A BLE 5.0 Extended Advertising Backscatter with Commodity Devices in Passive IoT Scenarios

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper presents a Passive BLE (PBLE) backscatter communication system utilizing commodity BLE 5.0 radios. Unlike existing systems, which face challenges like short carrier length and limited data capacity, this system overcomes these issues.

Key results include:

-            In FPGA board-level verification, the system achieves impressive performance, with an uplink distance of 10m when the downlink distance is 0.5m.

-            In chip testing, the system demonstrates a 7m uplink distance with a downlink distance of 1m.

-            The system operates at remarkably low power consumption, with a base-band power consumption of only 2μW and a total power consumption of 10μW.

-            This system eliminates the need for costly specialized RF sources.

-            Compared to existing BLE backscatter systems, the PBLE system significantly reduces frequency shift and increases data carrying capacity, making it a promising advancement in BLE-based passive IoT communication.

Suggested improvements are the following:

Some acronyms are not defined in the introduction (see line 45 & 47)

Utilizing on line 59-60 should be utilizes or remove the ‘that’

Comment more on power consumption? Compared to how much in general?

Other acronyms should be defined in lines 73 & 74.

Attention should be paid to the bibliography to uniformize it.

Correct generate to generates in line 165.

Repetition of the same sentence in lines 173 to 177.

Reference [22] is confusing in line 188.

There are no references to Figure 8 in the text.

The word Figures seems to be in bold in the whole text except for Figure 9 in line 207 and Figure 13 in line 249.

The sentence in line 262 should be rewritten and clarified. Suggestion: “Figure 14 displays the test results of the Bluetooth 5.0 single-tone signal generated by the NRF52832 chip.”

Figure 15 is not easy to read. Furthermore, the axes are not named and the units are not given. The results should be displayed in a clearer manner.

The sentence in line 272 should be clarified. It lacks a verb and does not form a complete thought. Here's a corrected version: “The distance R1 between the transmitter and tag is shown in Figure 13.”

The sentence in line 284 is mostly clear, but it could be improved for readability. Here's a suggestion: “The iPad reads the extended advertising packet with the name 'XDU' using the nRF Connect software. Figure 18(b) displays the software page received by the iPad.”

Figures 18 a and b should be in higher quality to be able to read them, plus, no reference to them is present in the text.

Could the author comment on the impact of the duration length of their system compared to the state of the art? Could they comment the key points given in Table 1 in the text?

 

 

 

Comments on the Quality of English Language

See comments and suggestions for author

Author Response

The authors sincerely appreciate the professional comments from the reviewer 1. This report provides a detailed response to the comments by the reviewer 1, seen attached file. Accordingly, significant improvement was made in the manuscript to address these points. The changes made in the revised manuscript are highlighted in yellow.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper introduces a passive BLE (PBLE) backscatter communication system leveraging commodity BLE 5.0 radios, offering a promising approach to low-power communication. The experimental setup and results showcased in the paper are intriguing, providing valuable insights into the feasibility and performance of the proposed system. However, there are some notable issues that need to be addressed before considering the paper for publication. Specifically, further clarification is required regarding certain technical aspects to ensure reliability of the findings. Additionally, enhancing the discussion on the limitations and potential applications of the proposed system would strengthen the paper's contribution to the field. 

1) In my view, the problem addressed by the authors is not clearly described in the article. The presentation of sections 2 and 3 is very confusing. They focus on aspects of lesser relevance to the work (e.g., balancing of 0s and 1s, transmission frames, etc). Additionally, the article does not clearly present the contribution of the paper or the pros and cons of the proposal.

2) The article lacks a review of related works. This hinders the correct assessment of how the article fits into the literature.

3) In my opinion, despite the authors mentioning the contribution of the article, upon reading it, I cannot identify an algorithm, a method, or a technique introduced innovatively by the manuscript. The authors should present more clearly what the truly innovative artifact brought by the article is.

4) Some figures are not mentioned or explained in the text. For example, Figure 6 should be better discussed in the text, including making comparisons of its differences with Figure 4. The authors should present in the text the particularities shown in each figure, for example, the meaning of the axis and the curve shown in figure 14 is not properly introduced, neither in the text nor in the figure itself.

5) I get the impression that the results of the article are underexplored. New results should be added to better explore the proposal of the article, or the authors should conduct a more in-depth analysis of the results presented, demonstrating why the results shown corroborate with the effectiveness of the authors' proposal.

6) As it stands, the results section appears to be a series of disjointed results that have not been logically constructed to demonstrate the effectiveness of the proposed approach.

 

Author Response

The authors sincerely appreciate the professional comments from the reviewer 2 . This report provides detailed response to the comments by the reviewer 2 Accordingly, significant improvement was made in the manuscript to address these points. The changes made in the revised manuscript are highlighted in yellow and please find our response to the comments as detailed below:

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I appreciate the authors' efforts in the revised version of the manuscript. In my previous review, I recommended a major revision for this article because I understood that there were some notable issues that needed to be addressed before considering the paper for publication. However, the revised version of the article came with minimal modifications (as can be evidenced by the low amount of content changed by the authors).

 

That being said, I acknowledge that the authors have written responses and modified the article with the intention of addressing my concerns. However, the responses were superficial, and the problems I raised in my initial review report, in my opinion, still persist in the article.

 

In my view, the article remains confusing, lacks a thorough literature review, has unclear contributions, the addressed problem is  presented in a confusing manner, and the results do not clearly argue or demonstrate the advantages and disadvantages of the proposed contribution.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf