OPNET University Program

University: Fondazione Ugo Bordoni (FUB)
Name of sponsoring Professor: Francesco Matera
Department: Next Generation Networks

FUB made numerical investigation on the European transport network, assuming a traffic matrix that takes into account the characteristics of the main cities, and nx40 Gb/s SDH WDM transmission. We used Transport Planner for wavelength and path assignment starting from an assigned fibre topology defined in the framework of the E-Photon/One EU project. First we assumed 3R regeneration every 500 km and we found the wavelength assignment according to OPNET CODE. In a second step, we used a FUB code that permits to evaluate optical WDM system performance, based on the split-step method (that takes into account all fibre impairments as chromatic dispersion and nonlinear effects); such a code permitted to optimize the transmission performance and to evaluate the maximum transmission distance for each channel. This way we were able to increase the maximum transmission distance (for an instance by using dispersion management with prechirp) and to avoid the use of 3R regenerations. In a third step we use OPNET to design the links that can be switched off as a consequence of a traffic reduction during the day. Such a topic was studied to evaluate the energy saving for traffic reduction.

By means of OPNET we studied the first network configuration in a VPLS environment trying to reproduce the FUB GMPLS test bed that consists of 4 core routers and three edge routers linked with fibre optic GbE transmission. We still have some problems to compare simulation and experimental results for restoration procedures based on VPLS.

We are studying the network evolution based on the use of Carrier Ethernet. In this environment, by means of OPNET, we investigated on the possibility to have a whole backbone network only based on GbE with restoration processed based on MPLS techniques. We showed that by means of MPLS we can achieve restoration times faster than in SDH techniques, also for multiple failures as in the case of disaster events.

We investigated on the management of QoS in WIMAX access connected to the optical backbone networks and we showed how to achieve End-to-End high QoS also in conditions of strong congestion both in the core and in the access.