Evaluations for transponder configuration in CD-ROADM optical networks using intra-node-contention-free RWA algorithm

We evaluate static ligthpath blocking performance under the different transponder (TP) bank numbers and bank scales, to optimize the TP-bank scale (i.e., number of transponders provisioned) in colorless and directionless reconfigurable optical add/drop multiplexers (CD-ROADMs), while maintaining similar blocking performance as that for a pure contentionless ROADM with sufficient TPs. In this paper, we consider ROADM structure of different bank numbers and scales as well as introduce an integer linear programming model to study the different number of TPs used. To achieve scalability, we develop an intra-node-contention-free RWA heuristic algorithm. Simulation results show that the Two-TP-bank structure can perform as contentionless in practical. In addition, the total number of TPs can be reduced to 68.7% with respect to the maximum TP numbers in the Two-TP-bank structure, which are the product of TP-bank numbers and the wavelength numbers in one fiber link (2×W).