This book constitutes selected and revised papers of the 9th International Conference, SENSORNETS 2020, Valletta, Malta, held in February 2020, and the 10th International Conference, SENSORNETS 2021, held virtually in February 2021. The 7 full papers presented were carefully reviewed and selected from 60 submissions. They focus in all aspects of sensor networks, including hardware of sensor networks, wireless communication protocols, sensor networks software, hardware and architectures, wireless information networks, channel characterization, data manipulation, signal processing, localization and object tracking through sensor networks, modelling and simulation, applications and uses.