• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.583-588
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• 2004

For the Explicit Multicast (Xcast) scheme, we propose a scheme that provides dynamic group membership and supports a large, dense multicast group. To do so, we use a hierarchical joining mechanism, where a domain agent joins a group on behalf of hosts. In our scheme, a sender transmits multicast packets to a domain agent, and then the agent forwards the packets to receivers in a domain. A host can join or leave a group at my time via the domain agent. Thus, a destination field of the Xcast header has addresses of domain agents instead of hosts. Simulation results show that our scheme can reduce more the Xcast header size and cost in forwarding packets than the Xcast, especially for a large multicast group. Like traditional multicast schemes, our scheme can support large multicast group members.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5B
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• pp.253-263
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• 2005

This paper proposed a mobile multicast technique to satisfy end-to-end QoS for various user requirements in mobile network environment. In order to provide seamless mobility, fast handoff technique was applied. By using L2 mobile trigger, it was possible to minimize remarkable amount of packet loss by delay occurred during handoff. To provide efficient multicast, concept of hierarchy was introduced to Xcast++, which results in a creation of HXcast++. HXcast++ optimized transfer path of multicast and reduced expensive multicast maintenance costs caused by frequent handoff. Suggestion of GMA (Group Management Agent) mechanism allows joining to group immediately without waiting IGMP Membership query during handoff. GMA mechanism will minimize the delay for group registration process and the resource usage due to delay of withdrawal process. And also use of buffering & forwarding technique minimized packet loss during generation of multicast tree. IntServ/RSVP was used to provide End-to-End QoS in local domain and DiffServ was used in global domain. To minimize reestablishment of RSVP session delay, extended HXcast++ control messages ware designed to require PATH message. HXcast++ proposed in this thesis is defined as multicast technique to provide end-to-end QoS and also to satisfy various user requirements in mobile network environment.