Magno et al. address a challenging issue of wearable devices for fitness and health tracking: low-power resources and wireless communication. The lifetime of these devices is limited by the small energy storage components that supply the wearable devices. The wireless communication, as they point out, is power hungry.

To reduce the communication power consumption, the authors show how “advanced power management can be exploited to increase the lifetime of [a wireless body network].” They present “an adaptive power management strategy combining an ultra-low power wake-up radio with context awareness. The context-aware power manager is based on activity recognition.”

For an elderly person in gait rehabilitation, one wearable sensor node is placed on each foot and a master node with a wake-up radio transmitter on his belt. The listening power of the main radio is reduced and an asynchronous ultra-low-power protocol is enabled. The evaluation shows improved monitoring of wearable devices in both the standing and walking states.

The authors keep the presentation informal with illustrations, charts, and tables to show the advantages of advanced power management with asynchronous power. Other than omitting the issue of security vulnerabilities of the wearable devices, this paper is definitely worth reading.