• Journal of KIISE:Information Networking
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• v.31 no.6
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• pp.566-572
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• 2004

In this paper, we define the secure authentication model to provide a mobile node with global roaming service and integrate the Fast Handoff scheme with our approach to minimize the service latency. By starting the AAA(Authentication, Authorization and Account) procedure with Fast Handoff simultaneously when a roaming occurs, authentication latency is reduced significantly and provision of fast and seamless service is possible. The previous works such as IPsec(Internet Protocol Security), RR (Return Routability) and AAA define the procedures performed after the completion of Layer2 Handoff which leads us to study a way of providing the real time and QoS guaranteed service during this period. The proposed scheme is for this goal and when appling it to roaming environment it shows the cost reduction up to 55% and 17% for the case of the MN receiving the FBACK and not respectively before L2 Handoff occurs.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.07a
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• pp.161-164
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• 2003

Mobile IP Low Latency Handoffs［1］는 Mobile IP 등록 요청 절차를 처리하는데 있어서 단말의 지연 때문에 생기는 블록킹 시간을 최소화 시켜 실시간 서비스를 가능하게 해 준다. 그러나 인증, 권한 검증, 과금을 지원하는 AAA 기반의 Mobile IP 망에서는 매 지역 등록이 일어날 때마다 새로운 세션 및 세션 키가 필요하며, 이를 위해 홈 망까지 등록 절차가 수행되어야 한다. 이로 인해, 이동 노드 재인증 절차와 방문 망에서 홈 망까지의 트랜잭션으로 인한 통신 지연이 발생한다. 이러한 지연을 줄이기 위해서 본 논문에서는 홈 망의 AAA 서버가 관여되지 않고, 이전에 할당된 세션 키를 재 사용하여 Low Latency Handoffs를 수행하는 기법을 제안한다. 이 기법에서는 이전 방문 에이전트와 새로운 방문 에이전트간 세션 키를 교환하는 단계에서 발생하는 보안 취약성을 해결할 수가 있으며 홈 망까지 트랜잭션이 필요 없고, 세션 키의 기밀성이 제공되므로 이동 노드가 빠르고 안전하게 핸드오프를 수행할 수 있다.

• International Journal of Computer Science & Network Security
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• v.23 no.4
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• pp.172-178
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• 2023

When the mobile device moves from the coverage of one access point to the radio coverage of another access point it needs to maintain its connection with the current access point before it successfully discovers the new access point, this process is known as handoff. During handoff the acceptable delay a voice over IP application can bear is of 50ms whereas the delay on medium access control layer is high enough that goes up to 350-500ms. This research provides a suitable methodology on medium access control layer of the IEEE 802.11 network. The medium access control layer comprises of three phases, namely discovery, reauthentication and re-association. The discovery phase on medium access control layer takes up to 90% of the total handoff latency. The objective is to effectively reduce the delay for discovery phase to ensure a seamless handoff. The research proposes a scheme that reduces the handoff latency effectively by scanning channels prior to the actual handoff process starts and scans only the neighboring access points. Further, the proposed scheme enables the mobile device to scan first the channel on which it is currently operating so that the mobile device has to perform minimum number of channel switches. The results show that the mobile device finds out the new potential access point prior to the handoff execution hence the delay during discovery of a new access point is minimized effectively.

• Journal of KIISE:Information Networking
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• v.31 no.6
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• pp.620-632
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• 2004

IP is not suitable for mobile nodes by network-based routing because mobile nodes are dynamically change their network attachment point. Mobile-IP is an IETF standard providing continuous access to the Internet for mobile nodes, but it has the triangle routing problem. Also it has a performance degradation problem by massive packet loss during layer 3 handoff of mobile nodes. Especially, two IETF multicast support schemes for Mobile-IP do not guarantee the quality of realtime multimedia services because they have several problems such as long routing path, packet duplication(hi-directional tunneling) and massive packet loss(remote subscription). In this paper, we propose a lossless remote subscription scheme that guarantees the quality of realtime multimedia services over Mobile-IP. From the result of simulation, we verified that the proposed scheme in this paper can reduce the delay time of remote subscription by the effect of the low latency handoff scheme that is extended to apply to the multicast group management and it requires only 0.58% buffer spaces of the previously proposed lossless remote subscription scheme.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2389-2396
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• 2014

Spectrum handoff is the process of exchanging progressing data transmission from the current channel to another idle channel. The essential goal of spectrum handoff in CR(Cognitive Radio) networks is to perform consistent data transmission while sustaining performance of ongoing transmission of secondary users. This handoff procedure can cause additional latency that eventually affects on the performance of CR transmission. Channel prediction method is expected to avoid the disruption to primary users and to reduce the handoff latency. In this paper, adaptive channel prediction is proposed to cope with time-varying channel and an adaptive channel prediction based proactive handoff procedure is designed to enhance data transmission performance.

