Avoiding Unnecessary 3G Data Transmission Through Mobile Sensors

Abstract: In recent years, instant messaging (IM) has started to replace short message service (SMS) in communication. IM offers more functionality but there is a great downside. IM demands more power and drains the mobile device battery faster. This paper shows the energy consumption of  IM when the user is not using the application and how the consumption  can be reduced by enabling mobile sensors and sending fewer packets by the application. We began by investigating the various sensors that are supported by mobile devices. With the retrieved vendor information, we evaluated the different sensors and chose two sensors, light sensor and proximity sensor in order to study their use for reduction of energy in  an instant messaging scenario. These two sensors can together estimate if the mobile device is placed in the pocket of the user. The development of a simple IM application was completed and sensors were used to create an extension to the application. The extension would lengthen the interval between the updates of the automatic update function when the mobile was inactive, reducing the energy consumption. Two types of tests were performed. The first test evaluated if the extension would correctly deduce that the mobile device was placed inside a pocket. The mobile device with the pocket-aware application was used in different common situations and the tests showed that the extension made a correct computation in seven of nine situations. The faulty situations were when the mobile device is placed with the screen faced down to a surface. The second test compared the energy consumed by a pocket-aware application compared to a mobile device without our extension. Based on the results that we retrieved, we estimated that during a one minute period the pocket-aware application with an update interval of ten seconds could save on average 12% and could save on average 62% when the update interval was increased to fifteen seconds.