Synchronization in Sensor Networks: an Overview

Configuration and maintenance of wireless sensor networks are complicated by random deployments, random finite sensor lifetimes, addition of new nodes, the desire to adhere to strict power and energy constraints, and perhaps mobility. The desire to maximize network lifetime, in the face of finite energy resources, leads to duty cycled radios that save energy by listening only at appropriate times. This implies a level of synchronization across the network. Synchronization is also needed to support the network goals, such as event detection and reporting. In this paper, we review the problem of wireless sensor network synchronization and associated key issues, including the fundamental signal processing tasks needed, such as estimation of the skew and offset between two clocks, round trip delay estimation, extension of synchronization to multiple nodes, as well as performance analysis and bounds