Spectrum-Convertible BVWXC Placement in OFDM-Based Elastic Optical Networks

Spectrum conversion can improve the performance of orthogonal frequency division multiplexing (OFDM)-based elastic optical networks (EONs) by relaxing the continuity constraint and consequently reducing connection request blocking probability during routing and spectrum assignment process. We propose three different architectures for including spectrum conversion capability in bandwidth-variable wavelength cross-connects (BVWXCs). To compare the capability of the introduced architectures, we develop an analytical method for computing average connection request blocking probability in a spectrum-convertible OFDM-based EON in which all, part, or none of the BVWXCs can convert the spectrum. An algorithm for distributing a limited number of spectrum-convertible bandwidth-variable wavelength cross-connects (SCBVWXCs) in an OFDM-based EON is also proposed. Finally, we use simulation results to evaluate the accuracy of the proposed method for calculating connection request blocking probability and the capability of the introduced algorithm for SCBVWXC placement.