ZEN-MAC: Zero Excess Node MAC for Multihop Sensor Networks With Energy Harvesting

The conventional receiver-initiated MAC (RI-MAC) protocol employed in energy-harvesting wireless sensor networks (WSNs) mandates a specific listening duration to identify communication partners, which consequently increases power consumption and impedes the development of ultralow-energy WSNs. To address these limitations, the novel zero excess node MAC (ZEN-MAC) protocol is introduced. This protocol strategically reduces idle listening time, which dominates the networks power consumption, through the implementation of low-power listening with multi-stage beacons and clear channel assessment. It further optimizes intermittent intervals based on the estimated power consumption of the network to enable distributed load control. These enhancements significantly reduce power consumption and help prevent node battery depletion, thereby improving both the reliability and efficiency of WSNs.