• Journal of Korea Society of Industrial Information Systems
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• v.14 no.1
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• pp.56-63
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• 2009

Contrast operating system installed on traditional PC, operating system installed to mobile IP host is a status not to be established a definite monopoly system. Accordingly, for the time being, it is expected that operating system operated in mobile IP host will be used various operating systems. Regardless of operating system, this condition is a very vulnerable to modified virus. Because operating system used in an individual host is very diverse, It makes technical development to cure complicated in detection efficiently these virus. In this thesis, By using VMware under the various operating system, I designed and implemented system which is able to test a modified virus. Also I implemented prototype system to operate under the real mobile condition.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.411-413
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• 2000

Internet망에서 mobile comupting에 대한 관심은 커져하고 있다. Mobile IP는 노드의 이동성을 지원하는 방법 중의 하나이다. 그렇지만 handoff 하는 과정에서 발생하는 패킷 손실 때문에 신뢰성의 문제가 발생한다. 게다가 mobile node(MN)와 foreign agent(FA)사이가 무선 링크인 경우 패킷 손실은 더욱 심각하다. TCP/IP는 고정된 네트워크에서 고안되어진 것이기 때문에 기존의 TCP/Mobile IP가 무선에는 부적합하다. 그러므로 본 논문에서 TCP/Mobile IP와 application사이에 midddleware로써 mobile agen(MA)를 사용하는 것을 제안했다. TCP mobile agent(TCP MA)을 여러 application에서 TCP 성능의 향상을 위해 제안했다. TCP MA는 FA와 MN를 위해 행동하고, 그리고 MN의 현재 위치에 상관없이 MN에 결과를 보낸다. 이러한 TCP MA는 handoff 동안에 발생하는 패킷 손실을 감소시킨다.

• Journal of Internet Computing and Services
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• v.5 no.3
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• pp.25-33
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• 2004

Mobile IP Low Latency Handoffs(l) allow greater support for real-time services on a Mobile IP network by minimizing the period of time when a mobile node is unable to send or receive IP packets due to the delay in the Mobile IP Registration process. However, on Mobile IP network with AAA servers that are capable of performing Authentication, Authorization, and Accounting(AAA) services, every Registration has to be traversed to the home network to achieve new session keys, that are distributed by home AAA server, for a new Mobile IP session. This communication delay is the time taken to re-authentication the mobile node and to traverse between foreign and home network even if the mobile node has been previously authorized to old foreign agent. In order to reduce these extra time overheads, we present a method that performs Low Latency Handoffs without requiring further involvement by home AAA server. The method re-uses the previously assigned session keys. To provide confidentiality and integrity of session keys in the phase of key exchange between agents, it uses a key sharing method by gateway foreign agent that performs a trusted thirty party. The proposed method allows the mobile node to perform Low Latency Handoffs with fast as well as secure operation.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.65-71
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• 2001

In this paper, we propose handoff scheme for BT(Bluetooth) IP and define signaling for the handoff scheme. In local area, BT IP use the concept of Cellular IP and the operation property of Bluetooth system. In case of accessing external internet, use the concept of Mobile IP. IP-based Mobility of Bluetooth Terminal provides efficient and rapid mobility in local area and flexibility on the internet.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.242-252
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• 2002

When a Mobile IP handoff occurs, the packets in flight can be lost because they are tunneled based on out-of-date location information. In this parer, we propose an enhanced handoff protocol that achieves no packet loss during Mobile IP handoff over a wireless LAN. Our handoff protocol predicts the next foreign agent that a mobile host is to visit by using: the information from the data link layer of wireless LAN. After that, when a Mobile IP handoff occult, the current foreign agent forwards the packets destined to a mobile host to the predicted foreign agent which buffers them. This eliminates packet loss and reduces the packet forwarding delay. Our handoff protocol is simulated using the Network Simulator-2 (ns-2) and shows the substantial performance enhancement of TCP with much less overhead up to 6.2 times compared to standard Mobile IP.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.396-398
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• 2000

