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University: Columbia University
Professor: Keren Bergman
Department: Department of Electrical Engineering

Simulation: Cross-Layer Based Networks using OPNET

The goal of our project is to enable cross-layer communications among network layers, with principal focus on the optical physical layer. We endeavor to overcome the current limitations due to the rigid notion of network layering. Within this framework, each layer is designed to provide bare-bones functionality that can be used by the layers above it and essentially simplify operation by hiding lower-layer information. While this construct has led to rapid deployment of protocols, applications, and services readily available in today’s Internet, it creates roadblocks for future networking applications. Our objective is to eliminate this rigidity in the current internet infrastructure by enabling deeper exposure of cross-layer information. The notion of a clean-slate network design with cross-layer optimized protocol stack has been explored to some extent within the wireless networking domain; as such, we plan to investigate the performance of cross-layer communications with an optical substrate using OPNET. In the course of the GENI Project (Global Environment for Network Innovations), we plan to develop the discrete-event network simulator OPNET to enable cross-layer communications, allowing for the simulation of real-time measurement based cross-layer communication within the GENI network. We plan to leverage OPNET's developed bit-error rate (BER) calculation and forward-error correction (FEC) functionalities to provide a means by which performance monitoring measurements can be used for cross-layer communications across network layers. In this way, the BER performance of the egressing packets can be monitored and degraded messages can be dropped prior to being received at the network output. We hope to show enhanced network performance associated with pro-actively dropping degraded high quality-of-service (QoS) packets.


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