Global Models of Smart Cities and Potential IoT Applications: A Review

Round 1

Reviewer 1 Report

The authors propose a review on Smart CiTy models.

They collect a lot of interesting contributions, but the main issue of the manuscript are the motivations description and the content organisation. What the authors intend for "smart city models"?

In the following some specific comments:

- Title: I suggest to update id as "Global Models of Smart City and Potential IoT Applications: a Review"

- The abstract is a general description of the concept of smart city and doesn't contain the main goal of the work: I suggest to modify it adding a sentence clarifying what is the scope of the proposed review work

- The same for the introduction section. Since this is a review, I think is needed a section (maybe at the end of introduction) where authors describe criteria used to select papers, what are the models and the objectives: for who can be this review useful?

- What is the goal of List 1-10 at page 3  and the following 2.X sub sections ? I suggest to simplify the structure and add a summary at the beginning. There are too many sub sub sections (with only 1 reference) and this make the paper very difficult to read

- The 2.12.4. Sensing section is too general. Moreover, I think that Body Area Network, even if interesting, are not so relevant in the Smart City context

- In table 1, the "use case" column can be use to connect IoT communication protocols to topics/categories described in section 2. Why LPWAN protocols (e.g. LoRaWAN) are not listed in the table? 

-How Smart city examples have been selected? Is it possible tho have one or more metrics for each city?

Minor comments:

- is the black border on figure 1 correct?

- Figure 3 contains only icons (that are not fully described in the text) and is not so useful . I suggest to remove it or add some labels.

- In the text uniform notation: figure X --> Figure X

I suggest to revise all contents to remove typos and uniform notations

Author Response

I would like to thank you for your valuable comments.

we have made all the required and recommended changes. 

1. we added multiple sentences to the abstract to indicate the main goal of the paper.
2. In the introduction, we added a paragraph indicating the smart city model selection criteria.
3.  we removed the sensing section in the smart health [BAN] and the corresponding figure as considered irrelevant to the main focus of the paper. 
4. In Table # 1, we added 3 LPWAN technology features and we introduce them in detail in a separate section. 
5. we added a new section related to the smart city evaluation metrics and summarize them in 8 tables for all 8 cities.  
6. All typos have been corrected.

Thank you 

Reviewer 2 Report

 Global Models of Smart City and Potential IoT Applications: A Review is an ambitious title and the paper aims at covering smart city models, possible IoT applications and the communication technologies enabling these.

The number of smart city models and the development is mentioned; a metric for evaluating smart cities and some of the best known/ most developed smart cities are presented. However, the metric is not used to characterize or discuss the level of development, e.g., with respect to use of IoT applications; this would have been interesting to move beyond counting and description.

The rather exhaustive listing of possible applications of IoT provides an overview of most connections where IoT can be useful (I cannot point to obvious missings). I have, nevertheless som problems with the listing. a) The ordering principle is not clear. In section 2, Smart Cities a list of 10 areas for IoT applications is presented. It is followed by a more detailed – but not related? - list of 22 ‘areas’ characterized both as functions (smart transportation; smart parking…) and technologies (robotics; unmanned aerial vehicles..). b) the listing is basically a listing; there is no discussion or analysis of the level of importance for the smart city; the level of maturity of the applications (xyz can be used to is dominant in the descriptions); or the requirements to the enabling communication technologies.

The communication technologies are not adequately described or analyzed in relation to IoTs.

In the introduction it is stated that cellular based legacy Fourth Generation (4G) Long Term Evolution (LTE) and emerging 5G are the key technologies candidates that can 46 provide the required global IoT connectivity to such a staggering number of “things”. On p24 it is – justifiably - stated that most massive scale deployment of IoT applications, however, requires low-cost devices that communicate infrequently, with low data rate, and low energy consumption ….. This is where low-power wide area (LPWA) networking technology is needed. A clarifying discussion would be relevant and useful.

-          It is mentioned the 4G is ‘the latest’ technology for mobile communication; this is followed by a description of 5G qualities (p24).

-          It is mentioned 4G includes HSPA+ - it is an enhancement of 3G

-          5G will also enable new use cases and mobile communication requirements beyond 4G cellular networks  - no discussion of which cases…(p25)

-          5G may be able to meet the QoS requirements of basic XR services or autonomous robotics, it will be unable to meet the QoS requirements 1040 of higher data rates (e.g., greater than 100 Gbps) (p 26): It is commonly agreed that he average 5G speeds range from 75 – 400 Mbps with top speeds going up to 1 Gbps.

It not convincing to include the remark in 2023, that By 2020, it is projected that….

In the conclusion it is mentioned that several challenges and considerations need to be addressed to realize the potentials of IoTs for smart cities; however these are not discussed or mentioned in the paper. This would be useful.

Comments for author File: Comments.pdf

Author Response

I would like to thank you for your valuable comments.

we have made all the required and recommended changes. 

1. we added a new section related to the smart city evaluation metrics and summarize them in 8 tables for all 8 cities.  
2. After the evaluation of the smart cities, The challenges to implementing the smart cities are discussed as well as recommendations to overcome these implementation challenges. 
3. we removed multiple sections as they were irrelevant to the main focus of the paper and keep only the sections that are most relevant to the smart city applications.  
4. Regarding the communication technologies, we adjusted the 4G section, 5G section, and the LPWAN techniques and summarize their features in Table # 1.  
5. Challenges have been addressed in a separate section and recommendations to solve the challenges are also discussed.

Thank you 

Round 2

Reviewer 1 Report

The paper has been improved. In the following some minor comments:

- In table 1 correct LORAWAN --> LoRaWAN

- I suggest to remove subsections only composed by 3-4 lines of text. Reorganise contents in order to use in example a bullet list.

- text in Figure 5 is not readable

I suggest a last final revision to remove possible typos

Author Response

We would like to thank you for your comments,

1. We change LoRaWan to LORAWAN.
2. We have improved Figure # 5 to make it readable.
3. We removed/improved some of the short sections.

Thank you

 

 

Reviewer 2 Report

Significant improvements; comments addressed adequately.

Section on communication technologies is still a bit weak, but acceptable.

Author Response

We would like to thank you for your comments.3

We add a 6G section in the smart city communications systems.

Thank you