近年來，隨著行動通訊網路的迅速發展，傳統電話單單只有語音的溝通模式已不符合需求，故網路視訊通話近年逐漸取代傳統硬體網路電話，但目前主要的網路視訊通話系統技術多集中在傳統電腦微軟、蘋果作業系統架構下，在傳統電腦硬體架構下不需考慮到視訊通話的電能耗損，但在Android系統上電能消耗為非常重要之議題，故目前Android系統未能有兼顧電能耗費與語音效果佳的視訊通話軟體。

VoIP技術包含語音與視訊的編/解碼，一般在視訊通話中最消耗電能的部份為編/解碼，故本研究特別針對不同的編/解碼模組進行分析研究，找出最適合在Android系統上運行的視訊通話軟體，並且比較現有的視訊通話軟體與本研究所提出之最佳編/解碼模組在Android系統上的耗電情況。本研究設計一系統架構包含：視訊通話伺服器、轉傳伺服器、Proxy伺服器、視訊通話使用者端軟體及記錄Android系統電能消耗軟體。且本系統仍依據RFC3261作為系統通訊規範。

本研究透過VoIP伺服器內的編/解碼核心可擴充性，將語音編碼GSM、Speex、PCMU、PCMA與G.722置入核心內，並將使用者端也置入相同的語音編碼，此時，即可利用使用者端Android 4.0智慧型手機進行語音會議，量測上述六種語音編/解碼的耗電能，在取得語音通話品質與電耗之間的最佳平衡點後，將其與目前市面上兩種主要VoIP系統Skype、Google Talk比較，在語音會議部分採用G.722可以獲得優化的通話品質與電能耗費，在視訊通話則採用G.722搭配H.264可獲得優化的通話品質與電能耗費。

Recently because of the rapid development of mobile communication networks, the traditional telephone system is using only for the communication of the voice, which does not meet the present customer demands. So the video calls in recent years gradually replace traditional PSTN, but the main network video technology is more concentrated in the traditional computer, Microsoft and Apple operating systems architecture. Without considering the traditional computer hardware architecture, taking into account of power consumption of the video call, on Android systems, very important issues still not have power consumption and quality applications.

VoIP technology involves voice and video encoding and decoding. Usually most of the video call encoding / decoding will have more power consumption. This study uses different encoding / decoding module, and identifies the most suitable video call application running on Android, and proposes optimal tradeoff encoding / decoding module power consumption on Android systems. The design system architecture includes: video call server, transmission server, a proxy server, a video call client application and recording Android systems power consumption application. This system is based on the RFC3261 specification for communications.

This study on scalability of VoIP server codec core embedded voice codec GSM, Speex, PCMU and PCMA, and the smartphone applications also have same codec. We use android 4.0 smartphones conduct voice conference, and measure six types of codec, therefore, we will get power consumption and voice quality tradeoff by methods execution. We compare commercial VoIP systems Skype and Google Talk, and then the voice conference in G.722 and video conference in G.722 and H.264 can get the optimized quality and power consumption.

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