Planning of Optical Connections in 5G Packet-Optical xHaul Access Network
Round 1
Reviewer 1 Report
Besides the relevance of the topic, the impact of statistic packet switching and the different requirements of the xHaul depending on the CU/DU/RU split and localization are not considered in the optimization proposed.
Author Response
Thank you so much for devoting your valuable time to review the manuscript. We have provided a detailed explanation of the changes in the manuscript in the pdf file attached.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this paper, the authors study the problem of planning optimal transmission paths in a 5G packet-optical xHaul access network. Specifically, the investigate the questions of selection of routing paths in the network and that of the placement of OADMs onto the paths for traffic aggregation. The goal is that of saving bandwidth/network paths . The optimization problem is formulated as an integer linear programming problem.
Overall, the approaches and results of this paper seem plausible to the reviewer.
On the bibliography, there is a strongly connected line of work which studied rate/bandwidth requirements from the RRUs to the base band unit, as well as coding techniques , from an information-theoretic and communication- viewpoint. See, e.g.,
A. Del Coso and S. Simoens, “Distributed compression for MIMO coordinated networks with a backhaul constraint,” IEEE Trans. Wireless Comm., vol. 8, no. 9, pp. 4698–4709, Sep. 2009.
I. Estella Aguerri and A. Zaidi, "Lossy compression for compute-and-forward in limited backhaul uplink multicell processing", IEEE Trans. on Communications, Vol. 64, No. 12, Dec. 2016, pp. 5227-5238.
S.-H. Park, O. Simeone, O. Sahin, and S. Shamai, “Robust and efficient distributed compression for cloud radio access networks,” IEEE Trans. Vehicular Technology, vol. 62, no. 2, pp. 692–703, Feb. 2013.
Aguerri et al. "On the capacity of cloud radio access networks with oblivious processing", IEEE Trans. on Inf. Theory, Vol. 65, No. 07, July 2019, pp. 4575-4596.
Wang et al. "On the achievability for downlink cloud radio access radio access networks with base station cooperation", IEEE Trans. on Inf. Theory, Vol. 64, No. 08, Aug. 2018, pp. 5726-5742.
L. Zhou and W. Yu, “Uplink multicell processing with limited backhaul via per-base-station successive interference cancellation,” IEEE Journal on Sel. Areas in Comm., vol. 31, no. 10, pp. 1981–1993, Oct. 2013.
The authors should discuss this strongly line of work, and add references to the aforementioned works.
Author Response
Thank you so much for devoting your valuable time to review the manuscript. We have provided a detailed explanation of the changes in the manuscript in the pdf file attached.
Author Response File: Author Response.pdf
Reviewer 3 Report
Presented article titled "Planning of Optical Connections in 5G Packet-Optical xHaul Access Network" is a contribution in the field of optical network transport, namely WDM multiplexing and usage of OADM modules within optical transport. The article proposes optimization solution based on integer linear programming.
The article consists of six chapters. It contains 13 pages of text, including the list of 26 references, 7 figures, 4 tables and 2 mathematic formulas.
The abstract is reasonably extensive and sufficiently explanatory. The list of references is fully sufficient.
The first chapter is broad introduction into optical networks, WDM and OADM systems and xHaul access networks. Second chapter is dedicated to related works in the topic area. In the third part of paper, there is shown transmission model used for further experiments. Fourth part proposes solution to optimization problem in the form of graph, and following integer linear programming problem. It also shows experiments done on two reference networks. In the fifth chapter, there are results of experiments. These are shown in clear and easy understandable tables and graphs. In the last part, there is final conclusion and possible direction of future works.
Regarding of the paper, to the best of my knowledge, I think that the topic of research is actual and proposed solution should work.
In my opinion, the chosen language is at very good level, the paper is easily readable and understandable. All objectives are clearly defined, and the steps during experiments are documented in detail. Considering mentioned I recommend the article for publication in the MDPI Applied Sciences journal.
Author Response
Thank you so much for devoting your valuable time to review the manuscript and for a positive evaluation of our work.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have revised their manuscript in a way that this reviewer finds suitable. Therefore I recommend Accept.
