Wake-Up Control Adapting to Destination's Active/Sleep State for On-Demand Wireless Sensor Networks

This paper focuses on on-demand wireless sensor networks (WSNs) where a wake-up receiver is installed into each node. In on-demand WSNs, each node sends a wake-up signal including a wake-up ID assigned to a specific destination node in order to remotely activate its main radio interface. This wake-up control helps each node to reduce energy consumed during idle periods, however, the wake-up signal transmitted before every data transmission results in overhead causing degradation of communication quality and increase of energy consumption at each sender node. In order to reduce the overhead for wake-up control, a scheme called Double Modulation (DM) has been proposed, where each node embeds a sensing data to be transmitted into the payload field of a wake-up signal. However, the efficiency of DM scheme becomes smaller as the size of sensing data is increased. Therefore, in this paper, we propose a scheme called Overhearing (OH) that can alleviate the negative impact of wake-up overhead for any size of sensing data. In OH scheme, each node observes frames transmitted by a destination node and suppresses the transmission of wake-up signal when detecting the active state of their destination. Furthermore, we propose a hybrid scheme that combines OH and DM schemes. Our simulation results show that the proposed hybrid scheme can effectively reduce the negative impact of wake-up overhead.