在WiFi和3G環境下的即時通訊服務省電機制

Abstract

近幾年來手持式通訊裝置普及率跟接受度越來越高，如何能夠在電力有限的手持式通訊裝置上執行許多應用，已經成為了一個熱門的話題。即時通訊服務為一熱門網路應用，即時通訊服務的使用時間相當長，同時也有相當頻繁封包傳送，因此在使用即時通訊服務中，手持式裝置電力消耗情形也更加嚴重，而本研究將針對即時通訊服務提出一套有效省電機制。 現今大多數的手持式裝置都是透過WiFi或是3G方式連線到網路，在本論文研究中，我們首先分析了WiFi和3G環境中資料封包傳輸的耗電特性，接著提出一個動態防火牆機制，希望藉由動態的控制防火牆開關，將不需要被即時傳輸的封包重新整理集中，接著再傳輸到使用者端，以達到同時減少總傳送封包量和總傳輸時間的目的，而達成省電效果。論文所提出的省電機制運作在WiFi AP和femtocall AP上面，目的是希望使用者透過掛載有省電機制的閘道器連線到網路，就能夠達到省電的目的，不需要額外的操作或者更換硬體設備。此外，論文同時提出了即時通訊服務主機自動偵測機制，讓掛載有省電機制的閘道器能夠偵測使用者是否啟用即時通訊服務，並對即時通訊服務主機啟用動態防火牆機制。 透過實際實作和電腦模擬所得到的結果，可以發現所提出的動態防火牆省電機制，在WiFi和3G環境中都能夠成功地降低電力消耗量，同時延長手持式裝置的使用時間。

Nowadays, mobile devices have been accepted and used widely. Thus, the power consumption of mobile devices is becoming a popular research issue. Instant messaging service is one of the popular mobile Internet applications. The period of instant messaging users stay in the instant messaging service is relatively long and there are often frequent packet transmissions in the instant messaging service. Therefore, the power consumption of mobile devices can be increased when logging into the instant messaging service. This thesis thus focuses on the instant messaging application and proposes an effective power saving mechanism. Most mobile devices connect to Internet via WiFi or 3G method. In this thesis, we analyze the power consumption behavior of packet transmissions in the WiFi and 3G environment, and then we propose a Dynamic Firewall mechanism, as a power saving mechanism. The Dynamic Firewall mechanism sets the firewall on and off dynamically for merging the non-real-time packets and transmitting these packets together. Thus, the amount of packet transmissions and length of total packet transmission period are decreased and then power saving is achieve. The proposed mechanism can operate over a WiFi AP/femto AP, and power saving can be achieved when users connect to Internet through such a power saving gateway without additional modification and hardware component replacement. Moreover, an instant messaging server auto-detection algorithm is presented in the thesis. The power saving gateway can identify the instant messaging server when users connect to the instant messaging service and execute the Dynamic Firewall mechanism with respect to these servers. Based on the results of simulations and actual measurements, the proposed Dynamic Firewall mechanism can achieve power saving in both WiFi and 3G environment, and effectively extend the battery life of mobile devices.