Data bundling for energy efficient communication of wearable devices

The amount of data that wearable devices send and receive is rapidly increasing and exceeds the capacity of the energy efficient link technologies (e.g., Bluetooth Low Energy). High capacity wireless link typically requires high connection setup cost, while wearable devices are intrinsically equipped with small battery. To deal with this dilemma, we propose to aggregate multiple data transmission requests into a single chunk and send the aggregated chunk at once to reduce the energy consumption for connection setup. Where this concept of 'data bundling' has been used for cloud storage services, we apply this concept to wearable devices. Data bundling extends the data delivery delay and therefore it is suitable to the applications that do not require strict real-time delivery. In this paper, we initially focus on reducing the energy consumption and then consider the tradeoff relationship between energy reduction and the penalty caused by the bundling delay. We design three bundling schemes and implement them in a commercial smartwatch which is connected to a smartphone via Bluetooth Classic link. The effectiveness of the proposed schemes is experimentally demonstrated and useful insights on the characteristics of bundling are discovered. (C) 2017 Elsevier B.V. All rights reserved.