# Advancing Digital Twin-Based Collision Avoidance:
## 5 Discussion  
In conclusion, this study introduces a theoretical approach to define the performance level of wireless safety functions in industrial settings. Nevertheless, it is crucial to recognize the inherent simplifications in our method, as it assumes that packet loss rates are a primary measure of system performance. The dynamic nature of real-world warehouses, e.g., constant changes such as goods rearrangement, challenges the accuracy of this simplified metric. Our in situ measurement study, validating the proposed method in a practical safety system for forklift trucks, underscores the necessity for a more nuanced examination of wireless communication in complex environments. While the theoretical framework holds value, it should be expanded to account for the dynamic nature of warehouses, accommodating fluctuations that may impact packet loss rates and, consequently, the precision of performance-level assessments. Furthermore, specific wireless system characteristics, including factors like reflections not addressed in our simplified model, add complexity to the real-world performance of collision avoidance systems. Future research should broaden the evaluation scope to include these additional influencing factors for a more comprehensive understanding of wireless safety systems. Additionally, it is crucial to recognize that reliability assessments should not be confined solely to burst-like packet loss scenarios. In safety-critical applications, factors such as positioning inaccuracies and varying packet loss rates, not necessarily stemming from burst events, must be thoroughly investigated. These factors, integral to the real-world complexities of industrial environments, significantly influence the overall performance and safety of communication networks. In summary, our exploration reveals that prominent standards such as ISO IEC 62061 [17], ISO 13849-1 [18], 26262 [28], and IEC 61508 [29] generally lack specific criteria tailored to wireless systems. These standards predominantly emphasize the functional safety of electrical, electronic, and programmable electronic systems without explicitly addressing the unique considerations of wireless communication. To date, there have only been a few examples of safety-oriented radio systems, such as remote controls for cranes, which are typically specified to performance level C (cf. EN 13849-1). However, in these cases, the functionality often limits itself to the \"stop\" condition as a safe state. In the context of collision avoidance systems, though, such a state is not feasible. In these systems, vehicles must remain maneuverable in the event of an incident and cannot transition into a complete stop. The lack of specific guidelines for wireless systems within existing norms emphasizes the necessity for a dedicated framework to thoroughly evaluate safety aspects in wireless applications. With industries incorporating wireless technologies into safety-critical processes, there is an escalating need to establish precise criteria and guidelines tailored to address the unique challenges presented by wireless communication. This study establishes the groundwork for further research endeavors aiming to bridge the gap between theoretical models and the intricate realities of industrial environments. Enhancing the method to incorporate the dynamics of warehouses and considering broader influencing factors will contribute to more practical and robust conclusions, facilitating the secure implementation of wireless technologies in safety-critical applications within the evolving landscape of Industry 4.0. Conceptualization, C.M., S.U. and J.T. ; methodology, S.U. ; software, C.M. and S.U. ; validation, C.M., S.U. and J.T. ; formal analysis, C.M. and J.T. ; investigation, C.M. and S.U. ; resources, C.M. and S.U. ; data curation, S.U. ; writing--original draft preparation, C.M., S.U. and V.K. ; writing--review and editing, C.M. and J.T. ; visualization, C.M. and S.U. ; supervision, C.M. ; project administration, C.M. ; funding acquisition, A.L.