Extending Body Sensor Nodes' Lifetime Using a Wearable Wake-up Radio

Body Area Networks (BAN) have received significant attention in recent years and have found a wide range of applications, including wearable devices for fitness and health tracking, mobile communications, among others. Energy storage devices such as batteries continue to be a bottleneck in these small form factor devices, thus requiring advanced power management techniques to sustain devices’ increasing power and lifetime demands. As radio transceivers are typically the most power hungry subsystem in wearable sensors devices, many techniques focus to reduce the communication power consumption. In this work, we focus on wake-up radios as a novel technology which can be in listening mode consuming only few nW, significantly reducing the overall power consumption of communication. We evaluate the performance of state-of-the-art wake-up receivers (WUR) in the BAN context, and the tradeoffs between its addressing capabilities, range, and sensitivity. Using in-field measurements, we quantify energy savings and estimate the resulting prolongation of the sensor node’s lifetime in a wearable gait-detection application, where nodes communicate via a Bluetooth main radio.