Joint Channel and Power Assignment for Underwater Cognitive Acoustic Networks on Marine Mammal-Friendly

Round 1

Reviewer 1 Report

The authors focus on addressing the conflicts and challenges that arise when marine animals and underwater acoustic sensor networks (UASNs) operate within the same spectral domain. Their primary concern revolves around the harmful impacts such systems can have on marine life, coupled with the inherent limitations of underwater spectrum resources. In response to these challenges, they introduce a novel algorithm that optimally allocates channels and power for these networks. However, there are areas where further elaboration would benefit the reader.

1- The assumption of marine animals as "authorized users" is intriguing but requires deeper justification. Why exactly are marine animals treated as authorized users? Is this a purely ethical decision, or are there technical reasons behind it?

2- While the paper presents the Nash equilibrium as a solution, it does not thoroughly discuss the potential challenges or limitations in reaching this equilibrium in real-world scenarios.

3- The criteria by which the algorithm's efficiency is measured could be expanded.

4- While system capacity and communication performance are crucial, it might also be interesting to evaluate the algorithm's efficiency in terms of energy conservation, latency, or other relevant metrics.

Moderate editing of English language required

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The research topic is fascinating.

It is necessary to review the text:

- "Chapter" for example, instead of Section.

- Terms were used before being defined. "MFPC" line 61, for example.

- Typos: like "fed back"

- "For instance, Reference[19] analyzed"

- insert an empty space between a word and citation: text [1] instead of text[1]

Did The authors draw Figure 1? It is not clear.

Section 3.2 needs to be reviewed. The variables need to be better explained. A proof could be inserted in an appendix.

The results are promising, but it is interesting to vary beyond the number of k and the number of different powers, the frequencies and spectrums. The coexistence between different frequencies could be interesting to show the method's scalability.

Several typos.

A native English person or a review service could be helpful.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

This paper proposes to allocate the channel and power of an underwater communications system while avoid causing interference to the marine animals. This is a great idea. However, there are several technical issues that need to be addressed before consideration of publication.

1. How can we obtain channel state information of marine organisms?

2. Following up the previous comments, another view is to treat the animal as eavesdropper in secure communications, where the communication energy would try to avoid the eavesdroppers. Then, only the position is needed, e.g., see [R1]. Please comment what is the advantage of viewing the animals as primary users rather than eavesdroppers ?  If both views are possible, it is suggested to mention another potential view in the paper.

[R1]  ``Angle Aware User Cooperation for Secure Massive MIMO in Rician Fading Channel," IEEE JSAC 2020.

3. Why treat the problem as a game-theoretic problem? Why not consider using conventional optimization approach ? In fact, channel and power allocation using optimization approach has been widely studied in wireless communications, e.g., [R2]. This paper should include the prior works on this topic in the literature review.

[R2] "Multiuser OFDM with adaptive subcarrier, bit, and power allocation," IEEE JSAC, 1999.

4. While it is proved that Nash equilibrium exist, is there any guarantee that the proposed algorithm in Fig. 2 would reach the Nash equilibrium ?

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

The authors proposed a mammal-friendly underwater acoustic sensor network algorithm for channel power allocation. The proposed algorithm treats the marine animals as authorized users while considering sensor nodes as unauthorized ones. Generally, the paper is well organized and the obtained results seem important. However, I have the following comments:

1) The English should be revised in the whole manuscript.

2) Try to correlate between abstract and conclusion.

3) Mention the major findings in the abstract.

4) In the paper layout paragraph, just before the Related Work, replace “Chapter” by “Section”.

5) Mention the complete text before the first use of abbreviation (for instance, MFPC).

6) Related work should be more enhanced and the authors must mention the limitations of the existing techniques not only describing them.

7) Give some types of acoustic sensors that are suitable to apply the proposed model.

8) Section 3.4 Algorithm flow should be moved to the beginning of section 3. System Model.

9) In section 4. Discussion, the authors mentioned “we conduct simulation experiments”, please specify if simulation or real experiments have been done to evaluate the proposed model.

10) The dimension of the network is not clear. Please mention the area of network considered in the simulation. In addition, the number of deployed sensors is very small. 

Moderate editing of English language required.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

This version addressed my concerns satisfactorily.

Reviewer 4 Report

The authors answered all my comments. I suggest the paper for publication in the journal.

 Minor editing of English language required