• Journal of information and communication convergence engineering
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• v.14 no.2
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• pp.89-96
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• 2016

In mobile communication, there are various types of handoff for the support of all forms of mobility. Proxy mobile IPv6 (PMIPv6) enables local network-based mobility management of a mobile node without any effect of mobility-related signaling. Recently, PMIPv6 has been considered for supporting mobility management in LTE/SAE-based mobile networks. To support seamless mobility in heterogeneous mobile networks, the overall cost of handoffs needs to be minimized and the procedure should be guaranteed to be secure. However, the reduction of the authentication cost has not been fully investigated to provide seamless connectivity when mobile users perform a handoff between the PMIPv6 domains. This paper proposes secure pre-authentication schemes, completing an authentication procedure before performing a handoff, for a fast handoff in PMIPv6. Analytic models have been used for measuring the authentication latency and for the overhead cost analysis. In addition to providing fast authentication, the proposed pre-authentication schemes can prevent threats such as replay attacks and key exposure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.781-785
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• 2004

Mobile IP maintains Internet connectivity while Mobile Hosts moving from one Internet attachment point to another. However, Mobile If is not appropriate for seamless mobility. Some micromobility protocols were proposed to complement Mobile IP by offering fast and seamless handoff control in limited geographical areas. In this paper, a new scheme, based on path prediction and resource reservation, is proposed to reduce the handoff latency by trying to eliminate the link setup time for fast handoff in all-IP wireless networks. Analytical results show that the proposed scheme offers shorter handoff delay and can improve the handoff efficiency.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.5
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• pp.25-35
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• 2015

Handoff is a critical issue for seamless roaming in IEEE 802.11-based wireless networks. In order to provide real-time services, handoff mechanism must be provided. However, the IEEE 802.11 standard handoff is not appropriate to provide the services, because it is based on the full-scanning approach which spends too much time searching Access Point (AP). In this paper, we propose a new scheme, which can reduce the scanning latency. A station performs full-scanning operation for finding APs when it enters wireless networks for the first time. The station sends the scanned channel information to AP. AP maintains the neighbor channel table based on the information received from stations. A station performs the partial-scanning by using the table. Therefore, the proposed scheme can reduce the scanning latency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.7A
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• pp.746-754
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• 2007

In this paper, we propose a fast handoff algorithm for micromobility management enhancement in HMIPv6 networks, which eliminates the DAD procedure involved in the regular HMIPv6 in order to o decrease handoff latency and increase the resource utilization efficiency. In the proposed scheme, the MAP is designed to guarantee the uniqueness of MN's interface identifier within a MAP domain as long as the MN moves in a MAP domain, so that the MN configures the new address without the DAD procedure resulting in the decreased handoff latency significantly When the MN resides in a subnet, MIPv6 is used adaptively as a mobility management protocol, which is to reduce bandwidth waste from the IP packet header overhead of IP-in-IP tunneling from the regular HMIPv6. We evaluate the performance of the proposed handoff micromobility algorithm in terms of handoff delay and packet loss thru computer simulation. Thru various computer simulation results, we verified the superior performance of the proposed scheme by comparing with the results of other schemes, MIPv6 and HMIPv6.

• Journal of KIISE:Information Networking
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• v.29 no.2
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• pp.197-203
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• 2002

This paper proposes a new agent based mechanism called a Multicast Handoff Agent (MHA) to reduce handoff latency for IP multicast. The MHA acts as a proxy for an Internet Group Management Protocol (IGMP) of Mobile Nodes (MNs) at each Base Station (BS) and keeps information for members of multicast groups in a cell. When an MN moves to a next cell, the MHA immediately sends unsolicited reports without waiting for the IGMP query. The mechanism was evaluated through simulation and analysis and compared with the IGMPv2 for micro-mobility and the IGMP traffic. Simulation results show that handoff latency for micro-mobility can be largely reduced and the IGMP control traffic on the wireless links during the duration of membership can be eliminated. Thus, this mechanism is superior to the existing mechanism in both micro-mobility and battery duration, as the need not to reply to a query conserves battery power.