• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.1
• /
• pp.466-474
• /
• 2014

This paper presents the line contention avoidance experiments with an optical switch, which was selected based on the comparison analysis and evaluation of the various characteristics. For example, the function, structure, strengths and weaknesses of the optical switches. After considering the nonblocking, modularity, upgrade ability and optical power loss of the several kind of the switch fabrics, a switch was selected. The selected switch fabric by using wavelength converters was controlled to avoid contention of the optical lines. In this experiment shows an example of three cases. As a result of this experiment, optical signal shows a changed peek of optical power in output. By showing a peak it confirms that the contention was avoided. By analyzing of changed optical power according to the channel setting time and release time to control of the switch could be determined. If this analysis applied to the network design, economical and efficient structures can be formed.

• Journal of the Korea Society of Computer and Information
• /
• v.11 no.1 s.39
• /
• pp.157-165
• /
• 2006

This paper proposes a new output-buffered multicast ATM switch with tandem crosspoints switching fabric, named the MTCOS(Multicast Tandem Crosspoint Output-buffered Switch). The MTCOS consists of multiple simple crosspoint switch fabrics, named TCSF(Tandem Crosspoint Switch Fabric) , and concentrated output buffers for efficient multicasting. The TCSF resolves the cell delay deviation problem which the self-routing crossbar switches inherently have. Further, it offers multiple concurrent pathes from one input to multiple output ports. It also provides multi-channel switching by easy software configuration and has several desirable characteristics such as scalability, high Performance, and modularity. A shared traffic concentration and output queuing strategies of the MTCOS results in lower cell loss as well as lower cell delay time over a wide range of multicast traffic. Furthermore, it has lower hardware complexity than that of the SCOQ and Knockout multicast switch to achieve the same Knockout concentration rate as the conventional switches. It is shown that the proposed switch can be easily applied to design high performance for any multicast traffic by analytic analysis and computer simulation.

• The KIPS Transactions:PartC
• /
• v.10C no.4
• /
• pp.463-470
• /
• 2003

Many types of switching fabrics have been proposed for use in ATM networks. Multistage Interconnection Networks (MINs) constitute a large class of ATM switching systems that are widely used in today´s internetworking. One of the most veil-known types of multistage networks is the banyan network. The banyan network is attractive for its simple routing scheme and low hardware complexity, but its throughput is very limited due to internal blocking and output contention. In this paper, we propose an input-buffered dual-banyan switch model with multiple switching fabric between switch input and output to avoid internal and Head-of Line blocking. By performance analysis and simulation, we show that our model has a lower ceil delay and 96% throughput which is much better than other banyan-type switch architecture.

• Information and Communications Magazine
• /
• v.13 no.11
• /
• pp.122-134
• /
• 1996

ATM관련 국제 표준안이 마련되어 감에 따라 규격화된 분야를 중심으로 상용 소자 개발이 활발히 진행되고 있다. 본 논문에서는 ATM에서 상용화의 대상이 되는 분야를 기능 및 규격 관점에서 살펴보고 물리계층 기능 처리 소자, ATM 계층 기능 처리 소자, 스위치 패브릭용 소자의 개발 현황을 설명한다. 또한 AAL(ATM Adaptation Layer) 기능 처리 소자에 대해서도 개발 현황을 정리한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10c
• /
• pp.316-318
• /
• 2004

유선, 무선을 합하여 초고속 네트워크의 사용이 급격하게 증가됨에 따라 고속의 네트워크 통신 서비스에 대한 요구가 증가 하였으며 차별화된 인터넷 서비스에 대한 요구가 증가함에 따라 IP 기반의 스위치가 등장하게 되었다. 이러한 스위치의 이슈는 IT 포워딩, 고속 스위치 패브릭 등의 문제를 포함하게 된다. 현재까지의 모든 패킷 스위치는 그 내부적으로 HOL블로킹에 의한 성능 저하의 영향을 최소화하기 위하여 여러 가지 스케줄링 알고리즘을 사용한다. 본 논문에서는 Gigabit 으로 동작하는 패킷 스위치 중에서 Strict Priority 알고리즘, Round Robin 알고리즘을 분석하고 각각의 스케줄러가 COS 기반과 어떤 관계가 있으며 더불어 COS 기반에 따라, 스케줄러를 동적으로 변경하여 기존의 Static 하게 정책적으로 사용되던Algorithm 과의 차별성을 두어 동적 스케줄러의 선택에 의한 Packet 처리 성능향상을 보이도록 한다.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.40 no.4
• /
• pp.10-21
• /
• 2003

