Centralized and distributed routing and spectrum assignment schemes for bandwidth-variable optical networks

Flexible bandwidth networking has recently been proposed as a spectrally efficient networking technology that effectively supports dynamically varying traffic demands [1]. This networking technology provides an opportunity to maximize spectral efficiency for each of many arbitrary bandwidth channels generated using one of many possible modulation formats [2]. Path Computation Element (PCE) is first introduced for dynamic routing and spectrum assignment problem in elastic optical network. We proposed three centralized and distributed routing and spectrum assignment solutions. They are Centralized Routing and Distributed Spectrum Assignment (CR+DSA), Centralized Routing and Centralized Spectrum Assignment (CR+CSA) and Distributed Routing and Distributed Spectrum Assignment (DR+DSA). The two centralized proposals both own PCE in its architecture. The performance of three proposed centralized and distributed routing and spectrum assignment solutions have been analyzed and compared. For the experimental evaluation, the performance of Centralized Routing and Centralized Spectrum Assignment is the most adaptable RSA strategy for the whole bandwidth-variable optical networks with dynamic traffic.