ABSTRACT
Elastic optical networks (EONs) have been introduced to address the issues of the existing scalable wavelength-division multiplexing (WDM)-based optical networks by providing spectrum-efficient and scalable transport of 100 Gb/s services and beyond. An EON has the potential to allocate spectrum to lightpaths according to the bandwidth requirements of clients. This chapter presents the motivation of the EON, introduces its unique concepts and its enabling technology. The WDM-based optical network divides the spectrum into separate channels. The WDM-based optical network requires full allocation of wavelength capacity to an optical path between an end-node pair. However, EONs provide a spectrum efficient bandwidth segmentation mechanism that provides fractional bandwidth connectivity service. EONs combine multiple physical ports/links in a switch/router into a single logical port/link to enable incremental growth of link speed as the traffic demand increases beyond the limits of any one single port/link. Advances in optical transmission techniques and devices have favored the emergence of EONs.
