• ETRI Journal
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• v.31 no.4
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• pp.466-468
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• 2009

In this letter, we propose a one-way ranging algorithm that is based on wireless synchronization with measured timestamps and clock frequency offsets. In our proposed algorithm, an active mobile node initiates a ranging procedure by transmitting a ranging frame, and the anchor nodes report their timestamps for the received ranging frame to a reference anchor node. The synchronization of a pair of nodes is provided with instantaneous time information, and the corresponding difference of distances can be calculated.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.565-566
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• 2020

본 논문에서는 이동 싱크 시스템을 위한 앵커 노드의 결정 방식에 대해 고려한다. 분산 지역의 센서 시스템에 대한 싱크 시스템의 방문에서 주기적 이동이 고려될 수 있다. 이동 싱크가 분산된 지역을 주기적으로 방문할 경우 분리된 지역의 센서 시스템은 싱크 시스템의 방문 시간을 예측할 수 있다. 싱크 시스템은 지정된 시간 안에 방문 지역에 접근하며 앵커 노드는 싱크 시스템과의 네트워크 연결을 수행한다.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.7-8
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• 2006

F-HMIPv6 is protocol that supports fast handovers for Hierarchical Mobile IPv6. Unlike HMIPv6 (Hierarchical Mobile IPv6), it sends FBU(Fast Binding Update) by predicted Router's Information for a potential handover. But, The current version of this protocol doesn't ensure impeccably between mobile node and router. To make up for the weak points of the security, we propose the architecture for F-HMIPv6 protocol to structurally reinforce the security and improve weak security of among mobile node, MAP(Mobility Anchor Point), and routers for binding update when mobile node conducts handovers.

• Journal of KIISE:Information Networking
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• v.36 no.3
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• pp.204-211
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• 2009

Proxy Mobile IPv6(PMIPv6) is that network-based mobility management protocol that network supports mobile node's mobility on behalf of the Mobile Node(MN). In PMIPv6 network, data packets from a Correspondent Node(CN) to a MN will always traverse the MN's Local Mobility Anchor(LMA). Even though, CN and MN might be located close to each other or within the same PMIPv6 domain. To solve this problem, several PMIPv6 Route Optimization(RO) schemes have been proposed. However, these RO schemes may result in a high signaling cost when MN moves frequently between MAGs. For this reason, we propose an adaptive route optimization(ARO) scheme. We analyze the performance of the ARO. Analytical results indicate that the ARO outperforms previous schemes in terms of signaling overhead.

• The KIPS Transactions:PartC
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• v.15C no.1
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• pp.37-44
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• 2008

In order to minimize the signaling delay for a resource reservation on the new routing path after the handover of Mobile Node(MN) is completed, it is important to discover the crossover node where the old and new routing paths meet. With the 크로스오버 노드 being found, the signaling messages only need to be transferred on the changed part of the end-to-end path. The crossover node is generally discovered using the end-to-end Session ID(SID) of the established session between MN and Correspondent Node(CN). However, in the Hierarchical Mobile IPv6(HMIPv6) network, if the Mobile Anchor Point (MAP) reserves the resource by aggregate with the Home Agent(HA), the crossover node discovery cannot be performed in the general way since the aggregate SID that has established between the previous MAP and HA is different from the that of the current MAP and HA after MN's handover. In this paper, we propose a mechanism to discover the crossover node within the tunnel between the MAP and the HA in an HMIPv6 network, assuming that the Next Steps in Signaling(NSIS) is deployed for the resource reservation and the aggregate reservation is applied over the MAP and HA tunnel. The local repair required for the change of path is performed upon the crossover node discovery. The simulation results show that the proposed scheme reduces the signaling delay for the reservation and outperforms the existing scheme with respect to throughput during the handover.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.941-945
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• 2007

이동 서비스를 지원하기 위한 프로토콜 중 현재 가장 주목 받고 있는 Proxy Mobile IPv6 (PMIPv6)에서 Mobile Node (MN)는 Local Mobility Anchor (LMA)와 Mobile Access Gateway (MAG)의 지원으로 무선 접속을 위한 기능 이외의 추가적인 동작 과정 없이 이동성을 가질 수 있다. PMIPv6 에서의 LMA 는 MN 에게 이동 서비스를 지원함에 있어서 가장 중추적인 역할을 하기 때문에 어떤 LMA 가 MN 에게 서비스를 지원하느냐에 따라 이동 서비스의 질은 직접적인 영향을 받는다. 따라서 본 논문에서는 이동 서비스에 영향을 미칠 수 있는 요소인 LMA 와 MAG 사이의 통신 비용과 LMA가 이동 서비스를 제공하고 있는 MN 의 수를 고려하여 Fuzzy Logic 을 이용한 LMA 선택 기법을 제안한다. 본 논문에서 제안하는 기법은 다수의 LMA 를 제공하는 사업자에게 있어서 적당한 LMA를 선택하여 서비스를 제공할 수 있도록 함으로써 MN 에게 항상 양질의 이동 서비스를 제공할 수 있도록 한다.

• Journal of Communications and Networks
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• v.11 no.3
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• pp.261-270
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• 2009

We propose a tree-based integration of infrastructure networks and MANETs (TUM) to efficiently extend the scope of mobile Internet protocol to mobile ad hoc networks and devise a tree-based routing protocol (TBRP) that is suitable for the TUM architecture. Infrastructure networks have a number of fixed Internet Gateways that connect two heterogeneous networks. Mobile nodes form a number of small trees named pMANETs, each of them growing from anchor node which can communicate directly with an Internet Gateway. A new node registers with foreign agent and home agent along the tree path without resorting to an inefficient flooding. Furthermore, the TBRP sets up a routing path efficiently by exploiting the tree information without relying on flooding. We show by resorting to simulation that our approach is competitive against the conventional AODV based approach.

• Journal of Internet Computing and Services
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• v.14 no.3
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• pp.67-79
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• 2013

In wireless networks, efficient mobility management to support of mobile users is very important. Several mobility management schemeshave been proposed with the aim of reducing the signaling traffic of MN(Mobile Node). Among them, PMIPv6 (Proxy Mobile IPv6) is similar with host-based mobility management protocols but MN does not require any process for mobility. By introducing new mobile agent like MAG (Mobile Access Gateway) and LMA (Local Mobility Anchor), it provides IP mobility to MN. In this paper, we propose the analytical model to evaluate the mean signalingdelay and the mean bandwidth according to the type of MN mobility. As a result of mathematical analysis, MF-PMIP (Multicasting-based FastPMIP) outperforms compared to F-PMIP and PMIP in terms of parameters for the performance evaluation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5A
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• pp.521-528
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• 2011

In sensor network environment, it is very important to localize sensor nodes. In order to know the position of nodes without GPS signals, the anchor robot approach is representatively used. Therefore, in this paper, we propose 4-Robot Localization Scheme (4RLS) that uses four mobile robots to efficiently localize sensor nodes for the fast time. Then, we show the improved performance of 4RLS in comparison with previously used three robot scheme through the real implementation and analysis.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.209-210
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• 2006

Hierachical Mobile IPv6 (HMIPv6) solves Micro-mobility protocol problem about Handover. Mobility Anchor Point(MAP) helps reducing the handover, but this makes a load on the MAP. Besides the MAP operates this work everytime, and every Nodes. In this paper, we propose the algorithm that reduces the amount of Map working.