Spectrum resource assignment method considering adjacent link conditions for AR requests in EON

Abstract

Elastic optical networks (EONs) have attracted attention as a means of accommodating the rapidly increasing traffic in core networks. In EONs, routing, modulation and spectrum assignment(RMSA) algorithm is implemented to flexibly allocate resources to optical paths. However, the application of EONs is limited because of the fragmentation of spectrum resources, which hinders further allocation of resources to new optical paths. Subsequently, the Min-RDDR method has been proposed to allocate resources for advance reservation requests. It defined an evaluation formula for calculating a metric to suppress fragmentation. Herein, we modified the Min-RDDR method and proposed a spectrum allocation method to further suppress fragmentation, wherein resources were considered not only within links but also between adjacent links. The simulation results confirmed that the proposed method causes a 47% reduction of request blocking probability, verifying its effectiveness toward fragmentation suppression.