QoT-aware performance evaluation of spectrally–spatially flexible optical networks over FM-MCFs

Abstract

In this paper, we study the quality of transmission (QoT) aware routing, modulation level, and resource assignment problem for transparent flexible optical networks over few-mode multi-core fibers. We consider two three-dimensional resource assignment (3DRA) algorithms, called liberal and conservative, that are compatible with fractional joint switching. The three resource dimensions are core, mode, and spectrum. Furthermore, we analyze two modulation-level selection (MLS) algorithms (one on-line and one off-line) and three path selection algorithms (favoring shortest path, best balanced load, or highest QoT). The results show that the liberal 3DRA algorithm has a similar blocking probability (BP) compared to conservative 3DRA. However, performance metrics such as computation time, optical signal-to-noise ratio (OSNR), and number of required lasers are all improved with conservative 3DRA. Moreover, the BP decreases and the average OSNR increases by applying the on-line MLS algorithm compared to the off-line algorithm. Finally, we use an on-line liberal algorithm with a path selection policy that favors load balancing to generate a solution with the lowest BP.