In recent years tremendous technological advances have led to the development of low-cost sensors capable of data processing activities. These sensor nodes are organized in to a network typically called wireless Sensor Network. WSN's are based on the principle of "Data Fusion" where the data collected from each sensor node is condensed into one meaningful result: Data Fusion is achieved by exchanging messages between the sensors. These messages are time stamped by each sensor node's local clock fuse reading. As noted in various references, Time Synchronization is a common feature used in networking in order to give the nodes a common time reference. Time Synchronization is an important middleware service in Wireless Sensor Networks, as physical time is needed to relate events to the physical world. WSN's require a great deal of synchronization accuracy so that information from many nodes can be cohesively integrated without creating time skews in the data. State-of-the-art research has been investigating the sources of error in attempting to synchronize the nodes in a network. The objective of this thesis is to define a Time Synchronization protocol for a Hierarchical Cluster Head based Wireless Sensor Network. Thus, the goals of this thesis are three fold: We first analyze the shortcomings of existing time synchronization protocols and propose a novel time synchronization protocol based on cluster tree based routing. We perform hardware-based simulation using Mica motes, TinyOS operating system and NesC programming language. Finally, we estimate the various sources of time error in package transmission in a WSN through basic simulation using OMNET++.
Library of Congress Subject Headings
Wireless sensor networks--Computer simulation; Wireless communication systems--Computer simulation; Computer network protocols--Computer simulation; Synchronization
Department, Program, or Center
Computer Engineering (KGCOE)
Krishnaram, Ramesh, "A clustering approach in sensor network time synchronization" (2006). Thesis. Rochester Institute of Technology. Accessed from
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