Robust node localization for wireless sensor networks.

摘要

Wireless Sensor Network (WSN) systems have been used in many promising applications including military surveillance, habitat monitoring and wildlife tracking. While many middleware services to support these applications have been designed and implemented successfully, node localization - finding the position of a sensor node - remains one of the most difficult research challenges to be solved.; In this dissertation we address the multidimensional requirements of the node localization problem in WSN by proposing problem specific, localization schemes and a run-time environment that allows the execution of a set of appropriate localization schemes. Our solutions are based on an asymmetric architecture in which the complexity associated with node localization is removed from sensor nodes and on realistic assumptions for targeted requirements.; First, we propose an event-based localization system, the first to achieve tens of centimeter accuracy, with virtually no additional hardware on sensor nodes, in a realistic, outdoor deployment. Elements of coding theory and the asymmetry in node localization architecture are used to develop new techniques for efficiently distributing events in the sensor network. Second, we propose the first localization scheme that, simultaneously, executes extremely fast (milliseconds to seconds) and achieves meter level accuracy. For this image-based, passive localization system we propose a constraint based label relaxation algorithm and four primitive and hybrid constraints. Third, we propose two localization schemes based on realistic assumptions for targeted environments: when the sensor nodes are deployed in a grid topology or manually. The schemes have good accuracy, have low overhead, are practical and outperform similar solutions in outdoor environments.; Finally, we propose multimodality as a new approach to providing robustness for node localization in WSN. We unify the aforementioned localization schemes in the first multi-phase, multi-protocol framework for node localization in WSN. This framework allows the composition and execution of an appropriate set of localization schemes, for a particular WSN deployment. The proposed localization schemes and the unifying framework enable us to build, for the first time, robust solutions to many realistic localization problems.