ESTS: Energy Stimulated Time Synchronization for Energy Harvesting Wireless Networks

In this paper, we develop a new time synchronization method, called the energy stimulated time sync (ESTS), for ultra-low-power wireless networks with energy harvesting ability. Compared with existing methods, ESTS does not rely on timestamp exchange between wireless nodes but uses short analog tones to synchronize the time across the network. ESTS can synchronize the time across the entire energy harvesting wireless network with much lower energy consumption than timestampbased synchronization methods. We have implemented ESTS on Microchip ATmega256RFR2 system-on-chip (SoC) and Powercast P1110B radio energy harvester. According to experiment results, ESTS achieves an average of 5 ms time precision with less than 20 μJ of energy consumption.