The future of 5G-A networks hinges on the seamless integration of diverse communication infrastructures, including terrestrial, satellite, and airborne systems. This paper explores the concept of a converged network architecture designed to provide ubiquitous, high-capacity connectivity in both urban and remote areas. By combining traditional cellular networks with non-terrestrial networks (NTN) such as Low Earth Orbit (LEO) satellites and unmanned aerial vehicles (UAVs), a unified communication framework can be realized. We analyze the technical challenges involved in this integration, including spectrum sharing, handover management, and interoperability across different platforms. Additionally, we examine the role of AI-driven network management and dynamic resource allocation in ensuring seamless connectivity across these heterogeneous systems. The paper also discusses potential use cases, such as global broadband coverage, emergency response, and IoT applications, illustrating how a converged network architecture will support the next generation of communication services.