EXTENDED GN MODEL FOR L-C BAND WITH FINAL EXPERIMENTAL VERIFICATIONSThe goal of this project is to analyze the GN-Model, to derive the GGN-Model and to compare both models. On the Introduction Chapter, the current state-of-the-art is briefly explained and which are the cutting-edge tools to estimate system performance. Nowadays, the huge data traffic growth has forced telecommunications companies and vendors to deploy ultra-wideband optical systems. To do so, they need of tools that allow them to estimate the system performance and to plan properly the optical network. Beyond of ASE noise impairments, the noise-like NLI power is also a critical issue that should be considered.