• Journal of Information Processing Systems
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• v.4 no.3
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• pp.87-96
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• 2008

This paper analyzes the handover latency of Mobile IP and mobile SCTP over IPv6 networks. The analytical results are compared with the performance by experiment over Linux testbed. For analysis, we consider the two handover scenarios: horizontal handover and vertical handover. From the results, we see that mSCTP can provide smaller handover latency than Mobile IP. Moreover, mSCTP can give much smaller handover latency for vertical handover, compared to horizontal handover.

• The KIPS Transactions:PartC
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• v.13C no.2 s.105
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• pp.177-184
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• 2006

A handover is a technology that enables data transmission and receipt seamlessly while a mobile station moves from the current base station to another base station. The handover is basically classified into two types; a horizontal handover which changes a radio link only without changing a network link, and a vertical handover which changes both in heterogeneous networks. In this paper, we propose a vertical handover protocol in a dual base station which supports both of W-CDMA and WiBro networks based on SDR (Software Defined Radio), verify the rightness using a state transition diagram and a Petri-net, and evaluate the performance of the proposed protocol using NS-2 simulator.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.171-172
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• 2014

This paper proposes a SDN based Proxy Mobile IPv6 (PMIPv6) architecture for heterogeneous vehicular networks (SDN-VANET), to provide the continuity of service during the horizontal handovers and to reduce the delay during vertical and horizontal handovers. SDN-VANET mainly relies on DSRC road side units (RSUs) for V2I communication and to overcome the coverage problem SDN-VANET performs the vertical handover between DSRC and LTE/UMTS. To date there is no standard to perform network layer vertical handovers. Therefore the proposed SDN-VANET architecture also doesn't provide any mechanism for vertical network layer handovers, but solves the horizontal network layer handovers in DSRC or LTE/UMTS through introducing PMIPv6 in the architecture.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.567-569
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• 2012

TCP의 성능저하는 버티컬 핸드오버에서만 발생하는 것이 아니라 호라이즌탈 핸드오버에서도 발생할 수 있다. 핸드오버 시 패킷 포워딩을 할 경우, 패킷은 라우터를 통해 소스 셀로 전송이 되었다가 단말이 이동한 타겟 셀로 다시 라우터를 통해 전송이 이루어지기 때문에 TCP 연결의 RTT가 증가하거나 패킷 리오더링에 의한 3dup ACK가 발생하는 문제가 있다. 또한 핸드오버 직후 포워딩된 데이터와 새 데이터가 합쳐져 일시적으로 데이터양이 급증하는 문제가 있다. 이 문제를 해결하기 위하여 Freeze TCP와 연동하여 패킷 리오더링과 타임아웃으로 인한 패킷 손실 문제를 해결한다. 핸드오버 직후 압축모드 기법을 사용하여 일시적인 데이터 폭주문제를 해결한다.