To resolve the tension between increasing data demands and aging infrastructure, building automation must undergo a paradigm shift—the migration from fragmented serial fieldbuses to a unified, IP-based single-pair Ethernet (SPE) architecture. The proposed answer is not replacement of certain network elements, but instead an evolution of the network reach. A modern, future-proof building uses a hierarchical Ethernet architecture:

• The IP Backbone (The Core): High speed, multi-pair gigabit Ethernet acts as the robust highway for the data in the building, connecting building management system (BMS), cloud servers, and floor-level distribution switches.
• The SPE Extension (The Edge): T1L and T1S Ethernet act as the capillaries that extend this network architecture directly to the most granular devices. Instead of going through a gateway that translates IP to a slow serial protocol, the data flows smoothly from the sensor to the core, and visa-versa, as standard Ethernet packets.