Spectrum allocation strategy in flex-grid optical networks: Signal transmission performance analysis

Abstract

Flex-grid optical networks have evolved as a promising solution for future optical transmission systems. In these networks, a spectrum allocation scheme is considered as one of the key research topics, since it is different from that in current fixed grid network. In this paper, we report on spectrum allocation strategy for a mixed 40/ 100/400 Gb/s system when considering signal transmission performance. Three key issues could be found based on the simulation results. First, with power balancing, the spectrum grouped scheme shows a similar transmission performance as the ungrouped one; thus the grouped scheme can be adopted for lower fragmentation. Second, the performance difference increases for the power unbalanced scenario, which indicates the necessity of power balancing in a flex-grid network. Last, it is found that placing 100 Gb/s PDM-QPSK signals as neighbors shows the best performance regardless of the line rate of the tested signal.