Fragmentation-Aware Routing and Spectrum Allocation Scheme Based on Distribution of Traffic Bandwidth in Elastic Optical Networks

Empowered by multirate transmission and bandwidth-variable switching technology, elastic optical networks (EONs) enhance spectrum utilization efficiency and increase network capacity to satisfy the rapid growth of Internet traffic. Routing and spectrum allocation (RSA) is one of the key elements in realizing EONs. However, previous RSA schemes with superior performance have had the drawback of high computational complexity. In this work, we focus on achieving superior RSA performance with reduced computational complexity. We first propose a dynamic network resource evaluation method that takes into account both the distribution of traffic bandwidth and the spectrum blocks' carrying capability. Based on this, we introduce traffic-based fragmentation-aware concepts into the RSA steps. In the routing step, we propose a low-complexity fragmentation-aware load-balanced shortest path routing scheme and a modified fragmentation-aware load-balanced k-shortest-path routing scheme. In the spectrum allocation step, we propose an efficient traffic-based fragmentation-aware spectrum allocation scheme. Simulation results prove that the proposed RSA schemes can reduce the computational complexity significantly and provide network accommodation that is comparable to and traffic blocking probability that is similar to existing dynamic RSA schemes.