3D Localization for Sub-Centimeter Sized Devices

Recent years have seen significant advances in wireless localization [1,2]. However, existing solutions do not meet the requirements for size-constrained IoT applications. The battery life of common radio technologies, such as BLE, LoRa, ultra-wideband (UWB) and Wi-Fi, is less than 5 months when run with small coin and button cell batteries. This shorter battery life limits the adoption of tracking solutions based on these radio technologies by making them inconvenient for consumer applications and infeasible for large scale commercial deployments. Requiring large batteries, on the other hand, prevents scaling down the size of IoT devices. While RFID tags are attractive from a power and size perspective, they have a limited range and do not work consistently through walls and other barriers. Consumers often deploy devices in rooms throughout homes and, similarly, commercial deployments in settings like hospitals require covering multiple patient rooms with a variety of obstructions and walls. Achieving localization in these scenarios would therefore require readers in every room, which significantly increases deployment cost.