Improving Energy Efficiency of Mobile WSN Using Reconfigurable Directional Antennas

Reconfigurable directional antennas (RDA) bring new opportunities to reduce data collision in wireless sensor networks (WSN). In this letter, a new reconfigurable directional antenna-based receiver-Initiated cycled receiver (RDA-RICER) medium access control (MAC) protocol is proposed for WSN nodes equipped with switched antennas. A low complexity and energy efficient scanning process is embedded in RDA-RICER to identify the direction providing the highest received signal strength Indicator between two nodes. OMNeT++ simulation results for a single hop network show that data collision rate can be drastically reduced compared with related MAC protocols, leading to a significant decrease in energy consumption. Our approach is also validated in the field using WSN platforms equipped with a four-direction RDA, and powered by solar cells.