A Method of Relay Node Selection for UAV Cluster Networks Based on Distance and Energy Constraints
Round 1
Reviewer 1 Report (Previous Reviewer 2)
The article has been reasonably improved. Further revision is needed to use experiments to verify the results.
Author Response
Response to Reviewer 1 Comments
The article has been reasonably improved.
Point 1: Further revision is needed to use experiments to verify the results.
Response 1: Thank you for your previous suggestions on this article. Following the suggestions you gave this time, the authors re have made reasonable improvements. Further modifications are needed to verify the results with experiments.
The grammar and expression of the article were carefully revised.
The changes in the manuscript are
Page 1. Lines 17-20.
Page 8. Lines 247-249,251-253,figure2,258-261,Table1.
Author Response File: 
Author Response.docx
Reviewer 2 Report (New Reviewer)
Please see the attached file.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 2 Comments
This paper proposed a cooperative communication relay selection method based on distance prediction and energy constraint in order to reduce the energy consumption in the communication process. Generally, the authors seem have done a solid work. However, many parts are not clear, and motivations should be further clarified. The reviewer has the following concerns:
Point 1: The following two sentences “The simulation results show that the improved method outperforms the current mainstream algorithm by comparing parameters such as network coverage and residual energy. Simulation results show that the performance of the improved method is better than the mainstream algorithm of present day by comparing parameters such as network coverage and residual energy.” has totally the same contents. Besides, the last two sentences are also repeatable and should be removed.
Response 1: First, thank you for your suggestions on the manuscript. Based on the suggestions made, the author has revised the repetitive sentences in the manuscript and also checked the entire paragraphs.
The changes in the manuscript are
Page 1. Lines 16-17.
Point 2: The authors should carefully check the whole paper to avoid writing errors, such as the missing space between In2020. Besides, do not set the reference number of the beginning of sentence, which looks confusing, such as “In 2021 [10] C Huang” and “[13] Agrawal D”.
Response 2: The author checked the spelling of sentences in the manuscript. Deficiencies in the manuscript were corrected. The author has reset the position of the reference symbols so that the reader can read the manuscript clearly.
The changes in the manuscript are
Page 2. Lines 38-109, Changes have been marked.
Point 3: Both the motivations and contributions are not well introduced, which should be much improved to emphasize the novelty of this paper.
Response 3: The authors have revised the introduction section of the manuscript. The motivation and contribution of the study have been strengthened. The innovative nature of the study is highlighted.
The changes in the manuscript are
Page 3. Lines 105-107, Lines 109-111, Lines 118-119.
Point 4: It is suggested to introduce the following recent works in cooperative communications field [R1]-[R3] and energy constraint field [R4] to highlight the state-of-the-art of this paper.
[R1] “Refracting RIS aided hybrid satellite-terrestrial relay networks: Joint beamforming design and optimization,” IEEE Transactions on Aerospace and Electronic Systems, vol. 58, no. 4, pp. 3717-3724, Aug. 2022.
[R2] “Joint beamforming and power allocation for satellite-terrestrial integrated networks with non-orthogonal multiple access,” IEEE Journal of Selected Topics in Signal Processing, vol. 13, no. 3, pp. 657-670, June 2019.
[R3] “Supporting IoT with rate-splitting multiple access in satellite and aerial-integrated networks,” IEEE Internet of Things Journal, vol. 8, no. 14, pp. 11123-11134, Jul. 2021.
[R4] “SLNR-based secure energy efficient beamforming in multibeam satellite systems,” IEEE Transactions on Aerospace and Electronic Systems, early access, Jul. 2022, doi: 10.1109/TAES.2022.3190238.
Response 4: Thank you for your suggestions. The authors have read the literature you suggested. Two reference was presented because the literature is closely related to the research. Two references were not presented because the literature is not very relevant to the study. Previous reviewers have suggested that I remove the literature on satellite communications. The literature you suggested would be very helpful for my subsequent research.
The changes in the manuscript are
Page 3. Lines 97-98;
Page 6. Line 219-220;
Page 14. Line 420 [18],452 [34].
Point 5: In section 2, the authors only refer the source node, surrounding nodes and relay node. Is there any connection with the UAV networks? Which node is UAV or terrestrial node?
Response 5: Thanks for your suggestion on the theoretical model, in UAV cluster communication, each UAV is a network node. It is responsible for linking the surrounding nodes. For the reader's convenience, the authors have added a diagram of the theoretical model.
