• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1895-1896
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• 2008

지능형 빌딩 환경 모니터링 시스템과 같이 실내에서 센서 네트워크를 이용하여 환경 데이터를 수집하는 네트워크가 점점 확산되고 있다. 이와 같은 건축물 내에서의 무선 센서 네트워크는 랜덤하게 센서 노드들이 뿌려지는 것이 아니라, 사람의 의지대로 배치가 된다. 따라서 위치정보를 모르는 상황의 무선 센서 네트워크들이 가지는 라우팅 방법을 사용하는 것이 아니라 더 간결하면서 강한 네트워크 유지 능력을 가지는 라우팅 방법이 사용되게 된다. 본 논문에서는 트리 라우팅을 이용한 건물 환경 모니터링 시스템에 에너지 효율을 높이기 위하여 네트워크의 상황을 고려한 SVM을 이용한 동적 라우터 선택기법을 포함한 동적 트리 라우팅 기법에 대한 연구와 이의 구현을 보이고 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3B
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• pp.214-219
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• 2011

The IMS (IP Multimedia Subsystem) is used for providing multimedia services to network provider. The IMS is composed of many nodes, depending on their function. According to the status (fault, performance, etc.) of each node, we need to provide dynamic routing algorithm. In this paper, we propose a dynamic routing algorithm for management of the IMS nodes using SNMP based on FCAPS (Fault, Configuration, Accounting, Performance and Security) in the IMS network.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.313-318
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• 1999

상호 운용성을 높이기 위해 제안된 HLA(High Level Architecture)는 분산되어 있는 모델과 사용자간의 실시간 상호 정보 교환의 구현이 가능하게 이종의 시간 관리 기반을 제공하는 장점이 있다. 본 논문에서는 동적 구조를 가지는 Wireless Network상에서 발생되는 메시지의 동적 라우팅을 RTI를 기반으로 구현하고, 그 결과로 HLA의 실시간 상호 정보교환에 대한 이점을 확인하여 실시간 분산 시뮬레이션에 대한 적용 가능성을 평가한다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.267-272
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• 2007

센서 네트워크는 일반적으로 지정된 지역 내에서 흩어져 있는 센서 노드들에 의해 주변 현상을 감지하여 싱크 노드로 전송한다. 각 센서 노드들은 요청된 질의나 사전에 지정된 질의의 결과를 주기적으로 싱크 노드로 전송한다. 하지만, 센서 노드들은 제한된 배터리 용량을 가지기 때문에 영구적인 수명을 보장할 수 없다. 따라서 중복된 데이터는 한번만 전송하거나, 대표 센서 노드가 값을 모아서 전송함으로서 네트워크 수명을 최대로 보장하는 것이 중요하다. 본 논문에서는 동적으로 데이터 전송 노드를 선정하는 라우팅 트리인 동적 트리기반의 에너지 효율적인 라우팅 알고리즘(EDRT)을 제안한다. 기존에 제안된 질의 기반 라우팅 트리(QSRT)는 질의의 결과들이 싱크 노드로 전송할 때, 데이터를 부분 집계 및 패킷 합병을 유도하여 데이터 전송 횟수를 줄였다. 본 논문에서는 각 센서 노드가 부모 노드뿐만 아니라 형제 노드 간에도 데이터를 부분 집계 및 패킷 합병을 할 수 있도록 하여 데이터 전송 횟수를 줄이고, 센서 노드의 에너지 소모량도 감소시킨다. 수행된 실험의 결과는 제안된 EDRT가 QSRT보다 향상된 성능을 보여 준다.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.406-416
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• 2001

Single path routing schemes using dynamic routing metric amy find out the dynamic network status and recompute paths to keep the traffic from the highly loaded regions of the network. This type of routing approach, however, may lead to a routing oscillation, and further, it cannot exploit multi-paths that may frequently exist in the real network. We propose a multipath routing scheme with dynamic load balancing, called MP-DLB, which is capable of reducing the overhead incurred by the multipath routing with dynamic load balancing approach while taking advantage of the high routing performance provided by the approach. According to the analysis of Internet packet traces which show that a high percentage of network traffic is destined for a small number of networks, MP-DLB applies the multipath routing with dynamic load balancing only to a limited subset of all the destinations in the network. For the rest of the destinations, it applies traditional single path routing scheme. This approach may reduce overall routing overheads by limiting the number of destinations to apply the more complicated routing scheme while it can keep the routing performance high by providing efficient routing for the most significant traffic in the routing performance. A series of simulations are done to analyze the performance of MP-DLB. The simulation results show that MP-DLB may effectively cope with the congestion and achieve high routing performance by distributing traffic streams that are generated from varying sources and heading toward a specific hot destination over multi-paths.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.868-870
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• 2004

