Towards bounded-latency Bluetooth Low Energy for in-vehicle network cable replacement

Vehicles today employ many different sensors to provide information such as tire pressure, proximity to objects and so on to Electronic Control Units for state maintenance and actuation functions. This has resulted in an increase in the number, weight and complexity of wiring as well as wiring harness for in-vehicle communication networks. Reducing the amount of cables will improve fuel efficiency; reduce cost of manufacturing and maintenance of vehicles greatly. Bluetooth Low Energy (BLE) is a great candidate for cable replacement given its supported data rates and widespread adoption in many markets. BLE device discovery is required to establish the presence of nodes within each other´s communication range and begin reliable exchange of data. In our system, the nodes are the sensors and actuators. The fundamental problem in such device discovery is that energy consumption and discovery latency are inversely related. Therefore an efficient trade-off BLE connection setup that reduces energy-consumption while being able to provide worst-case discovery latency guarantees is critical especially in the automotive industry. We propose a mechanism that exploits Chinese Remainder Theorem (CRT) to provide worst-case latency guarantees during the connection setup phase of BLE devices. We provide the required modifications in BLE as well as provide evaluation results to show the improved performance. To the best of our knowledge this is the first work that considers providing bounded-latency connection setup for BLE devices using CRT and its application for automotive cable replacement.