3 research outputs found

    Heterogeneous wireless networks for smart cities

    Get PDF
    In the near future, a world of smart cities is envisioned in which many devices equipped with sensors and communication interfaces can be used to collect and share data in order to derive maps or infer information on some parameter of interest. Wireless technologies are enabling this smart city paradigms, where many items are networked for the growth of society. This scenario opens new challenges to wireless network designers, with new performance metrics, coverage and privacy needs, as well as the need for a tighter integration of different networks. This is the fundamental concept of Heterogeneous Networks. Enclosing humans in the loop, through crowdsensing techniques, will dramatically increase the amount of data available for the mapping process, with obvious benefits in terms of the resulting accuracy. On the other hand, the huge amount of data generated represents also a challenge that, along with the irregular, uncontrollable, spatial distribution of measurements represent serious challenges to be addressed. Another important aspect of smart cities scenarios is represented by vehicular networks. Several technologies have been proposed to address such application. Among the others, an interesting solution is provided by Visible Light Communications (VLC). Based on the use of the light emission diodes (LEDs) that are already available on the majority of vehicles, VLC would enable short range communication in large, unlicensed, and uncongested bands with limited costs. In the framework of smart cities scenarios, my research activity aimed at formulating and solving some of the issues arising from the envisioned challenging services, with both analytical and simulation-based approaches

    COST EFFICIENT PROVISIONING OF MASS MOBILE MULTIMEDIA SERVICES IN HYBRID CELLULAR AND BROADCASTING SYSTEMS

    Full text link
    Uno de los retos a los que se enfrenta la industria de las comunicaciones m贸viles e inal谩mbricas es proporcionar servicios multimedia masivos a bajo coste, haci茅ndolos asequibles para los usuarios y rentables a los operadores. El servicio m谩s representativo es el de TV m贸vil, el cual se espera que sea una aplicaci贸n clave en las futuras redes m贸viles. Actualmente las redes celulares no pueden soportar un consumo a gran escala de este tipo de servicios, y las nuevas redes de radiodifusi贸n m贸vil son muy costosas de desplegar debido a la gran inversi贸n en infraestructura de red necesaria para proporcionar niveles aceptables de cobertura. Esta tesis doctoral aborda el problema de la provisi贸n eficiente de servicios multimedia masivos a dispositivos m贸viles y portables utilizando la infraestructura de radiodifusi贸n y celular existente. La tesis contempla las tecnolog铆as comerciales de 煤ltima generaci贸n para la radiodifusi贸n m贸vil (DVB-H) y para las redes celulares (redes 3G+ con HSDPA y MBMS), aunque se centra principalmente en DVB-H. El principal paradigma propuesto para proporcionar servicios multimedia masivos a bajo coste es evitar el despliegue de una red DVB-H con alta capacidad y cobertura desde el inicio. En su lugar se propone realizar un despliegue progresivo de la infraestructura DVB-H siguiendo la demanda de los usuarios. Bajo este contexto, la red celular es fundamental para evitar sobre-dimensionar la red DVB-H en capacidad y tambi茅n en 谩reas con una baja densidad de usuarios hasta que el despliegue de un transmisor o un repetidor DVB-H sea necesario. Como principal soluci贸n tecnol贸gica la tesis propone realizar una codificaci贸n multi-burst en DVB-H utilizando c贸digos Raptor. El objetivo es explotar la diversidad temporal del canal m贸vil para aumentar la robustez de la se帽al y, por tanto, el nivel de cobertura, a costa de incrementar la latencia de la red.G贸mez Barquero, D. (2009). COST EFFICIENT PROVISIONING OF MASS MOBILE MULTIMEDIA SERVICES IN HYBRID CELLULAR AND BROADCASTING SYSTEMS [Tesis doctoral no publicada]. Universitat Polit猫cnica de Val猫ncia. https://doi.org/10.4995/Thesis/10251/6881Palanci
    corecore