Joint Offloading and Energy Harvesting Design in Multiple Time Blocks for FDMA Based Wireless Powered MEC
Round 1
Reviewer 1 Report
Interesting work. It would be interesting to see how this algorithm would behave in an actual implementation and if the results from the simulation would still hold true
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The paper addressed the issue of residual energy maximisation in the WP-MEC systems. The authors proposed a joint optimisation technique that combines the convex optimisation technique with the KKT condition and transforms the problem into a univariate contained convex optimisation problem. To solve the problem, the authors proposed a combined method of bisection method and sequential unconstrained minimisation based on RLT.
The authors validated their proposed approach using simulation. The experimental results showed that the results of the proposed technique outperform the existing benchmark schemes for the residual energy maximisation problem. The results not only reduce energy but also prove its efficiency in terms of computation complexity.
I found the paper interesting, well written and the proposed approach was backed up with many analysis and comparisons to the existing techniques. However, the proposed approach needs to be tested in the real environment for full validation. In addition, the conclusion is very limited, I suggest for authors to extend it and also extend future works. Authors need to make sure to eliminate the highlights in the paper, they are distracting the readers.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
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
In this paper authors investigate in computation and Wireless resource allocation under multiple time blocks, to maximize residual energy. The work is done considering devices that will harvest energy from RF.
From the reviewer point of view the RF energy harvesting is interesting conceptually, but the numbers obtained so far from energy perspective are far from being usable in real applications as the scenarios proposed in this paper.
For example, in this recent article,
“Paolini, D. Masotti, M. Guermandi, M. Shanawani, L. Benini and A. Costanzo, "An Ambient-Insensitive Battery-Less Wireless Node for Simultaneous Powering and Communication," 2020 50th European Microwave Conference (EuMC), Utrecht, Netherlands, 2021, pp. 522-525”
You can see some numbers of realistic RF energy transfer, and the numbers obtained are far form thinking on a scenario with task offloading (due to the overhead of communicating data for the offloading).
Authors did not give any realistic number about energy and cost of all the process. Simulation results are fine, but the real scenario perspective is quite important here. I think this is the main problem of this work.
Authors comment that a 300 W RF source is used to transmit power. More consideration should be given again to the feasibility of using such amount of energy in a real scenario.
Minor issue: In the sentence “This paper adopts the Frequency Division Multiple Access (FDMA) protocol to…”, from my point of view, FDMA is a technique, not a protocol.
I think this work lacks of more scientific base considering the application that is targeting. Mathematical work could be correct and results (from authors starting point) can be promising, but the problem is that the starting point is too unrealistic.
Reviewer 2 Report
- Some parts of the paper are not well structured and written,
- More literature review in this area and in the challenges presented should be included.
- Some figures are drawn but they are not explained in detail or cited to them. For instance
Reviewer 3 Report
This article presents a joint optimization framework for wireless power transmission and computation offloading. Although the article is well presented and its technical details are well-described, the novelty of the article is doubtful because the authors published recently the following similar article in Future Internet and they did not explain the novelty of the current article in respect with the published one. In my opinion, the two articles study the same research problem under different setting (TDMA vs FDMA) and the proposed solutions have many similarities and they follow actually the same methodology. Thus, the novelty of the submitted manuscript is weak. I suggest to submit the manuscript as a conference paper in a relative venue.
Li, L.; Xu, G.; Liu, P.; Li, Y.; Ge, J. Jointly Optimize the Residual Energy of Multiple Mobile Devices in the MEC–WPT System. Future Internet 2020, 12, 233. https://doi.org/10.3390/fi12120233
