\r
\institute{FEMTO-ST Institute, UMR 6174 CNRS, University of Franche-Comt\'e, France}\r
\r
-\def\received{Received 21 October 2014}\r
+\def\received{Received 23 October 2014}\r
\r
\maketitle\r
\r
interest of $(50 \times 25)~m^2 $ in such a way that they cover the field with a\r
high coverage ratio.\r
\r
-We chose as energy consumption model the one proposed proposed \linebreak\r
-by~\cite{ChinhVu} and based on ~\cite{raghunathan2002energy} with slight\r
-modifications. The energy consumed by the communications is added and the part\r
-relative to a variable sensing range is removed. We also assume that the nodes\r
-have the characteristics of the Medusa II sensor node platform\r
-\cite{raghunathan2002energy}. A sensor node typically consists of four units: a\r
-MicroController Unit, an Atmels AVR ATmega103L in case of Medusa II, to perform\r
-the computations; a communication (radio) unit able to send and receive\r
-messages; a sensing unit to collect data; a power supply which provides the\r
-energy consumed by node. Except the battery, all the other unit can be switched\r
-off to save energy according to the node status. Table~\ref{table4} summarizes\r
-the energy consumed (in milliWatt per second) by a node for each of its possible\r
-status.\r
+We chose as energy consumption model the one proposed\r
+by~\cite{ChinhVu} and based on ~\cite{raghunathan2002energy} with\r
+slight modifications. The energy consumed by the communications is\r
+added and the part relative to a variable sensing range is removed. We\r
+also assume that the nodes have the characteristics of the Medusa II\r
+sensor node platform \cite{raghunathan2002energy}. A sensor node\r
+typically consists of four units: a MicroController Unit, an Atmels\r
+AVR ATmega103L in case of Medusa II, to perform the computations; a\r
+communication (radio) unit able to send and receive messages; a\r
+sensing unit to collect data; a power supply which provides the energy\r
+consumed by node. Except the battery, all the other unit can be\r
+switched off to save energy according to the node status.\r
+Table~\ref{table4} summarizes the energy consumed (in milliWatt per\r
+second) by a node for each of its possible status.\r
\r
\begin{table}\r
\caption{Energy consumption model.}\r
where $n$ is the number of covered grid points by active sensors of every\r
subregions during the current sensing phase and $N$ is the total number of grid\r
points in the sensing field. In our simulations, we have a layout of $N = 51\r
- \times 26 = 1326$ grid points.\r
+ \times 26 = 1,326$ grid points.\r
\r
\item {{\bf Energy Consumption}:} energy consumption (EC) can be seen as the\r
total amount of energy consumed by the sensors during $Lifetime_{95}$ \r
\begin{center}\r
\scalebox{0.5}{\includegraphics{R/CR.pdf}}\r
\end{center}\r
-\caption{Coverage ratio}\r
+\caption{Coverage ratio.}\r
\label{fig3}\r
\end{figure} \r
\r