Networking Benefits of Time Domain Hybrid Modulation Formats in Transparent WDM Optical Networks

Abstract

Rapid increase in data rate intensive applications result in the progressive growth of IP traffic volume, especially in backbone network. To fulfill the requirement of high traffic demand, many operators are searching for the solution to avoid new installment and replacement in the existing network infrastructure. To maximize network capacity or efficient spectrum utilization is one of the best ways to resolve this problem in the existing network infrastructure. Therefore, in this thesis we attempt to evaluate networking benefits of using time domain hybrid modulation formats (TDHMF) over four conventional modulation formats as Binary Phase Shift Keying (BPSK) Quadrature Phase Shift Keying (QPSK)/16 Quadrature Amplitude Modulation (QAM)/64 QAM. To validate the benefits of TDHMF, we consider three different types of fibers that are Standard Single Mode Fiber (SSMF) Non-zero Dispersion Shift Fiber (NZDSF)/ Pure Silica Core Fiber (PSCF). We consider a detailed transmission layer model based on GN model, which includes both; linear and Non-Linear Impairments (NLI). Simulation results are obtained by using Direct Lightpath heuristic (DLH) and greedy electronic IP- traffic Grooming Heuristic using Impairment Aware routing (IA-IGH) on a 37-nodes PAN-EU and 12 nodes Abilene network. The simulation results have shown that TDHMF always performs better than conventional moduv lation formats for all types of fiber in the terms of total network capacity, average bit rate per lightpath, number of blocked request and number of lightpaths. TDHMF with IA-IGH technique gives best performance in all three types of fiber as compared to the PMF with IA-IGH and DLH; TDHMF with DLH. Moreover, sensitivity analysis on average link length and request blocking ratio are performed to prove the networking benefits of TDHMF technique