% compared with that of the sequential interworking model.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.3
• /
• pp.217-222
• /
• 2012

Using modal transmission-line theory (MTLT), it explores rigorously the polarization characteristics of plasmonic optical polarizer. To verify the validity of the approach proposed in this paper, a novel polarization condition, which is called mode suppression ratio, is defined. The numerical results reveal that the polarization length of plasmonic optical polarizer is $10{\mu}m$ dramatically shorter than that of conventional dielectric optical polarizer. Furthermore, the insertion loss of plasmonic polarizer consisting of metal Ag is small enough to be neglected below -1dB.