Abstract
Typical wireless sensor network applications follow duty-cycle mechanisms, yielding important energy savings by reducing the power consumption of idle listening. However, this approach still dictates predefined cycles of active operation, which in some application scenarios is meaningless. Extended lifetime can be achieved by asynchronously awakening sensor network's nodes only when truly required. In this work we present NITOS wake-up receiver that can be employed by typical sensor nodes to provide asynchronous wake-ups and substantially reduce their energy expenditure. Our wake-up circuit operates in the 868 MHz band and is activated by LoRa frames using OOK modulation. The developed system supports selective awakenings with the aid of a low-power micro-controller dedicated to sample the acquired signal and identify the wake-up address.