• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.78-79
• /
• 2000

재구성이 가능한 광 크로스-커넥트(optical cross connect)는 전광 네트워크를 구성하기 위한 핵심소자 중의 하나이다. 일반적인 구조의 파장분배기는 공간분할 스위치(space division switch)를 두 쌍의 파장 다중화기(multiplexer)와 역다중화기(demultiplexer)의 가운데에 삽입하여 구현된다$^{(1)}$ . 최근에, 광섬유 브래그 격자와 광스위치 쌍을 직렬 연결하여 재구성이 가능한 광 크로스-커넥트가 제안되었다$^{(2)}$ . 그러나, 이 구조는 광신호에 따라 광섬유 브래그 격자에 반사되면서 겪는 광스위치에 의한 삽입손실이 다르다는 문제점이 있다. 이러한 문제를 해결하기 위하여 본 논문에서는 한 쌍의 파장 다중화기/역다중화기와 파장가변 광섬유 브래그 격자를 이용한 새로운 구조의 광 크로스-커넥트를 제안하고자 한다. 또한, 제안된 구조는 일반적인 구조의 파장분배기에 비해 파장 다중화기/역다중화기의 개수를 반으로 줄일 수 있는 장점이 있다. (중략)

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1997.10a
• /
• pp.245-248
• /
• 1997

As the increasing the demand on information service, high-capacity and high-speed telecommunication networks are required. For the networks, very intelligent telecommunication equipments such as DCS(Digital Cross-connect System) will be employed for the fast service on the various types of information including voice, data and image. This paper considers the transmission networks composed of DCSs and optical fibers as nodes and links of the networks, respectively. For the networks, some types of restoration algorithms are compared their characteristics for their potential applications. And a distributed control algorithm is described as an empirical example which is implemented on the BDCS(Broadband Digital Cross-connect System), where the BDCS is a type of DCS developed in Korea. Finally, some remarks on the associated further researches are added.

• Convergence Security Journal
• /
• v.13 no.6
• /
• pp.3-9
• /
• 2013

With the rapidly changing information communication environment and development of technologies, the informati on networks are evolved from traditional fixed form to an active variable network that flexible large variety of data can be transferred. To reflect the needs of users, the next generation using DWDM (Dense Wavelength Division M ultiplexing) transmission system and OXC (Optical Cross Connect) form a dynamic network. After that GMPLS (Ge neralized Multi-Protocol Label Switching) can be introduced to dynamically manage and control the Reconfigurable Optical Add-drop Multiplexer (ROADM)/Photonic Cross Connect (PXC) based network. This paper propose a softw are architecture of Path Computation Element (PCE) protocol that has proposed by Internet Engineering Task Force (IETF) to path computation. The functional blocks and Application Programming Interface (API) of the PCE protoco l implementation are also presented.

• ETRI Journal
• /
• v.24 no.2
• /
• pp.69-81
• /
• 2002

This paper reviews the existing research activities on signaling and control procedures for IP over optical networks. We focus on the IP-centric signaling and control architecture based on the generalized multi-protocol label switching (GMPLS) protocol and analyze various scenarios and technical issues for deploying the IP over an optical network. We analyze the signaling and operations and administration and maintenance requirements for integrating an IP network and an optical network in order to cope with the high bandwidth and poor resource granularity of the optical network, including the optical cross-connect system. On the basis of network architecture and a reference configuration model, we investigate the GMPLS-based control architecture and interconnection model appropriate for controlling IP bandwidth and optical lambda resources. The signaling and control procedure based on GMPLS on optical user-network interface and network-network interface are comparatively investigated to provide the optical lightpath. We also study protection and restoration procedures to protect link failure when it applies to generalized MPLS signaling.

• Proceedings of the KIEE Conference
• /
• 2000.11c
• /
• pp.594-596
• /
• 2000

The best simulation condition for the fiber collimator that uses ball lenses was investigated. This kind of fiber collimator can be used in a Micro-Optical-Cross-Connects(MOXC). MOXC is composed of collimating ball lenses, micro mirrors and single-mode fibers. In order to design a MOXC, it is very important to calculate beam path, beam radius, divergence angle that determines the insertion loss of the MOXC. Since the beam profile from the fiber facet is not exact Gaussian profile, it was found that the simulation condition in which beam waist exists on the fiber facet, ignoring Numerical Aperture(NA), gives best agreement with the experimental results. Beam radii were measured with conventional knife edge method.

