5,314 research outputs found

    Demonstration of wireless backhauling over long-reach PONs

    Get PDF
    An IEEE 802.16e-2005 (WiMAX) compliant, longreach passive optical network is demonstrated, focusing on the development of next generation optical access with transparent wireless backhauling. In addition to the extended feeder reach, a wavelength band overlay is used to enhance network scalability by maintaining passive splitting in the field and with some design modification at the optical line terminal and remote base station. Radio-over-fiber is used to minimize network installation and maintenance costs through the use of simple remote radio heads complemented by frequency division multiplexing to address individual base stations. The implementation of overlapping radio cells/sectors is also proposed to provide joint signal processing at wireless user terminals. Experimental measurements confirmed EVMs below -30 and -23 dB downstream and upstream, respectively, over fiber link lengths of up to 84.6 km. In addition, adjacent channel leakage ratio measurements demonstrated that a figure of -45 dB with 40 MHz subcarrier spacing, as specified by the standard, can be readily achieved.Peer reviewe

    A robot swarm assisting a human fire-fighter

    Get PDF
    Emergencies in industrial warehouses are a major concern for fire-fighters. The large dimensions, together with the development of dense smoke that drastically reduces visibility, represent major challenges. The GUARDIANS robot swarm is designed to assist fire-fighters in searching a large warehouse. In this paper we discuss the technology developed for a swarm of robots assisting fire-fighters. We explain the swarming algorithms that provide the functionality by which the robots react to and follow humans while no communication is required. Next we discuss the wireless communication system, which is a so-called mobile ad-hoc network. The communication network provides also the means to locate the robots and humans. Thus, the robot swarm is able to provide guidance information to the humans. Together with the fire-fighters we explored how the robot swarm should feed information back to the human fire-fighter. We have designed and experimented with interfaces for presenting swarm-based information to human beings

    GUARDIANS final report part 1 (draft): a robot swarm assisting a human fire fighter

    Get PDF
    Emergencies in industrial warehouses are a major concern for fire fighters. The large dimensions together with the development of dense smoke that drastically reduces visibility, represent major challenges. The Guardians robot swarm is designed to assist re ghters in searching a large warehouse. In this paper we discuss the technology developed for a swarm of robots assisting re ghters. We explain the swarming algorithms which provide the functionality by which the robots react to and follow humans while no communication is required. Next we discuss the wireless communication system, which is a so-called mobile ad-hoc network. The communication network provides also the means to locate the robots and humans. Thus the robot swarm is able to provide guidance information to the humans. Together with the fire fighters we explored how the robot swarm should feed information back to the human fire fighter. We have designed and experimented with interfaces for presenting swarm based information to human beings

    GUARDIANS final report

    Get PDF
    Emergencies in industrial warehouses are a major concern for firefghters. The large dimensions together with the development of dense smoke that drastically reduces visibility, represent major challenges. The Guardians robot swarm is designed to assist fire fighters in searching a large warehouse. In this report we discuss the technology developed for a swarm of robots searching and assisting fire fighters. We explain the swarming algorithms which provide the functionality by which the robots react to and follow humans while no communication is required. Next we discuss the wireless communication system, which is a so-called mobile ad-hoc network. The communication network provides also one of the means to locate the robots and humans. Thus the robot swarm is able to locate itself and provide guidance information to the humans. Together with the re ghters we explored how the robot swarm should feed information back to the human fire fighter. We have designed and experimented with interfaces for presenting swarm based information to human beings

    Adjustment of Xia - Bertoni's propagation model for planning urban mobile environments through campaign results measurement

    Get PDF
    Aquesta tesis conté l'avaluació del model de propagació de Xia-Bertoni i l'ajustament de la seva fórmula en entorns urbans mòbils mitjançant una campanya de mesures. Aquest ajust tot i estar realitzat mitjançant mesures DVH-SH és òptim per a tota la banda UHF. Per altre part es pot considerar aquesta tesis com una guia per a tractar les dades obtingudes en campanyes de mesures, així com l'ajust dels models de propagació. Els resultats obtinguts en l'anàlisi d'aquest model de propagació un cop ajustat, indiquen que es tracta d'un model de propagació molt precís que amb molta probabilitat serà un dels més utilitzats per a la planificació en entorns urbans mòbils. També hi tenen cabuda en aquesta tesis les mesures necessàries i els passos a seguir en un futur per a millorar l'anàlisi d'aquests models de propagació així com una proposta de recorregut en la ciutat de Barcelona per a la propera GSMA Mobile World Congress
    corecore