Integrating LoRa-Based Communications into Unmanned Aerial Vehicles for Data Acquisition from Terrestrial Beacons
Round 1
Reviewer 1 Report
This paper contains very general and already pubished topic. The work includes very poor analysis and graphical results. In current research work the LoRa technology is evaluated in detail analytically and theoritically. This work lacks of novelty and mathematical background.
Author Response
We appreciate the time and effort you have put into reviewing the article and appreciate the work you have done. Below we respond to each of the questions raised.
Point 1: This paper contains very general and already pubished topic. The work includes very poor analysis and graphical results. In current research work the LoRa technology is evaluated in detail analytically and theoritically. This work lacks of novelty and mathematical background.
Response 1: The aim of the paper is to propose a novel gateway between isolated sensors and a central system using LoRa. Our intention wasn’t to analyze nor improve LoRa technology, since as reviewer has commented, this work has been performed in current research. Our approach has been focused on developing a solution to those environments where sensors location is a real problem due to poor or null communication coverage. Although some works have been published dealing with UAVs and LoRa, and most of them have been referenced in the introduction section of the paper, our work not only proposes an approach to communicate with isolated sensors, but also approaches the development of a new beacon to combine different type of sensors, integrates novel sensors to the system (e-noses) and, applies machine learning algorithms to extract information. The real novelty of our work is to combine all these aspects in a single system. According to the scope of Electronics, its aim is to publish experimental or theoretical works, and we really think our work fits in this first classification. Following this idea, there can be found papers recently published in this journal dealing only with experimental approaches with no mathematical background provided. Some examples of experimental works recently published are the followings:
- Lin, T.-L.; Chang, H.-Y.; Wang, Y.-H. A Novel Unmanned Aerial Vehicle Charging Scheme for Wireless Rechargeable Sensor Networks in an Urban Bus System. Electronics 2022, 11, 1464. https://0-doi-org.brum.beds.ac.uk/10.3390/electronics11091464
- Li, C.; Chen, H.; Xiong, Y.; Chen, Y.; Zhao, S.; Duan, J.; Li, K. Analysis of Chinese Typical Lane Change Behavior in Car–Truck Heterogeneous Traffic Flow from UAV View. Electronics 2022, 11, 1398. https://0-doi-org.brum.beds.ac.uk/10.3390/electronics11091398
- Alhussan, A.A.; Al-Dhaqm, A.; Yafooz, W.M.S.; Razak, S.B.A.; Emara, A.-H.M.; Khafaga, D.S. Towards Development of a High Abstract Model for Drone Forensic Domain. Electronics 2022, 11, 1168. https://0-doi-org.brum.beds.ac.uk/10.3390/electronics11081168
- Sastre, C.; Wubben, J.; Calafate, C.T.; Cano, J.-C.; Manzoni, P. Safe and Efficient Take-Off of VTOL UAV Swarms. Electronics 2022, 11, 1128. https://0-doi-org.brum.beds.ac.uk/10.3390/electronics11071128
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors should better customize and improve their figures
Author Response
We appreciate the time and effort you have put into reviewing the article and appreciate the work you have done. Below we respond to each of the questions raised.
Point 1: The authors should better customize and improve their figures.
Response 1: Figures 7,8 and 9 have been updated with higher quality.
Author Response File: Author Response.pdf
Reviewer 3 Report
In this paper, the authors developed a remote sensing system based on IoT, including an electronic nose sensing module, LoRa-based air-ground communication module, and data warehouse module. The organization of this paper is good. Yet there are some questions that may benefit the quality of this paper.
1. The contribution of this paper is not highlighted. The authors claimed a novel system composed of a heterogeneous sensors network (lines 84-85). However, only one sensor type was developed in the system. The authors should have specified the challenges in developing a heterogeneous sensors network and showed the outcome of this development.
2. The authors used a neural network for the electronic nose. However, the performance of the algorithm is not verified.
3. The reviewer is not very sure what the authors want to present in section 3.2.
4. Figures 7 to 9 are not clear enough. Please use figures with higher resolutions.
5. Line 170: Please double-check the config of the battery
Author Response
We appreciate the time and effort you have put into reviewing the article and appreciate the work you have done. Below we respond to each of the questions raised.
Point 1: The contribution of this paper is not highlighted. The authors claimed a novel system composed of a heterogeneous sensors network (lines 84-85). However, only one sensor type was developed in the system. The authors should have specified the challenges in developing a heterogeneous sensors network and showed the outcome of this development.
Response 1: Thank you for your comment, as you have noted the work has focused on the ability of the system to maintain communication with an isolated beacon. Each beacon is made up of several sensors that can even be different thanks to the possibility of connecting them via bluetooth with the beacon itself. In this sense, the article shows a case as an example with an electronic nose. The UAV allows communication with these beacons and although the work has focused on supporting the communication of one beacon, the expansion to several beacons forming a heterogeneous network of sensors is simple, it would be enough to place new beacons in different positions and plan routes of UAVs passing through each position. The paper have been updated with this information (lines 290 – 294).
Point 2: The authors used a neural network for the electronic nose. However, the performance of the algorithm is not verified.
Response 2: As the reviewer comments, the performance of the neural network algorithm has not been included, but it has already been calculated using the validation data set obtained in the laboratory tests. A success rate of 98.072% is achieved in the classification process. This information is added to the document on lines (208-209).
Point 3: The reviewer is not very sure what the authors want to present in section 3.2.
Response 3: Section 3.2 presents the data that have been obtained using the electronic nose when it is exposed to the three different compounds considered in the article (hydrogen peroxide, ethanol and clean air). The data obtained by the different sensors of the nose is shown in each figure (7,8 and 9). This information is important because it will be sent through LoRa and the UAV to the central system so that it can be processed by applying machine learning algorithms and thus be able to detect dangerous situations.
Point 4: Figures 7 to 9 are not clear enough. Please use figures with higher resolutions.
Response 4: Figures 7,8 and 9 have been updated with higher quality.
Point 5: Line 170: Please double-check the config of the battery.
Response 5: Thanks for the correction, the real value is 3-cell and 5000 mAh. Line 168 of the paper have been updated.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I did not find any improvment from previous version. The main concern to estimate the performance of UAV communication system, it is important to analyze the mathematical modeling and validate the proposed mechanism analytically. Without detail mathematical background the proposed system can not be evaluated efficiently. So, from my point of view the paper must be improved by evaluating the analytical approach, and compare the proposed work with published work.
Author Response
LoRa has been rigorously analyzed with regard to its functionalities and applications in previous works. According to the characterization of LoRa communication recently published [1], this paper applies this model to support UAV-beacon communication. All the information about the mathematical model of LoRa communication can be evaluated accesing to this work. The aim of our paper is not to provide any novelty to LoRa mathemathical model, but apply it in a real scenario where communcation coverage is not guarantee. According to the scope of Electronics journal, experimental works are considered, and this is reason why this paper is proposed.
[1] Haritsa, T.R., Yashu, B.M., Kumar, U.V. et al. Mathematical Characterization and Simulation of LoRa. Wireless Pers Commun 115, 1481–1506 (2020). https://0-doi-org.brum.beds.ac.uk/10.1007/s11277-020-07638-y
Author Response File: Author Response.pdf
Reviewer 3 Report
I suggest that the authors highlight the contributions in the introduction. There's no 3.1 under section 3.
Author Response
Thank you for your comments, the enumeration has been updated and as you suggests, the contributions of the paper have been highlighted in the introduccion section (lines 85-88).
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
Thanks
