Impairment-aware Virtual Network Embedding Using Time Domain Hybrid Modulation formats in Optical Networks

The rapid increase in bandwidth-intensive applications has resulted in the progressive growth of IP traffic volume, especially in the backbone networks. To address this growth of internet traffic, operators are searching for innovative solutions which avoid new installation and replacement of the existing network infrastructure. In this context, efficient spectrum utilization is one of the key enablers to extract the residual network capacity. This paper proposes an innovative algorithm exploiting electronic traffic grooming and using impairment-aware routing to address the virtual network embedding problem (IA-TG-VNE) in optical networks. We also analyze the networking benefits of using time-domain hybrid modulation formats (TDHMF) over four conventional modulation formats; binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), 16 quadrature amplitude modulation (QAM), and 64 QAM. The analysis is performed on a detailed physical layer model based on the Gaussian Noise (GN) model, which includes the effect of both linear and nonlinear impairments. The simulation results are obtained on realistic network topology: a 37-nodes PAN-EU. The simulation results show that TDHMF always performs better than conventional modulation formats for all types of fiber in terms of total network capacity, the average bit rate per lightpath (LP), number of LPs, and request blocking ratio.