Dynamic routing and spectrum assignment algorithms in flexible optical networks: An overview

In this paper, we examine the current research on the dynamic routing and spectrum assignment (RSA) problem in flexible optical networks. The existing RSA algorithms are classified into three main categories: fixed routing (FR), fixed alternative routing (FAR) and adaptive routing (AR). We select the representative algorithms within each category, and briefly introduce their concept, advantage and drawback. Comparison among these algorithms is made in respect of blocking performance, computational complexity and so on.