Jangir, Mahendra KumarSingh, KaranKhan, TayyabAhmadian, Ali2026-02-152026-02-1520261389-12861872-706910.1016/j.comnet.2026.1120302-s2.0-105027943585https://doi.org/10.1016/j.comnet.2026.112030https://hdl.handle.net/20.500.14517/8767Wireless Sensor Networks (WSNs) are essential in modern applications like environmental monitoring, industrial automation, and security. However, they suffer from pivotal issues of internal threats, congestion, and power constraint, crippling their efficiency and reliability. These threats include data manipulation and congestion, which degrade network performance. Addressing these challenges is crucial to ensure WSNs can maintain reliable operation while effectively managing energy resources and combating malicious activities. Thus, to address these limitations, this paper introduces CATER (Congestion Aware Trust-Enabled Routing), a new trust-based congestion-aware energy-constrained routing protocol for WSNs. CATER's primary contributions are: (1) an end-to-end multi-dimension trust evaluation model consisting of direct trust, indirect trust, energy trust, and an expected positive probability trust model for robust trust estimation; (2) an adaptive congestion control model for dynamically adjusting transmission rates according to real-time network status using the buffer capacity and queue length as variables; and (3) a trust-enabled routing module performing secure and efficient data transmission employing trusted sensor node selection. After trust evaluation, the proposed CATER protocol detects the congestion in the WSN. The congestion is detected using buffer capacity and queue length at a sensor node. Once congestion is detected at a node, the congested node sends a feedback message to the neighbor (source) node to optimize the transmission rate. The proposed CATER protocol always selects energy-efficient and trustworthy next-hop to transfer available data packets toward the sink. MATLAB simulations readily verify that CATER improves energy efficiency by 15.82%, packet drop ratio by 46.95%, and decreases end-to-end delay by 31.81% compared to other state-of-the-art existing routing protocols like CHicDra and SEFR. CATER also improves network throughput and packet delivery ratio (PDR) even in over-loaded and adversarial environments up to 50% adversarial nodes. The findings conclusively demonstrate CATER to be a very effective tool for providing efficient, reliable, and congestion-aware routing for WSNs with profound implications for real-world industrial and IoT applications.eninfo:eu-repo/semantics/closedAccessTrustCongestionRoutingEnergy EfficiencyThroughputDelayArticle