An Event -Triggered Time Synchronization Scheme for Sensor Networks

Distributed time synchronization is an important part of sensor networks. Due to the limited battery capacity of the sensor nodes, applicable schemes should concern the energy consumption of the networks. To achieve better efficiency, an event-triggered time synchronization scheme (ETTS) is presented, which aims at providing on-demand time synchronization in sensor networks. The scheme is composed of two phases: skew correction phase and estimation of offset phase. When timestamps from different clocks need to be compared, they can be reconciled after the event. ETTS removes the need to predict application requirements in advance, which means that the synchronization energy is only expended after an event has occurred. Compared to traditional schemes, for example, TPSN, simulation results show that ETTS achieves desired energy efficiency when the frequency of event is low.