Analysis of Existing Approaches and a New Hybrid Strategy for Synchronization in Sensor Networks∗

Prior work on sender-receiver-based time synchronization in sensor networks can be categorized into two approaches: two-way packet exchange and one-way packet dissemination. We provide a comprehensive analysis of synchronization errors with these two approaches. We find that one-way dissemination approach provides good relative drift estimation and poor drift estimation while the two-way exchange approach provides good drift estimation but poor relative drift estimation. Consequently, both approaches can result in significant cumulative error propagation over multiple hops. We develop and analyze a hybrid one-way dissemination/two-way exchange technique. The results suggest that this hybrid approach can provide bounded error propagation in multi-hop settings.