A Wake-up Radio protocol based on adaptive backoff and dynamic CCA in Wireless Sensor Networks

Abstract

Asynchronous wake-up communication based on wake-up radio (WuR) is an important energy-saving method in wireless sensor networks (WSNs). The Clear Channel Assessment (CCA) is a major section of energy consumption in asynchronous WuR-based nodes. The traditional static backoff will lead to longer waiting delay which increase the energy consumption of successful sending packets when the network traffic becomes heavier. So a protocol DNAP-WuR is proposed to solve these problems in the terminal initiated (TI) communication mode. It first implements the dynamic CCA optimization (DCO) mechanism which allows nodes to interrupt the CCA process as soon as the channel is busy. Nodes can go to sleep faster during busy periods, instead of performing CCA detection until the counter is reduced to zero. And then, the WuR based adaptive logarithm backoff (WALB) algorithm is used to predict the backoff time sequences which can reduce the WuC's collision probability and decrease the energy consumption according to the nodes number and the packet arrival rate. In order to avoid the phenomenon that the backoff window size is reduced too fast or increased slowly after packets transmitted. Compared with CSMA-WuR protocol, the DNAP-WuR has 4.6% reduction in energy consumption and 12.1% promotion in throughput.