• Journal of KIISE:Computing Practices and Letters
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• v.6 no.6
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• pp.643-656
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• 2000

MPOA proposed and standardized by the ATM Forum is a protocol tllat provides effective bridging and routing for ATM networks in a diverse network environment. Its plimary goal is to transfer unicast data effectively among the subnets. In this paper, MPOA components are implemented using the SDL(Specification and Description Language) which the ITU has standardized for the development of communication systems. In addition, MPOA procedures for various operations such as address translation for packets from upper layers, Ingress/Egress cache management and shortcut configuration, are examined with tlle help of the SDT(SDL Design Too]) simulator.

• The Transactions of the Korea Information Processing Society
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• v.6 no.10
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• pp.2764-2771
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• 1999

ATM has recently received much attention because of its high capacity, its bandwidth scalability, and its ability to support multiservice traffic. However, ATM is connection oriented whereas the vast majority of modern data networking protocols are connectionless. The alternative to support current service on ATM will be a router with attached switching hardware that has the ability to cache routing decisions. In this paper, we described the router using a switch and simulated the performance. From the results of the simulation, the routing delay was decreased as the number of flow channels. Cell-delay was shortest at 30,000 cell-time when the keeping time of a flow channel was. The line utilization was rapidly decrease when a flow-setup time is 20 30 cell-time. The results of this simulation could be applied to predict the performance of the router using ATM switch.

• Journal of Sensor Science and Technology
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• v.19 no.4
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• pp.297-305
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• 2010

A home healthcare system based wireless sensor network, which can continuously monitor and manage the elderly's electrocardiogram(ECG) signal at any space at home without space limit is proposed. The communication coverage of wireless network is expended by multi-hop wireless sensor network. In order to send the elderly's ECG data wirelessly, a small size ECG sensor node was designed to forward the ECG data over multi-hop relay network. The packet acquired by mobile ECG node is transmitted through wireless intermediate nodes to base station for analyzing the packet reception rate. Modified minimum cost forwarding(MMCF) protocol and flooding protocol are designed and implemented to check the transmission efficiency of a packet in a wireless sensor network. The developed MMCF protocol shows an advantage of high reception rate by reduced network traffic.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.8
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• pp.586-590
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• 2009

The objective of this paper describes the design of MapReduce over Peer-to-Peer network for dynamic environments applications. MapReduce is a software framework used for Cloud Computing which processing large data sets in a highly-parallel way. Based on the Peer-to-Peer network character which node failures will happen anytime, we focus on using a DHT routing protocol which named Pastry to handle the problem of node failures. Our results are very promising and indicate that the framework could have a wide application in P2P network systems while maintaining good computational efficiency and scalability. We believe that, P2P networks and parallel computing emerge as very hot research and development topics in industry and academia for many years to come.

• The KIPS Transactions:PartC
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• v.17C no.2
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• pp.153-158
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• 2010

Mobile IPv6 is one of method can keep Mobile node's session. To solve legacy Mobile IPv4's triangular routing problem, in Mobile IPv6, Mobile Node could directly communicate with Correspond node by Binding Update. But, attacker could interfere Return Routability Procedure that is Correspond node check Home address and Care of address reachable. At this result, Attacker is able to hijack Session to correspond node from Mobile node. In This paper, We propose new Binding Update scheme for solving that problem. Our approach is that MN gives association both home token and care of token using onewayness of keyed hash fuction. From security and performance analysis, we can see that proposed binding Update Scheme can achieve stronger security than legacy scheme and at the same time requires minimal computational overhead.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1408-1414
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• 2008

Development of internet and IP network technology creates various fusion services such as IPTV, VoIP and so on. Next generation IPv6 which will solve lack of IP is very important on IPTV which needs best quality of service about security, QoS and bandwidth. In this paper, we suggest a routing protocol standard in which we can service best quality of image using PSNR which is most commonly used as a measure of quality of reconstruction in image on IPv6 network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.306-309
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• 2009

