• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.179-186
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• 2012

Nowadays, the multihomed host equipped with multiple network interfaces has been interested research in next generation wireless network, because the mobile users expect that they can be able to access services not only anywhere, at any time and from any network but also simultaneously. This paper addresses the mobility simulation model of the multihomed node for supporting MIPv4 and MIPv6 function in an interworking of Worldwide Interoperability for Microwave Access (WiMAX) and IEEE 802.11 WLAN. The multihomed node with two air interfaces has been developed based on WiMAX and WLAN workstation node model in simulation software. The main point of the developed model is to support both MIPv4 and MIPv6 function, and provide network selection policy for the multihomed node between WiMAX and WLAN network. Based on the received Router Advertisement along with the interface number, we can manage the access interfaces in ordered list to make handover decision while the multihomed node is moving. In the end of this paper, the simulation scenarios and results are shown for testing MIPv4 and MIPv6 function.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.225-226
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• 2015

본 논문은 PMIPv6 기반 무선 네트워크 환경에서 입체영상을 송수신하는 멀티인터페이스 이동노드의 핸드오버 수행 시 손실을 최소화하기 위한 MPTCP 기반의 입체영상 전송기법을 제안하다. 제안하는 입체영상 전송 기법은 입체영상 단말 이동 시 멀티인터페이스 간 입체영상으로 정의된 플로우의 플로우 이동성이 수행되며 플로우 이동성 발생 시 단대단 연결 단절 현상을 MPTCP Sublflow 기능을 통해 극복한다. 기존 기법에 비해 제안하는 기법은 데이터 손실 및 단대단 지연을 최소화하며 이동성 환경에서 입체영상의 좌우영상 싱크문제를 극복하는 방법이다.

• Journal of Korea Multimedia Society
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• v.13 no.8
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• pp.1221-1234
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• 2010

MANET(Mobile Ad-hoc Network)s have been researched primary at routing protocols and at the guarantees of QoS(Quality of Service) for mobile environments. Otherwise the Ubiquitous Sensor Networks (USNs) have some limitations in power energies and in processing of sensing data, as well as their network topologies are frequently changed by fading off and node failures. Thus we should redesign network protocols with concerning to energy efficiency for the USNs above all. In this paper, we focus on the protocol interface for managing for USNs based on the surveys. And then we figure the topology of USNs out and design the network protocol interface to make power saved, with data gathering and processing more efficient using our designed packet structures.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.111-119
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• 2010

With the rapid progress of wireless technologies today, mobile terminals with multiple access interfaces are emerging. In recent years, WLAN (Wireless Local Area Networks) has become the premier choice for many homes and enterprises. WiMAX (Worldwide Interoperability for Microwave Access) has also emerged as the wireless standard that aims to deliver data over long distances. Therefore, it is important to explore efficient integration methods for delivering multimedia data between heterogeneous wireless networks. In this paper, we developed the simulation models and environments for the mobile multihomed node that has both WiMAX and WLAN interfaces and can move around in both networks by using mobile IP. In order to verify the developed models, we designed and constructed several simulation scenarios, e.g. movement in WiMAX/WLAN, group mobility, MANET, and nested MIP under the various traffic environments such as oneway or bothway UDP packets, FTP traffic, and voice with SIP protocol. The simulation results show that the developed models are useful for mobility studies in various integrated wireless networks.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.15-20
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• 2010

This paper proposes a multihoming-based vertical handover scheme using Proxy binding update to minimize handover delay and packet loss while a mobile node moves to a heterogeneous access network. When a mobile node moves to a heterogeneous access network, the proposed scheme can provide a mobile node with fast and seamless handover by performing layer-3 handover using its new interface while the other interface is still communicating in the old access network. The proposed Proxy binding update is different from the Mobile IP binding update in that it includes home addres (HoA) of the old interface instead of the new interface. The performance analysis shows that the proposed scheme can efficiently reduce vertical handover delay and packet loss.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1085-1091
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• 2006

For an experiment in this paper, designed test bed to secure confidentiality of data and safe transmission that Mobile node exchanges in Mobile network. And, For IPsec use that support basically in MIPv6, modeling and experimented IKEv2 protocol that is used for reliable authentication key management and distribution between End Point. When Mobile node handoff in Mobile network, analyzed effect that authentication key re-exchange and limited bandwidth that happen often get in key exchange. And studied about Performance and latency about authentication setting and exchange process that use multi interface. To conclusion, when Mobile node transmits using IPSec, re-authentication of key confirmed that re-setting by limit of bandwidth that existent Mobile network has can be impossible. According to other result, proposed MN's multi interface is expected to minimise key exchange latency by hand-off when transmit IPSec.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.986-989
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• 2006

