• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04a
• /
• pp.697-699
• /
• 2004

오늘날 무선 통신 기술의 급속한 발전과 이동 단말의 소형화, 고성능화가 실현됨에 따라 이동 중 데이터 통신이 가능하도록 하기 위해서는 이동 단말의 이동성을 효율적으로 관리하는 것이 매우 중요하다. 본 논문에서는 IETF에서 개발한 Mobile IPv6를 기반으로 지역적 이동성 기능을 제공하기 위하여 이동 노드의 기능을 강화한 방안을 구현하고 실측을 통하여 성능을 분석하였다. 본 논문에서 구현한 방안은 이동 단말이 외부 도메인 내에서 핸드오프 시 바인딩 메시지를 지역 내에서 처리하여 자신의 위치를 갱신하는 시간을 감소시킴으로써 Mobile IPv6보다 패킷 손실을 줄이고 TCP 처리율을 높임을 알 수 있었다.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2001.05a
• /
• pp.127-131
• /
• 2001

휴대용 단말기와 이동통신 기술의 발달로 무선 네트워크의 사용이 급증하면서 호스트가 이동중에도 지속적인 네트워킹이 가능한 프로토콜들이 개발되고 있다. Mobile IP는 이동 노드(mobile node)가 인터넷상의 임의의 다른 위치에 접속하여 IP 주소를 변경하지 않고, 홈 주소를 이용하여 통신하며 위치에 따른 care-of address에 의해 데이타를 터널링하여 전달받는다. 본 논문에서는 컴퓨터 시뮬레이션을 통해 self-similar 트래픽을 갖는 mobile IP의 성능을 분석한다. 일반적으로 데이타 트래픽, 바인딩 갱신시간, 버퍼관리 방법 등은 핸드오프 동안 mobile LP의 성능에 많은 영향을 비친다. 따라서 시뮬레이션 모델을 이용하여 self-similar 트래픽 환경에서 위에 언급된 성능 파라미터들의 영향을 분석한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.11a
• /
• pp.858-861
• /
• 2002

As mobile devices have become widely popular, users want to use devices not only wireless but also mobile. Mobile IP is used to support mobility on TCP/IP network. In mobile IP, when a terminal changes location, the terminal requests a registration to Home Agent through Foreign Agent in new location. After the request is accepted by Home Agent, the terminal can use network again. We call this process as handoff. In mobile n, handoff provokes loss of data packets and network delay. In this paper, we describe the implementation of pre-registration which is a solution of the handoff problems. Pre-registration improves the traditional handoff mechanism by requesting registration through current FA before location change. This muchanism can decrease packet loss and network delay.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.18 no.5
• /
• pp.103-113
• /
• 2008

Reducing handoff latency is essential in providing seamless multimedia service in Wireless LAN based on the IEEE 802.11 standard. Reducing authentication delay is critical in reducing handoff latency. To this end, several authentication protocols for fBst handoff have been proposed. Mishra et al. used proactive key distribution to improve the authentication delay incurred in the current standard and Park et al. proposed a new authentication protocol based on Blom's key pre-distribution scheme. In this paper, we propose an enhanced authentication protocol based on Bresson et al.'s group key protocol. If a mobile node has previously access the network, our proposed protocol only requires simple hash operations in providing mutual authentication between a mobile node and access points. Our protocol is more efficient than Park et al.'s and Mishra et al.'s technique can be used in our protocol to further enhance our protocol.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.1 no.2
• /
• pp.120-126
• /
• 2006

In this paper, we propose for improving QoS in hospital wireless network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it has its vulnerability in frequent handoff environment. This handoff state machine using differentiated handoff improves quality of services in Cellular-IP/PRC. Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. When speech quality is secured considering increment of interference to receive in case of suppose that proposed acceptance method grooves base radio station capacity of transfer node is plenty, and most of contiguity cell transfer node was accepted at groove base radio station with a blow, groove base radio station new trench lake acceptance method based on transmission of a message electric power estimate of transfer node be. Do it so that may apply composing PC(Paging Cache) and RC(Routing Cache) that was used to manage paging and router in radio Internet network in integral management and all nodes as one PRC(Paging Router Cache), and add hand off state machine in transfer node so that can manage hand off of transfer node and Roaming state efficiently, and studies so that achieve connection function at node. Analyze benevolent person who influence on telephone traffic in system environment and forecasts each link currency rank and imbalance degree, forecast most close and important lake interception probability and lake falling off probability, GoS(Grade of Service), efficiency of cell capacity in QoS because applies algorithm proposing based on algorithm use gun send-receive electric power that judge by looking downward link whether currency book was limited and accepts or intercept lake and handles and displays QoS performance improvement.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.3 no.3
• /
• pp.188-194
• /
• 2008

