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Raman amplification will, in a closer future, penetrate into the access network, bringing new challenges and difficulties to be overcome. In this article, we present the performance assessment of Raman amplification solutions suitable for Coarse Wavelength Division Multiplexing (CWDM) access networks applications. For this purpose, a pumping scheme with three lasers allows a bandwidth of 78 nm which is suitable for four CWDM channels. For this scheme, the gain and noise figure dependence with the pumping configuration was evaluated. The gain equalization was experimentally obtained based on a previously developed model using the Genetic Algorithm (GA) for pump allocation. A comparative study of Raman amplification in different types of Raman fibers (single mode fiber and dispersion shifted fiber) is also presented as well as the use of composite links. Those applications were tested in a local network and the obtained results comply with the modeling foreknowledge, showing the feasibility of Raman amplification over CWDM networks.

Vehicular Ad hoc Networks (VANETs) support the development of safety and infotainment applications, allowing vehicles to communicate between each other and with the infrastructure, assuring their connection and of its occupants to the Internet. These VANETs may rely on different technologies for their deployment such as IEEE 802.11p (WAVE) or IEEE 802.11a/g/n (Wi-Fi), but even then complete coverage and full connectivity may not be assured. Therefore, this dissertation has the main objective of creating the necessary network mechanisms to allow the VANET, with mobility and multihoming support, to make use of an additional communication interface via commercial cellular networks, increasing its availability. The work developed in this dissertation has allowed the integration of a commercial cellular network in the inter-technology mobility mechanisms available in the vehicular network, that served as the base work for this project. The implementation of the integration of a cellular solution allows the vehicles to maintain communication to the Internet through the VANET, even when there is no available connection through mainstream VANET technologies, such as IEEE 802.11p. The proposed solution uses commercial cellular networks without the need of any contribution by the network providers and maintaining transparency to the end-user. The implemented approach was evaluated with real systems in laboratory and real-world scenarios, in order to evaluate the performance of the proposed solution. The obtained results show that with the cellular solution it is, in fact, possible to maintain connectivity to the VANET, but in high traffic tests the cellular network starts to underperform. Nevertheless, it was possible to validate the correct execution of the VANET with the cellular solution, automatically reacting to the respective necessities to maintain connection between the vehicles and infrastructure, without the need of intervention by any external entity in the process.