1. Coherent optical fibre networking in the nonlinear regime
- Author
-
Ives, D. J. and Savory, S. J.
- Subjects
621.3 - Abstract
Optical networks form the backbone of modern communications and the Internet and with the ever increasing popularity of video streaming and other high bandwidth applications to ever more connected and mobile devices the amount of traffic is increasing rapidly. It is the overall aim of this work to investigate ways to maximise the efficient use of the backbone optical network infrastructure by considering a holistic approach optimising the whole optical network while considering the transmission impairments that degrade the optical signal. The work begins by considering the dominant linear and nonlinear impairments to optical transmission and develops a simple model of transmission quality based on amplified spontaneous emission noise and nonlinear interference through the Gaussian noise model. The assumptions and accuracy of the model are discussed along with possible future extensions and improvements. The quality of transmission model is used to optimise the signal to noise ratio of signals transmitted in a link and a simple three node network. It is shown that the individual signal launch powers can be adjusted to evenly distribute the signal to noise ratio margin, slightly improving the margin of the worst signal over a uniform launch power. The optimisation is extended to a mesh network where the full optimisation of modulation format, routing, wavelength and launch power are shown to increase the network throughput by upto 100~\% over a fixed modulation format, fixed power, go anywhere optical signal. Finally the use of the quality of transmission model in sequential demand loaded networks is also considered. This work will inform future planned work to include transmission impairments in the abstraction of the optical transport layer to allow for a more robust design of co-existing virtual networks.
- Published
- 2015