Energy Optimized Cross-Layer Routing Protocol for Underwater Acoustic Sensor Networks

Underwater Acoustic Wireless Sensor Networks (UAWSNs) are characterized by severe bandwidth limitations, high propagation delay, dynamic topology, and constrained battery resources. Channel-Aware Routing Protocol (CARP) improves reliability through link-quality-based forwarding; however, it generates periodic traffic irrespective of environmental events, leading to excessive energy consumption. This paper proposes an Energy Optimized Cross-Layer Routing Protocol for Underwater Acoustic Sensor Networks (EO-CLR) that integrates environmental temperature thresholds into routing decisions. Data transmission is triggered only when abnormal temperature conditions are detected. The proposed scheme is implemented and evaluated using ns-3 with Aqua-Sim-NG. Simulation results demonstrate significant improvements in residual energy, network lifetime, and reduced channel congestion compared to conventional CARP.