Evaluations of transponder bank size and network performance for CD-ROADMs

We evaluate static ligthpath blocking performance under the different transponder (TP) bank sizes, to optimize the TP-bank size (i.e., number of transponders used) in colorless/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 Two TP-bank architecture of ROADM and introduce an integer linear programming model to study the different number of TPs used. To achieve scalability, we develop an efficient heuristic algorithm. Simulation results show that the number of TPs in standby bank can be reduced to 37.5% of that in the active bank, where TP number is same as the number of the wavelengths in one fiber link.