Guaranteed-delivery Geographic Routing under Uncertain Node Locations
Stefan Funke, Nikola Milosavljevic
Geographic routing protocols like GOAFR or GPSR rely on \emph{exact} location
information at the nodes, as when the greedy routing phase gets stuck at a
local minimum, they require, as a fallback, a planar subgraph whose
identification, in all existing methods, depends on exact node positions. In
practice, however, location information at the network nodes is hardly precise;
be it because the employed location hardware, such as GPS, exhibits an inherent
measurement imprecision, or because the localization protocols which estimate
positions of the network nodes cannot do so without errors.
In this paper we propose a novel naming and routing scheme that can handle the
uncertainty in location information. It is based on a macroscopic variant of
geographic greedy routing, as well as a macroscopic planarization of the
communication graph. If an upper bound on the deviation from true node
locations is available, our routing protocol guarantees delivery of messages.
Due to its macroscopic view, our routing scheme also produces shorter and more
load-balanced paths than common geographic routing schemes, in particular in
sparsely connected networks or in the presence of obstacles.
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