ad-hoc 망에서 라우팅 프로토콜의 부하균등(load balancing)은 이동성과 전송 지연사이의 trade-off로 인하여 성능 관점에서 중요한 이슈가 되어왔다. 부하균등을 고려한 SLAP(Simple Load-balancing Ad-hoc routing Protocol)이 제안되었으나 혼잡이 발생하거나 망의 토폴로지가 변화하였을 때 유연하게 대처하지 못한다. 본 논문에서는 ad-hoc 망에서 트래픽 혼잡 제어와 망의 이동성에 적응하기 위하여 동적인 임계치를 사용하는 부하균등 라우팅 프로토콜을 제안하였다. 제안된 프로토콜은 성능은 GloMoSim으로 시뮬레이션을 수행하여 AODV, DSR, SLAP과 지연, 패킷 전송률 등을 비교하여 평가하였다.

• The Journal of Society for e-Business Studies
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• v.13 no.3
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• pp.1-20
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• 2008

Today's computing environment which is getting distributed to communicate with various systems needs dynamic inter-connectivity of the systems. MOM(Message Oriented Middleware) is popularly used for transmitting XML messages among the distributed systems for the inter-connectivity. But, they do not support event-based message routing functionalities with XML transformation for processing effective message routing, which is essential to inter-connectivity, and there is no integrated platform to cope with these requirements. Although event-based message routing and XML transformation have been studied in a wide range of computer science areas, development of message routing systems is considered as a tough job due to the technological difficulties. In order to address these requirements, we proposed a novel system, named RMRS(Rule-based Message Routing System), which supports event-based message routing as well as XML message transformation. To make the proposed system easy to use, we also redesigned ECA(Event- Condition-Action) rule to fit in our system and developed a tool to map source XML structure into target XML structure.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1209-1218
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• 2001

In this dissertation, we propose a dynamic source routing protocol supporting asymmetric path for mobile ad hoc networks. At present, the existing dynamic source routing protocol supports only symmetric path for routing. However, in fact, there can exist unidirectional links due to asymmetric property of mobile termenals or current wireless environment. Thus, we implement a mobile ad hoc routing protocol supporting asymmetric routing path, which is fit for more general wireless environment. Especially, the proposed protocol uses an improved multipath maintenance method in order to perform rapid route reconfiguration when route error due to mobility is detected.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.573-582
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• 2002

We propose centralized server based QoS routing schemes, where a route server is responsible for determining QoS paths on behalf of all the routers in a routing domain. In the proposed server based schemes, the dynamic link QoS state information, which is required for a QoS path computation, is implicitly maintained at route server as it assigns or gets back QoS paths. By maintaining the network state information this way, we may not only eliminate the overhead to exchange network state update message but also achieve higher routing performance by utilizing accurate network state information in path computation. We discuss path caching techniques for reducing the amount of path computation overhead at the route server, and evaluate the performance of the proposed schemes using simulation. The simulation results show that the path caching schemes may significantly reduce the route server load. The proposed schemes are also compared to the distributed QoS routing schemes proposed in the literature. It has been shown that the proposed server based schemes not only enhance the routing performance, but they are also competitive with respect to routing overheads.

• Journal of KIISE:Databases
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• v.30 no.6
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• pp.629-640
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• 2003

A shared disk (SD) cluster couples multiple nodes for high performance transaction processing, and all the coupled nodes share a common database at the disk level. In the SD cluster, a transaction routing corresponds to select a node for an incoming transaction to be executed. An affinity-based routing can increase local buffer hit ratio of each node by clustering transactions referencing similar data to be executed on the same node. However, the affinity-based routing is very much non-adaptive to the changes in the system load, and thus a specific node will be overloaded if transactions in some class are congested. In this paper, we propose a dynamic transaction routing scheme that can achieve an optimal balance between affinity-based routing and dynamic load balancing of all the nodes in the SD cluster. The proposed scheme is novel in the sense that it can improve the system performance by increasing the local buffer hit ratio and reducing the buffer invalidation overhead.