Introduction

Wireless Body Area Networks (WBAN) consist of many small and low-power sensor nodes centered around the human body. They communicate wirelessly with a more powerfull master node, for example a smart phone. The main challenge is to reduce the power consumption of the smaller sensor nodes, since it is impractical and often impossible to replace their batteries on a regular basis. In this chapter the wake-up receiver (WURx) concept is introduced, which is used to reduce the overall power consumption of the wireless sensor nodes. Furthermore, the trends in both industrial and academic research are summarized and remaining research challenges are identified.