Routing and spectrum assignment algorithm with most fragmented path first in elastic optical networks

Elastic Optical Networks have drawn a lot of attention in recent years because of its ability to transmit different data rates by increasing or decreasing the optical spectrum according to the necessary demand, ensuring a high spectral efficiency. However, establishing and tearing down different connections end up segmenting the spectrum in several small fragments, making it difficult to attend incoming requests. Another recurrent problem in elastic optical networks, called Routing and Spectrum Assignment (RSA), aims to find a path and assign to it a contiguous number of spectrum slots using the smallest possible amount of spectral resources. This paper proposes a novel RSA algorithm to minimize the spectrum fragmentation problem in Elastic Optical Networks by choosing the most fragmented path first. Results obtained through simulations indicate that the proposed algorithm outperforms other conventional algorithms in terms of blocking probability and spectrum fragmentation ratio.