• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.04a
• /
• pp.583-585
• /
• 2012

PMIP (Proxy Mobile IPv6)은 네트워크 기반 이동성 지원 프로토콜로, 호스트 기반 이동성 프로토콜에 비해 핸드오버 시간을 줄였지만 완전히 제거하지 못하였고 핸드오버 시의 패킷 손실에 대해서도 고려하지 않는다. 따라서 핸드오버 시간을 줄이고 패킷 손실을 방지하여 끊김 없는 서비스를 제공하기 위한 빠른 predictive 핸드오버 방식이 제안되었다. 하지만 이 방식을 이용할 경우 predictive 모드에서의 핸드오버 절차를 진행하기 위해 불필요한 핸드오버 지연이 발생할 수 있다. 본 논문에서는 GPS를 이용하여 MN (Mobile Node)의 위치정보를 파악하고 이를 통해 predictive 모드에서의 빠른 핸드오버 절차 진행 시 발생하는 문제점 해결을 위한 기법을 제안한다.

• Journal of KIISE:Information Networking
• /
• v.27 no.4
• /
• pp.396-406
• /
• 2000

유선 네트웍과는 달리 무선 네트웍에서는 단말기들이 이동하기 때문에 핸드오버가 발생한다. ATM네트웍은 연결 지향통신을 하기 때문에 핸드오버가 발생하면 통신을 위한 경로를 재 설정해 주어야 한다 높은 서비스 품질을 제공하기 위해 요구되는 빠르고 효율적이며 끊김이 없는 경로 재 설정방법으로 두 단계(사용중인 경로에서 새로운 경로와의 접합점인 크로스오버 스위치)를 찾는 단계와 찾아진 크로스오버 스위치까지 새로운 경로를 설정하는 단계로 이루어지기 때문에 핸드오버 지연시간이 길고 시그널링 부담이 크다. 본 논문은 핸드오버 지연 시간을 줄이고 시그널링 부담을 최소화하기 위해 경로설정을 위한 시그널링 메시지에 기존의 경로 정보를 포함시킴으로써 크로스오버 스위치의 탐색과 부분 경로 재 설정을 한 단계로 단일화하는 기법을 제안한다. 또한 시뮬레이션을 통해 기존의 방법과 비교 평가함으로써 제안하는 기법이 핸드오버 지연 시간과 시그널링 부담을 줄였음을 보인다.

• Proceedings of the KIEE Conference
• /
• 2008.10b
• /
• pp.398-399
• /
• 2008

본 논문에서는 이기종 무선 망 환경에서 사용자가 특정 hot spot 지역을 출입 시 효율적인 이동성 지원을 위해 IEEE802.21(MIH) 기술과 RFID 시스템을 적용한 핸드오버 절차와 기법에 대해 제안한다. 기존의 방법들은 주로 수신된 신호 세기(Received Signal Strength Indication)을 측정하여 신호 감도에 따라 핸드오버할 시점을 결성한다. 하지만 이런 방법들은 갑작스런 신호세기 감소나 불안정한 신호 지역에서 현재 사용 중인 세션이 완전히 끊겨버릴 수 있는 문제점이 있다. 제안한 기법은 사용자가 핸드오버가 절대적으로 필요한 장소에서 출입 시 마다 자동적으로 핸드오버가 일어나게 하여 불필요한 전력 소모를 줄일 누도 있고, 응용의 세션이 갑작스럽게 끊어지는 현상을 방지할 수 있어서 보다 더 안정된 서비스를 제공할 수 있는 장점이 있다. 또한 접속 망 선택 시 사업자의 정책을 반영 한 망 기반의 핸드오버를 제공한다.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.17 no.2
• /
• pp.103-114
• /
• 2007

The existing handover authentication schemes have authentication delay and overhead of the authentication server since they have been separately studied handover authentication at the link layer and the network layer. This paper proposes a handover authentication scheme initiated by Mobile Node on FMIPv6 based mobile access networks. The main idea of the paper is to generate a session key at the mobile node side, and transfer it to the next Access Router through the authentication server. Also, the scheme has a hierarchical key management at access router. There are two advantages of the scheme. First, the generated session key can be utilized for protecting the binding update messages and also for access authentication. Second, hierarchical key management at the access router reduced the handover delay time. The security aspects on the against PFS, PBS, and DoS attack of proposed scheme are discussed.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.8A
• /
• pp.802-812
• /
• 2007

