An analysis on the network access pricing rules

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Broadband futures : content, connectivity and control

This introduction to the Broadband Futures: Content, Connectivity and Control special issue begins with the claim that we are at the start of a new period of debate and analysis about network infrastructure and use that declares government failure and reinvigorates the drive to a free-market solution in Australia and New Zealand. But questions remain about the effectiveness and social value of network developments, regardless of the degree of government investment and regulation. As canvassed in this introduction, and the articles that make up the special issue, we can only move forward, both in research and practical implementation, if we accept the intricate weaving together of past, present and future interactions between governments, service providers and their consumers in broadband development

Transparent heterogeneous terrestrial optical communication networks with phase modulated signals

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.

Recent developments in neural network PID autotuning

PID controllers are widely used in industrial applications. Because the plant can be time variant, methods of autotuning of this type of controllers, are of great economical importance, see (Astrom, 1996). Since 1942, with the work of Ziegler and Nichols (Ziegler and Nichols, 1942), several methods have been proposed in the literature. Recently, a new technique using neural networks was proposed (Ruano et al., 1992). This technique has been shown to produce good tunings as long as certain limitations are met.

New developments in network forensics - tools and techniques

Network forensics is a branch of digital forensics which has evolved recently as a very important discipline used in monitoring and analysing network traffic-particularly for the purposes of tracing intrusions and attacks. This paper presents an analysis of the tools and techniques used in network forensic analysis. It further examines the application of network forensics to vital areas such as malware and network attack detection; IP traceback and honeypots; and intrusion detection. Further, the paper addresses new and emerging areas of network forensic development which include critical infrastructure forensics, wireless network forensics, as well as its application to social networking. © 2012 IEEE.