Hybrid Energy-Aware Time Synchronization Protocol for WSNs in Coal Mine

Time synchronization is an important issue in multi-hop, ad-hoc wireless sensor networks. Many applications of sensor networks need local clocks of sensor nodes to be synchronized, requiring various degrees of precision especially for safety supervision in coal mine. We design a hybrid energy-aware time synchronization (HEATS) method integrating RBS with TPSN to reduce the number of transmissions required to synchronize an entire network and develop single-hop synchronization methods to operate in large multi-hop networks. In order to maintain network connectivity and coverage while providing higher accuracy, HEATS can concentrate on energy efficiency. In case the source sensor´s battery power drops below an established threshold, a new source node is chosen and the network is re-established. The HEATS algorithm can adapt accordingly to transmission and reception power consumption. Simulation results corroborate that HEATS can operate as desired and adapt accordingly to transmission and reception power.