• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.261-268
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• 2005

Recently, Many People have studied in Mobile Ipv6 to provide seamless service. FMIPv6 is designed to reduce the procedure of handover and will be used SIP, VoIP and Mobile Internet moving picture service. But, If mobile node moves fast, it will happen to packet loss and interruption problem in handover procedure. So, In this paper, designed and evaluated traffic control mechanism using WFQ scheduling to reduce the packet loss that occurred to handover procedure.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.6
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• pp.265-278
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• 2013

With the recent advancements in various wireless communication technologies, the importance of mobile multicasting is coming to the fore, in an effort to use network resources more efficiently. In the past, when various mobile IP-based multicast techniques were proposed, the focus was put on the costs needed for network delivery for providing multicast services, as well as on minimizing the multicast handover delay. For techniques using MIPv6 (Mobile IPv6), a host-based mobility management protocol, however, it is fundamentally difficult to resolve the problems of handover delay and tunnel convergence. To resolve these problems, a network-based mobility management protocol called PMIPv6 (Proxy Mobile IPv6) was standardized. Although performance is improved in PMIPv6 over MIPv6, it still suffers from the problems of handover delay and tunnel convergence. In this paper, to overcome these limitations, a technique called LFH (Low-cost and Fast Handoff) is proposed for fast and low-cost mobility management with multicasting support in PMIPv6 networks. To reduce the interactions between the complex multicast routing protocol and the multicast messages, a simplified proxy method called MLD (Multicast Listener Discovery) is implemented and modified. Furthermore, a TCR (Tunnel Combination and Reconstruction) algorithm was used in the multicast handover procedure within the LMA (Local Mobility Anchor) domain, as well as in the multicast handover procedure between domains, in order to overcome the problem of tunnel convergence. As a result, it was found that LFH has reduced multicast delay compared to other types of multicast techniques, and that it requires lower costs as well.

• Journal of KIISE:Information Networking
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• v.37 no.6
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• pp.459-465
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• 2010

Mobile IPv6(MIPv6) features have several defects such as overloading of nodes, loss of wireless signals, packet loss, movement problem and so forth. Proxy Mobile IPv6 (PMIPv6) got over the limit of MIPv6 problems. MIPv6 features have several defects such as overloading of nodes, loss of wireless signals, packet loss, movement problem and so forth. Research on PMIPv6, which features network-based mobility is actively in progress in order to resolve these issues. PMIPv6 is emerging as a new paradigm that can overcome the limitations of the existing MIPv6. Nevertheless, such PMIPv6 also incurs problems during hand-over. While it offers a solution to node-based problems, it does, too, create long delay times during hand-over. Since MN (Mobile Node) has been sensing its own movements on MIPv6, fast handover can be done easily. However it can't apply fast handover like MIPv6, as it can't apply fast handover like MIPv6 In this paper, the author solved hand-over problem on MIPv6. MAG knows location information of MN and if MN moves into other MAG's area, Location Server gives MN information to the MAG. Therefore, this mechanism makes hand-over process easier.

• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.437-452
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• 2008

IEEE 802.16j MR networks introduce RSs (Relay Stations) within the IEEE 802.16 system in order to enhance the data throughput and extend the coverage. However, the current standardization defines that the BS (Base Station) controls MS's (Mobile Station's) handover, not only it induces the large signaling overhead but also handover latency could increase. In this paper, we propose a handover protocol in the MR networks where the high capability RSs that can process the MS's control functions are deployed. First, we classify the handover scenarios for the MR networks with the high capability RSs. Then, we define the MAC handover procedure, corresponding MAC management messages and the transmission routes for the proposed messages so that an 802.16e MS can perform seamless handover without noticing it is attached to an MR network. The simulation results show that the proposed handover protocol not only reduces the MAC management message overhead transferred through the wireless links compared to IEEE 802.16j/D1, which is the current standard for MR networks, but also performs the rapider and more secure MS handover than IEEE 802.16e and IEEE 802.16j/D1.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.251-254
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• 2011

본 논문에서는 예약주소를 사용한 HMIPv6로 각 통신 노드에 따른 그룹 군집화와 MIH 패킷의 Service Specific TLVs의 변형을 통해 기존의 핸드오버에서 좀 더 가볍고 빠른 Searching과 효율적인 인증을 이룰 수 있도록 하였다. 군집(Aggregate) 세션 단위로 자원예약을 하는 경우 종단간 SID(Session ID)와는 별도로 군집 SID를 사용하는데 MIH의 Service Specific TLVs를 통해 터널링을 이루고 변형된 Service Specific 공간을 통한 효율적인 핸드오버를 지원한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.64-66
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• 2023

