• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4A
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• pp.377-386
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• 2008

In this paper, a new handover management scheme has been proposed to reduce handover latency and to support fast handover without packet losses, so that it may be applicable to the wireless mobile Internet system such as IPv6-based WiBro system. To minimize the handover latency in processing of movement detection, we propose the handover management scheme which simplifies the handover message exchanging procedure between mobile subscriber station (MSS) and network by integrating layer 2 and layer 3 handovers efficiently based on the layer2 information. To reduce the processing delay from new care-of-address (NCoA) configuration during handover, we propose that NCoA is created, distributed and managed by new access control router (NACR). In addition, in order to minimize the packet transmission delay and eliminate the packet losses, the proposed scheme employs a crossover router (CR) which is upper network located over PACR and NACR and employs the packet buffering for MSS. The simulation study shows that the proposed scheme achieves loss-free packet delivery and low latency in the environment of narrow overlapped cell area or high velocity of the MSS, comparing the performance with the conventional schemes.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.509-512
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• 2003

본 논문은 무선랜 환경에서 Mobile IPv6 Node가 이동 시에 발생하는 Handover Latency 를 줄이기 위한 새로운 알고리즘을 제안한다. 현재 Mobile IPv6 Fast Handover Protocol 은 Layer2 에서의 Handover 의 도움을 전제로 하기 때문에 실제 구현상에서 Real-time 이나Delay 에 민감한 Application 에 적용하기 어렵다. 이 문제를 해결하기 위해 무선랜에서 사용하는 Beacon 신호를 이용한 Dominant NAR 알고리즘을 적용하여 MIPv6 Fast Handover 과정을 선 처리하여 Handover Latency를 줄이고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.66-69
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• 2008

As a mobility support for IP have studied, Internet Engineering Task Force(ITEF) standardized the mobile IPv6 protocol. When a mobile node moves between networks, MIPv6 maintains connectivity to network and supports seamless communication, and these processes are called a Handover. IEEE 802.21 standardized MIH(Media Independent Handover) for seamless Handover. MIH used three services for Handover between low layer and upper layer. In this paper, we designed two modes on existing MIH for seamless Handover. We implemented a dual-interface mobile host(MH) model in network simulation2 (ns2) to evaluate how it performs in comparison with single-interface MH.

• The KIPS Transactions:PartC
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• v.14C no.6
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• pp.503-508
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• 2007

Since the Wibro service realize mobile network on the public, it has been considered that it is not enough to support real time service at vehicular speed. The standard Fast Mobile IPv6 Handover Protocol using HMIPv6 may guarantee seamless service as long as the Mobile Node moves in the same domain MAP however it does not regard fast handover over inter-MAP domain. Thus Macro Mobility Handover in HMIPv6 was proposed to reduce handover latency in inter-MAP domain. But it is still not enough to support real-time service. So we propose an Improved FHMIPv6 over 802.16e network to reduce the overall handover latency. We embedded Layer 3 handover messages of the FHMIPv6 into the Layer 2 handover messages. So the MN is able to $^-nish$ overall handover procedure earlier in our scheme. The numerical results show the performance of IFHMIPv6 has improved about 32% in comparison with FHMIPv6.

• The KIPS Transactions:PartC
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• v.13C no.1 s.104
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• pp.121-128
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• 2006

In Mobile IPv6, a handover latency is an important issue. To reduce the handover latency, mipshop working group in IETF has studied the fast handover(FMIPv6) which creates and verifies a new care-of address(NCoA) in advance before a layer 2 handover resulting in reduced handover latency. Even in FMIPv6, the NCoA must be registered in a home agent(HA). This registration still creates a significant amount of delay. To reduce registration latency, we propose a tentative and early binding update(TEBU) scheme that the NCoA is registered in the HA in advance during the layer 2 handover based on FMIPv6. We use cost analysis for the performance evaluation. As a result, we found that the TEBU scheme guarantees lower handover latency than FMIPv6 as much as approximately 21%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7A
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• pp.550-556
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• 2005

This paper proposes a path prediction-based seamless handover scheme to minimize service disruption and packet loss due to handovers for mobile networks such as Dams. This scheme exploits a peculiar characteristics of trains which move on a predetermined path. The mobile router on the train can predict a handover point and then perform network-layer handover before link-layer handover occurs. This leads to the reduction of handover latency and packet loss during handovers. The performance evaluation showed that the proposed scheme could provide excellent performance, compared with the NEMO basic support scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.651-659
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• 2004

The Fast Handover protocol ［1］ provides seameless handover in wireless If networks by minimizing handover latency, which uses anticipation based on layer 2 (L2) trigger information. Therefore, it incurs higher signaling costs compared with the basic Mobile U protocol. Furthermore, since the L2 trigger is based on fluctuating wireless channel states, the handover anticipation may sometimes be incorrect. In the case of incorrect anticipation, unnecessary buffer space may be used for the purpose of providing a smooth handover. Therefore, it is essentical to analyze these overhead costs, in order to evaluate and compare the performance of Fast Handover with that of the basic Mobile U protocol. In this paper, we analyzed the overhead associated with Fast Handover including the signaling cost and the packet delivery cost. We formulated these costs based on a timing diagram and compared Fast Handover with basic Mobile Ipv6 in terms of their packet loss rates and buffer requirements. Also, we studied the impact of the L2 triggering time on the total overhead cost.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.54-62
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• 2007

Mobile IPv6 is the representative standard protocol proposed to offer mobility of mobile hosts, but it has drawbacks such as high handover latency and packet loss during handover. To complement these drawbacks, several protocols have been proposed and they can support faster handover than the Mobile IPv6, but there still exists inevitable packet loss during handover in those protocols. In this paper, we propose a new handover procedure of mobile host who has a dual link for minimizing packet loss rate during micro handover to improve mobility capability of Cellular Ethernet system that supports mobility at layer 2. And we derive the superiority of proposed scheme by comparing in terms of packet loss rate, handover latency and throughput of proposed scheme with those of Hierarchical Mobile IPv6 which is the representative IP-layer micro mobility protocol by simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11B
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• pp.968-980
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• 2008

Providing handover with guaranteed QoS for real-time multimedia service such as VoIP, video/audio streaming, and video conferencing in wireless LAN is a challenging task. In this paper, we present efficient layer 2 handover mechanism in wireless LAN, which can provide fast handover with guaranteed QoS for real-time multimedia service. To this end, the scanning period and the number of channels per scanning for handover are dynamically adapted to the type of applications and wireless networking environment, so that both the degradation of application service quality and signaling overhead are minimized simultaneously. The performance of the proposed mechanism is verified by the simulation. The simulation results show that the proposed mechanism guarantess QoS of each multimedia application with minimal power consumption.

• Journal of Korea Multimedia Society
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• v.13 no.2
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• pp.205-215
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• 2010

It is necessary to provide a fast and secure handover for seamless real-time multimedia services based on IEEE 802.11. In this paper, we propose FMIPv6 handoff protocol integrating L2/L3 layer based on IEEE 802.11 WLAN environment. In that, we propose a hierarchical key management scheme and authentication mechanism for protecting the handover signaling messages. The number of connections with AAA server is minimized for the fast handover. It is also compared and analyzed the handover cost with previous method.