Performance of transparent optical networks with multiple bandwidth channels

This work presents an analysis of the performance of different routing and wavelength assignment (RWA) and routing and spectrum assignment (RSA) algorithms applied to transparent optical networks supporting channels with multiple bandwidths. Two cases are considered. The first one regards an elastic grid. The second concerns a situation where optical spectrum is divided in blocks that are individually assigned to channels with different bandwidths. A new RSA based on the search for the shortest path with maximum number of free frequency slot units (SPMFF) is proposed. Investigation encompasses three scenarios characterized by different channel connection probabilities. Computer simulation results indicate that first-fit algorithm provides minimum blocking probability for low traffic loads, but is outperformed by SPMFF at higher loads. It is also verified that SPMFF allows the highest network bandwidth occupation, which is of 54% for a blocking probability of 10%.