Energy aware and adaptive routing protocols in wireless sensor networks

Recent technological advances have enabled distributed micro-sensing for large scale information gathering through a network of tiny, low power devices or nodes equipped with programmable computing, multiple sensing and communication capabilities. This network of sensor nodes, known as a wireless sensor network, has revolutionized remote monitoring applications because of its ease of deployment, ad hoc connectivity and cost-effectiveness. In this dissertation, we design distributed routing protocols for minimizing energy consumption in a sensor network. There are two main contributions of this work.; The first contribution is the design of an energy aware multiple path routing protocol to route heavy data traffic between a source and a destination node in a sensor network. The protocol spreads the routing load between the source and destination nodes over a large number of sensor nodes to minimize disparity in the energy levels of the sensor nodes. We also grade the multiple paths based on their route length to support time critical queries on the shortest available paths.; The second contribution is the design of a communication architecture that supports distributed query processing to evaluate spatio-temporal queries within the network. We represent these queries by query trees and distribute query operators to appropriate sensor nodes. As operator execution demands high computation capability, we propose use of a heterogenous sensor network where query operators are assigned to sparsely deployed resource-rich nodes within a dense network of low power sensor nodes. We design an adaptive, decentralized, low communication overhead algorithm to determine an operator placement on the resource-rich nodes in the network to minimize cost of transmitting data in the routing tree constructed to continuously retrieve data from a set of spatially distributed geographical regions to the sink. To the best of our knowledge, this is the first attempt to build an energy aware routing infrastructure to enable in-network processing of spatio-temporal queries. In order to maximize energy savings the proposed multiple path routing protocol can be used to route data between the nodes that form the routing tree.