ABSTRACT
This chapter provides the backgrounds of time synchronization to enable new developments or enhancements of timing techniques for the sensor networks. The sensor networks are application driven; the design challenges of a time synchronization protocol are also dictated by the application. These challenges are to provide an overall guideline and requirement when considering the features of a time synchronization protocol for sensor networks; they are robust, energy aware, server-less, lightweight, and tunable service. The regardless of the design challenges that a time synchronization protocol wants to address, the protocol needs to address the inherent problems of time synchronization. The factors describes the influence the error budget of the synchronized clocks, the purpose of a time synchronization protocol is to minimize the effects of these factors. The root node synchronizes the nodes in a hierarchical way. The range of applications in the sensor networks is wide, new timing techniques are encouraged for different types of applications.
