Summary: | 碩士 === 國立交通大學 === 資訊工程研究所 === 81 === Advanced communication satellites with store-and-forward packet
switching capabilities have been proposed for constructing
space-based computer networks. Satellites at the geosynchronous
orbits are easier to manage, but incur long propagation delays.
Low Earth Orbit(LEO) satellites are an alternative to reduce
this delay which is critical for many delay sensitive
applications. Because of the low altitude of LEO satellites,
each satellite node is no longer geostationary and the network
topology changes dynamically. The distance of communication
links varies in time. In addition, links are often blocked by
the earth. Therefore the network topology must be maintained by
frequent link reconfigurations. This is an unique link
assignment problem for LEO satellite networks. If each
satellite is equipped with several communication links and the
network is large, multiple disjoint communication paths exist
between each pair of source and destination nodes. Routing data
packets using multiple paths is of particular importance for
networks with rapidly changing topology. In our thesis we
analyze the effectiveness of link assignment algorithms for
maintaining good network connectivity. Given instances of
network connection, algorithms for computing multiple disjoint
paths are studied. The computed multiple communication paths
are used to demonstrate a proposed multiple packets multiple
paths routing algorithm for improving system performance and
reliability.
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