From Ubiquitous Sensing to Native Intelligence: A Survey of 6G WSNs

Abstract

Wireless Sensor Networks (WSNs), serving as the nerve endings of the Internet of Things (IoT) and the digital twin world, are undergoing a profound transformation from traditional active sensing toward "Passive IoT" and "native intelligence" in the 6G era. With the exponential growth of node density and the emergence of extreme application scenarios, conventional WSNs face severe bottlenecks in battery lifetime, spectrum efficiency, and massive data processing. This paper systematically reviews recent breakthroughs in the WSN field, comprehensively examining core enabling technologies such as Reconfigurable Intelligent Surface (RIS)-aided coverage, millimeter-wave backscatter communication, Tiny Machine Learning (TinyML), and semantic communication. We highlight that AI-empowered Passive IoT and integrated sensing, communication, and computation architectures are reshaping the foundational logic of WSNs. Furthermore, this paper provides a forward-looking analysis of cutting-edge applications in the Industrial Internet of Things, smart cities, and non-terrestrial networks (NTNs), and concludes by identifying open challenges in physical-layer security and cross-domain collaboration.