This is the context for the second edition. It is designed to build on the foundations
laid out in the first edition while reflecting the new developments of the past 9 years:
a maturing underlying technology, new tools for network control, and a recognition of
the latest directions of optical network deployment and research. These new directions
include cost-effective metropolitan area network architectures tailored to the strengths of
current optical transmission and switching equipment, passive optical networks to bring
high-speed access to the end user, hybrid optical/electronic architectures supporting the
merging of multiwavelength and Internet technologies, and networks of the future based
on all-optical packet switching.