# 5G-MEC Testbeds for V2X Applications
## 6 Discussion and Conclusions  
5G-MEC solutions are proving to be fundamental to delivering high-latency applications with strict requirements and improving the user experience. MEC technology is a value-added service for MNOs and user application developers and MEC solutions are increasing their commercial importance. However, there are research and practical development gaps between the ETSI-defined deployment model and the end solutions. The commercial or community solutions for the MEC system building blocks are incomplete and some critical issues remain:  
1. How can open source 5G-MEC tools/platforms be integrated to create 5G-MEC testbeds or run experiments? 2. Are there any platforms that can be used to run 5G-MEC V2X simulations/emulsions? 3. Are the different MEC building block tools compatible with each other? 4. What APIs are available and how can interfaces be developed between MEC elements? 5. How can existing open source 5G-MEC testbeds be used to experiment with V2X applications? In this paper, we examined existing 5G-MEC V2X testbeds and categorized them. Most 5G-MEC testbeds are built using open source platforms and tools with specific hardware requirements. However, communities and commercial solutions have been developed based on the various 5G and MEC building blocks, as described in Section 5. Open source communities are actively working to offer support and develop API interfaces for integrating MEC elements. Standard VIMs can be integrated with most open source MANO tools; however, MANO tools lack interface development for MEC platforms and MEC platform managers. To facilitate the development and testing of 5G-MEC scenarios, the ETSI created an MEC sandbox solution that enables user application developers to experiment with the existing 5G-MEC environment. This sandbox solution simulates the 5G-MEC environment and allows developers to gain a better understanding of the ETSI-defined MEC services. The MEC system is divided into building blocks according to their functionalities. Scientific communities are working on each building block separately, which may shed light on issues such as compatibility. The ETSI defined the interfaces between the building blocks of the MEC system and presented their definitions and the REST API model. However, the development of the interfaces by the communities is still ongoing and needs to be completed. In this paper, we examined and presented the existing open source 5G-MEC testbeds, some of which can be replicated and some of which can be used for running experiments. For replicating a 5G-MEC testbed for V2X application integration, one can use a SUMO simulator or access a smart highway V2X testbed. The architectural approaches presented in [106; 107; 108] include programmable edge-to-cloud virtualization, cloud-to-edge meta-operating systems, and ML-assisted applications, which aim to minimize the amount of data transferred between the cloud-edge-IoT continuum. This is crucial for developing efficient and scalable systems. However, the surveyed testbeds face several challenges in supporting and testing future data-intensive applications and IoT-based systems that run at the far edge. These testbeds offer limited storage capacities and finite processing capabilities for end-users and cannot easily integrate novel 5G-V2X wireless access solutions, such as NR-V2X, which are able to satisfy the requirements of automotive applications. In general, the 5G-MEC and 5G-MEC-V2X testbeds can provide a flexible platform and integration to potentially enhance the solution, which involves complexity and compatibility issues due to their adaptability and the need for more standardization. Finally, these testbeds do not natively integrate AI/ML, which are now mature enough to provide efficient solutions for complex optimization and prediction problems necessary to improve the orchestration and network automation functions of beyond-5G systems. Conceptualization, P.V.W., R.G.G., and G.N. ; investigation, P.V.W. ; resources, P.V.W. ; writing--original draft preparation, P.V.W.