ILP model and algorithms for restoration of anycast flows in Elastic Optical Networks

Elastic Optical Network (EON) is a promising technology proposed recently to provide flexible and multi-bitrate data transmission in the optical layer. EONs utilize various modulation format conversion and smaller spectrum granularity, what provide more efficient use of spectrum resources comparing to currently used fix-grid WDM networks. Concurrently, growing popularity of network services provided by Data Centers located in different network nodes and related to cloud computing and Content Delivery Network applications triggers the need to address anycast transmissions as an effective way to improve network performance. This paper focuses on modeling and optimization of anycast flows in EONs in the context of network restoration. Specifically, we formulate an original NP-hard Routing and Spectrum Allocation for Restoration of Anycast Flows (RSA/RAF) problem. In order to solve the problem, we design, implement and evaluate four greedy algorithms and a metaheuristic derived from Simulated Annealing. Extensive numerical experiments prove high practical applicability of presented algorithms.