Low Earth Orbit(LEO) Non-Terrestrial-Network(NTN) 은 위성을 사용하여 통신 서비스를 제공하지 못하는 도시 이외의 산간, 바다, 항공기 또는 외진 지역에 통신 서비스를 제공하는 모델이다. Terrestrial Network(TN) 핸드오버에서 사용되는 Measurement-Based Triggering(MHT)의 경우 User Equipment(UE)에서 측정된 값을 기반으로 Measurement Report를 전달한다. 그러나 NTN 환경에서의 HO triggering은 TN 과는 달리 장거리 통신을 요구하고 위성이 빠른 속도로 이동함에 따라 MHT에 사용되는 지표들을 대체할 방법이 필요하다. 이 논문에서는 측정 유효성을 대체할 수 있는 지표로 UE와 셀 중심 간의 거리 및 고도 각을 활용하여 HO triggering을 예측하는 시스템을 제안한다. 제안한 예측 시스템은 핸드오버 triggering 예측에 대해 우수한 성능을 보였으며 좋은 측정 결과를 얻을 수 있었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8B
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• pp.492-501
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• 2007

UMTS-WLAN interworking approach can make the best use of the advantages of both networks by eliminating the stand-alone defects of the two services. For the interworking mechanisms of WLANs and UMTS networks, two major solutions have been proposed, namely loose coupling and tight coupling. The loose coupling approach provides separate data paths for WLAN and UMTS. On the other hand, the tight coupling provides a full integration of the WLAN network and the UMTS core network. The loose coupling has been preferred due to the simplicity and less reconfiguration requirement. However, loose coupling is worse in seamless mobility, QoS provision, and network security. In order to lessen the problems involved in the UMTS-WLAN interworking approaches, we propose a new interworking network architecture and a fast vertical handover scheme by employing Mobility Anchor(MA) for interworking between the two different networks. MA can enable authentication and session initialization before L2 handover of the mobile terminal, so that the seamless and fast vertical handover become possible. Thru analysis and numerical experiments, we proved that the proposed scheme has been validated.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.107-119
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• 2013

This paper reinforced security under the network evaluation of wire wireless integration of NEMO (NEwork MObility) supporting mobility and network-based PMIPv6 (Proxy Mobile IPv6). It also proposes $SK-L^2AS$ (Symmetric Key-Based Local-Lighted Authentication Scheme) based on simple key which reduces code calculation and authentication delay costs. Moreover, fast handover technique was also adopted to reduce handover delay time in PMIPv6 and X-FPMIPv6 (eXtension of Fast Handover for PMIPv6) was used to support global mobility. In addition, AX-FPMIPv6 (Authentication eXtension of Fast Handover for PMIPv6) is proposed which integrated $SK-L^2AS$ and X-FPMIPv6 by applying Piggybacks method to reduce the overhead of authentication and signaling. The AX-FPMIPv6 technique suggested in this paper shows that this technique is better than the existing schemes in authentication and handover delay according to the performance analysis.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.57-66
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• 2011

The current trend of the handover authentication delay time is gradually increased according to the interworking between 3G cellular network and WLANs. Therefore, authentication mechanism minimized in delay is required to perform the seamless handover and support the inter-subnet and inter-domain handover. In this paper, we propose a novel pre-authentication scheme based on the fast channel switching which directly performs the authentication with the next access point in advance. In addition, the proposed scheme is efficient in the inter-domain handover and can be easily implemented in current WLANs since it just modifies the client side of user. To analysis and evaluate our scheme, we compare the packet loss ratio and the delay time with the two standard 802.11 authentication schemes. The analytical results show that our scheme is approximate 10 times more effective than the standard schemes in packet loss and the delay time is minimized down to 0.16 msec.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.6
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• pp.37-47
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• 2009

In this paper fast mobile multicast handover mechanism based on IEEE 802.21 MIH (Media Independent Handover) is proposed. We solve long multicast handover delay time caused by L3 movement detection mechanism of the existing mobile multicast methods. The proposed architecture adopts multicast manager concept to MIH framework in order to efficiently perform mobile multicast handover, and adds the new MIH messages dedicated for mobile multicast. Since multicast channel zapping operations of mobile users effectively make a mobile terminal handover, the architecture should consider the situations. Multicast network selection algorithm is designed by means of terminal speed and fair selection algorithm named AHP/GRA. Finally the performance of the proposed architecture against the legacy mobile multicast mechanisms is evaluated in terms of signaling cost and multicast handover delay time.