Wake-Up Radio Impact in Self-Sustainability of Sensor and Actuator Wireless Nodes in Smart Home Applications

This work discusses the impact of Wake-Up Radio (WuR) technology to extend the battery life on sensor and actuator nodes in a smart home scenario. The focus is on nodes that harvest energy from light or a temperature gradient and implement DASH7, an open-source low-power protocol supporting both query-response and beaconing communication models. A prototype WuR is used, with a quiescent current less than 1 μA and a sensitivity of -38 dBm compatible with indoor applications. Experimental data show that integrating WuR is not convenient in nodes that need to send a message to the network coordinator periodically, e.g. sensor nodes implementing beaconing communication models. On the contrary, in request-response mode, integrating the WuR, the average actuator current consumption reduces from 35 μA down to 6 μA during a reference period where no data or commands are exchanged between the network coordinator and the node. Thanks to the WuR, we find that an average light intensity of 150 lux throughout daytime and less than 14 min of a temperature gradient of 10°C between the hot and cold side of a thermoelectric generator are sufficient to turn the actuator nodes for water flooding and smart heating control into an energetically autonomous mode.