A Distributed Relay Selection Scheme for Sleep Delay Minimizing in Wireless Sensor Networks

Sleep delay is a critical issue in wireless sensor networks (WSNs) since it may induce more overhead and higher frame collision probability. Without the accurate knowledge of the intended next-hop relay state, sending node will keep trying to establish communication with the intended relay at each packet delivery hop unless backoff number reaches the predefined backoff threshold (BT). In this letter we propose a simple distributed relay selection (DRS) scheme to choose a cooperative relay to replace the intended one being asleep. Simulation results are presented to verify the improvement of sleep delay, energy consumption and backoff number experienced by sending node compared with IEEE 802.11 binary exponential backoff (BEB).