Simulation analysis of virtual geographic routing

Homeland defense applications will use large-scale ad-hoc networks of small devices. Routing is a crucial problem, for naive means do not scale well. Geographic Routing (GR) (Xarp 2000; Giordano, Stojmenovic, and Blazevic 2003) offers hope for scalability, under the assumption that every device knows its geographic coordinates, e.g., through GPS. This solution is unsuitable thou-h when there is no easy means of establishing a device's physical location. indoors. To address this limitation we propose Virtual Geographic Routing where we construct a virtual coordinate space and use GR within it. This paper describes VGR, compares the characteristics of paths VGR identifies with those that GR identifies, then presents theoretical and empirical evidence for its scalability.