Reliable and energy efficient cooperative relaying scheme (REECR) in wireless sensor networks

In this paper, a reliable and energy efficient cooperative relaying (REECR) scheme was proposed for multi-hop communications in wireless sensor networks (WSNs). The scheme investigates node cooperation in conjunction with power control to conserve transmission energy and improve communication reliability in the presence of fading. By using a set of relay nodes that are located between transmitter and receiver to assist packet delivery, the scheme is capable of reaping both spatial diversity gains and path-loss savings. Local channel information is utilized in the relay selection process and the power control to reduce the energy consumption of data packet transmission. Moreover, a cooperative automatic repeat request (ARQ) is incorporated, whereby an intermediate node is chosen to help packet retransmission. Our simulations and analyses show that the proposed scheme improves energy efficiency, packet delivery ratio and extends nodes´ battery lifetime.