The changes in the manuscript are
Page 4. Lines 105-107,135-136.
Point 6: It is suggested to draw a system model for better understanding of readers.
Response 6: Thank you for your suggestions. The authors have added a schematic diagram of the UAV cluster network to the model research. The reader can understand the studied model by looking at the diagram.
The changes in the manuscript are
Page 4. Lines 122-123,Figure 1.
Point 7: The characteristics of channels are not referred at all, such as the channel fading, distribution and frequency band.
Response 7: Thank you for your suggestions on the details in the research. The research focuses on solving relaying by distance and energy constraints, thus simplifying the properties of the communication channel. The authors have added the necessary properties.
The changes in the manuscript are
Page 3. Line 133-135;
Page 4. lines 154-156;
Page 5. lines 181-182.
The grammar and expression of the article were carefully revised.
Author Response File: Author Response.docx
Reviewer 3 Report (Previous Reviewer 1)
The paper can be accepted now, thanks for all authors for the modifications
Author Response
Response to Reviewer 3 Comments
Point The paper can be accepted now, thanks for all authors for the modifications
Response Thank you for your review of the manuscript. Your suggestions have enhanced the innovative nature of the research.The grammar and expression of the article were carefully revised.
Round 2
Reviewer 1 Report (Previous Reviewer 2)
Authors did not address the concerns of reviewers.
Author Response
Response to Reviewer 1 Comments
Authors did not address the concerns of reviewers.
Point 1: Further revision is needed to use experiments to verify the results.
Response 1: Thank you for your suggestions on this article. Following the advice you gave earlier about the experiments，the authors have re-run the experiments on the networking of 20 UAVs. The experiments verified the results of the simulations. The structure and content of the article manuscript was reworked.
First, the authors simulate the process of different relay selection algorithms. The simulation results compare the parameters of the three algorithms, which include network coverage, communication time and residual energy.
Second, the authors organize a practical test of the network with 20 UAVs. The tests verify the correctness and practicality of the simulation results. In accordance with the requirements of the Chinese government's Ministry of Industry and Information Technology "Interim Measures for Civilian Unmanned Aerial Vehicle Radio Management".The maximum number of drones tested is 20. The upper limit of UAV flight altitude is 3000 meters. The measures can be downloaded "https://www.miit.gov.cn/gzcy/yjzj/art/2022/art_1fade0b65d8140698eb6c7ae1714ec73.html"
Third, the authors reworked the structure and content of the manuscript. First, the manuscript describes the results of simulation simulations. Secondly, the manuscript records the results of the actual tests. Finally, the comparison results are discussed.
The changes in the manuscript are
Page 1. Lines 16-19. The authors have modified the description of the two experimental results in the abstract.
Page 8. Lines 247-252. The authors have added descriptions of two experiments. The purpose and order of the experiments were expressed.
Page 11. Lines 315-342. The authors added 20 UAVs for network communication tests. The documentation of the test procedure contains diagrams and tables. Verification of the simulation results by the test experiments is added in the last paragraph.
Page 12. Lines 364-366. The authors elaborate on the results in the conclusion of the manuscript
Reviewer 2 Report (New Reviewer)
The authors have addressed my concerns, no further comments.
Author Response
Response to Reviewer 2 Comments
Point The authors have addressed my concerns, no further comments.
Response Thank you for your review of the manuscript. Your suggestions have enhanced the innovative nature of the research.
Round 3
Reviewer 1 Report (Previous Reviewer 2)
Comments are not addressed.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
This paper is in line with the scope of this journal with some significant contributions, but I am concerned about the following questions:
l The authors should further analyze the results, In conclusion, I think the author's analysis of the research results is very shallow, so they must further summarize the research findings based on the research results
l Please define all acronyms in the abstract. - State clearly the research question in the Introduction.
l I think that not all symbols are defined for equations, especially in the part where a novel method is presented.
l Expend conclusion to include details regarding the future work.
l There are some technical and English language errors, please read the manuscript carefully and revise.
Author Response
Response to Reviewer 1 Comments
Point 1: The authors should further analyze the results, In conclusion, I think the author's analysis of the research results is very shallow, so they must further summarize the research findings based on the research results
Response 1: First of all, thank you for your suggestions on the concluding section of the manuscript. Following the suggestions given, the authors have re-summarized the results of the three simulation experiments. Also the authors add a separate section to discuss the results of the study.
