gLCB: an energy aware context broker

Context: Worldwide mobile device sales will reach 821 Million units in 2012 and will rise to 1.2 Billion in 2013 [1]. Inevitably the paradigm for access information and Internet services is increasingly migrating to mobile. Context-aware services can help to improve the user experience because they can adapt themselves to the users' context but, despite the improvements in terms of hardware, the the main obstacle towards a widespread adoption of such services is the limited battery life. A context-aware service requires the installation of a Context-Broker Application, which generates a continuous flow of data from the smartphone and a constant usage of its equipped sensors: as a consequence the considerable increase of energy consumption becomes a problem. Aim: The aim of this work is to propose gLCB an Energy Efficient Context-Aware middleware for Android OS, which is able to collect Context Information and to send it to a remote platform in an energy-efficient way. The gLCB application proposes a new energy-aware data collection based on user profiles. Methods: We define policies based on battery consumption profiles, which are selected depending on modifications of the context information. Moreover, we have implemented an automatic consumption testing mechanism and a statistical treatment of results to provide a reliable validation of gLCB in terms of energy efficiency. Results: Experimental results show that our middleware got the best trade-off between number of server uploads and battery lifetime with the policies computed automatically by the device. This means that the way in which software is written can impact the energy consumption of a mobile device and service adaptation can be based on the actual value of the battery charge. (C) 2012 Elsevier Inc. All rights reserved.