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.2198-2200
• /
• 2000

This paper reports on the measurement of angle between micro mirror and substrate in. the Micro Optical Cross Connect(MOXC). MOXC consists of beam collimators and $N{\times}N$ micro mirrors that are fabricated by using MEMS technology. Using subpixel level image processing, it is possible to measure the angle with the resolution of 0.27$^{\circ}$.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.2
• /
• pp.220-223
• /
• 2006

In this paper, we studied about the level controller of optical signal with 40 channels by 4 VOA(Variable Optical Attenuator) with 12 channels. Total 8 microprocessors control 40 chamois for control of optical signal level so that a microprocessor controls 5 channels each. Moreover a microprocessor was added to communicate with outside and transfer instruction to each microprocessor. The output optical signal is measured and VOA is controlled as a result of it. The VOA outputs is inputted into PD(Photo Detector) at once. We could control multi-channel optical signals simply like this.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05b
• /
• pp.655-657
• /
• 2004

채널 레벨 컨트롤러는 DWDM(Dense Wavelength Division Multiplexing) 방식의 OXC(Optical Cross Connect), OADM(Optical Add/Drop Multiplexer), 광 증폭기(EDFA : Erbium Doped Fiber Amplifier) 둥의 시스템에서 채널별 광신호의 세기를 조절하여 시스템의 신뢰성을 높이는 중요한 제어기다. 본 논문에서는 12채널 VOA(Variable Optical Attenuator) 4개를 사용하여 40채널의 광 신호 레벨을 제어할 수 있는 컨트롤러를 구현하였다. 각 채널의 광 신호 레벨을 제어하는데 하나의 마이크로 프로세서가 5개의 채널을 제어하고 총 8개의 마이크로프로세서로 40채널을 분산 제어하도록 구성하였다. 또한 외부와 통신을 하고 사용자로부터의 명령을 각각의 마이크로프로세서에 전달하기 위한 마이크로프로세서를 추가하였으며, 출력되는 광 신호의 세기를 측정하여 VOA를 제어하는데 있어서 VOA 출력에서 바로 PD(Photo Detector)로 입력하여 AWC(Arrayed Waveguide Grating) 출력에서 광 신호를 다시 분파하여 PD에 입력하는 번거로움을 개선하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.5
• /
• pp.1716-1729
• /
• 2010

In this paper, we deal with a hierarchical ring-mesh optical network design problem. The objective is to minimize the total cost of optical add-drop multiplexers (OADMs) handling intra-ring traffic, optical cross-connects (OXCs) handling inter-ring traffic, and cabling cost among OADMs and among OXCs, while satisfying intra-ring and inter-ring capacities. We develop an integer programming (IP) formulation for the problem and devise some cutting planes that partially break the symmetry of rings. Dealing with the inherent computational complexity of the problem, we devise an effective heuristic procedure that finds a good quality feasible solution within reasonable computing times. Computational results demonstrate the efficacy of the proposed solution procedure; the developed symmetry breaking inequalities significantly reduce the computing time to find an optimal solution for small size problems, and the heuristic procedure finds a better feasible solution than that CPLEX, a commercial optimization software, finds for large size problems.

• Earthquakes and Structures
• /
• v.18 no.1
• /
• pp.57-72
• /
• 2020

This paper presents the results of a monodirectional shaking table test on a full-scale unreinforced masonry cross vault characterized by asymmetric boundary conditions. The specimen represents a vault of the mosque of Dey in Algiers (Algeria), reproducing in detail the mechanical characteristics of masonry, and the constructive details including the presence of some peculiar wooden logs placed within the vault's abutments. The vault was tested with and without the presence of two steel bars which connect two opposite sides of the vault. The dynamic behaviour of both the vault's configurations were studied by using an incremental dynamic analysis up to the collapse of the vault without the steel bars. The use of an innovative high-resolution 3D optical system allowed measure displacement data of the cross vault during the shake table tests. The experimental results were analysed in terms of evolution of damage mechanisms, and in-plane and out-of-plane deformations. Moreover, the dynamic properties of the structure were investigated by means of an experimental modal analysis.