최근 무선 통신 기술의 발달과 휴대용 컴퓨터의 소형화, 수요증가에 따라 휴대용 컴퓨터에서의 통신은 차차 우리 생활에 없어서는 안될 요소가 되어가고 있으며 IP 기반에서의 Mobility 제공을 그 목적으로 하는 Mobile IP 기술은 차세대 인터넷망의 핵심기술이 될 전망이다. 이에 본 논문에서 Mobile IP Protocol을 Mobile Node를 중심으로 객체지향 개념을 도입하여 설계, 구현한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.728-735
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• 2003

It is a mainly issue that provide mobility smoothly in Mobile IP networks. The IP mobility support being standardized in the IETF utilized tunneling of IP packets from a home agent to foreign agent and utilized reverse tunneling of IP packets from foreign agent to home agent. In this paper, We propose that solve the triangular routing problem in IP mobility and that lessen the messages about IETF routing optimization. Through the Mobile Routing Table on the edge router, agent process the message instead of a end node when handoff occur and that lessen the routing path length by sending directly from FA to to Correspond Node's router. This action lessen the message occurrence frequency and the packet drop. We compare the standard IP, Routing Optimization of Mobile IP, Wu's method and the proposed algorithm. Finally, the simulation results are presented.

• Smart Media Journal
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• v.4 no.4
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• pp.47-55
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• 2015

Recently, the computing paradigm has been changing and VoIP technology is being revisited to support various services in ICT field. In this paper, we have designed and implemented the systems of software PBX open source Asterisk using light-weighted virtualization Docker technique, hardware platform, and mobile devices to support voice service based on secured mobile VoIP. And we verified the delay test of network traffics and the secured voice communication test in global real network environment.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.508-510
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• 2002

본 논문은 기존 멀티캐스트 라우팅 프로토콜이 이동성이 없고 수신자 불명의 방송형 응용에 초점을 맞추어 설계되어 있는 점에 비추어, 이동중이며 구체적인 멤버들의 존재를 알고있는 경우에 적합한 명시적 멀티캐스트 전송기술을 Mobile IP의 확장으로 설계하고 개발한다. Mobile IP에 명시적 멀티캐스트 전송 기법을 적용하기 위해서는 이동 에이젼트의 각 모듈들이 명시적 멀티캐스트를 지원할 수 있도록 수정ㆍ보완되어야 한다. 기존 Mobile IP에 멀티캐스트를 적용하게 되면 극단적인 경우 중복된 패킷의 전송 및 수신으로 통신망에 큰 부하가 걸리게 되는데, 이를 해결하기 위한 방안으로 명시적 멀티캐스트 전송기술도 제안한다.

• The Journal of the Acoustical Society of Korea
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• v.28 no.3E
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• pp.99-108
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• 2009

In this paper, we suggest criteria for objective measurement of speech quality in mobile VoIP (Voice over Internet Protocol) services over wireless mobile internet such as mobile WiMAX networks. This is the case that voice communication service is available under other networks. When mobile VoIP service users in the mobile internet network based on packet call up PSTN and mobile network users, but there have not been relevant quality indexes and quality standards for evaluating speech quality of mobile VoIP. In addition, there are many factors influencing on the speech quality in packet network. Especially, if the degraded speech with packet loss transfers to the other network users through the handover, voice communication quality is significantly deteriorated by the transformation of speech codecs. In this paper, we eventually adopt the Gilbert-Elliot channel model to characterize packet network and assess the voice quality through the objective speech quality method of ITU-T P. 862. 1 MOS-LQO for the various call scenario from mobile VoIP service user to PSTN and mobile network users under various packet loss rates in the transmission channel environments. Our simulation results show that transformation of speech codecs results in the degraded speech quality for different transmission channel environments when mobile VoIP service users call up PSTN and mobile network users.