The changes in the manuscript are
4.2. Communication Link Topology Simulation Com-parison, page 9, lines 289 to 291.
4.3. Simulation Comparison of Cooperative Comm-unication Process, page 10, lines 306 to 313.
4.4. Comparative simulation of system residual energy lines 326 to 330 on page 11.
The new section is
4.5.Discussion of the Results, lines 332-341 in pages 11 to 12.
Point 2: Please define all acronyms in the abstract. - State clearly the research question in the Introduction.
Response 2: Thank you for your suggestions on the abstract and introduction sections of the manuscript.
Following your suggestions, the authors have expanded the abbreviations for drones in the abstract. The changes are shown in line 10 of manuscript P1, the authors have reworked the entire abstract.
Following your suggestion for the introduction, the authors have reworked the introduction of the manuscript. The revisions are shown in Introduction in manuscript P1. The revisions reorganize the research area and problem, and clarify that the research problem is to solve the relay selection problem for UAV population networks.
Point 3: I think that not all symbols are defined for equations, especially in the part where a novel method is presented.
Response 3: Thank you for your suggestions on the definition of symbols in the manuscript.
Following the suggestions given, the authors have checked and revised the symbols in the manuscript.
The changes are described in Chapter 2 of the manuscript Multi-relay Selection Theory based on Energy Allocation. the authors have reworked the symbols to include network nodes, energy, channel information, transmission power in both phases, expressions for the most functions, etc., and have also checked the formulas and symbols.
Point 4: Expend conclusion to include details regarding the future work.
Response 4: Thank you for your suggestions in the conclusion section of the manuscript. Following the suggestions given, the authors have further summarized the conclusion section.
The revisions can be found in lines 343 to 370 of the manuscript P12. The revisions include the findings of the study, comparative validation of the findings and possible future work.
Point 5: There are some technical and English language errors, please read the manuscript carefully and revise.
Response 5: First of all, thank you for your suggestions on the technical and English language in the manuscript. Following the suggestions given, the authors have checked the sections on terminology and theoretical studies, and have also improved the language expressions. There are many changes in the manuscript, and the main parts that were revised are listed below.
The abstract section clarifies the research problem, condenses the research method, summarizes the research results, and improves the significance of the research.
In the introduction section, the research topic and research questions are simplified, the references are rechecked, and finally the research objectives and research methods are clarified.
In the theoretical basis, the formulas and symbols are rechecked and the logical sequence is strengthened.
The discussion of the results of each experiment is expanded in the simulation experiments, and a summary of the research results is also added.
Finally, the discussion is supplemented with the proposed methodology, the extension of future work.
The modified manuscript is detailed in the attached document, the modified part of the document has been marked with yellow background
Reviewer 2 Report
The efforts into algorithm for large-scale UAV network is worth encouraging. However, the following shortcomings need to be overcomed during revision:
1. There is no research method section but a section of equations explaination, which is not encouraged. Methodology shall be explained in detail;
2. The introduction section is too long. Actually, some parts in the introduction can be extended and put into the literature review section.
3. There is no literature review section.
4. There is no emperical data. Instead, there is only simulation in this study, which is not sufficient for validation.
Author Response
Response to Reviewer 2 Comments
Point 1: There is no research method section but a section of equations explaination, which is not encouraged. Methodology shall be explained in detail.
Response 1: First of all, thank you for the suggestion about the absence of research methods in the manuscript. Following the suggestions given, the authors have modified the research method section and the research is refined in four parts according to cluster head competition selection, link mutual information solving, constructing disruption probability and designing the optimal function.
The main modified sections are as follows.
2.1. Cluster head selection method based on competition mechanism, p. 4, lines 155 to 158.
2.2. Alternative set of link distances, page 5, lines 198 to 201.
2.3. Energy allocation strategy in cooperative communica-tion process, page 5, lines 216 to 220.
2.4. Optimal solution of interruption probability, page 7, lines 235 to 237.
Point 2: The introduction section is too long. Actually, some parts in the introduction can be extended and put into the literature review section.
Response 2: Thank you for your suggestions on the introduction section of the manuscript.
According to the template given by the journal, the implied section contains an introduction to the research topic, a literature review of the existing results of the research question, a description of the research idea and the research methodology.
