Resolving Routing and Spectrum Allocation with Optimal Revenue Problem in Spectrum-Sliced Elastic Optical Path Networks

Routing and Spectrum Allocation (RSA) is the key problem in Spectrum-Sliced Elastic Optical Path (SLICE) networks. The difficulty of RSA problem lies on three factors: first, the allocated sub-carriers have to be continuously available along each established spectrum path; second, the allocated sub-carriers have to be consecutive in the spectrum domain as implied by the OFDM technology of SLICE networks; and third, sub-carriers of spectrum paths sharing the same fiber have to be separated by the guard-band that is determined at run-time. As a decision problem, the RSA has been proven to be NP-Complete. In this work, we study an optimization version of the RSA problem with the goal of maximizing the revenue from the accommodated requests. We present Integer Liner Programming (ILP) formulations for the problem, namely Routing and Spectrum Allocation with Optimal Revenue (ROR). Also, we present detailed design of a framework that utilizes techniques of relaxation, decomposition and auxiliary graphs, which can be employed to obtain a near optimal solution that has a per-instance guarantee on the closeness to the optimal solution.