Ethernet, dense wave division multiplexing (DWDM), passive optical net- work (PON), and data-aware Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) (next-generation SONET) technologies to connect businesses to optical transport for WAN and Internet access. Resi- dential customers will ultimately have access to fiber and intelligent optical-networking gear, but in the near future, customers will have to use DSL, cable, and fixed wireless access technologies to meet their demand for increased bandwidth.5 Optical networking and evolving Ethernet WAN technologies have the potential, at least in principle, to foster changes in network design, services, and economics. New service providers have emerged that deploy both the evolving and the new technologies, and position themselves to deliver new broadband services at the 100-, 1,000-, and 10,000-Mbps range in the metro access/metro core portions of the network, as well as end-to-end over the long haul. We also refer to them as metropolitan area service providers (MASPs) to focus on their role at the functional level. Some MASPs, partic- ularly the ones that have labeled themselves ELECs, may or may not have a future, due to their limited service scope and restrictive architecture. Car- riers with a solid business plan do have a future. Incumbent providers are also looking into new technologies, although they have a major embedded base of previous-generation systems supporting narrowband applications. Figure 1-3 encapsulates some of these needs.7 Figure 1-3 End Customer Requirements: Challenges of today's - Increasingly faster and transparent networks networks. - Reliability and 100% uptime - Low-cost bandwidth only when they need it - Low-cost network services Carrier Requirements: - Higher channel counts >80 As, 25-50 GHz - Higher data rates 10-40 Gbps in LH and ULH; 10 Gbps in metro Longer reach >3500km (ULH) - Less "dumb," static networks Tunable networks - Lower fixed cost of deployment, and decreased complexity in planning and management of ne