MANET(Mobile Ad-hoc Network)은 기간망에 의존하지 않는 이동 노드들로 구성된 자율망 또는 추론망 토폴로지에 의한 멀티홉 무선 네트워크이다. MANET을 구성하는 각 노드의 이동성, 속도 그리고 에너지와 같은 다양한 속성정보는 망의 특징과 운영을 결정하는 요인이다. 특히 망의 운영상, 전송 대역폭과 에너지 사용에 따른 제약을 가지며 이러한 특징을 고려한 라우팅 프로토콜의 설계 및 하드웨어 개발이 중요하게 요구된다. 본 논문에서는 계층적 클러스터 구조의 MANET 환경에서 노드의 에너지 속성과 네트워크의 트래픽 상태를 고려한 적응적 시간차 노드관리 기법인 ATICC(Adaptive Time Interval Clustering Control)을 제안한다. 제안된 ATICC은 시간차 노드 관리기법인 TICC(Time Interval Clustering Control)[1]에 기반하며 노드에 최적화된 Active/Sleep, Idle Listening 상태를 적응적으로 설정한 후 패킷을 전송함으로서 계층적 클러스터 내의 각 노드의 균형적인 에너지 소모를 이루는 에너지 효율적인 방식이다. 제안한 노드관리 방법은 기존의 LEACH, TICC과 비교 실험하고 그 성능을 검증하였다. 실험 결과, 제안한 노드관리 방법이 노드별 에너지 소모량을 줄였으며 전체 네트워크의 생존시간을 연장함으로서 기존의 방법 보다 우수함을 확인하였다.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.4
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• pp.11-18
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• 2014

Recently, ICT technology has been evolving towards an M2M (Machine to Machine) environment that allows communication between machine and machine from the communication between person and person, and now the IoT (Internet of Things) technology that connects all things without human intervention is receiving great attention. In such a network environment, the communication network between object and object as well as between person and person, and person and object is available which leads to the sharing of information between all objects, which is the essential technical element for us to move forward to the information service society of the era of future ubiquitous computing. On this paper, the protocol related to DTMNs in a Sparse M2M environment was applied and the improved routing protocol was applied by using the azimuth and density of the moving node in order to support a more efficient network environment to deliver the message between nodes in an M2M environment. This paper intends to verify the continuity of the study related to efficient routing protocols to provide an efficient network environment in the IoT and IoE (Internet of Everything) environment which is as of recently in the spotlight.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.590-593
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• 2011

Time goes on, Ad Hoc network is hot issues. So far, there are a lot of protocols have been proposed for Ad Hoc routing protocol to support the mobility. This paper presents an enhanced DSDV(Destination-Sequenced Distance Vector) routing protocol which nominates one node to take care of a specific area. Simply Area-Aware(AA) DSDV routing protocol has one nominee to take care of some area. It has two jobs. One is to take care of its neighbour and another is to transfer the routing table to its other node as it works. It is called as Area Nominee(AN). The new scheme extends the routing table to include the nominee in the area. The general node is the same as the previous DSDV routing protocol. In the other hands, the node which is nominated has two routing protocols. One is for Regional Routing(RR) table which is the same routing table in DSDV. Another is Global Routing(GR) table which is about the area round its area which it cares nearby. GR table is the table for the designated node like the nominee. Each area has one nominee to transfer between ANs. It has only nominee's information about every area. This concept decreases the topology size and makes the information of topology more accurate.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.833-836
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• 2008

모바일 기기 보급이 급증함에 따라 모바일 환경에서 이루어지는 Peer-to-Peer(P2P)방식에 대한 연구가 활발히 진행되고 있다. 모바일 기기는 무선통신이라는 특성이 있기 때문에, 이동하는 peer의 에너지 절약이 항상 요구된다. Peer에 저장된 에너지를 모두 사용하게 되면 네트워크에 참여할 수가 없고, 에너지가 없는 peer 수가 지속적으로 증가되면 파일 탐색이 불가능하게 된다. Super peer를 기반으로 하는 계층적인 P2P 시스템은 기존의 단일 계층인 P2P 시스템보다 적은 양의 메시지를 이용하여 파일을 탐색할 수 있다는 장점이 있지만, super peer로 선정된 peer는 주변의 sub-peer들로부터 파일 탐색 요청 메시지를 지속적으로 받게 되어 빨리 에너지가 소모되는 단점이 있다. 본 논문은 super peer를 이용한 모바일 P2P 시스템에서 peer들의 남은 에너지를 고려하여 에너지가 적은 peer의 사용을 피하여 상대적으로 에너지가 많이 남은 peer들의 사용을 유도하는 시스템을 제안하였다. 실험을 통해서 성능평가를 하였으며, 제안된 시스템의 네트워크 유지시간이 기존 super peer를 이용한 시스템보다 오래 지속됨을 확인하였다.