Transparent heterogeneous terrestrial optical communication networks with phase modulated signals

Abstract

This thesis presents a large scale numerical investigation of heterogeneous terrestrial optical
communications systems and the upgrade of fourth generation terrestrial core to metro legacy
interconnects to fifth generation transmission system technologies. Retrofitting (without changing infrastructure) is considered for commercial applications.
ROADM are crucial enabling components for future core network developments however
their re-routing ability means signals can be switched mid-link onto sub-optimally configured
paths which raises new challenges in network management. System performance is determined by a trade-off between nonlinear impairments and noise, where the nonlinear signal distortions depend critically on deployed dispersion maps. This thesis presents a
comprehensive numerical investigation into the implementation of phase modulated signals
in transparent reconfigurable wavelength division multiplexed fibre optic communication
terrestrial heterogeneous networks.
A key issue during system upgrades is whether differential phase encoded modulation
formats are compatible with the cost optimised dispersion schemes employed in current 10 Gb/s systems. We explore how robust transmission is to inevitable variations in the dispersion mapping and how large the margins are when suboptimal dispersion management
is applied. We show that a DPSK transmission system is not drastically affected by
reconfiguration from periodic dispersion management to lumped dispersion mapping. A novel DPSK dispersion map optimisation methodology which reduces drastically the optimisation parameter space and the many ways to deploy dispersion maps is also presented. This alleviates strenuous computing requirements in optimisation calculations. This thesis provides a very efficient and robust way to identify high performing lumped dispersion
compensating schemes for use in heterogeneous RZ-DPSK terrestrial meshed networks with ROADMs. A modified search algorithm which further reduces this number of configuration combinations is also presented. The results of an investigation of the feasibility of detouring signals locally in multi-path heterogeneous ring networks is also presented.

Date of Award	31 Oct 2012
Original language	English
Supervisor	Sergei Turitsyn (Supervisor)