Publish/Subscribe-Middleware-Based Intelligent Transportation Systems: Applications and Challenges

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dera Authors,

I have read your manuscript with interest. The issue you have raised is of interest and importance.

I have some comments to the manuscript:

1. In the Abstract, you state "In this survey, we explore the various applications of publish/subscribe middleware in transportation. Due to the lack of surveys that cover this topic, we aim to improve knowledge and research in this area by providing a comprehensive understanding of how publish/subscribe middleware technologies optimize and enhance different transportation systems.". In Lines 95-97 there is another statement "This review seeks to analyze papers focused on middleware in transportation, exploring its applications, contributions, employed models and techniques, and associated challenges." Somehow, they mismatch. On the other hand, the statement in the Abstract is too ambitious.
2. I believe you mix survey and review. There are no surveys presented in the manuscript.
3. In Lines 144-145, you indicate that you use "entries from 2003 to 2024.", while in other places, 2009-2024. What is the reason?
4. I'm sorry, but I do not believe that there were only "87 publications" (Line 144) on the topic from 2003 to 2024. Please check just www.sciencedirect.com, www.mdpi.com, or another publisher, and I am sure you will find more publications.
5. What information is provided to the reader in Figure 7, "Number of Annual Publications and Citations on Middleware-based ITS."? Is the topic out of interest?
6. Somehow (especially in the Conclusion part) I have missed the purpose of this review article. Or it is not well described. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The article presents a review on a topic of high interest, related to Intelligent Transportation Systems (ITS) and Publish/Subscribe Middleware. I consider that the article should improve in several aspects, which are detailed below:

1. In the abstract it is important to make clear the importance of publish/subscribe middleware in transportation, something is mentioned, but very superficially.
2. At the beginning of the Introduction, several concepts are presented (Smart Transportation, Smart Transportation System, Intelligent Transportation System, but none are delved into. I recommend, considering the title and content of the article, that you focus on ITS, its definition, the reference architectures, the areas of transportation proposed by the reference ITS architectures, which ones are you going to mainly consider and why?
3. The statement "Smart transportation comprises two primary components: (1) intelligent traffic control management and (2) autonomous vehicles.", should be supported in one or more references, since "Smart Transportation" covers many more areas.
4. I do not consider it advisable that there be a subsection 1.1, if there is not at least another subsection 1.2.
5. It is not advisable to present a figure (Figure 1 for example) without having previously referenced it in the text of the document. Please review and correct similar cases, regarding figures and tables as well.
6. I consider that Section 3 is too extensive, I do not believe that providing a background on Middleware is the main objective of the article, so I consider that it is better that they leave most of the information in an annex and in the main content of the article summarize this section.
7. I recommend reviewing the relevance of Section 4, I do not consider it relevant to the content of the document, perhaps you can leave it as an annex.
8. I consider it necessary to considerably improve the Conclusions section, regarding each ITS domain analyzed (infrastructure, transportation modes, and communication technologies).

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

1. The article is substantively valuable, but it is worth paying attention to the consistency of terminology, especially when referring to algorithms and parameters.
2. In the case of the methodology, it is worth adding more details about the implementation of the algorithm. In particular, how parameters such as vehicle reaction time, minimum distances or speeds of other vehicles in the system are calculated. It is also worth explaining in more detail how individual parameters affect the results of the algorithm in different road scenarios.
3. The article lacks details about tests conducted in real road conditions.
4. It is worth developing a comparative analysis with other similar methods in the literature. How does the proposed algorithm compare to other methods that were presented in the literature review?
5. It is worth discussing the limitations of the adopted method and results in more detail. For example, how the algorithm can cope with errors in obstacle detection or in unfavorable weather conditions (e.g. rain, fog, etc.).

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The paper considers 40 studies that apply publish/subscribe middleware to intelligent transportation, classifying them by infrastructure, transport mode, and communication technology. It shows how broker based and brokerless designs tackle latency and interoperability while talking about issues in privacy and connectivity. The review concludes that publish/subscribe middleware is central to future smart-mobility ecosystems but needs deeper empirical validation and unified performance metrics.

