Summary: | 碩士 === 中原大學 === 電機工程研究所 === 94 === In this thesis, we consider the problem of
providing multicast to mobile hosts using mobile IP for network routing support and propose a new multicast routing scheme to improve multicast
efficiency in mobile IP networks. The proposal also can avoid some problems of multicast over mobile IP, such as reconstruction of multicast delivery tree and packet loss due to handoff, etc.
In our proposal, at first we introduce a hierarchical mobility management approach and adopt the multicast agent which is a multicast router by using the Core Based Tree protocol (CBT) in each multicast group to shield mobility within foreign domain. Then, we organize adjacent cells where mobile host visits the foreign network into virtual domain. By informing the adjacent base stations to subscribe to the same multicast group before a handoff occurs, we can get better efficiency and overcome some problems that mobile hosts cross foreign networks.
The contributions of our research are as
follows:
(1) The hierarchical mobility architecture using
the multicast agent can isolate the mobility
of the mobile hosts from the main multicast
tree.
(2) By employing the virtual domain, we can
achieve fast handoff performance so as to
reduce disruption to multicast reception.
(3) It also limits the reconstruction frequency
of multicast delivery tree due to the
handoff and eliminates multicast group join
and graft latencies.
With comparison of the proposed scheme and some existing schemes, we can find that our proposal have better efficiency.
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