Cross-Layer Design

The chaptercross-layerdesign is organized as follows. Sections 16.1 to 16.3 constitute the first part of the chapter, namely, physical network layer design. In Sect. 16.1, the physical impairments that affect long-haul optical fiber networks are described. Models for predicting and measuring the quality of transmission (qualityof transmission (QoT)) of network connections are detailed. In Sect. 16.2 various routing and wavelength assignment (routing and wavelength assignment (RWA)) algorithms are presented, some of which only guarantee QoT requirements in the presence of PLIs, while others optimize network performance while taking into account the PLIs. The latter, called PLI-aware algorithms, can significantly improve the performance of the network, i. e., lower the blocking probability. Sample numerical results illustrating the efficacy of cross-layer methods are presented. Section 16.3 addresses the design of protection and restoration techniques for physically impaired optical networks. The survivability of these networks to link failures is greatly enhanced by including information about the PLIs directly within the protection or restoration algorithms. The second part of the chapter, focusing on application-network-layer design, consists of Sects. 16.4 to 16.6. An application-aware metro-access programmable architecture is presented in Sect. 16.4. Resource allocation and path protection based on software-defined networking (software-definednetwork (SDN)) is presented in Sect. 16.5, and Sect. 16.6 presents application-aware converged wireless-access resource scheduling. The chapter is concluded in Sect. 16.7.