ENCORE: an energy-efficient cluster-based multi-hop routing framework for WNSNs in IoNT

The internet of nano-things (IoNT) uses wireless nano-sensor networks (WNSNs) with stringent network limitations for its many applications, such as biological monitoring and environmental sensing. Network lifetime and communication reliability are fundamentally limited by the ultra-restricted onboard energy of nano-sensor nodes and the absence of post-deployment energy replenishment. This study proposes Energy-efficient Network Clustering and Optimized Routing based on Environments (ENCORE), an energy-aware clustering and multi-hop routing framework for dense three-dimensional WNSNs. ENCORE employs topology-adaptive cluster-head selection based on residual energy and sink proximity, together with a structured, sink-oriented, loop-free multi-hop backbone to balance communication load and mitigate premature node depletion. Network behaviour is evaluated using a pulse-oriented nano-communication energy model capturing continuous energy degradation. Simulation results across multiple randomized deployments show that ENCORE improves network lifetime, residual energy retention, and packet delivery compared with Flooding (FLD), LGN, and DEEPNT, achieving up to a 45% lifetime improvement over DEEPNT and nearly a threefold gain over LGN.