A routing and spectrum assignment algorithm in elastic optical network based on minimizing contiguity reduction

Abstract

Elastic optical network, due to its flexibility of spectrum assignment, has been the most promising technology in the next generation of backbone transport network. Routing and spectrum assignment (RSA) is one of its key issues. Several RSA algorithms have been proposed in recent years. In the spectrum assignment process, the more contiguous the idle frequency slices, the more likely it is to find available spectrum blocks for connection requests. Therefore, in this paper, we first give the concept of link/path contiguity reduction (LCR/PCR) to express the change of spectrum contiguity on a link/path after a spectrum block is used. Then, we propose a RSA algorithm named Min-PCR-LCR, which always chooses a spectrum block with the minimum path contiguity reduction to a connection request, and if there is a tie, the one with the minimum sum of link contiguity reductions is finally chosen. Simulation results show that the Min-PCR-LCR algorithm can get lower blocking probability than the existing well-performed RSA algorithms.