Cross-Layer Design for Cognitive Radio Networks

Nowadays, due to the tremendous growth of wireless communications technologies and multimedia applications, the radio spectrum is starting to be crowded and scarce to meet the continuous growth of frequency requirements. Additionally, interference management is one of the key issues in wireless networks. Therefore, network solutions and evolutions have crucial challenges to overcome the inefficiency in configuring and managing network resources. To optimize wireless network operations and spectrum scarcity, a new networking paradigm, known as cognitive radio networks (CRNs), has been introduced. Due to the limited capabilities of the conventional layered protocol, CRNs adjust layer parameters adaptively according to the spectrum environment and Quality of Service (QoS) requirements. Hence, cross-layer design (CLD) solutions were necessary to allow for improving and optimizing CRNs performance. This chapter provides an extensive and exclusive overview of cognitive networks, CLD methodologies and properties, and cross-layer optimization (CLO) schemes among different layers. Moreover, it presents possible research solutions for cognitive networking. Finally, indispensable highlights of future work research directions are provided.