Design and evaluation of elastic optical network with centralized multi-carrier light source

Current optical networks strictly follow the fixed and coarse wavelength grids and channel spacings, which results in low spectrum utilizations and poor supports of high-speed transmission signals such as 400 Gb/s and beyond. This paper presents the design and evaluation of an elastic optical network with a centralized multi-carrier light source (C-MCLS). The C-MCLS generates thousands of optical carriers with uniform and narrow channel spacings. These optical carriers are distributed to network nodes on demand as light sources through elastic ROADMs designed with the carrier-drop function. This paper also studies how channel spacings of optical carriers impact on the network performance under variable traffic demands. We perform both network analysis and simulations to evaluate the network performance of lightpath blocking probability (LP-BP) and spectrum efficiency. Simulation results show that the proposed network with narrow channel spacings greatly reduces the LP-BP and largely improves the average effective spectrum efficiency than the traditional ROADM network. The optimal channel spacing evaluations show that narrow channel spacings such as 6.25 GHz largely improve the LP-BP performance when low bit-rate traffic requests dominate in the traffic model. However, as the high bit-rate traffic requests increase, the performance advantage of narrow channel spacings is gradually disappearing.