Dear Editor and Reviewers,
-Comments (here in red color) raised by the reviewer n°1 after a first revision have been carefully considered. Please find below our answers highlighted in green. We did our best to satisfy your requests.
+Comments (here in red color) raised by the reviewer n\textsuperscript{o}1 after a first revision have been carefully considered. Please find below our answers highlighted in green. We did our best to satisfy your requests.
%Journal: Engineering Optimization
%Reviewer's Comment to the Author Manuscript id GENO-2015-0094
-\noindent {\bf 3.} The communication and information sharing required to
+\noindent {\textbf{3. \textsc{Reviewer's comment:} } } The communication and information sharing required to
cooperate and make these decisions was not discussed.\\
\textcolor{blue}{\textbf{\textsc{Answer:} The communication and information
\textcolor{red}{\textbf{\textsc{Reviewer's response:} I see at the end of page 8 the description of the INFO packet. However, you are not including any description of the position coordinates, remaining energy, sensor node ID, etc. in the write up. I suggest adding this into the write up to make the communication clear.}}\\
-\textcolor{green}{\textbf{\textsc{Answer:} blbla}}\\
+\textcolor{green}{\textbf{\textsc{Answer:} Right, we have included more description about the INFO packet and the ActiveSleep packet at the end of section~3.}}\\
-\noindent {\bf 7.} The methodology is implemented in OMNeT++ (network simulator)
+\noindent {\textbf{7. \textsc{Reviewer's comment:}}} The methodology is implemented in OMNeT++ (network simulator)
and tested against 2 existing algorithms and a previously developed method by
the authors. The simulation results are thorough and show that the proposed
method improves the coverage and network lifetime compared with the 3 existing
\textcolor{red}{\textbf{\textsc{Reviewer's response:}
I agree that you should show the same performance indicators and that this paper is
about the way you formulated the problem. The mathematical optimization model is the main
-contribution but it’s less convincing since the results are slightly better if not the same for the two
+contribution but it's less convincing since the results are slightly better if not the same for the two
methodologies you have developed. Could you include some other measure that shows that the
PeCO is better? Maybe include computation time or something that is as convincing as the energy
-consumed per sensor.}}
+consumed per sensor.}}\\
-\textcolor{green}{\textbf{\textsc{Answer:} blbla}}\\
+\textcolor{green}{\textbf{\textsc{Answer:} In fact, we defined in section 5.1 a new performance metric linked to the energy, called Energy Saving Ratio (ESR). We added a new section (5.2.3) in the result part related to this performance metric which shows that our PeCO protocol provides better energy saving compared with other approaches.}}\\
-\noindent {\bf 8.} Since this paper is attacking the coverage problem, I would
+\noindent {8. \textbf{\textsc{Reviewer's comment:}}} Since this paper is attacking the coverage problem, I would
like to see more information on the amount of coverage the algorithm is
achieving. It seems that there is a tradeoff in this algorithm that allows the
network to increase its lifetime but does not improve the coverage ratio. This
the end of Section 5.2.4.}}\\
\textcolor{red}{\textbf{\textsc{Reviewer's response:}
-I’m glad you added the explanation. I am confused with your conclusion in the last
-sentence though, “DiLCO is better for coverage ratios near $100\%$, but in that case PeCO is not
-ineffective for the smallest network sizes”. I suggest adjusting it to something like this. “DiLCO
-outperforms PeCO when the coverage ratio is required to be $>90\%$, but PeCo extends the network
-lifetime significantly when coverage ratio can be relaxed. “ Also, can you add applications where
+I'm glad you added the explanation. I am confused with your conclusion in the last
+sentence though, "DiLCO is better for coverage ratios near $100\%$, but in that case PeCO is not ineffective for the smallest network sizes". I suggest adjusting it to something like this. "DiLCO outperforms PeCO when the coverage ratio is required to be $>90\%$, but PeCo extends the network lifetime significantly when coverage ratio can be relaxed." Also, can you add applications where
you would want to have a coverage ratio of $50\%$? This seems like a very small ratio and as you
-increase it, DiLCO becomes the methodology that has the maximum network lifetime. If you don’t
-include application examples, your statement “Indeed there are applications that do not require a
-100$\%$ coverage of the area to be monitored.” stronger. }}
+increase it, DiLCO becomes the methodology that has the maximum network lifetime. If you don't
+include application examples, your statement "Indeed there are applications that do not require a
+100$\%$ coverage of the area to be monitored." stronger. }}\\
-\textcolor{green}{\textbf{\textsc{Answer:} blbla}}\\
+\textcolor{green}{\textbf{\textsc{Answer:} Thank you so much for your suggestion, we modified the sentence at the end of Section 5.2.5. (previously Section 5.2.4.). As recommended, we added some applications examples. We also changed the figure 10 (previously figure 9) by replacing DilCO/50 and PecO/50 by DilCO/70 and PeCO/70.}}\\
