GreenHub Farmer: Real-world data for Android Energy Mining

GreenHub Farmer: Real-world data for Android Energy Mining

Abstract—As mobile devices are supporting more and more ofour daily activities, it is vital to widen their battery up-time asmuch as possible. In fact, according to the Wall Street Journal,9/10 users suffer from low battery anxiety. The goal of our workis to understand how Android usage, apps, operating systems,hardware and user habits influence battery lifespan. Our strategyis to collect anonymous raw data from devices all over the world,through a mobile app, build and analyze a large-scale datasetcontaining real-world, day-to-day data, representative of userpractices. So far, the dataset we collected includes 12 million+(anonymous) data samples, across 900+ device brands and 5.000+models. Click Here And, it keeps growing. The data we collect, whichis publicly available and by different channels, is sufficientlyheterogeneous for supporting studies with a wide range of focusesand research goals, thus opening the opportunity to inform andreshape user habits, and even influence the development of bothhardware and software for mobile devices.

 COLLABORATIVELYCOLLECTING ANDSHARINGDATA

 The GreenHub initiative is committed to provide the meansto support a symbiotic relationship with the mobile commu-nity. In fact, the success of the initiative is dependent on itsdata, and to keep such data coming in, we plan to give backto the community in concrete and valuable ways.The development was inspired by Carat [30], an Androidapp which collects data regarding apps running on a device,and uses it to provide battery-saving recommendations, suchas when to close an app. Initially, we forked its open-sourcecode to take advantage of the data collection and storagemechanisms. We also updated its data model to consider moredetails on modern devices (NFC, Flashlight, etc,.).In the same spirit, not only is our tool able to be freelyused by others, but it is also entirely open-source. In contrast,all our collected data is permanently and publicly available, to4https://greenhubproject.org/strongly encourage and help others in collaborating, inspectingand/or reusing any artifact that we have developed or collected.The initiative relies on a multi-component technologicalplatform. An overview of our platform’s architecture is shownin Figure II.1. It is composed of three open-source modules5,which will be described in detail in the following sub-sections. 
A. BatteryHub - Data CollectionBatteryHubis a mobile application for Android which isavailable at Google’s Play Store6.BatteryHubtracks systemevent broadcasts such as changes to the battery’s state, andwhen such an event occurs, it obtains a sample of the device’scurrent state. Each sample characterizes a wide range ofaspects7that may affect battery usage, such as sensor usage,temperature or what applications are in use.BatteryHubeitheruses the official Android SDK or custom implementationsfor universal device compatibility support, and periodicallycommunicates with the server application (over HTTP) toupload, and afterwards remove, the locally stored samples.We would like to mention that the data collected fromeach user is made anonymous by construction. Indeed, it isassociated with a random unique identifier and no personalinformation, such as phone number, location, or IMEI, iscollected. 
This mean that it is (strictly) not possible to identifyany user ofBatteryHub, nor is it possible to associate any datawith the user who originated it.As to start giving back to our users as early as possible,Bat-teryHubalready provides detailed information on their device.Currently, it indicates: i) the electric current level, temperature,voltage levels in a given period, and ii) model specifications,network information, memory usage, or storage details. Infor-mation in i) is re-actively updated when the battery’s statechanges, and in ii) when a system event occurs. A fullyfeatured task manager is included, and the application alsoprovides interactive charts throughout different time periodsshowing the changes on the different aspects of the battery.The app allows for configurable alerts, e.g. when the batteryreaches a certain temperature, and our plan is to useBattery