• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6B
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• pp.382-389
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• 2007

In this paper we report the development of mobility test bed, the realization of basic protocol that supports L3 mobility and the measurement of performance parameters that can affect handover performance. Previously proposed mobility management system, BBM (Break Before Make) method such as MIPV6 and Fast MIPV6, uses one interface in wireless network. In this method, to connect to new AP, it first disconnects existing AP and tries to connect to new AP. This can cause packet loss for the traffic vulnerable to delay such as VoIP. To provide seamless handover between different wireless networks, we propose MBB (Make Before Break) handover method having two network interfaces. Comparative study of previous method and proposed method on mobility and handover was conducted under simulated real environment on the test bed. Almost no packet loss was found with newly proposed method. In conclusion, it is shown that mobility protocol with proposed handover method can be applied to the application services sensitive to delay and packet loss.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.478-484
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• 2008

When a mobile node moves, MIPv6 operates an authentication process for the new connection. These kinds of frequent binding update and authentication processes cause much traffic and delay the service. To solve this problem, PMIPv6 provides a network-based mobility protocol in order to lessen the load on a mobile node. However, when it is moved from a domain to a domain or in a domain, there still lies a need fDr a new address, so MIPv6's demerit still exists. In IPsec, too, a new negotiation should be made when it is moved to WAN(Wide Area Network). This causes load to the mobile node. In this paper suggests MBB(Make Before Break) system to eliminate disconnections or delays resulted from the address change or renegotiation for security. When the mobile node receives a CoA address, IPsec negotiation gets operated. Its identity is authenticated by sending the identifier used for the prior negotiation to CN(Correspondent Node) through the BID message suggested. After that, negotiation Bets simplified that disconnections can be eliminated, and in the IPsec negotiation, the load on the mobile node can be lessened as well; moreover, two addresses are used for the communication simultaneously, so the probability of packet loss can be reduced.

• Information and Communications Magazine
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• v.26 no.2
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• pp.53-61
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• 2009

최근 무선인터넷에 대한 소비자들의 니즈는 네트워크와 기술, 장소와 시간, 디바이스에 구애 받지 않는 저렴한 음성/데이터/영상 서비스이다. 무선망 사업자들은 소비자의 니즈에 비용효율적으로 부합하기 위해 전폭적인 망 확장 투자보다 이기종 망을 언종하는 방안을 고려하고 있다. 본 고에서는 WIBRO와 HSDPA가 공존하는 상황에서 코어망을 수정하지 않고, MIH 기반으로 이종망 연동을 빠르게 제공할 수 있는 방안을 제공한다. 제시하는 방법은 MIH 프레임워크 위에 단말에 MM(Mobility Manager)과 CMIP 클라이언트를, 서버에 핸드오버 정책엔진, 이종 주변망 정보서버를 개발하고, MBB(Make Before Break) 방식으로 구현하여 WIBRO-HSDPA망간 핸드오버시 15ms 이내의 지연을 보장하였다. 모바일 IPTV 등 실시간 응용실험에서 핸드오버로 인한 지연이 응용의 품질에 영향을 미치지 않았다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4B
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• pp.677-686
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• 2010

In this paper, we propose the virtual interface management scheme on the multi-mode mobile node for supporting multiple connections to various access networks in fixed mobile convergence (FMC) networks. The proposed scheme supports the virtualization of multiple physical network interfaces by presenting only the virtual interface to beyond IP layers and hiding physical network interfaces from them. In the proposed scheme, only one IP address is allocated to virtual interface without any IP allocations to physical network interfaces. Therefore, the proposed scheme does not change its IP address and keep it during the vertical handover, so that it can support the seamless handover of real-time multimedia services among heterogeneous access networks. The proposed scheme is implemented on the multi-mode mobile node with multiple network interfaces by using NDIS (Network Driver Interface Specifications) libraries. Through the mobility test-bed and the test application of virtual interface, we evaluate and analyze the performance of the proposed scheme.