Recently, the optical subscriber interface module uses the high performance network processor to quickly develop new application services such as MPLS, VPN, RPR and EPON with a short time-to-market. Although a number of vendors are developing the network processor at 2.5Gbps, only the IBM NP4GS3 can provide packet processing with wire-speed at 2.5Gbps. IBM NP4GS3, however, uses its unique speed DASL interface instead of CSIX-Ll interface, which has standardized by M: Forum currently Therefore, we implement an interconnection mechanism to use the switch fabric with CSIX-Ll interface. In this paper, we suggest the architecture and a packet control mechanism supporting interconnection between IBM NP4GS3 DASL and CSIX-Ll switch interface using the common IBM UDASL ASIC and XILINX FPGA.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.5 s.37
• /
• pp.123-132
• /
• 2005

In this Paper, we present an improvement of switch node for wavelength multiplex optical network. Currently because of quick increase of internet traffic a big network capacity is demanded. Wavelength multiplex optical network Provides the data transfer of high speed and the transparent characteristic of the data. Therefore optic network configuration is the most powerful technology in the future. It will be able to control the massive traffic from the optical network in order to transmit the multimedia information of very many quantify. Consequently the node where the traffic control is Possible, is demanded. The optical switch node which manages efficiently the multiple wavelength was Proposed. This switch is composed of a optical switch module for switching and a wavelength converter module for wavelength conversion. It will be able to compose the switch fabric without optical/electro or electro/optical conversion using optical MEMS(Micro Electro Mechanical Switches) module. Finally, we present the good test result regarding the operational qualify of the switch fabric and the performance of optical signal from the switch node. The proposed switch node of the optic network will be able to control the massive traffic with all optical.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.49 no.12
• /
• pp.209-218
• /
• 2012

Recently, the Field Programmable Stateful Logic Array (FPSLA) was proposed as one of the most promising system integration technologies which will extend the life of the Moore's law. This work is the first proposal of the FPSLA design automation flow, and the approaches to logic synthesis, synchronization, physical mapping, and automatic placement of the FPSLA designs. The synchronization at each gate for pipelining determines the x-coordinates of cells, and reduces the placement to 1-dimensional problems. The objective function and its gradients for the non-linear optimization of the net length and placement density have been remodeled for the reduced global placement problem. Also, a recursive algorithm has been proposed to legalize the placement by relaxing the density overflow of bipartite bin groups in a top-down hierarchical fashion. The proposed model and algorithm are implemented, and validated by applying them to the ACM/SIGDA benchmark designs. The output state of a gate in an FPSLA needs to be duplicated so that each fanout gate can be connected to a dedicated copy. This property has been taken into account by merging the duplicated nets into a hyperedge, and then, splitting the hyperedge into edges as the optimization progresses. This yields additional 18.4% of the cell count reduction in the most dense logic stage. The practicality of the FPSLA can be further enhanced primarily by incorporating into the logic synthesis the constraint to avoid the concentrated fains of gates on some logic stages. In addition, an efficient algorithm needs to be devised for the routing problem which is based on a complicated graph. The graph models the nanowire crossbar which is trimmed to be embedded into the FPSLA fabric, and therefore, asymmetric. These CAD tools can be used to evaluate the fabric efficiency during the architecture enhancement as well as automate the design.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.258-259
• /
• 2002

광회선 분배 시스템(OXC)은 전광통신망(Optical Transport Network)에서 광신호 간 연결을 원격으로 설정해 줄 수 있는 노드(Optical Network Element)이다. OXC는 다수의 입력/출력 링크를 가지며 하나의 입력/출력 링크에는 다수의 파장 다중된 광신호 채널이 존재한다. OXC는 하나의 입력 링크를 통하여 입력되는 다수의 파장 채널을 서로 다른 출력 링크로 연결해 주거나, 다수의 입력 링크로부터 입력되는 파장채널을 하나의 출력 링크로 연곁해 줄 수 있는 optical grooming 기능을 수행한다. 또한 자국에서 광신호를 Add/Drop할 수 있는 기능을 가질 수 있다. (중략)

• 한국정보통신설비학회:학술대회논문집
• /
• 2004.08a
• /
• pp.100-104
• /
• 2004

광대역통합망 환경에서 에지 라우터에 요구되는 여러 가지 기능 및 성능항목들 중에서 차세대 개방형 시스템 플랫폼을 적용하면서도 10Gbps 라인속도를 제공할 수 있는 방안을 연구하고 그에 따른 상위수준의 시스템 구조를 제안한다. 10Gbps 인터페이스에 대해서 라인속도를 제공하기 위해서는 스위치 카드와 라인카드간의 물리적 연결에 최소한 10Gbps의 두배에 해당하는 20Gbps 대역폭 할당이 필요하며 이를 위해서 개방형 플랫폼의 패브릭 인터페이스에서는 라인카드당 8개의 연결 링크를 사용하는 듀얼-듀얼 성형 토폴로지를 사용하여야 한다.