A Vehicle–Ground Integration Information Network Scheme Based on Small Base Stations

Round 1

Reviewer 1 Report

The authors have presented a vehicle ground integration information network scheme for EMU based for solving the problem of poor bandwidth in high-speed mobile scenarios. The presented approach by the authors is tested and the experimental results are extracted, which show better signal coverage and capacity in high-speed scenario. The manuscript can be accepted after the following modifications.

 

• Kindly explain more about the operating frequency and bandwidth of the proposed system.
• Provide a brief results or explanations about the effects of the velocity on the presented system.
• Some typos should be corrected in the manuscript. For example, some abbreviations are not expanded at the first seen such as: EMU, CDN, LTE, FR, SS-SINR, SS-RSRP, and etc.
• It is better to not use abbreviations in the title of the manuscript.
• The quality of Figures 11 and 12 should be improved.
• Please use the number of the table instead “following table” in line 104.
• It is written in lines 178 and 179 that “In the 5G era, the frequency band has increased from 1.8 to 2.6 GHz and from 2.3 to 4.9 GHz”. There are several bands in 5G; it should be mentioned that which specific bands are meant by authors.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

• English wording needs an improvement, specially the Introduction. Some expressions are hard to understand ('doppler frequency bias' = 'Doppler shift'?)
• All acronyms should be introduced when mentioned first (i.e. ARPU)
• In the intro, my suggestion is to explain clearly the environment (why do high-speed trains need a solution like this? ,etc.). Perhaps more overview/general papers on mobile communications for railways could be referenced
•  For example "For example, Deutsche Bahn, Moscow Aeroexpress,  Stadler-Newag Konsortium Siedlce have all deployed 2G, 3G, and 4G repeater on the trains to ensure the coverage of 2G, 3G, and 4G networks for their internet operators[8]. The existing European train on-board repeater technology has been relatively mature in 2G, 3G, and 4G FDD systems, but it cannot meet the diversified service operation needs of EMU[9]." --> I don't understand this sentence. This means that Deutsche Bahn has no EMUs? Which is the European train on-board repeater technology? I am not aware of it 
• In Table 1 you provide some figures for the penetration losses but the unit for this is dBm (!!!) which does not represent power loss but... power. This is an error that must be fixed. 
• For that same table, the source for the data is [10]? If so, please include a reference to it in the table caption. If not, please include a proper reference to the source. Please review the paper in order to include missing references. 
• On the other hand, if the paper is focused on 5G, this table should include more frequencies allocated for 5G communications (like 700 MHz or perhaps mmwave, among others) 
• High speed trains run at least at 250 km/h. In China, for example, there are lots of trains running at 350 km/h 
• Equation (2) is one of several path loss models. There are lots of them and some work better in some particular scenarios (cuttings, viaducts, etc.) and some others not. There's a huge complexity that is skipped with no mention at all. 
•  

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Thanks for your response and for following my suggestions. However, the needed changes were major and this second iteration does not fulfill this requirement. 

For example (and this is a minor change) not all the acronyms are introduced the first time they are mentioned. Only the acronym that I put as an example has been taken into account. 

Moreover, I get no answer to my comments 2,3 and 4. 

The novelty, soundness, etc., this is, the overall quality of the paper remains more or less the same as before, so I think that this paper must be rejected. 

 

Author Response

 We thank the reviewer for reviewing our paper and providing helpful comments. According to the comments we received, we have revised our manuscript to address the raised concerns.We appreciate the help and opportunity to significantly improve the manuscript.  The specific responses have been shown in the attachment.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

My previous comments have been addressed