A Fast handover protocols for Mobile IPv6 networks can support seamless service by reducing handover latency to mobile nodes. To gain advantage derived from the fast handover in IEEE 802.16e networks, we propose a new fast handover protocol using a multiple simultaneous binding mechanism and a handover protocol based on trigger event for IEEE 802.21 in order to integrate IEEE 802.16e handover protocol and FMIPv6 handover protocol using link layer trigger. Through the numerical analysis, we compare performance of the proposed protocol and FMIPv6 protocol.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.1A
• /
• pp.7-16
• /
• 2003

Handover is very important to support the mobility of user because wireless ATM networks have smaller cell size such as micro/pico cell for broadband mobile multimedia service In this paper, we propose dynamic path reservation handover scheme for fast inter-MSC (Mobile Switching Center) handovers To reduce the handover delay for connection re-routing, the proposed scheme reserves virtual channels from nearest common node to neighbor MSC in advance Especially, our handover scheme predicts the number of inter-MSC handover calls at each period by the prediction algorithm and reserve virtual channels The simulation and analysis results show that our scheme reduce handover complexity and has higher reservation channel utilization, compared with DVCT scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.37 no.1
• /
• pp.23-31
• /
• 2000

In this paper, we propose an adaptive handover scheme in wireless network. The proposed handover scheme is a hybrid type of virtual path extension and rerouting. The proposed handover scheme chooses the virtual path management scheme according to the service QoS instead of the network topology which is used in the previous hybrid handover schemes. The proposed scheme supports the seamless service and small buffering during virtual path rerouting handover through the multicasting service. To evaluate the performance of the proposed scheme, we computed the number of signaling message used for handover and perform computer simulation. The simulation results show that the proposed scheme provides more efficiency in the handover delay and seamless service than the previous methods.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.2
• /
• pp.112-121
• /
• 2011

The IEEE WAVE standard specification does not support handover operation since it is designed to transmit mainly the ITS-related messages that are limited in length. More advanced multimedia applications such as Internet browsing and streaming of video clips produced by CCTVs, however, require handover support such that a sequence of data packets can be received seamlessly while an OBU's association with the RSUs changes. This paper presents a new handover scheme that can operate without performance degradation in the cases where there are multiple RSUs in the areas of handover by making use of the IEEE 802.11f IAPP Move-notify messages, based on the fast handover scheme with proactive caching by disassociation messages introduced previously. Experimental results from the simulation shows that the proposed handover scheme outperforms the scheme based solely on multicast.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.12C
• /
• pp.1273-1279
• /
• 2006

In this paper, we address the design of adaptive handover schemes based on the signal strength measurement for cellular communications systems. Conventional handover algorithms, which are based only on the downlink measurement, cannot guarantee the required uplink quality because uplink channel can differ greatly from downlink channel quality. Therefore, we proposes a new suboptimal adaptive handover algorithm that considers both the uplink and downlink channel quality in order to achieve the best cell selection gains when there is a wide difference between the uplink and downlink signal quality. Simulation results show that the proposed scheme achieves better performance compared to conventional handover schemes.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.4
• /
• pp.56-63
• /
• 2009

Resource reservation scheme is effective for better QoS guarantee to handover call for the next generation cellular systems where handover rate highly increases. However, resource reservation for handover call can incur negative impact on the new user admission. In this paper, we propose a random access based adaptive group-wise reservation to effectively reduce dropping rate of handover call, while protecting new local call. In the proposed scheme, target base station divides adaptively future handover users into groups based on the expected handover time, and then does group-wise reservation, where service allocation within each group is done on random access basis. Markov approach is also provided to analyze the performance of the proposed scheme. By computer simulation, it is shown that theoretical analysis on the performance is similar to the simulation results and the proposed reservation scheme outperforms the conventional scheme with respect to dropping probability of handover call.