• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.11
• /
• pp.1689-1700
• /
• 1993

WDM(Wavelength Division Multiplexing) based-on fixed wavelengths is a new means of utilizing the bandwidth of optical fibers. In this Paper, an improved virtual topology called "(a, $\beta$,${\gamma}$) ShuffleNet " is introdced for designing large-scale WDM switches. The proposed one is an architecture created by vertically stacking x planes of a ($\beta$,${\gamma}$) ShuffleNet in parallel via $\beta$r nodes called "bridge nodes" so that N-by-N(N=(x*$\beta$${\gamma}$*${\gamma}$) switching is achieved based on the self-routing algorithm for each ($\beta$,${\gamma}$) ShuffleNet. With the topological parallelism, in contrast to the conventional virtual topologies, the diameter of 2${\gamma}$ hops can be fixed and high utilization and performance are provided while N increases. Such a scalability characteristic allows to design a growable broadband switch. As for the delay, we show that the traffic locality, due to the topological feature. result in low delay characteristics.lay characteristics.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.4B
• /
• pp.235-245
• /
• 2005

In this paper, a simplified QoS model of MPLS-based backbone network. Conventional scheme proposed by IETF(IETF schem) is to embed a DiffServ model in MPLS network. However, this approach results in overall upgrade of MPLS system and so it is difficult to deploy this approach. Our proposed model, however, uses a Vidual Link which is a set of Label Switched Path(LSP) connected from an Ingress Label Edge Router(LER) to an Egress LER. In this model, Per-Hop-Behavior(PHB) is implemented only at each LSP in ingress LER and Core Label Switch Routers(LSRs) just guarantee each LSP's bandwidth, not service. This bandwidth guarantee service is fully provided by legacy MPLS model. Also we propose flow allocation mechanism and the flow distribution among LSPs of the virtual link by the flow according to the network status. To evaluate the simplified approach, the characteristics of the approach are compared logically with these of IETF's one through simulations.

• International journal of advanced smart convergence
• /
• v.3 no.2
• /
• pp.1-5
• /
• 2014

Sensor nodes depend on batteries for energy source in Wireless Sensor Networks (WSNs). Low Energy Adaptive Clustering Hierarchy (LEACH) is a representative cluster-based routing protocol designed to ensure energy use efficiency whereas the virtual cluster exchange routing (VCR) information only with its closest node to build a network. In this paper, a protocol scheme was proposed wherein member nodes are designed to compare the currently sensed data with the previously sensed one and to switch to sleep mode when a match is achieved. The design is to help improve the transmission energy efficiency too.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.11a
• /
• pp.127-130
• /
• 2003

웹 클러스터 시스템은 인터넷에서 요청되는 부하를 여러 실제 서버들에게 분산시켜서 어플리케이션에 따른 처리와 응답을 하는 서버 단 시스템이다. 부하는 서비스를 제공하는 서비스에 따라 다른 성향을 띄게 되므로 서비스 제공자는 부하의 특성을 파악하여 알맞은 웹 클러스터 시스템을 사용하여야 효율적이고 좋은 성능을 보이게 된다. 이 논문에서는 7 개의 다른 성향의 부하 상황과 Alteon Web Switch, ALBM Traffic Manager와 Linux Virtual Server를 사용하여 클러스터를 구성하고 각 부하 상황에서 클러스터 시스템들이 어떤 성능을 보여주는지 비교 분석한다.

• Journal of Industrial Technology
• /
• v.34
• /
• pp.61-66
• /
• 2014

Recently, Because the consumption of electricity is increased, having stable electricity supply and diagnosis of the power device is important. In this paper, I propose a diagnostic techniques of the leakage current for switchgear based on LabVIEW NI's. Using the data obtained from the leakage current sensor installed in switchgear panels, in performed continuously diagnosis, notifications and warnings can be the administrator immediately results. It is expected accordingly, the administrator will be able to take prompt action. Using the virtual switchgear with a PXI NI's, war tested the proposed techniques.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.08a
• /
• pp.103-106
• /
• 2003

In this study, an ultrasonic transducer is fabricated with 1-3 type composite resonators. Pulse-echo responses of an ultrasonic transducer are investigated in underwater dependent on the variable designated water-level. LED Output signals of a level limit with changing a water level is obtained by the 1-3 type self-made composite transducer and electric measuring unit. LED is turned on at above the up-limit level with increasing a water level, and LED is turned on at less than the down-limit level with decreasing a water level. There was good agreement between the virtual water level and output LED signal by using the self-made water-detecting system.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.10e
• /
• pp.127-129
• /
• 2002

