Study Of Power Saving Methods For Instant Messaging Applications In Mobile Devices

Recently, with the fast development of wireless network, lots ofmobile devices such as smart-phones have become popular in our daily life,and have been making our lives more and more convenient. At the same time,lots of applications have been developed for these mobile devices. However,mobile devices generally with small size and have very limited powersupply from their embedded batteries. When these applications arefrequently used, the phone batteries will be drained so quickly and thelifetime of them is therefore reduced that brings great inconvenience tothe people. As a result, there is a great interest in the mobile communityfor R&D technologies to reduce energy consumption of mobile devices. Thesepower management techniques typically target communication devices suchas wireless network interfaces. This is because when communicating withthe internet, in mobile devices, the wireless network interface card (WNIC)consumes a significant portion of overall system energy. In this paper,in order to overcome these problems, we present two strategies forreducing energy consuming. To a certain extent, these strategies help tosolve power consumption problem.In this paper, we analyze the common technique used in instantmessaging applications which is called polling. It s known to all thatit requires clients send a request to server in a fixed time for updatingmessages. The messages delay caused by polling has great relationship with the selection of time slices. At the same time, it also produces muchuseless communication traffic when in low network loading. One effectiveway to reduce energy consumed by devices is to transition the WNIC to alow-power mode when data is not being transmitted or received. In thispaper, based on our self-developed communication platform, we investigatetwo energy conserving methods for instant messaging application in mobiledevices. One is based on Comet long pulling technology. It holds a HTTPconnection and server can push new messages to user when new messagesarrive. It avoids useless query and decrease delay. The other one is animproved polling method. By tracking each conversation and connection,adjust the time interval adaptively. It decreases the times of queryingand keeps the WNIC in low-power mode as long as possible. It achieves goodbalance between message delay and power saving.Finally, we evaluate the performance of these two methods through aseries of experiments. Experimental results show that the two methods canreduce energy consuming and it won’t affect the using of other service.