Evolution from Wavelength-Switched to Flex-Grid Optical Networks

Abstract

This chapter reviews the basics of Dense Wavelength Division Multiplexing (DWDM) and shows how this will be superseded by a more flexible use of the optical fibre spectrum, together with more flexible transponders offering multiple bit rates from the same device. The chapter explains the benefits of this new approach and examines the optical filter technology that enables it. Finally, the chapter looks at how networks will migrate towards this new network operating paradigm.