Spectrum continuity based routing algorithm for flexible grid optical networks

Spectrum-sliced elastic optical path networks (SLICE) can maximize spectral resource utilization by using a fine granular spectrum range unit, called frequency slot, and allowing that multiple slots be assigned to lightpaths. The Routing and Spectrum Assignment (RSA) algorithm has a direct influence on the spectral resource utilization. We propose in this paper a novel routing algorithm, referred to as Spectrum Continuity based Shortest Path (SCSP). The SCSP finds a route with the lowest cost based on information of the link length and spectrum continuity. In all simulations, some effects of physical layer are considering as ASE noise, optical amplifier gain and ASE saturation in the amplifiers. The modulation formats are selected during the RSA process to optimize the spectrum resource utilization. We compared the performance of our proposal through simulation with the Shortest Path (SP) and Minimum Hop (MH) routing algorithms for three different network topologies.