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A DISTANCE BASED SLEEP SCHEDULE ALGORITHM FOR ENHANCED LIFETIME OF HETEROGENEOUS WIRELESS SENSOR NETWORKS

by SEKHAR, SANDHYA

Abstract (Summary)
This thesis describes the concept of sensor networks which has been made viable by the convergence of MEMS system technology and efficient routing protocols. Sensor nodes possess finite, non-renewable energy that they expend in sensing a multitude of modalities including temperature, moisture, pressure, light and infrared radiation. A radio-interconnected collection of such sensors forms a sensor network and the information collected from the network is transmitted for analysis at a distant location termed as the sink. The main purpose of a sensor network is to gather information about the various parameters of the area in which it is deployed and to transmit this information to the sink for appropriate utilization. A wireless sensor node is capable of only a limited amount of communication and processing. Therefore, unlike traditional networks, where the objective is to maximize channel throughput, the chief consideration in a sensor network is to extend the system lifetime as well as system robustness. Wireless ad hoc and sensor networks are comprised of energy–constrained nodes. This limitation has led to the dire need for energy-aware protocols to produce an efficient network. Heterogeneity is introduced in a wireless sensor network by having a large number of low power sensor nodes and a small number of more powerful nodes to serve as cluster heads. We propose a self-tuning scheme that improves the lifetime of a heterogeneous wireless sensor network by appropriately scheduling the transmission rate of individual sensor nodes in the network. We consider a distance based sleep scheduling problem for equal energy consumption rates in low power sensor nodes and evaluate the optimal settings required in a heterogeneous sensor network. We evaluate the efficiency of our proposed algorithm based on an analytical model and perform simulations to verify the adequacy of our scheme in terms of important network parameters and compare with existing heterogeneous sensor networks. We provide an estimate of the optimal number of clusters required, expected energy in a cluster head and the extent of network coverage. The proposed scheme is observed to improve network lifetime while conserving energy and maximizing information gathering at the sink.
Bibliographical Information:

Advisor:

School:University of Cincinnati

School Location:USA - Ohio

Source Type:Master's Thesis

Keywords:energy aware systems low power design mobile environments heterogeneous sensor networks wireless

ISBN:

Date of Publication:01/01/2005

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