We study the problem of spanner construction in wireless ad-hoc networks through power assignments under two spanner models-distance and energy. In particular, we are interested in asymmetric power assignments so that the induced communication graph holds good distance and energy stretch factors simultaneously. In addition, we consider the following optimization objectives: low total energy consumption, low interference level, low hopdiameter, and high network lifetime. Two node deployment scenarios are studied: random and deterministic. For n random nodes distributed uniformly and independently in a unit square, we present several power assignments with varying construction-time complexities. The results are based on various geometric properties of random points and shortest path tree constructions. Due to the probabilistic nature of this scenario, the probability of our results converges to one as the number of network nodes, n, increases. For the deterministic case, we present two power assignments with nontrivial bounds. These are established in addition to shortcut edges that satisfy desired threshold stretch. To the best of our knowledge, these are the first results for spanner construction in wireless ad-hoc networks with provable bounds for both energy and distance metrics simultaneously. Our power assignments, in addition, try optimizing additional network properties, such as network lifetime, interference, and hop diameter.
- Approximation algorithms
- Geometric and energy spanners