An Energy Efficient and Accurate Slot Synchronization Scheme for Wireless Sensor Networks

Existing slotted channel access schemes in wireless networks assume that slot boundaries at all nodes are synchronized. In practice, relative clock drifts among nodes cause slot misalignment over time and can result in catastrophic data loss in such systems. We propose a simple network-wide slot synchronization scheme (Slot-Sync and Slot-Resync) suitable for duty-cycling wireless sensor networks. The proposed scheme attains high accuracy by circumventing dominant sources of error inherent in traditional time synchronization protocols. At moderate duty-cycle frequencies, the proposed scheme also has the unique advantage of eliminating re-synchronization (re-sync) overhead completely, thereby achieving slot re-sync essentially for free. We provide an energy efficient slot guard time and resync interval design for the proposed scheme and analyze several spanning tree structures for slot-alignment message propagation. In addition, we derive upper bounds on the synchronization (sync) error ...

• Type: Conference
• Year: 2006
• Where: BROADNETS
• Authors: Lillian Dai, Prithwish Basu, Jason Redi
• Keywords: BROADNETS 2006, Slot Synchronization, Slot Synchronization Scheme, Spanning Tree