Android系統下智慧排程省電機制

Abstract

近年來隨著iPhone、Android手機的風行，智慧型手機已經漸漸在大眾間普及了，多元化應用與大量商機隱藏於其中。除了傳統的撥打接聽電話、傳送接收簡訊以外，人們也將智慧型手機拿來瀏覽網頁、玩遊戲、觀看線上影片、查看社群網站、定期更新新聞天氣資訊…等等，所以使用無線介面諸如Wi-Fi與3G也變成了一種趨勢。然而，由於電池技術的緩慢發展與無線介面的大量耗電使得手機的使用時間大幅縮減，因此如何在無線介面上省電以延長總使用時間是個現今相當重要且熱門的議題。為了達成這個目的，我們提出了利用控制封包來做智慧排程的機制。我們鎖定在那些會定時更新資訊的應用程式，紀錄他們上次同步的時間且得知他們的週期後，我們可以預測他們之後幾次進行同步的時間點。我們將較早同步的應用程式的DNS封包延遲一段時間傳出，使得這些應用程式的同步時間會越來越接近，最終將能在同一時間進行同步，進而減少無線介面花在閒置狀態的時間，如此達到了省電效果。實驗結果顯示分別在Wi-Fi與3G的環境下皆能達到省電的效果，尤其以3G的省電百分比最高。我們也另外考慮非週期性應用程式的DNS封包，使得他們亦能加入同時傳出的行列裡。

With popularity of iPhone and Android phones in recent years, smartphones are becoming universal and common, and a variety of applications and plenty of commercial potential are within it. Apart from traditional dialing and text messaging, people also use smartphones to browse webpages, play games, watch online videos, use social networking services, update information of news and weather, etc. As a result, using wireless interfaces has become a trend custom. However, with the slow development of battery technology and the huge power consumption of wireless devices, the lifetime of smartphone is reduced sharply. Consequently, we propose a smart scheduling mechanism by controlling packets. We focus on the periodic applications, recording their last sync time and remember their period, so that we can predict their future sync time. We delay the DNS packet of the front application, so the distance between the applications will become closer with time. At last, they can sync simultaneously, reducing the time of wireless interfaces spent on staying in idle mode, so as to achieve the goal of energy saving. The experiment results show that energy saving is achieved in both Wi-Fi and 3G scenarios, especially in 3G. We also consider the DNS packets of non-periodic applications, making them send out with other applications simultaneously if possible.