Doctor's Theses (authored and supervised):

H. Stratil:
"Advantages and Limitations of Position-based Communication in Wireless Ad-hoc Networks";
Supervisor, Reviewer: U. Schmid; Technische Informatik, E182/2, 2005; oral examination: 2005.

English abstract:
Wireless ad-hoc networks are a hot topic in distributed computing research, which is fueled by promising future applications of military, government and commercial customers. Wireless ad-hoc networks are made up of computing nodes that communicate with each other over a wireless medium in the absence of a fixed infrastructure and any centralized control. Direct communication between arbitrary nodes is generally not possible and requires a multi-hop routing protocol. This thesis presents SDT/VAR, an efficient protocol for communication in wireless ad-hoc networks. The Short delaunay triangulation (SDT) is a powerful topology based on the construction rules of the Delaunay triangulation. The Voronoi-aided routing (VAR) protocol is an efficient implementation of the well known greedy/perimeter routing approach atop of the SDT. The big advantage of our approach is efficiency: The computation of the Short delaunay triangulation automatically provides the local Voronoi diagrams required for the efficient implementation of Voronoi-aided routing. Algorithms proposed until today generally separate topology control and routing. Our findings reveal that a joint development based upon a common efficient data structure leads to considerably increased performance. The second important part of this thesis is on fault-tolerance and reliability of greedy/perimeter routing. Most existing wireless ad-hoc network routing protocols assume a fault-free environment during message delivery. However, this assumption does not hold in realistic environments. We analyze the behavior of greedy/perimeter routing in the context of crash failures and the reliability of greedy/perimeter routing with respect to imprecise position information and mobile nodes.

Created from the Publication Database of the Vienna University of Technology.