Latency‐Aware Cross‐Layer Signaling for Energy‐Efficient CRNs

With the rapid development of wireless communication technology and the increasing scarcity of spectrum resources, cognitive radio networks (CRNs) have emerged as an effective means to improve spectrum utilization. This paper investigates the cross‐layer design (CLD) issues in CRNs, exploring the collaborative mechanisms among the physical layer, MAC layer, network layer, and application layer. Initially, a CLD framework considering multiple network layers is constructed. Subsequently, efficient spectrum sensing algorithms for the physical layer, dynamic spectrum access control mechanisms for the MAC layer, adaptive routing protocols for the network layer, and service quality assurance strategies for the application layer are proposed. Against two recent baselines, our CLD delivers 27% higher energy efficiency and 25% lower latency without reliability loss. These gains are attributed to the first four‐layer joint optimization framework, a latency‐aware signaling protocol, and closed‐form Pareto weight selection.