# Cyber5 Gym: An Integrated Framework for 5G Cybersecurity Training
## 1 Introduction
It fills the gap by (i) offering a hands-on training experience for emulating 5G network environments using open sourced tools such as Open5 GS [15] and UERANSIM [16], along with real-time attack scenarios incorporating defensive strategies, and (ii) enhancing its operational efficiency through the automation and virtualization of its training modules, utilizing Docker for virtualization and Shell scripts for automation of tasks. Additionally, we have deployed our system on Naver Cloud for demonstration. The integration of open-source tools for 5G network emulation, along with the implementation of multiple attack scenarios and their countermeasures, makes our cyber range replicable, extendable, and scalable. 2. Our proposed system offers a cybersecurity training environment that is adaptable for both individual learning and the development of multi-users. The system is designed for a dynamic number of participants, though centralized control is achieved through a master server, which enriches the training process within a managed environment. This system is crucial for conducting synchronized attacks from multiple points and for crafting coordinated countermeasures. This kind of training ground is imperative for equipping cybersecurity experts with the skills necessary to address evolvingchallenges in 5G network security, thereby playing a significant role in bolstering the robustness and defense of essential 5G infrastructures. 3. The Cyber5 Gym testbed is designed to offer the hosts (trainees) a series of realistic 5G network emulations, such as autonomous operational tasks to configure all host networks and execute intricate cyberattack scenarios and their countermeasures. Trainees are exposed to advanced threats as use cases, such as NAS-5G SMC Replay attacks, Denial of Service (DoS), and Distributed Denial of Service (DDoS) attacks. This diversity in attack scenarios equips trainees with a hands-on understanding of cybersecurity threats and their countermeasures. Furthermore, the automation scripts are used to perform autonomous operational tasks such as 5G network emulation and monitoring the log activities of trainees. These scripts are pivotal in enabling the master server to securely connect with individual trainee hosts, thereby facilitating seamless 5G networking across all trainee setups. 4. We showcased a comprehensive evaluation by deploying our framework at Naver Cloud, involving 20 trainees, each of them accessing an emulated 5G network and managing 100 UEs. Our assessment focused on key metrics, including the successful establishment of the 5G network, accurate execution of attack scenarios, and the efficient deployment of countermeasures through automated shell scripts. This evaluation not only validates the effectiveness of the deployment of our framework in real-world conditions but also highlights its potential to significantly enhance the resilience and security of 5G infrastructures through the open-source, replicable, and adaptable foundation of our training system. The structure of the paper is organized as follows: Section 2 delves into the background. Section 3 presents an overview of the existing literature relevant to 5G cybersecurity training systems. Section 4 details the proposed system architecture. In Section 5, we demonstrate the implementation of the proposed system with 5G emulation, attack scenarios, and countermeasures. In Section 6, we assess the Cyber5 Gym framework, focusing on its limitations, scalability, security, and prospective enhancements in 5G cybersecurity training. Finally, Section 7 concludes the paper and outlines future directions.