Seamless Vertical Handoff in Overlay Networks

• Main Authors: Rong-Jyh Kang, 康容致
• Other Authors: Reui-Chuan Chang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/95006831456846164217

碩士 === 國立交通大學 === 資訊科學系 === 90 === In the last decade, many new wireless communication systems have been developed. Those communication systems have different extents of network coverage, thus formed a hierarchical overlay networks. When moving between those networks, a vertical handoff mechanism is needed to handle the handover between different hierarchies of networks. The problem of current vertical handoff approaches is that the network infrastructures needed to be modified, which is almost impossible. In this thesis, we propose a seamless vertical handoff approach that can integrate the overlay networks to achieve high service availability. Our approach only modifies the two end nodes of a communication path so that we can keep the network infrastructure unmodified. It performs vertical handoff through TCP migration. To verify the feasibility of our approach, we implement a prototype system on Linux. The experiment results show that the time for vertical handoff performed by the system is short and acceptable for most of the applications.