## 5 Discussion
Figure 4: Factor of reliability improvement for strategy of cross-domain redundancy with the first algorithm of reserve resources management compared with the first one. The analysis of Figure 5 underscores the substantial benefits of implementing cross-domain redundancy in RED/BLACK communication systems. It shows that the ability to access BLACK domain resources when RED domain reserves are exhausted can dramatically improve overall system reliability, particularly in systems with inherently reliable components. This approach offers a powerful method for enhancing the resilience of critical communication infrastructure without the need for extensive additional hardware investments in the high-security RED domain. The graph illustrates that the channel availability in the RED domain increases when the number of standby radios \(m\) in the BLACK domain increases. At the same time, the availability of channels dramatically increases with the increased reliability of the radio stations. The implementation of the RED/BLACK concept in air traffic management communication systems introduces a robust framework for maintaining the integrity and security of classified and unclassified information. The study of the efficiency of cross-domain redundancy by leveraging BLACK domain resources for bolstering RED domain reliability reveals several key insights. The analysis of a cross-domain redundancy strategy reveals substantive reliability improvements in the high-assurance RED domain by leveraging the BLACK domain's backup resources. The flexibility of controlled resource sharing counters the limitations of isolated RED/BLACK architectures. The Markov model affirms the integration of supplemental BLACK radios significantly enhancing RED channel availability. The reliability factor's mathematical invariance for highly reliable systems cements the approach's applicability across varied network configurations and scales. Additionally, the selective pooling of BLACK backups for RED needs aligns with emerging standards on managing costs and complexities for mission-critical networks through dynamic redundancy. The model-based methodology demonstrates quantifiable reliability gains from such architectures. Currently, aviation communication systems are subject to stringent requirements, including the \"five nines\" availability standard, which translates to a system being operational with a probability of 0.99999 [34]. This level of reliability is critical in ensuring continuous and secure communication channels, which are vital for safe and efficient air traffic management. Modern redundant radio communication channels in air traffic control systems are designed to meet or exceed this availability standard, already providing a channel availability of at least 0.99999 [35]. The approaches to ensuring reliability that are proposed in this article, particularly the cross-domain redundancy strategies, are designed to further enhance this availability. Figure 5: Factor of channel availability improvement for proposed strategy compared with traditional one. As demonstrated in Figure 5, the implementation of the proposed reserve management strategies can lead to a significant increase in the availability of communication channels. The graph clearly shows that these strategies have the potential to increase availability by orders of magnitude, thereby moving beyond the already stringent \"five nines\" benchmark. The approaches presented in the study significantly enhance the reliability and availability of communication channels in aviation systems, making them even more resilient and capable of meeting the highest industry standards. In comparing the results to prior studies, we observe that the proposed strategies for cross-domain redundancy management offer significant improvements in system reliability. For example, unlike traditional approaches that often rely on static redundancy configurations, proposed dynamic resource allocation strategies provide greater flexibility and robustness.