Roadm Architectures and WSS Implementation Technologies

In the last few years the focus has shifted from these large port count optical cross - connects (OXCs) to reconfigurable optical add/drop multiplexers (ROADMs) that are smaller network elements that can efficiently be used to direct wavelength channels in an optical network. This chapter describes several promising ROADM architectures and two degree, multidegree, colorless, and directionless-type architectures. It discusses in detail the wavelength-selective switch (WSS) technologies used to implement the ROADM architectures. The chapter then provides several experimental and commercial ROADM deployments, and concludes with a discussion on future ROADM design and deployment issues. Controlled Vocabulary Terms optical add-drop multiplexers; optical crosstalk; passive optical networks