variables and $P*T$ undercoverage variables. The number of constraints is equal
to $P*T$ (for constraints (\ref{eq16})) $+$ $A$ (for constraints (\ref{eq144})).
-\iffalse
-\subsection{Sensing phase}
-
-The sensing phase consists of $T$ rounds. Each sensor node in the subregion will
-receive an Active-Sleep packet from WSNL, informing it to stay awake or to go to
-sleep for each round of the sensing phase. Algorithm~\ref{alg:MuDiLCO}, which
-will be executed by each sensor node~$s_j$ at the beginning of a period,
-explains how the Active-Sleep packet is obtained.
-\fi
\section{Experimental framework}
\label{exp}
AVR ATmega103L microcontroller~\cite{raghunathan2002energy} to use numerical
values.}
-\iffalse
-\subsection{Energy model}
-
-We use an energy consumption model proposed by~\cite{ChinhVu} and based on
-\cite{raghunathan2002energy} with slight modifications. The energy consumption
-for sending/receiving the packets is added, whereas the part related to the
-sensing range is removed because we consider a fixed sensing range.
-
-For our energy consumption model, we refer to the sensor node Medusa~II which
-uses an Atmels AVR ATmega103L microcontroller~\cite{raghunathan2002energy}. The
-typical architecture of a sensor is composed of four subsystems: the MCU
-subsystem which is capable of computation, communication subsystem (radio) which
-is responsible for transmitting/receiving messages, the sensing subsystem that
-collects data, and the power supply which powers the complete sensor node
-\cite{raghunathan2002energy}. Each of the first three subsystems can be turned
-on or off depending on the current status of the sensor. Energy consumption
-(expressed in milliWatt per second) for the different status of the sensor is
-summarized in Table~\ref{table4}.
-
-\begin{table}[ht]
-\caption{The Energy Consumption Model}
-\centering
-\begin{tabular}{|c|c|c|c|c|}
- \hline
-Sensor status & MCU & Radio & Sensing & Power (mW) \\ [0.5ex]
-\hline
-LISTENING & on & on & on & 20.05 \\
-\hline
-ACTIVE & on & off & on & 9.72 \\
-\hline
-SLEEP & off & off & off & 0.02 \\
-\hline
-COMPUTATION & on & on & on & 26.83 \\
-\hline
-\end{tabular}
-
-\label{table4}
-\end{table}
-
-For the sake of simplicity we ignore the energy needed to turn on the radio, to
-start up the sensor node, to move from one status to another, etc.
-Thus, when a sensor becomes active (i.e., it has already chosen its status), it
-can turn its radio off to save battery. MuDiLCO uses two types of packets for
-communication. The size of the INFO packet and Active-Sleep packet are 112~bits
-and 24~bits respectively. The value of energy spent to send a 1-bit-content
-message is obtained by using the equation in ~\cite{raghunathan2002energy} to
-calculate the energy cost for transmitting messages and we propose the same
-value for receiving the packets. The energy needed to send or receive a 1-bit
-packet is equal to 0.2575~mW.
-
-The initial energy of each node is randomly set in the interval $[500;700]$. A
-sensor node will not participate in the next round if its remaining energy is
-less than $E_{R}=36~\mbox{Joules}$, the minimum energy needed for the node to
-stay alive during one round. This value has been computed by multiplying the
-energy consumed in active state (9.72 mW) by the time in second for one round
-(3600 seconds). According to the interval of initial energy, a sensor may be
-alive during at most 20 rounds.
-\fi
-
\subsection{Metrics}
\textcolor{blue}{To evaluate our approach we consider the performance metrics
%nodes have been drained of their energy or each sensor network monitoring an area has become disconnected.
\end{enumerate}
-\iffalse
-\begin{enumerate}
- \setcounter{5}
-\item {{\bf Execution Time}:} a sensor node has limited energy resources and
- computing power, therefore it is important that the proposed algorithm has the
- shortest possible execution time. The energy of a sensor node must be mainly
- used for the sensing phase, not for the pre-sensing ones.
-
-\item {{\bf Stopped simulation runs}:} a simulation ends when the sensor network
- becomes disconnected (some nodes are dead and are not able to send information
- to the base station). We report the number of simulations that are stopped due
- to network disconnections and for which round it occurs.
-\end{enumerate}
-\fi
\section{Experimental results and analysis}
\label{analysis}