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I am using OPNET for my PhD research work. In the 1st year of the PhD programme I have developed a Power Excursion Aware Routing algorithm, as preliminary research work. I have matured this work recently, and submitted a paper to OFC 2009, that was accepted.
My PhD proposal is to design a GMPLS system for provisioning optical core and access networks for Multicast TV. I will use OPNET to simulate my system.
1. Power Excursion Aware RoutingThe preliminary research work for my PhD was to develop a novel heuristic with the aim of reducing the power excursion problem in optical networks. A brief description follows.
The implementation of all-optical networks needs to take into account the sensitivity of the system to channel power excursions generated by saturated amplifier gain. The sudden disappearance of several WDM channels (due to link failures, for instance), may degrade the performance of the surviving channels. The loss-of-light generates power excursion affecting the BER in channels not directly affected by the fibre cut.
Until now, most of the solutions to mitigate power excursions operate at the physical level. However, these solutions have some drawbacks: they are expensive and can cause significant gain reductions. Cugini et al proved that the 3dB power excursion threshold is exceeded if more than half of the total channels go down in a single link and proposed a Routing and Wavelength Assignment (RWA) policy to mitigate this problem. Hence they solve the problem at the network layer. Nevertheless, their solution has one problem. They propose an ILP formulation for routing avoiding critical links, hence their solution is not scalable.
With this in mind, my preliminary research work was to develop a scalable power excursion aware routing algorithm.
More detailed information can be found in the paper recently accepted for presentation at OFC 2009.
 Filippo Cugini, Paolo Ghelfi, Antonella Bogoni, Luca Valcarenghi, Piero Castoldi, Rodolfo Di Muro, and Bimal Nayar. Rwa for mitigating power excursion eŽects in edfa-based all-optical metro networks. In 33rd European Conference and Exhibition on Optical Communication Proceedings. 2007.
2. Design of a GMPLS system for provisioning optical core and access networks for Multicast TV
proposal is to design a GMPLS system for provisioning optical core
and access networks for Multicast TV. The purpose of this PhD
proposal is to check how Traffic
Engineering can be used in a multicast scenario, to see if we can
improve the quality for some (or even all) IPTV
users (either by reducing viewers, using
different paths, etc.).
For the moment I am not using OPNET for teaching.
F.M.V. Ramos, A. Giorgetti, F. Cugini, P. Castoldi, J. Crowcroft, I.H. White, "Power Excursion Aware Routing in GMPLS-Based WSONs", to appear in Proc. of OFC, 2009
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