LAUSR

Elastic optical network (EON) is a promising technology for the next generation of optical transport network. Routing, modulation and spectrum assignment is one of the key issues in EON. In the problem, the constraints of spectrum continuity and contiguity must be satisfied. In this paper, we propose a spectrum assignment policy named minimizing sum of weighted resource reductions ($\boldsymbol {\min \Sigma w\Delta R}$) algorithm. The algorithm includes three contributions: 1) The concept of resource reduction ($\boldsymbol {\Delta R}$) is defined to measure variation of idle resources in a path when a spectrum block is assigned to a connection request, which is combination of changes of continuity and contiguity in the path. 2) When a spectrum block in a path is used, resource reductions in all associated paths rather than only the current path are taken into account. 3) A function of path's hop is used as a weight to adjust the path's impact. Simulations were carried out based on the national science foundation network (NSF-Net) and the pan-European Cost239 network (Cost239) to investigate the performance of the algorithm, by comparing with three well-performed benchmarks. Simulation results show that, when the parameters of the metric are set to appropriate values, the proposed algorithm can significantly decrease blocking probability in both two topologies.