An opportunistic energy-efficient medium-access scheme for wireless sensor networks

This paper introduces an opportunistic medium-access control (MAC) scheme for controlling the uplink message transfer from sensor nodes to a central controller in wireless sensor networks (WSN). By equipping the controller with multiple antennas to communicate with single-antenna sensors, we propose a scheme that benefits from diversity reception at the controller and leads to a considerable reduction of battery energy consumption in sensor nodes. The performance of the scheme is illustrated using a Rayleigh fading channel model. © 2005 IEEE.