5G NR小型基站的性能規劃與應用集成是現今製造商所關注的，而O-RAN(Open Radio Access Network)便是其中一個重點項目。雖然已經有廠商提出O-RAN小型基站的商用產品，然而不可否認的，O-RAN的開發依舊是困難的。其中一個原因在於O-RAN模擬上仍不完備:即便是O-RAN聯盟的官方release也有尚未完成的部分。這使得在開發上，O-RAN的模擬與現實存在一些差距，即效能的驗證上存在困難。
本文結合既有的、完整的網路模擬器—NS3來補足模擬器的不足。藉由NS3來替代不完備的底層系統，從而進行更加貼近現實的網路環境模擬，可以使xApp、Near/Non-RT RIC這類智能管理的效能評估更加可靠。除此之外，我們也利用NS3的可編輯性，快速而有效的實現了對多種網路環境的模擬，從而證明了這個系統的可行性與可靠性。

The performance planning and application integration of 5G NR small cells is the focus of today's manufacturers, and O-RAN (Open Radio Access Network) is one of the projects. Although some manufacturers have proposed commercial products of O-RAN small base stations, the development of O-RAN is still difficult. One of the reasons is that the O-RAN simulation is still incomplete: even the official release of the O-RAN Alliance has unfinished parts. This makes the O-RAN simulation and reality have some gaps in development, that is, there are difficulties in the verification of performance.
This paper combines the existing and complete network simulator - NS3 to make up for the shortage of the official release. Replacing the incomplete low layer system with NS3 can simulate a more realistic network environment, which can make the performance evaluation of intelligent management such as xApp and Near/Non-RT RIC(RAN Intelligent Controller) more reliable. In addition, we also use the editability of NS3 to quickly and effectively simulate a variety of network environments, thus proving the feasibility and reliability of this system.

[1] Stefan Pongratz, “Open RAN Momentum Is Solid.” [Online]. Available:
https://www.delloro.com/open-ran-momentum-is-solid/
[2] ADLINK Technology Inc., “ADLINK Joins the O-RAN AL-
LIANCE to Accelerate Network Interoperability and Enterprise Migra-
tion to 5G.” [Online]. Available: https://www.adlinktech.com/en/news/
adlink-joins-o-ran-alliance-edge-computing-5g-innovation
[3] o-ran alliance, “About O-RAN ALLIANCE.” [Online]. Available: https:
//www.o-ran.org/about
[4] ns-3, “ns-3 — a discrete-event network simulator for internet systems.” [Online].
Available: https://www.nsnam.org/
[5] 5G-LENA, “5G LENA: 5G-LENA module.” [Online]. Available: https://5g-lena.
cttc.es/
[6] B. Bojovi ́c, S. Lag ́en, and L. Giupponi, “Realistic beamforming design using
srs-based channel estimate for ns-3 5g-lena module,” p. 81–87, 2021. [Online].
Available: https://doi.org/10.1145/3460797.3460809
[7] J. Puttonen, L. Sormunen, H. Martikainen, S. Rantanen, and J. Kurjenniemi, “A
system simulator for 5g non-terrestrial network evaluations,” pp. 292–297, 2021.
[8] H. S. D. S. S. R. B. J. H. R. N. S. S. Y. Solmaz Niknam, Abhishek Roy, “Intelligent
O-RAN for Beyond 5G and 6G Wireless Networks,” may 2020. [Online]. Available:
https://arxiv.org/abs/2005.08374v1
[9] H. Lee, J. Cha, D. Kwon, M. Jeong, and I. Park, “Hosting ai/ml workflows on o-ran
ric platform,” pp. 1–6, 2020.
[10] S. D. S. B. T. M. Michele Polese, Leonardo Bonati, “ColO-RAN: Developing
Machine Learning-based xApps for Open RAN Closed-loop Control on
33
Programmable Experimental Platforms,” jan 2022. [Online]. Available: https:
//arxiv.org/abs/2112.09559
[11] S. Mollahasani, M. Erol-Kantarci, and R. Wilson, “Dynamic cu-du selection for
resource allocation in o-ran using actor-critic learning,” pp. 1–6, 2021.
[12] O-RAN Software Community, “sim-e2-interface.” [Online]. Available: https:
//github.com/o-ran-sc/sim-e2-interface
[13] ——, “ric-app-hw-python.” [Online]. Available: https://github.com/o-ran-sc/
ric-app-hw-python
[14] ——, “Near Realtime RIC Installation.” [Online]. Available: https://wiki.o-ran-sc.
org/display/GS/Near+Realtime+RIC+Installation
[15] ——, “Hello World xApp Use Case Flows.” [Online]. Available: https:
//wiki.o-ran-sc.org/display/GS/Hello+World+xApp+Use+Case+Flows
[16] O-RAN Software Community Documentation, “User-Guide (new).” [On-
line]. Available: https://docs.o-ran-sc.org/projects/o-ran-sc-ric-plt-submgr/en/
latest/user-guide.html
[17] o-ran, “D Release (Jul 2021).” [Online]. Available: https://wiki.o-ran-sc.org/pages/
viewpage.action?pageId=20878658
[18] ——, “E Release (Dec 2021).” [Online]. Available: https://wiki.o-ran-sc.org/pages/
viewpage.action?pageId=41452927
[19] ——, “F release (Jul 2021).” [Online]. Available: https://wiki.o-ran-sc.org/display/
REL/F+Release