Date Added: Aug 2012
Current optical transport networks use optical channel carriers (wavelengths) that are defined and constrained by a fixed ITU-T Dense Wavelength Division Multiplexing (DWDM) grid. Such a grid is not adapted to high data rates (beyond 100 Gb/s) and is inefficient when a wavelength is assigned to a low-rate optical signal. Consequently, the ITU-T is updating the set of DWDM reference frequencies with the inclusion of a smaller channel spacing (e.g., 6.25 GHz) while allowing the allocation of frequency slots, that is, variable-sized frequency ranges composed of a number of slices. In this paper, the authors propose the design, implementation, and experimental validation of a Generalized Multi-Protocol Label Switching/Path Computation Element (GMPLS/PCE) control plane for such flexible optical networks, using optical Orthogonal Frequency Division Multiplexing transmission technology, given its unique flexibility, bit-rate/bandwidth scalability, and sub-wavelength granularity.