Serpedin E., Chaudhari Q.M. Synchronization in Wireless Sensor Networks: Parameter Estimation, Performance Benchmarks, and Protocols

Cambridge University Press, 2009. — 246 p. — ISBN: 0521764424.The clock or time synchronization problem in wireless sensor networks (WSNs) requires a procedure for providing a common notion of time across the nodes of WSNs. In general, clock synchronization is viewed as a critical factor in maintaining the good functioning of WSNs due mainly to their decentralized organization and timing uncertainties caused by the imperfections in hardware oscillators and message delays at the physical and medium access control (MAC) layers. In addition, synchronization of the nodes of wireless sensor networks is crucial for implementing fundamental operations such as power management, transmission scheduling, data fusion, localization and tracking, and security protocols to name only a few applications.
The aim of this book is to provide an introduction to the clock synchronization problem of WSNs from a statistical signal processing viewpoint. Therefore, most of the topics presented in this book deal with building efficient clock offset estimation algorithms and performance benchmarks for general synchronization approaches that rely on sender–receiver and receiver–receiver timing packet exchange mechanisms. A summary of the key features of the most representative protocols proposed for clock synchronization of WSNs is also presented, together with some interesting open research problems.Signal Models for Time Synchronization
Time Synchronization Protocols
Fundamental Approaches to Time Synchronization
Minimum Variance Unbiased Estimation (MVUE) of Clock Offset
Clock Offset and Skew Estimation
Computationally Simplified Schemes for Estimation of Clock Offset and Skew
Pairwise Broadcast Synchronization (PBS)
Energy-Efficient Estimation of Clock Offset for Inactive Nodes
Some Improved and Generalized Estimation Schemes for Clock Synchronization of Inactive Nodes
Adaptive Multi-hop Time Synchronization (AMTS)
Clock Drift Estimation for Achieving Long-Term Synchronization
Joint Synchronization of Clock Offset and Skew in a Receiver–Receiver Protocol
Robust Estimation of Clock Offset
Conclusions and Future Directions