Realistic modeling of wireless communication graphs for design of efficient sensor network routing protocols

Recent advances in low-power processor technology, radios, sensors and actuators will allow us to monitor and instrument the physical world with unprecedented granularity and precision. These new types of systems, often referred to as wireless sensor networks, present unique challenges compared to current networked and embedded systems. One of the most important challenges is the design of efficient routing protocols considering the particular characteristics of the underlying communication graph.;Sensor network deployments are characterized by a number of non-idealities such as spatio-temporal variation in wireless link quality, link asymmetry, hardware variance, node heterogeneity and randomized placement. Our thesis is that a realistic modeling of the underlying communication graph incorporating these effects is necessary to design highly efficient routing mechanisms for sensor networks. We substantiate this thesis by developing a realistic communication graph model and incorporating it into the design of a geographic routing mechanism and a random walk-based querying mechanism.;First, we provide an in depth analysis of the so-called transitional region in multi-hop wireless networks, and propose a more realistic link layer model. Then, based on this model we present analytical results on the impact of channel multi-path on geographical routing. Finally, we use our model to study random walk-based queries and show that their performance can be enhanced by exploiting the node degree heterogeneity present in real wireless sensor networks.