Planning and operation of elastic flex-grid optical networks with OFDM variable bandwidth capabilities

Planning and routing in future elastic optical networks will depend on the underlying technology and more specifically on whether standard grid or flex-grid technology will be used. In particular, for dynamic flex-grid networks, resource allocation and routing concern both path establishment and allocation of specific spectrum, which in turn relates to the modulation format of the transmitted signals. Moreover, if variable bandwidth transponders are utilized simultaneous optimization of allocated spectrum and transponder reach should be performed. In this context, all the above should be integrated in both planning and operation phases of an elastic flex-grid optical network. This paper elaborates on a methodology for integrating design constraints into the planning and operation of elastic optical networks and investigates the benefits of flex-grid technology with variable bandwidth OFDM transponders regarding both the blocking performance and spectral efficiency when compared to their standard-grid counterparts.