diff --git a/figures/tables/tableALL.tex b/figures/tables/tableALL.tex index bae9af4..e29282b 100644 --- a/figures/tables/tableALL.tex +++ b/figures/tables/tableALL.tex @@ -52,6 +52,7 @@ \num{10} & \texttt{Android News and Weather} & 0.254 \\ \bottomrule \bottomrule +\num{10} & & \\ \num{9} & \texttt{WhatsApp Messenger} & 0.095 \\ \num{8} & \texttt{Twitter} & 0.078 \\ \num{7} & \texttt{Yahoo Mail} & 0.077 \\ @@ -85,6 +86,7 @@ \num{7} & \texttt{Android Calculator} & 9.189 \\ \num{8} & \texttt{Twitter} & 8.645 \\ \num{9} & \texttt{Chrome Browser} & 8.524 \\ +\num{10} & & \\ \bottomrule \num{10} & \texttt{Yahoo Mail} & 3.287 \\ \num{9} & \texttt{ESPN SportsCenter} & 3.184 \\ @@ -101,6 +103,8 @@ \caption{\small \textbf{Apps sorted by foreground energy efficiency.}} +\label{table-foreground} + \end{subtable}% \begin{subtable}[t]{0.5\textwidth} {\small @@ -118,6 +122,7 @@ \num{7} & \texttt{Twitter} & 5610.394 \\ \num{8} & \texttt{Android Clock} & 5085.873 \\ \num{9} & \texttt{Yahoo Mail} & 5083.615 \\ +\num{10} & & \\ \bottomrule \num{10} & \texttt{NFL Mobile} & 1275.985 \\ \num{9} & \texttt{UB Parking} & 1071.529 \\ @@ -132,6 +137,8 @@ \end{tabularx} } +\label{table-content} + \caption{\small \textbf{Apps sorted by content energy efficiency.}} \end{subtable} diff --git a/results.tex b/results.tex index 2e38f58..dd52e5b 100644 --- a/results.tex +++ b/results.tex @@ -39,7 +39,7 @@ it through a survey completed by 47~experiment participants. Unfortunately, our results are inconclusive and open to several possible interpretations which we conclude by discussing. -\subsection{Total Consumption} +\subsection{Total Energy} \input{./figures/tables/tableALL.tex} @@ -52,29 +52,33 @@ list of low consumers is dominated by apps with few installs. This table does serve, however, to identify the popular apps in use by \PhoneLab{} participants, and as a point of comparison for the remainder of our results. -\subsection{Consumption Rate} +\subsection{Power} -Computing the rate at which apps consume energy by scaling their total energy -usage against the total time they were running, either in the background or +Computing each app's power consumption by scaling their total energy usage +against the total time they were running, either in the background or foreground, reveals more information, as shown in Table~\ref{table-rate}. Our results identify Facebook Messenger, Google+, and the Super-Bright LED Flashlight as apps that rapidly-consume energy, while the Bank of America and Weather Channel apps consume energy slowly. Differences between apps in similar categories may begin to identify apps with problematic energy consumption, such as contrasting the high energy usage of Facebook Messenger -with other messaging clients such as WhatsApp, Twitter, and Android Messaging. +with other messaging clients such as WhatsApp, Twitter, and Android +Messaging. \subsection{Foreground Energy Efficiency} -Consumption rate alone, however, is insufficient to answer important -questions about how efficient smartphone apps are. Pandora, for example, may -consume a great deal of energy either because it is poorly written, or -because it is delivering a great deal of content. Given the observations -about background usage presented earlier, we were interested in using an apps -foreground time as a utility metric to compute energy efficiency. In this -conceptual framework, smartphone apps deliver utility through screen time -with users, and should consume energy in proportion to the amount of time -users spend actively interacting with them. +Isolating the foreground component of execution time provides a better +measure of value, since it ignores the time that users spend ignoring apps. +Table~\ref{table-foreground} shows a measure of energy efficiency computed by +utilizing foreground time alone as our value measure. Some surprising changes +from the power results can be seen. Some apps have remaining in their former +categories: Bank of America, which was identified as a low-power app, is also +a highly-efficient app when using foreground time as the value measure; and +Facebook Messenger, which was identified as a high-power app, is also marked +as inefficient. Other apps, however, have switched categories. ESPN +Sportscenter and Yahoo Mail do not consume much power, but also don't spend +much time in the foreground; interestingly, none of the high-power apps +looked better when their foreground usage was considered. \subsection{Content Energy Efficiency}