앞으로의 네트워크는 Convergence와 Integrate라는 키워드를 기반으로 IP 중심의 통합된 망으로 발전되고 있다. IP 중심의 망은 각각의 다양한 access 기술을 포함하며, voice, multimedia, 그리고 새롭게 정의되는 서비스가 모두 제공될 수 있어야 한다. 따라서 점차 인터넷을 중심으로 하는 하나의 통합된 망의 형태로 진화 될 것이다 이러한 차세대 네트워크상의 단말은 소형화, 지능화, 그리고 이동성을 지니고 있으며, 다양한 access 기술을 사용하기 위한 multiple 인터페이스를 가진 멀티호밍 환경에 놓여있다. 따라서 이 네트워크는 기본적으로 이동성과 멀티호밍을 지원해야 하는 것이다. 그러나 현재 인터넷의 핵심인 Internet Protocol 구조는 이를 지원하지 못한다. 현재 IP 주소는 최종 단말의 식별자 (Identifier)와 단말의 위치 식별자 (locator)의 의미를 함께 사용하고 있어, 통신 중인 단말이 이동하면 IP 주소도 변경되어 통신 중인 세션이 끊기는 문제가 발생한다. 멀티호밍 환경에서도 역시 통신 중인 노드들의 경로를 바꾸게 되면 세션이 끊기게 되는 문제가 발생한다. 본 논문은 이와 같은 린 구조의 근본적인 문제를 해결하기 위해 Identifier와 locator를 분리하며, 단순하게 단말에 스택으로 존재하는 L3SHIM을 소개하고, 모든 단말에 이 기능이 지원되었을 때 기존의 인터넷 프로토콜의 확장과 인터넷의 구조에 어떤 영향을 줄 수 있는지에 대해 선행 연구를 하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.34-43
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• 2007

Recently, in addition to the sharp increase of mobile nodes, various kinds of wireless technologies are available for mobile nodes. If IPv6 technology is applied to the network, multi-homing terminals which have several public IP addresses on one interface will be common. Accordingly, there are many research activities on mobility management for multi-interface, multi-homming nodes. In this paper we propose an extended fast handover mechanism for multi-interface MIPv6 environments that uses multi-interface FBU (MFBU) message instead of the existing FBU message. The MFBU message has the "tunnel destination" mobility option that points a specific tunnel destination other than NAR, and "T" flag that indicates the existence of tunnel destination option. The proposed mechanism can improve the TCP performance by mitigating packet reordering during FMIPv6 handover that can cause unnecessary congestion control due to 3 duplicate ACKs. In this paper, we implemented a multi-Interface MIPv6 simulator by extending a single-interface MIPv6 simulator in NS-2, and showed that the performance of TCP traffic is improved by using the proposed multi-interface fast MIPv6.

• The KIPS Transactions:PartC
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• v.12C no.2 s.98
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• pp.267-280
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• 2005

In this paper, we implement and verify XMIP integrating IETF Mobile IP and the Explicit Multicast mechanism for a great number of small group multicast communications. U a source node sends Xcast packets explicitly inserting destination nodes into the headers, each Xcast router decides routes and forwards the packets toward each destination node based on unicast routing table without the support of multicast trees. n is a straightforward and simple multicast mechanism just based on a unicast routing table without maintaining multicast states because of the inheritance from the Explicit Multicast mechanism. This research modifies and extends the functionality of IETF Mobile IP's mobility agents, such as HA/FA to HA+/FA+ respectively, considering interworking with Xcast networks. Xcast packets captured by HA+ are forwarded into X-in-X tunnel interfaces for each FA+ referred to the binding table of HA.. This X-in-X tunneling mechanism can effectively solve the traffic concentration problem of IETF Mobile IP multicast services. Finally WLAN-based testbed is built and a multi-user Instant messenger system is developed as a Xcast application for finally verify the feasibility of the implemented XMIP/Xcast protocols.

• Journal of Korea Multimedia Society
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• v.4 no.5
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• pp.377-389
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• 2001

It has a tendency to build Workflow Systems based on the web with the spread of web environment. The important function in Workflow Systems are to automatize job flow according to the predefined regulations, procedures or conditions. Hence, there needs to consider excluding passive jobs, supporting GUI and a migratory information processing for information flow. Distributed Workflow System for workflow of a distributed service system should perform transfer control and Fault-Tolerance between tasks based on process logic, and real time processing. However, the existing mail systems being used are just for transmission and it doesn't fit to automatize job flow. To solve the matter, there needs a Distributed Workflow Engine to design workflow and automatize its control. In this paper, we design a web browser with graphic interface using web mail, a browser creating a script code for a procedural performance. Also, we design a Process-engine has a Preprocessor which tolerates process scheduler for task transaction or server node's faults on distributed environment. The proposed system enhances the reliability and usability of a system reduces the cost rather than a workflow system based on database, for they execute as proxy for a server's fault or suers' absence.