A study of Reactive Spectrum Defragmentation Approaches in Elastic Optical Networks

Abstract

Spectrum Fragmentation is one of the main factors affecting the efficiency of the Elastic Optical Netwoks (EON) [3], causing the rejection of connection request due to the continuity and contiguity constraints [3]. The Defragmentation Problem is being studied in the literature, and two different approaches were presented: proactive (it takes evasive action to avoid spectrum fragmentation) and reactive (the defragmentation it’s triggered when a connection request will be rejected). In this work we study the different Reactive approaches found in the literature, to analyze and compare their performance in a specific scenario and evaluating the effects of the defragmentation on the Routing and Spectrum Assignment (RSA) algorithms.