11.1 Introduction

The remarkably rapid evolution of the commodity or public Internet contributes to vastly increased expectations for bandwidth on-demand, QoS (Quality of Service) guarantees, gigabyte and terabyte transmission rates, and instantaneous connectivity. Saturated by bottlenecks, the commodity Internet is incapable of provisioning enough bandwidth to support current and leading-edge broadband applications. Demand for high-capacity networks that accommodates the proliferation of new generations of bandwidth-intensive applications and services contributes to the emergence of next-generation networks that feature sophisticated wireline and/or wireless technologies, protocols, and architectures.