ABSTRACT
The performance of the elastic optical network (EON) depends on its network and node architectures. This chapter presents the architecture of the EON and its operation principle. Bandwidth-variable transponders (BVTs) are used to tune the bandwidth by adjusting the transmission bit rate or modulation format. BVTs support high-speed transmission using spectrally efficient modulation formats, e.g., 16-quadrature amplitude modulation (QAM), with 64-QAM used for shorter distance lightpaths. The SBVT architecture was introduced in order to support sliceability, multiple bit rates, multiple modulation formats, and adaptive code rates. The chapter discusses various node architecture, which are the building blocks of spectrum efficient EONs. The broadcast-and-select architecture has been used to determine the elastic optical node architecture that uses spectrum selective switches. The spectrum routing node architecture is being designed to overcome the problems with the broadcast-and-select node architecture. The bandwidth-variable crossconnects is used to allocate an appropriate-sized crossconnection with the corresponding spectrum bandwidth to support an elastic optical lightpath.
