Optical Fiber Telecommunications VIB: Chapter 18. Advancements in Metro Regional and Core Transport Network Architectures for the Next-Generation Internet (Optics and Photonics)

The increasingly important role of Internet-based, “cloud” service delivery is motivating the evolution of the Internet to a flatter hierarchy of more densely interconnecting networks that shall cost-effectively scale to Zettabytes of bandwidth with improved operational efficiency, under increased traffic variability, and forecast unpredictability. This chapter reviews the implications of this evolution in its underlying metro regional and core transport network architectures, and evaluates the most important innovations in photonics, optical transport, routing, and traffic engineering technologies enabling it. Most notably, 1) a new generation of coherent DWDM systems with more than 2 b/s/Hz spectral efficiency is scaling the existing fiber infrastructure, albeit at a significantly higher proportion, typically more than 50%, of the total transport network cost, while 2) the convergence of IP/MPLS with flexible DWDM promises the most cost-efficient transport evolution, in open architectures that combine advancements in photonics, routing, multi-layer control-plane and management coordination, with interoperability, to improve operation, automate provisioning and restoration, and may optimize network utilization.