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The worst visibility walk in a random Delaunay triangulation is $O(\sqrt{n})$

Olivier Devillers 1 Ross Hemsley 2
1 VEGAS - Effective Geometric Algorithms for Surfaces and Visibility
LORIA - ALGO - Department of Algorithms, Computation, Image and Geometry, Inria Nancy - Grand Est
2 GEOMETRICA - Geometric computing
CRISAM - Inria Sophia Antipolis - Méditerranée , Inria Saclay - Ile de France
Abstract : We show that the memoryless routing algorithms Greedy Walk, Compass Walk, and all variants of visibility walk based on orientation predicates are asymptotically optimal in the average case on the Delaunay triangulation. More specifically, we consider the Delaunay triangulation of an unbounded Poisson point process of unit rate and demonstrate that the worst-case path between any two vertices inside a domain of area $n$ has a number of steps that is not asymptotically more than the shortest path which exists between those two vertices with probability converging to one (as long as the vertices are sufficiently far apart.) As a corollary, it follows that the worst-case path has $O(\sqrt{n}\,)$ steps in the limiting case, under the same conditions. Our results have applications in routing in mobile networks and also settle a long-standing conjecture in point location using walking algorithms. Our proofs use techniques from percolation theory and stochastic geometry.
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Contributor : Olivier Devillers <>
Submitted on : Thursday, October 15, 2015 - 5:12:56 PM
Last modification on : Tuesday, December 18, 2018 - 4:18:26 PM
Long-term archiving on: : Thursday, April 27, 2017 - 4:32:16 AM


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  • HAL Id : hal-01216212, version 1


Olivier Devillers, Ross Hemsley. The worst visibility walk in a random Delaunay triangulation is $O(\sqrt{n})$. [Research Report] RR-8792, INRIA. 2015, pp.25. ⟨hal-01216212⟩



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