YBS heuristic for routing and spectrum allocation in flexible optical networks

Spectrum-sliced elastic optical path networks (SLICE) enable flexible bandwidth provisioning, which allows efficient resource utilization and support to heterogeneous bandwidth demands. This makes SLICE a very promising networking architecture. In SLICE, finding a route and a slice of the spectrum is an important design problem, which is known as the Routing and Spectrum Assignment (RSA) problem. In this paper, we present a new heuristic, based on Yen's k-shortest path algorithm and capable of dealing with the traffic heterogeneity to find appropriate sets of paths for each source-destination node pairs to mitigate the bottleneck in the network. The results show that the proposed algorithm reduces the lightpath blocking probability and achieves significantly improved spectrum efficiency. We also analyse the maximum number of alternate shortest paths for minimising the blocking probability.

I. Introduction

The explosive growth of Internet data traffic has been driving an accentuated ever increasing bandwidth demand of the communications systems backbones [1]. According to research conducted by Cisco Systems [2], the global Internet traffic will reach 1.6 zettabytes by 2018 with a growth of 21 percent from 2013 to 2018. This increase is due to applications such as online video, VoIP, online game, Digital TV, Mobile Email and social networking, which have distinct bandwidth demands. Recently, several studies [1], [3]–[7] have pointed out that it is possible to allocate spectrum resources in accordance with the required traffic demand. This new optical network architecture is commonly referred to as Elastic Optical Network (EON), SLICE network, Flexible-Grid Optical Network or Gridless Network.