Energy-Latency Characterization of an Integrated Wake-Up Radio SoC

Ultra-low power Wireless Sensor Networks (WSNs) require communication mechanisms that minimize idle listening while preserving reliability. Wake-up radios (WuRs) represent a promising alternative to traditional duty-cycled approaches, but most existing works rely on simulations or on external standalone modules, limiting the evaluation of fully integrated commercial solutions. This paper presents an experimental characterization of the STM32WL33CC, a System-on-Chip embedding both a sub-GHz main radio and a Low-Power Autonomous WuR. The analysis includes power profiling of the integrated WuR and Deepstop modes, a comparison between software-based and hardware-based address filtering, and the evaluation of a flooding-based multi-query routing protocol on a real multi-hop testbed. Results show that hardware-level filtering reduces overhearing energy consumption by up to 97% compared to payload-based approaches. The flooding phase is dominated by the OOK wake-up preamble, with an energy cost approximately 20 times higher than the subsequent data response. However, the proposed multi-query mechanism effectively amortizes this overhead while maintaining stable Packet Delivery Ratio under moderate traffic conditions.