 

1. It is also good to mention other types of security measures such as physical layer security
2. In the latency formula $T=D / B+H$. Isn’t D in bytes while $B$ is bits/sec? Please clarify.
3. How did you verify that the 40 retained papers implement a publish/subscribe layer ?
4. Why is DDS placed only under brokerless systems when several vendors allow an optional broker?
5. Why are ML based vision systems and publish/subscribe treated in the same sentence as if they were interchangeable? It is not clear for this reviewer.
6. When addressing potential security and privacy issues in Wi-Fi, authors can mention that Wi-Fi can also find the exact location of transmitting nodes, with the aid of a preamble field of the Wi-Fi 802.11 frame [REF01]. Kindly motivate for security and privacy.
7. Do you consider message authenticity orthogonal to privacy?
8. When introducing ICN, contrast its name-based routing delay with brokerless DDS multicast in tabular form.
9. There does not seem to be error bars. When fitting the visibility-range model $V=\alpha I^{-\beta}$, include standard errors for a and $\beta$, otherwise it is hard to assess.

 

References

[REF01] “Single snapshot joint estimation of angles and times of arrival: A 2D Matrix Pencil approach,” 2016 IEEE International Conference on Communications (ICC), Kuala Lumpur, Malaysia, 2016, pp. 1-6, doi: 10.1109/ICC.2016.7511158

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for your answers to the questions and the updated manuscript version.

I have no further comments on the manuscript.

Maybe in the future it would be worth checking not only the publications, but also publicly available projects (e.g. through the Dimentions AI https://orcid.dimensions.ai/grants/select), how analysed activities are reflected there.

Author Response

Comment 1: Maybe in the future it would be worth checking not only the publications, but also publicly available projects (e.g. through the Dimentions AI https://orcid.dimensions.ai/grants/select), how analysed activities are reflected there.

Response 1: Thank you, sir. I will definitely study publicly available projects in my future work. 

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have made all the adjustments requested by both reviewers, attempting to comprehensively address each reviewer's needs. The adjustments made considerably improve the content and organization of the article.

Author Response

Comment 1: The authors have made all the adjustments requested by both reviewers, attempting to comprehensively address each reviewer's needs. The adjustments made considerably improve the content and organization of the article.

Response 1: Thank you, sir.

Reviewer 3 Report

Comments and Suggestions for Authors

The scope of the literature review has been significantly expanded compared to the first version of the manuscript, which is commendable. In particular, the improved background on middleware classifications and the inclusion of new use case examples in ITS are valuable additions.
1. However, the manuscript still lacks a deeper, critical comparative analysis of the reviewed solutions. The paper remains largely descriptive, listing examples without drawing generalizations or presenting a functional taxonomy. I strongly encourage the authors to develop a functional meta-analysis, e.g., grouping middleware by core roles such as communication, security, V2X integration, or routing. A comparative table of middleware solutions based on unified evaluation criteria is highly recommended. 
2. The technical descriptions of publish/subscribe architectures may be reduced or streamlined. In their current form, some sections resemble technical documentation. A scientific paper should focus more on the implications and comparisons than on architectural or implementation-level details.
3. While the current diagrams (e.g., Fig. 2, Fig. 3) are helpful, a system-level conceptual model of an ITS architecture incorporating the middleware layer would be beneficial. This would support a more comprehensive understanding of the role of middleware within larger intelligent transport systems.
4. The final conclusions are too general and require refinement. Rather than reiterating points from the introduction, the conclusions should clearly identify which middleware solutions demonstrate actual added value in specific ITS applications and which ones fall short.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

This reviewer has no further comments.

Author Response

Comment 1: This reviewer has no further comments.

Response 1: Thank you, sir.

Round 3

Reviewer 3 Report

Comments and Suggestions for Authors

Suggestions for Improvement
1) It might be helpful to add some validation to the model — for example, using data from a real transport company or a typical TMS setup.
2) The results section could be expanded with a few sensitivity tests for key parameters, like the cooperation willingness factor.
3) Consider adding a few more recent references from 2021 to 2024, especially those related to MAS in urban logistics.

Author Response

Thank you for the comments

However, we respectfully note that this comment appears to reference a modeling-based manuscript involving parameter sensitivity and multi-agent systems in urban logistics, which does not align with the scope or content of our paper.

Our work is a systematic review and comparative analysis of publish/subscribe middleware solutions in Intelligent Transportation Systems (ITS), focusing on communication infrastructure and middleware classification within the ARC-IT framework. As such, it does not involve the development or simulation of a specific model or the use of transportation management system (TMS) data.