Time synchronization protocol for wireless passive sensor networks with communication coverage

Wireless passive sensor networks (WPSN) designed to operate using MB do not have the lifetime constraints of conventional WSN. System lifetime of wireless sensor networks (WSN) is inversely proportional to the energy consumed by critically energy-constrained sensor nodes during RF transmission. In that regard, modulated backscattering (MB) is a promising design choice, in which sensor nodes send their data just by switching their antenna impedance and reflecting the incident signal coming from an RF source. The communication performance of WPSN is directly related to the RF coverage provided over the field the passive sensor nodes are deployed. This paper puts forward the ITPSN protocol, which makes the original single two nodes two-way messages exchange way into the third node monitor mode, greatly reduces the synchronous time, saves the time and energy for synchronization, adds the judgment of the node failure and treatment of node failure, and improves the robustness and expansibility. The simulation results show that ITPSN inherited TPSN’s low energy consumption, low average errors and can effectively reduce the time and energy needed for synchronization, strengthening its robustness.