In this paper, we propose for improving QoS in Hospital wireless network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP and propose for performance of realtime and non-real time handoff service using Handoff state machine Paging Route Cache. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it has its vulnerability in frequent handoff environment. This handoff state machine using differentiated handoff improves quality of services in Cellular-IP/PRC Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. When speech quality is secured considering increment of interference to receive in case of suppose that proposed acceptance method grooves base radio station capacity of transfer node is plenty, and moat of contiguity cell transfer node was accepted at groove base radio station with a blow, groove base radio station new trench lake acceptance method based on transmission of a message electric power estimate of transfer node be. Do it so that may apply composing PC(Paging Cache) and RC(Routing Cache) that was used to manage paging and router in radio Internet network in integral management and all nodes as one PRC(Paging Router Cache), and add hand off state machine in transfer node so that can manage hand off of transfer node and Roaming state efficiently, and studies so that achieve connection function at node. Analyze benevolent person who influence on telephone traffic in system environment and forecasts each link currency rank and imbalance degree, forecast most close and important lake interception probability and lake falling off probability, GoS(Grade of Service), efficiency of cell capacity in QoS because applies algorithm proposing based on algorithm use gun send-receive electric power that judge by looking downward link whether currency book was limited and accepts or intercept lake and handles and displays QoS performance improvement.

• Journal of Internet Computing and Services
• /
• v.5 no.1
• /
• pp.25-32
• /
• 2004

Mobile computing environment makes it possible for computing activities to be maintained during movement even if a user changes its network point of attachment. Mobile IP is a standard protocol designed to be used in such mobile computing environment. However, Mobile IP has a drawback to incur a lot of handoff delays and waste network resources, since CoA(Care of Address) registration packets need to go through a HA(Home Agent) first whenever a mobile node moves. To solve this long-standing problem, this paper proposes a new scheme that, for infra-domain movement, efficiently performs local handoff without notifying the HA Specifically, based on the notion of load balance, the proposed scheme allows every FA(Foreign Agent) in a domain to become the root FA(also known as domain FA) dynamically, thus distributing the registration task into many other foreign agents. The dynamic root assignment through load balancing ultimately leads to fast network response due to less frequent transmission of registration packets.

• Journal of the Korea Society of Computer and Information
• /
• v.11 no.5 s.43
• /
• pp.165-173
• /
• 2006

Network Mobility Basic Support protocol enables mobile network to change their point of attachment to the Internet, but causes some problems such as suboptimal muting and multiple encapsulations. The proposed scheme, combining Prefix Delegation protocol with HMIPv6 concept can provide more effective route optimization and reduce the amount of packet losses and the burden of location registration for handoff. It also uses hierarchical mobile network prefix (HMNP) assignment and provides tree-based routing mechanism to allocate the location address of mobile network nodes (MNNs) and support micro-mobility. In this scheme, Mobility Management Router (MMR) not only maintains the binding informations for all MNNs in nested mobile networks, but also supports binding procedures to reduce the volume of handoff signals oyer the mobile network. The performance is evaluated using NS-2.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.14 no.1
• /
• pp.79-89
• /
• 2004

Mobile IP Low Latency Handoffs allow greater support for real-time services on a Mobile W 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-authenticate 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 funker 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 ousted thirty party. The Proposed method allows the mobile node to perform Low Latency Handoffs with fast as well as secure operation

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.7B
• /
• pp.991-1000
• /
• 2010

The Hierarchical Mobile IPv6 (HMIPv6) has been proposed to accommodate frequent mobility of the Mobile Node. HMIPv6 can effectively reduce the signaling overhead and latency. However, it has a problem that the registration of a mobile node concentrates on the furthest MAP(Mobility Anchor Point) when the mobile node enters into a new domain. This paper proposes a new load distribution mechanism by using the concept of Nash Bargaining Solution. The main advantage of the proposed scheme can prevent load concentration from being registered to the specified MAP based on the weight value according to the available resource-ratio of a MAP. With a simulation study, the proposed scheme can improve network performance under widely diverse traffic load intensities.