CESP: A power efficient, accurate coefficient exchange synchronization protocol

Time synchronization is a fundamental problem in any distributed system. In particular, wireless sensor networks require scalable time synchronization for implementing distributed tasks on multiple sensor nodes. This paper proposes an energy efficient Coefficient Exchange Synchronization Protocol (CESP) based on a receiver-receiver synchronization scheme that minimizes the impact of access-time delays. Most of the existing synchronization protocols focus on improving the synchronization accuracy while neglecting energy consumption. The proposed time synchronization protocol achieves a synchronization accuracy as good as the classic Reference Broadcast Synchronization (RBS) protocol but resulting in a dramatic reduction on communication overhead to achieve a low energy consumption. CESP works in a fundamentally different way from RBS: in order to synchronize two receivers, RBS exchanges all beacon packets between the two receivers, while CESP receivers first process a large number of received beacon packets and only exchange the minimum amount of information between the two receivers, i.e., synchronization coefficients. The synchronization performance is evaluated and compared with that of other well-known synchronization protocols.