Following the suggestions given, the authors have streamlined the research topic and research questions in the introduction. Also the authors have revised the references as given and finally the authors briefly introduce the research ideas and research methods.
The modifications are detailed in the introduction section of the manuscript on page 1.
First paragraph, research questions and research implications.
Second paragraph, literature review of collaborative communication.
third paragraph, literature review of dynamic relay selection methods.
Fourth paragraph, research methodology and ideas.
Point 3: There is no literature review section.
Response 3: Thank you for your suggestion of a literature review of the manuscript.
According to the template given by the journal, the literature review is the 2nd part of the introductory chapter.
Following the suggestions given, the authors have reworked the literature and have summarized and compared the existing results.
The authors' changes regarding the literature are detailed in the manuscript on pages 2 to 3, lines 39 to 121.
Lines 39 to 76 on page 2. The authors summarize in detail the literature review of relay selection methods in collaborative communications.
Lines 77 to 121 on page 3. The authors summarize in detail the literature review of dynamic relay selection methods.
Point 4: There is no emperical data. Instead, there is only simulation in this study, which is not sufficient for validation.
Response 4: Thank you for the suggestion on the manuscript data.
Following the suggestions you gave, the authors rearranged the actual data for the UAV communication in the study. We have added the data used in the simulation to the manuscript.
The authors' changes regarding the literature are detailed in the manuscript on page 8, lines 266 to 270.
Lines 266 to 269. The authors describe the sources and uses of the actual data.
Line 270. The table shows the node coordinates of the UAV population network with coordinate data from the actual data of 20 Chinese DJI brand UAVs.
The modified manuscript is detailed in the attached document, the modified part of the document has been marked with yellow background
Reviewer 3 Report
The authors propose a new algorithm to solve the inefficiency problem of relay node selection in moving UAV networks. The paper has several typos, and the quality of the English is poor. Moreover, the workers lack novelty. I do not believe the algorithm adds much to the improvement of UAV networking communication. That is why I suggest the paper is rejected.
The English in this article needs to be improved significantly. The introduction is hard to read and understand
Pp 2, lines 48, 57, 67: it seems there is a typo in this line. The reference number should be put in front of the authors’ name.
Pp 3, line 134: the authors need to provide a paragraph on the organization and motivation of the research
pp5: the equations need more explanation and must be organized more appropriately. Subscript/superscript needs to be fixed.
Author Response
Response to Reviewer 3 Comments
Point 1: The English in this article needs to be improved significantly. The introduction is hard to read and understand。
Response 1: Thank you for your suggestions on the English expression of the manuscript.
Following the suggestions you gave, the authors have reworked the English language in the article, and the changes point out the inclusion of English abbreviations, formula meanings, sentence grammar, etc.
Since the changes to the English expressions comprise the majority of the manuscript, we have highlighted the changes for easy comparison so that they can be read frequently.
Point 2: Pp 2, lines 48, 57, 67: it seems there is a typo in this line. The reference number should be put in front of the authors’ name.
Response 2: Thank you for your suggestions on the English expression of the manuscript.
Following the suggestions you gave, the authors have reworked the English in the article. Among them, lines 48, 57 and 67 in page 2 have been corrected, and other literature has also been corrected.
Point 3: line 134: the authors need to provide a paragraph on the organization and motivation of the research
Response 3: Thank you for your suggestions on the motivation of the manuscript research.
Following the suggestions you gave, the authors have reworked the problem formulation and research motivation in the article.
In order to ensure the logic of the document, the authors have integrated the research motivation and the research methodology. Lines 122 to 125 in page 2 of the manuscript state the motivation of the research, and after line 125 the research idea and the research methodology are presented.
Point 4: pp5: the equations need more explanation and must be organized more appropriately. Subscript/superscript needs to be fixed.
Response 4: Thank you for your suggestions on the manuscript equations.
Following the suggestions you gave, the authors have rechecked and revised the equations of the theoretical study in the manuscript. The revision work mainly contains the correctness of the equations, the expressions of the letters and the logical presentation of the theory.
The corrections to the document can be found in the derivation of 20 equations and their explanations in lines 151 to 237 of the manuscript.
The modified manuscript is detailed in the attached document, the modified part of the document has been marked with yellow background
Round 2
Reviewer 2 Report
This study is based on only paper work without experiment. UAV is not an expensive device so experiments are needed to support the findings.
