Cyber-physical production systems (CPPS) require interconnectivity, flexibility, and scalability, demanding high-performance communication technologies. While wireless communication is essential for flexible automation, existing wireless field-level technologies often lack the required deterministic, low-latency connectivity. This paper proposes a Networks-in-Network-(NiN-)architecture integrating specialized wireless subnetworks into mobile communication infrastructures to address these challenges for closed-loop industrial control. An architecture for the integration of subnetworks for closed-loop control of industrial automation processes is developed. The framework is implemented using a low-latency wireless communication technology. Experimental evaluation controlling an inverted pendulum demonstrates stable performance comparable to a wired connection, outperforming a standard WiFi-based approach under network load. The results indicate that minimizing communication jitter is more critical for control stability than minimizing latency. Furthermore, benefits, challenges, and future research directions for the use of NiN are outlined.