Exploiting node heterogeneity for time synchronization in low power sensor networks

Cyber-Physical Systems are a powerful and central element of the upcoming Internet of Things (IoT), as they provide spatially distributed interfaces to physical systems, can collect and pre-process the data, and forward it to a back end database system. Time synchronization is crucial in such networks for data aggregation as well as duty cycling of the nodes. Existing time synchronization mechanisms concentrating on improving synchronization accuracy leads to large overhead that may restrict its applicability in such low power scenarios. In this paper we propose a time synchronization mechanism that exploits the heterogeneity in power availability of the nodes to provide high synchronization accuracy as well as high energy efficiency. Analytical as well as empirical results indicate that in the proposed protocol, the control message overhead is considerably less compared to a popular existing scheme with modest increase in the error rate.