Efficient Bluetooth Low Energy Operation for Low Duty Cycle Applications

Bluetooth Low Energy (BLE) has shown higher energy efficiency and robustness than other well known Wireless Sensor Network (WSN) protocols, making it a strong candidate for implementation in IoT scenarios. In addition, BLE is in almost every smartphone, turning it into perfect ubiquitous remote controls for smart homes, buildings or cities. In this paper we propose new operating modes for BLE to provide a much wider applicability range covering asynchronous, aperiodic and very low frequency scenarios while extending lifetime, without modification of the existing BLE specification. In order to estimate battery lifetime, we propose a coin cell battery model. We show how to efficiently adapt the protocol for different IoT scenarios based on their requirements, thus extending battery lifetime as much as possible while guaranteeing acceptable latency. Our results on two typical test-cases show that by using an optimized configuration and appropriate operating mode based on scenario requirements, lifetime can be increased up to ~2x (4.1 to 7.3 years) for a BLE master in a first case, and ~58x (3.05 months to 14.82 years) for a BLE slave in a second case. This shows BLE compatibility with a vast amount of IoT-related use cases.