NP Forum에서는 다양한 밴더의 네트워크 프로세서와 스위치 패브릭간에 물리적 인터페이스를 제공하기 위해 CSIX-L1(Common Switch Interface-Level 1 )인터페이스를 표준화하였다. IBM 네트워크 프로세서는 MPLS 및 VPN, VLAN, Security, Ipv6와 같은 다양한 어플리케이션과 TBI. SMII CMII. POS bus등 다양한 가입자 인터페이스를 지원하며, L2 기 반에서 2.5Gbps 이상의 패킷 처리를 수행하기 때문에 많은 시스템에 사용된다. 그러나 IBM네트워크 프로세서는 스위치 인터페이스로 DASL인터페이스를 사용한다. 따라서 DASL인 터페이스와 CSIX-L1 인터페이스를 정합하기 위해서는 IBM UDASL칩을 이용해 DASL인 터페이스를 UTOPIA-L3인터페이스로 변환해야 하며, 이것을 다시 CSIX-L1인터페이스로 변환해야 한다. 따라서 본 논문에서는 UTOPIA-L3인터페이스 패킷과 CSIX-L1인터페이스 프레임을 상호 변환하는 모듈을 설계하였으며, 32비트 데이터 버스와 최대 125MHz로클록을 사용해 최대 4Gbps의 패킷처리를 제공하도록 구현하였다. 또한 스위치 패브릭의 특정 포트에서 과잉 트래픽 전달로 인해 발생할 수 있는 블로킹을 방지하기 위해 네트워크 프로세서에게 3개의 Priority／최대 64개 포트수의 VOQ(Virtual Output Queue)를 제공하는 기법에 대해서 기술한다.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.10
• /
• pp.12-19
• /
• 1996

Many recent supercomputers employ a kind of switch-based multistage interconnection network architectrues (MINs) for constructing scalabel parallel compters. This paper proposed a new routing method, hybrid wormhole and virtual-cut through routing (HWCR) for the prevention of rapid performance degradation comming from a conflict in links usage at hot traffic situation. This HWCR through (VCT) for the fast removing temporal stagger, result in seamless flow of packet stream. When the blocked link is removed, wormhole routing is resumed. The HWCR method adopted a hierachical buffer scheme for improving the network performance and reducing the cost in BMINs. We could get optimum buffer size and communicatin latency through the computer simulation based on proposed HWCR, and the results were compared to those using wormhole and VCT.

• Proceedings of the KIEE Conference
• /
• 2001.07d
• /
• pp.2603-2605
• /
• 2001

In this paper, we introduce the concept and construction of a web-based bidirectional remote laboratory system. In this configuration, students build and test circuits using internet at home, and the circuit components and experimental equipments at the school are interconnected following student's design. This means that it is possible to choose components, build circuits, connect experiment equipments, control the equipment. and receive measurement results at home in real-time. Labview and Java are used to control this system efficiently and to provide user-friendly environments. Computer-based function generator, DMM, and oscilloscope are used and switch module is used to change interconnections. It was found that a system adopting computer-based instruments, which include PXI/CompactPCI modules and PC plug-in board, provide better performance than that adopting stand-alone instruments connected with GPIB. It is believed that, if this system is installed, the real experiments, not the virtual experiments based on simulation, can be done at home effectively, resulting in revolutional change in engineering education.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.04a
• /
• pp.211-213
• /
• 2003

가상랜(VLAN:Virtual LAN) 기술은 멀티 캐스트 트래픽의 감소 효과가 크고, 효율적인 네트워크 보안 및 관리를 지원하므로, 대부분 최근의 상용 스위치는 가상랜 환경에서의 동작을 지원하고 있다. 가상랜 환경에서 동작하는 스위치에서 가상랜 정보를 주고받기 위하여 사용하는 프로토콜이 GARP/ GVRP(Generic Attribute Registration Protocol/GARP VALN Registration Protocol)이다. 이 프로토콜은 네트워크 환경에서 가상랜 정보가 바뀔 때마다 동적으로 각 스위치의 가상랜 정보를 설정해 줌으로써 네트워크 관리자의 수고를 덜어주며, 효율적으로 가상랜을 관리하는 방법을 지원하는 것이다. 따라서 가상랜 환경에서 동작하는 스위치는 대부분 GARP/GVRP를 내장하고 있으나, 범용 소스가 없이 생산업체 별로 자체 구현한 GARP/GVRP를 각각의 스위치에 탑재하고 있다. 본 논문은 이렇게 가상랜 환경을 지원하는 스위치에 필수적인 프로토콜인 GARP/GVRP를 리눅스 커널에 삽입 가능한 모듈 형태로 개발하였다. 또 개발한 모듈을 기가빗 이더넷 스위치(Gigabit Ethernet Switch)에 이식된 리눅스 커널에 삽입. 동작시키고 공인된 테스트 집합을 이용하여 프로토콜이 정확하게 동작함을 검증하였다.