State-of-the-Art Overview of 3GPP Ambient IoT Radio Access Aspects

The number of connected IoT devices is expected to reach billions in the foreseeable future. The prosperity of the IoT market attracts the interest of fifth generation of cellular network (5G) and beyond evolution to promote new IoT technology supporting passive devices. Such devices, which are battery-less or with limited energy storage, are powered by harvesting energy from the ambient environment and are referred to as Ambient IoT (A-IoT) devices. This paper provides a state-of-the-art overview of the third generation partnership project (3GPP) A-IoT radio access techniques. We describe use cases, scenarios, and distinct device architecture and its impact on designs. We discuss the challenges and solutions of A-IoT and demonstrate advancements over existing passive IoT system in terms of link performance, coverage, and inventory efficiency.